bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel BK channel regulatory mechanism by protein kinase C in guinea pig urinary bladder smooth muscle (865.1)
Authors: Hristov Kiril , Parajuli Shankar , Smith Amy , Malysz John , Petkov Georgi 
Published: June 2021

Large conductance Ca2+‐activated K+ (BK) channels are critical regulators of urinary bladder smooth muscle (UBSM) function. Here, we provide a novel mechanistic insight into BK channel regulation by protein kinase C (PKC) in UBSM. Voltage‐clamp experiments showed that pharmacological activation of PKC with phorbol 12‐myristate 13‐acetate (PMA), inhibited the spontaneous transient BK currents (TBKCs) in native freshly‐isolated guinea pig UBSM cells. Current‐clamp recordings revealed that PMA significantly depolarized UBSM membrane potential, and reduced the spontaneous transient hyperpolarizations in UBSM cells. The PMA inhibitory effects on UBSM membrane potential were abolished by the selective BK channel inhibitor paxilline and were not observed with its inactive analog, 4‐alpha‐PMA. PMA did not affect the amplitude of the whole cell steady‐state BK current or single BK channel open probability (recorded in cell‐attached mode) upon inhibition of all major Ca2+ sources for BK channel activation with thapsigargin, ryanodine, and nifedipine. PMA elevated the intracellular Ca2+ levels in UBSM cells, and increased spontaneous phasic and nerve‐evoked contractions of UBSM isolated strips. The results support the concept that PKC activation leads to a reduction in BK channel activity in UBSM via a Ca2+‐dependent mechanism, thus increasing UBSM contractility.Grant Funding Source: Supported by R01 DK084284 to G. V. Petkov
PKC‐dependent inhibition of MAP kinase activity and caldesmon phosphorylation in rabbit bladder smooth muscle (865.14)
Authors: Wei Dongyu , Sivilich Sarah , Moreland Robert 
Published: June 2021

Smooth muscle contraction is primarily regulated by myosin light chain (MLC) phosphorylation although thin filament proteins, specifically caldesmon, may also be involved. Our previous studies have shown that in vascular smooth muscle, p42 mitogen activated protein kinase (MAPK) but not p44 MAPK activity was enhanced in the presence of an inhibitor of PKC, bisindolylmaleimide‐1 (Bis). The goal of this study was to determine if this is a vascular‐specific pathway or a pathway common to all smooth muscles. Experiments were performed using carbachol‐stimulated rabbit bladder smooth muscle in the presence and absence of Bis; p42 and p44 MAPK activity and caldesmon phosphorylation were measured at different time points during the contraction. Our results showed that carbachol‐dependent p42 MAPK activity is enhanced in the presence of Bis with a concomitant increase in caldesmon phosphorylation in bladder smooth muscle. Carbachol dependent force generation increased concurrently with p42 MAPK phosphorylation which was reduced by inhibition of PKC during the entire contraction; a result not found in vascular smooth muscle. Together with our previous results, this novel signaling pathway appears to be general to both vascular and non‐vascular smooth muscles, however the effects on force are different. Future studies will be aimed at determining the mechanism by which inhibition of PKC increases p42 MAPK activity.Grant Funding Source: NIH DK 85734
Interleukin‐8 stimulates CFTR‐mediated mucus secretion by submucosal glands in swine (869.10)
Authors: Hansvall Haylee , Ianowski Juan 
Published: June 2021

Cystic Fibrosis (CF) is an autosomal recessive condition caused by mutations in the gene encoding the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) anion channel. As a result epithelial fluid and ion transport is compromised. Many organs are affected in CF patients, but most of the mortality and morbidity arise from airway disease characterized by chronic infection and inflammation. However, the events leading from CFTR mutation to airway disease are not fully understood. Recent data suggest that abnormal bacteria clearance due to abnormal mucus secretion is the pathogenic event that triggers airway disease in CF. Thus we studied the response of airway epithelia to proinflammatory cytokines, such as Interleukin‐8 (IL‐8), that are released in response to bacterial infection and are elevated in CF airways.Secretion assays and electrophysiological techniques were used to measure the response of submucosal glands, the principal mucus source, to IL‐8. The mucus secretion rate increased from 0.052 to 0.156 nl/min upon the addition of IL‐8 (50 ng/ml). IL‐8 stimulated Na+ flux across the serous acini of the submucosal glands. Both effects were blocked by treatment with the CFTR inhibitor, CFTRinh172. Exposure to CFTRinh172 reduced IL‐8‐stimulated mucus secretion to 0.062 nl/min and abolished Na+ transport across the serous acini.Our results suggest that, in normal lungs, bacteria‐activated secretion increases mucus and bactericidal compounds in the airways, thereby facilitating bacterial removal by mucociliary clearance and reducing the proinflammatory stimulus. In CF airways, bacteria would activate proinflammatory signalling to trigger innate immune responses, but CFTR‐mediated mucus secretion and the resulting “bacterial flush” would be missing, leading to sustained inflammation that may permanently alter the physiology and anatomy of the airways.Grant Funding Source: Supported by APS, University of Saskatchewan, NSERC, Cystic Fibrosis Canada
Neuroepithelial bodies as airway hypoxia sensors: re‐evaluation of the concept in different mouse live cell imaging models (869.6)
Authors: Schnorbusch Kathy , Brouns Inge , Lembrechts Robrecht , Pintelon Isabel , Kemp Paul , Timmermans Jean‐Pierre , Adriaensen Dirk 
Published: June 2021

In pulmonary neuroepithelial bodies (NEBs), acute hypoxia has been suggested to close O2‐sensitive K+ channels, resulting in membrane depolarization, voltage‐gated Ca2+ entry and subsequent transmitter release.To visualize this mechanism in NEBs, our established live cell imaging (LCI) model, based on lung vibratome slices, was applied. Real‐time changes in different cellular processes were monitored during hypoxic challenge in NEBs of postnatal, prenatal and GAD67‐GFP mice.As a proof of concept, LCI experiments were performed on isolated mouse carotid body, proving that our LCI set up is indeed capable of visualizing hypoxia‐induced changes. However, in none of the NEBs studied in the lung slice models, severe (2% O2), mild (12% O2) or intermittent hypoxia, resulted in a rise in intracellular Ca2+ ([Ca2+]i) or subsequent neurotransmitter release. Moreover, low O2 levels appeared to decrease NEB cell excitability. The observed hypoxic mitochondrial membrane depolarization and increased ROS production rather seemed to be part of a general cellular defense mechanism, as supported by the non‐selective and non‐functional expression of the key O2 sensing protein NADPH oxidase.All together, our data argue for a reconsideration of the proposed straightforward hypoxic signal transduction pathway in pulmonary NEBs.Grants: FWO (G.0589.11), Hercules Foundation (AUAH‐09‐001); UA (GOA BOF 2007)
In vitro elastogenesis (87.1)
Authors: Hinderer Svenja , Shen Nian , Ringuette Léa‐Jeanne , Hansmann Jan , Reinhardt Dieter , Elaine Davis , Schenke‐Layland Katja 
Published: June 2021

Background: Elastic fibers are one of the main components of the extracellular matrix (ECM), providing dynamic tissues such as lungs, skin, blood vessels, heart valve leaflets and ligaments with flexibility and elasticity. However, the complex process of elastic fiber assembly is poorly understood und the generation of elastic fibers on a human base is a missing link in tissue engineering.Methods: A constant shear stress providing, fluid flow bioreactor system was designed and evaluated. For in vitro studies, human vascular smooth muscle cells (VSMCs) were seeded onto three‐dimensional (3D) electropsun scaffolds and cultured in the bioreactor system. After 6 days dynamic culture, the scaffolds were harvested and analyzed regarding elastin gene and protein expression. The produced ECM was investigated applying immunostaining of elastogenesis‐associated proteins and transmission electron microscopy (TEM).Results: After a 6 day dynamic culture of VSMCs on 3D scaffolds, a significant increase of elastin gene and protein expression was detected when comparing to the 2D cultures and static controls. Moreover, TEM confirmed a proper developed ECM similar to native fetal tissue, including long bundels of microfibrils, collagen and elastin. This is the first report showing developing elastic fibers as well as the availability of elastogenesis‐associated proteins on a human‐based tissue engineered construct.
Glycoconjugate expression in the extracellular matrix of the mouse lung (87.7)
Authors: Bennett Robert , Ysasi Alexandra , Belle Janeil , Wagner Willi , Ackermann Maximilian , Konerding Moritz , Mentzer Steven 
Published: June 2021

Introduction: Glycoconjugates have been implicated in various lung extracellular structures such as the galactose‐binding elastin receptor complex; however, little is known about expression of carbohydrate moieties in lung extracellular matrix (ECM). Methods: To investigate structural implications of glycoconjugate expression in the ECM, we used a panel of 33 biotinylated lectins to label decellularized mouse lungs harvested from 8‐11 week C57/B6 mice. Lungs were decellularized by serial washes through the trachea and pulmonary artery. Standard OCT thin section analysis as well as precision‐cut lung slice (200‐300μm) histology were performed. Lung samples were labeled with lectins (20μg/mL), secondarily labeled with a streptavidin‐fluorescein conjugate and analyzed by fluorescence confocal microscopy. Results: Decellularized mouse lungs showed a lectin‐binding pattern consistent with differential staining of the axial and peripheral connective tissue elements. Some lectins (N=10) demonstrated weak signal interpreted as negative. Others (N=17) stained pleural and subpleural zones suggesting selective staining of the peripheral connective tissue system. Another group (N=7) prominently stained the acinar septae suggesting selective staining of the axial connective tissue system. All lectin labeling was demonstrated at wavelengths that preclude elastin autofluorescence. Conclusions: The differential labeling pattern of the ECM with lectins suggests their utility as monospecific probes of both peripheral and axial connective tissue systems in the decellularized mouse lung.Grant Funding Source: Supported by NIH grant 04925
microRNA‐98 negatively regulates nicotine‐induced nerve growth factor expression in primary mouse lung fibroblasts (870.4)
Authors: Kang Bum‐Yong , Grooms Kora , Sutliff Roy , Hart C. Michael , Wongtrakool Cherry 
Published: June 2021

We previously demonstrated that chronic nicotine exposure 1) increases branching morphogenesis resulting in altered airway geometry associated with increased airway hyper‐responsiveness (AHR) in adulthood, and 2) increases Nerve Growth Factor (NGF) expression levels. To explore post‐transcriptional mechanisms of nicotine‐induced NGF expression, we hypothesized that microRNA (miR‐98) negatively regulates nicotine‐induced NGF expression to promote increased airway remodeling and AHR. Using bioinformatics prediction algorithms, we identified the miR‐98/let‐7 family as potential post‐transcriptional regulators of NGF. Of all of the miRNAs examined, only let‐7c, let‐7g, and miR‐98 were significantly decreased in mouse lung fibroblasts treated with nicotine for 72h compared to control conditions. Nicotine increased NGF, fibronectin, and ET‐1 (a known target of miR‐98) levels and reduced HUWE‐1 (host gene of miR‐98) levels, whereas these effects were reversed by miR‐98 overexpression. Overexpression of miR‐98 decreased branching morphogenesis in lung explants harvested from C57BL/6J mice at embryonic day 11.5 compared to control conditions. These findings suggest that miR‐98 may provide a novel therapeutic target for asthmatics exposed to nicotine in cigarette smoke.Grant Funding Source: Supported by AHA‐SDG 13SDG14150004, Atlanta VA1I01BX001910,CDA IK2BX001306,NIH HL074518,DK102167
Somatic dysfunction and effect of OMT on pulmonary function in healthy adult male subjects (871.7)
Authors: Kochhar Kanika , Hines Patrick , Heinking Kurt , Henderson Kyle 
Published: June 2021

The effects of osteopathic manipulative treatment (OMT) on pulmonary function have been equivocal. Our long‐term goal is to design hypothesis driven research to determine the efficacy of OMT. We hypothesize that treatment of somatic dysfunction with OMT will increase chest compliance and vital capacity. IRB approval was obtained and healthy adult males were randomly divided into a control group (n=17) or OMT group (n=20). Pulmonary function was measured at baseline, ~10min post‐OMT or quiet reading (control), and repeated at 24hrs. Somatic dysfunction was assessed and treated with OMT. There were no statistical differences between the control and OMT groups at baseline, or changes in pulmonary function in controls acutely or 24hrs. Of the OMT group, 75% of the subjects had somatic dysfunction in the C2‐C7, T5‐T9, ribs, and L1‐L5 regions. After OMT, upper thoracic excursion increased from 5.7±0.5 to 6.3±0.5cm (p = 0.03), and forced vital capacity (FVC) increased from 5.13±0.20 to 5.24±0.19L (p = 0.02) at 24hrs. Of note, OMT treatment of subjects with rib dysfunction significantly improved FVC at 24hrs (p = 0.02). Our data demonstrate significant somatic dysfunction in otherwise healthy adult males and suggest OMT can increase upper thoracic excursion and lung volumes. These data support the possibility that OMT can improve pulmonary function in patients with extrinsic restrictive lung disease.Grant Funding Source: Supported by: AHA 10SDG2640219
Iba1+ microglia/macrophages in the rat hypothalamic paraventricular nucleus are both resident and bone marrow‐derived in Ang II induced hypertension (875.5)
Authors: Santisteban Monica , Zubcevic Jasenka , Kim Seungbum , Marulanda‐Carvajal Jessica , Zingler Michael , Joseph Jessica , Raizada Mohan 
Published: June 2021

We have previously demonstrated that Angiotensin II (Ang II)‐induced hypertension increases activated microglial cells in the hypothalamic paraventricular nucleus (PVN). The objective of this study was to determine whether the origin of these cells is, in part, bone marrow (BM). We investigated whether minocycline (Mino), an antibiotic that crosses the BBB, would attenuate the microglial/macrophage responses and thereby the Ang II‐dependent increase in blood pressure (BP). Methods: SD rats underwent BM ablation followed by reconstitution with whole BM from eGFP donors. Following a 3 month recovery, animals were randomized to receive SC saline + H2O; SC Ang II + H2O; or SC Ang II + oral Mino (50 mg/kg). BP was measured weekly by tail‐cuff (n=5 per group) for 7 weeks. Iba1 antibody was used to image and quantify microglia expressing GFP (n=3 per group). Results: The Ang II/H2O group showed increased mean arterial pressure (MAP; 178 ± 9 vs. 104 ± 2 mmHg; p<0.001) and 4.3‐fold increase in GFP+/Iba1+ cells (p<0.05) from Saline/H2O group. Oral Mino attenuated the increased MAP (121 ± 7 mmHg) and caused a 37% decrease in GFP+/Iba1+ cells in the PVN. Conclusion: These data demonstrate that AngII‐induced hypertension is associated with an increase in the BM‐derived microglia/macrophages in the PVN and oral Mino treatment attenuated both the hypertension and extravasation of BM cells into PVN.Grant Funding Source: This research is supported by NIH grant (HL 33610 to MKR).
Exceptional locomotory performance in Paratarsotomus macropalpis mites (878.1)
Authors: Rubin Samuel , Wright Jonathan , Young Maria , Whitaker Dwight , Ahn Anna 
Published: June 2021

The Southern California erythracarid mite species, Paratarsotomus macropalpis, was filmed using a high frame‐rate video camera in the field to analyze speed, stride frequency, acceleration and deceleration. We also recorded higher resolution lab footage of mites starting, stopping and turning to analyze gait and kinematic mechanisms. Mites running in the field on concrete substrates at high temperatures (40°C to 60°C) were shown to travel at mean relative speed of 192.4 bl s−1 (body lengths per second), exceeding the highest currently documented speed for land animals (171 bl s−1). Despite this exceptional value, it conforms broadly with predictions based on interspecific scaling. Stride frequencies were also exceptionally high (as fast as 135 Hz), and increased significantly with substrate temperature. Mites accelerate and decelerate rapidly (mean values of 7.2 ms−2 and −10.1 ms−2, respectively), although the forces involved are simiilar to those found in other running animals. Calculations show that air resistance is a minor contributor to deceleration; the forces are likely borne by a combination of muscle and cuticle ligament strain. During normal running, adjacent and opposite tarsi are 180 degrees out of phase. This gait cycle is preserved during turning, although the two front pairs of tarsi initiate acceleration cycles and duty factors increase for inner tarsi during turns.Grant Funding Source: Supported by the Howard Hughes Medical Institute
High levels of the small chaperone HSP25 in naked mole‐rats may be a determinant of rodent longevity (880.5)
Authors: Rodriguez Karl , Buffenstein Rochelle 
Published: June 2021

Proteostasis is an integral component of healthy aging. In most metazoans, protein quality declines during aging, resulting in accrual of damaged or self‐aggregating cytotoxic proteins, linked to several age‐associated diseases (e.g, Alzheimer’s Disease, Parkinson’s Disease) and pathology (e.g.,sarcopenia). The mouse‐sized naked mole‐rat [NMRs] lives ~5 times longer than expected based on body size, and despite detected high levels of oxidative damage even at a young age, maintain good health for most of their long lives. Like other long‐lived animal models, both in vivo and in vitro studies reveal that NMRs are resistant to a broad spectrum of environmental stressors. Collectively these findings suggest that NMRs possess efficient mechanisms to maintain protein quality. Our research has previously shown that this is attributed in part to altered proteasome forms and subcellular location. However, changes in proteasome‐related molecular chaperone activity that assists in the transport of damaged proteins into the proteasome may also play a role in this decline. Here we examine key proteasome‐related molecular chaperones [HSPs] and the heat‐shock factor 1 [HSF1] transcription factor in the brain, heart, liver, spleen, kidney, testes, and quadriceps leg muscle in mice and NMRs. HSP70 was higher in NMR for most tissues compared to mice with the exception of the spleen where mouse levels were greater. For HSP110, HSP90, and HSP70 co‐chaperones, such as HSP40, protein levels showed tissue‐specific trends where there was no difference, higher levels in one or the other species. HSF1 and HSP25 both showed higher levels of protein in NMRs compared to mice in all the tissues examined. Hence we measured HSP25 protein content in seven rodents with ages ranging from four to 32 years in both liver and muscle. This comparison resulted in a significant correlation with longevity suggesting that HSP25 may play a key role in age‐related maintenance of protein homeostasis in long‐lived animals.Grant Funding Source: Supported by NIA Training Grant
Anxiolytic‐like effects of a new 1‐N substituted analogue of melatonin in pinealectomized rats (883.2)
Authors: Picazo Ofir , Espinosa‐Raya Judith , Bustamante‐García Ruth , Gomez‐Martínez Atonatiu , Lira‐Rocha Alfonso , Espejo‐González Ofelia 
Published: June 2021

In spite of the wide variety of drugs available for treating anxiety, this disorder continues to represent a worldwide health problem that is classified within the first 10 causes of disability. New antianxiety agents not related to benzodiazepines are being proposed to face this problem. Even though melatonin has been prescribed as an anxiolytic drug, its use is currently reduced due to its short half‐life and photo‐sensitivity, among other disadvantages. The present study explores the antianxiety properties of a new 1‐N substituted melatonin analogue, M3C, in pinealectomized rats submitted to two behavioral tests (the cumulative burying behavior paradigm and the elevated plus‐maze). Results from both tests show that M3C is effective as an anxiolytic agent, at doses lower than any other melatonin analogue previously reported. The blocking of these actions by luzindole, a melatoninergic antagonist showing a high affinity for MT2 receptors, suggests a mechanism independent of MT1 receptors.Grant Funding Source: Supported by COFAA and SIP‐IPN
Weight loss with or without exercise: effect on classic and novel biomarkers of cardiovascular risk (884.24)
Authors: Mikus Catherine , Huffman Kim , Redman Leanne , Ravussin Eric , Kraus William 
Published: June 2021

We previously reported that novel metabolomics‐derived biomarkers (dicarboxyl/hydroxyl acylcarnitines (DC/OH‐ACs) and amino acid‐related metabolites (AAs)) are independent predictors of CAD, CV events, and death and add predictive value to classic CV risk factors in cardiac catheterization patients. Here, we evaluated associations between traditional CV risk factors (FRS; Framingham Risk Score) and DC/OH‐ACs and AAs in sedentary, overweight adults (N=46) randomized to 6 months of: AHA weight maintenance diet (CONTROL), 25% calorie restriction (CR), 12.5% CR + 12.5% increase in exercise energy expenditure (CR+EX), or 15% weight loss via low calorie diet (890 kcals/d; LCD). At baseline, serum DC/OH‐ACs and AAs predicted 97% of FRS. At 6 months, weight loss was greater in LCD (‐11±1 kg) than CR or CR+EX (‐8±1 kg) and in all groups relative to CONTROL (‐1±1 kg). Only in CR+EX did FRS change significantly (‐10±4%) or differ from the change in FRS in CONTROL (+7±4%). Across all groups, changes in serum DC/OH‐ACs and AAs predicted 97% of FRS change. Thus, CR+EX appears to be more effective than CR or LCD in reducing CV risk. Further, DC/OH‐ACs and AAs may have strong predictive value in overweight adults.Grant Funding Source: Supported by U01 AG20478 (ER) and F32 HL112575 (CRM). and
Adenosine signaling via A2B receptor regulates erythrocyte 2,3‐bisphosphate induction at high altitude (885.6)
Authors: Liu Hong , Zhang Yujin , Sun Kaiqi , Song Anren , Quintana Harry Karmouty , Grenz Almut , Kellems Rodney , Eltzschig Holger , Roach Robert , Blackburn Michael , Xia Yang 
Published: June 2021

To function effectively in O2 uptake, and unload, erythrocytes rely on sophisticated regulation of hemoglobin (Hb)‐O2 affinity by allosteric modulators. One of the best known allosteric modulators is 2,3‐bisphophosphoglycerate (2,3‐BPG). Earlier studies demonstrated that erythrocyte 2,3‐BPG levels are elevated at a high altitude. However, what triggers its induction at high altitude is unknown. To address this question, we recruited 24 individuals and placed them at high altitude for different time points. Here we report that 1) Plasma adenosine and erythrocyte 2,3‐BPG levels were significantly elevated in normal individuals at high altitude after 24 hours compared to sea level; 2) their levels are further enhanced at high altitude after 16 days; 3) Elevated circulating adenosine levels significantly correlated with increased erythrocyte 2,3‐DPG levels in normal individuals at high altitude. Next, we provide in vitro evidence that adenosine signaling via A2B receptor (ADORA2B) directly induced 2,3‐BPG production in a protein kinase A‐dependent manner in cultured human erythrocytes. Finally, we provide genetic and pharmacological evidence that that ADORA2B is essential for elevated adenosine induced 2,3‐BPG production and triggers O2 release in mice. Taken together, we reveal ADORA2B signaling cascade regulating erythrocyte 2,3‐BPG induction as a function of altitude and identify new targets to enhance O2 release under hypoxia conditions.Grant Funding Source: NIH