bluuebunny/crossref_metadata_2025_split huggingface dataset:
B2 bradykinin receptor‐expressing nociceptors are differentially sensitive to the microtubule‐targeting agent, paclitaxel (659.3)
Authors: LoCoco Peter , Scofield Harrison , Chavera Teresa , Mooberry Susan , Berg Kelly , Clarke William 
Published: June 2021

Paclitaxel (TAX) produces debilitating peripheral neuropathy accompanied by pain. Interestingly, patients complain more frequently of increased sensitivity to cold but not hot temperatures. Thus, we hypothesize that TAX differentially damages functional subpopulations of peripheral pain‐sensing neurons (i.e. nociceptors). Here, we evaluated TAX effects on bradykinin (BK) receptor‐expressing nociceptors. Paw withdrawal latency (PWL) to a heat or cold stimulus was determined following TAX treatment. PWL of TAX rats to cold was decreased, whereas PWL to heat was increased, suggesting that TAX differentially affected cold‐ and heat‐responsive nociceptors. We then evaluated PWL to cold and heat following i.pl. BK injections. As expected, BK produced a transient cold and heat allodynia in vehicle rats. By contrast, TAX treatment reduced heat, but prolonged cold allodynia. Treatment of primary nociceptor cultures with TAX produced a time‐dependent, tri‐phasic effect on BK‐stimulated phospholipase C activity that was blocked by a B2, but not B1, antagonist. Taken together, these data suggest that nociceptor subpopulations are differentially sensitive to TAX. Understanding why some nociceptors are resistant to effects by TAX could reveal novel treatment/preventative strategies for chemotherapy‐induced peripheral neuropathy.Grant Funding Source: Supported by USPS grant 8ULITR000149, Greehey Fellowship, and Translational Science Training Program
Inhalation of multi‐walled carbon nanotubes affects lung resistance and compliance and evokes airway hyperreactivity to methacholine in rats (660.1)
Authors: Fedan Jeffrey , Thompson Janet , Frazer David , Porter Dale , Tsuruoka Shuji , Endo Morinobu , McKinney Walter 
Published: June 2021

The incorporation of carbon nanotubes into new materials has raised concerns about their potential hazards to workers exposed during manufacturing. In animals, following pharyngeal aspiration, i.t. instillation and inhalation exposures to MWCNT, airway inflammation and lung fibrosis have been reported. However, the effects of inhalation of MWCNT on pulmonary function and reactivity to inhaled methacholine (MCh), a bronchoconstrictor, have not been studied. Therefore, we investigated whether inhaled MWCNT affect lung resistance (RL) and dynamic compliance (CDyn), and/or reactivity to inhaled MCh aerosol. Male rats were exposed for 6 h to filtered air or 5 mg/m3 of aerosolized MWCNT (MWNT‐7; Hodogaya Chemical Co.; 20 ‐ 50 walls; median length, 3.86 μm; mean width, 49 nm; mass median aerodynamic diameter, 1.5 μm; particle count aerodynamic diameter mode, ~0.4 μm). Basal RL and CDyn were measured 18 h and 7 d after the end of exposure, and responses to increasing concentrations of MCh were obtained. Eighteen h after exposure basal RL was increased and basal CDyn was decreased; 7 d after exposure basal RL and CDyn were not changed. Reactivity to MCh (RL) was increased and CDyn responses were decreased at 18 h but not 7 d after exposure. The results indicate that lung function and airway reactivity changes occur acutely, but that these changes subside over time following a single MWCNT inhalation exposure.Grant Funding Source: Supported by NIOSH
Nerve growth factor reduces amiloride‐sensitive Na+ transport in human airway epithelial cells through a trkA‐Erk1/2 mediated pathway (660.10)
Authors: Shimko Michael , Zaccone Eric , Thompson Janet , Fedan Jeffrey 
Published: June 2021

Nerve growth factor (NGF) is over‐expressed in airways of patients with inflammatory lung diseases. Ion transport by the epithelial cells of the lung is responsible for controlling the periciliary liquid layer, and changes in ion transport can accompany disease. To investigate NGF’s effects on airway epithelium, human primary cultured epithelial cells were placed in an Ussing chamber to measure short‐circuit current (Isc). NGF (1 ng/ml), applied apically, reduced Isc (4.5%) and reduced amiloride (apical, 3.5×10‐5 M) ‐sensitive Na+ transport (control, 52%; NGF‐treated, 38%). To investigate whether the NGF receptor, trkA, is responsible for mediating the responses to NGF, cells were incubated with either the tyrosine kinase inhibitor K‐252a (10 nM, apical) or DMSO (0.004 %) in the absence or presence of NGF. K‐252a did not affect Na+transport, but attenuated the NGF‐induced reduction in Na+ transport. To investigate whether trkA activates the Erk1/2 signaling cascade, which results in the down‐regulation of ENaC, cells were incubated with PD‐98059 (30 µM, apical and basolateral) or DMSO (0.06 %) in the absence or presence of NGF. PD‐98059 did not affect Na+ transport, but attenuated the NGF‐induced reduction in Na+ transport. These results indicate that NGF reduces Na+ transport through a trkA‐Erk1/2 mediated signaling pathway.Grant Funding Source: Supported by NIOSH
The efficacy of apocynin in mitigating LPS‐induced acute lung injury when given prior to, but not after LPS insult (660.3)
Authors: Lee Intae , Dodia Chandra , Chatterjee Shampa , Feinstein Sheldon , Fisher Aron 
Published: June 2021

Apocynin (4‐hydroxy‐3‐methoxyacetophenone; APO) is an inhibitor of NADPH oxidase (NOX2) activation and a possible scavenger of reactive O2 species (ROS). Regulating NOX2 may play a crucial role in LPS (lipopolysacharide)‐induced ROS production and the pathogenesis of ALI. To evaluate the effect of APO on lung injury in mice following intra‐tracheal infusion of LPS (0111:B4 from E. coli) at 1 mg/kg, mice received iv APO at 2.5 mg/kg at 0.5h prior to LPS or 2h post LPS. Measurements were performed 24h post LPS. LPS significantly increased lung infiltration with inflammatory cells, lung alveolar‐capillary permeability (lung wet to dry ratio, leakage of protein and FITC‐dextran into the bronchoalveolar lavage fluid), expression of pro‐inflammatory cytokines (IL‐6, TNF‐α) and a chemokine (MIP‐2). APO dramatically reduced all of these parameters when administered at 0.5h prior to LPS but had no significant effect when administered at 2h post LPS. Thus, APO when administered prophylactically prevented lung inflammation, excessive ROS production, and cell injury but was not effective when administered during the early stages of LPS‐induced inflammation. These findings contrast with the recently reported effectiveness of MJ33, also an inhibitor of NOX2 activation, when administered 2 h post LPS. The mechanism for the difference between the 2 inhibitors requires further investigation.Grant Funding Source: NHLBI‐R01‐HL105509 (PI: Dr. Aron B. Fisher)
A novel approach to bronchodilation: combining the Kv7 channel activator retigabine with the β2‐adrenergic agonist formoterol (660.9)
Authors: Haick Jennifer , Brueggemann Lioubov , Byron Kenneth 
Published: June 2021

Kv7 potassium channels are expressed in airway smooth muscle cells (ASMCs) and bronchoconstrictor agonists, such as methacholine and histamine, inhibit Kv7 currents. Inhibition of Kv7 channels in rat and human airways is sufficient to induce bronchoconstriction. Long‐acting β2‐adrenergic agonists (LABAs) are commonly used in the treatment of asthma. However, long term use of these drugs may lead to tolerance. Here we provide evidence that the Kv7 channel activator retigabine can oppose agonist‐induced suppression of Kv7 currents and enhance bronchodilation by the LABA formoterol. Dose‐dependent bronchodilation by retigabine and formoterol was measured using rat precision cut lung slices (PCLS). A submaximal dose of formoterol (10nM) induced relaxation of methacholine‐constricted airways, but this relaxation was transient despite continued treatment. The approximate EC50 dose of retigabine (10µM) enhanced formoterol‐induced relaxation and eliminated the apparent desensitization. Similar results were obtained in human PCLS pre‐constricted with histamine, suggesting a beneficial effect of combining a Kv7 channel activator with standard bronchodilator therapy.Grant Funding Source: Supported by Loyola University Chicago
Effects of self‐administered methamphetamine on learning‐to‐learn in the squirrel monkey (661.1)
Authors: Kangas Brian , Bergman Jack 
Published: June 2021

Long‐term chronic exposure to methamphetamine (MA) has been related to profound neural impact including, but not limited to, damage to monoamine nerve terminals. In turn, neural changes following repeated MA administration may be related to adverse effects on learning and other cognitive performance. However, the characterization of such neurobehavioral deficits remains incomplete. The present study assessed the effects of ongoing MA self‐administration on touchscreen‐based discrimination learning in nonhuman primates. Prior to daily sessions of MA self‐administration (i.e., 20‐hr after the previous day’s session), monkeys engaged in a repeated acquisition task in which changes in the rate of discrimination learning for a stimulus pair were assessed over the successive presentation of novel stimulus pairs. Results thus far indicate that ongoing MA self‐administration produces markedly deleterious effects on the development of learning sets in discrimination learning. Importantly, the magnitude of adverse effects on learning appears to be correlated with the level of daily MA intake among individual subjects.Grant Funding Source: Supported by grant K01‐DA035974 from NIDA
Reinforcing effects of abused “bath salts” constituent 3,4‐methylenedioxypyrovalerone in mice and rats (661.7)
Authors: Gannon Brenda , Norwood Andrew , Tai Sherrica , Bailey Jessica , Fantegrossi William 
Published: June 2021

Recently, synthetic analogues of naturally‐occurring cathinone in commercial “bath salt” preparations have emerged as psychostimulant‐like drugs of abuse. 3,4‐Methylenedioxypyrovalerone (MDPV) is a common constituent of these illicit products, and recent studies implicate monoamine transporters as mediators of its pharmacological effects. In these studies, adult male NIH Swiss mice and Sprague Dawley rats were used to assess reinforcing effects of MDPV in assays of two‐bottle choice oral self‐administration (mice), responding maintained by a drug‐paired stimulus complex (mice), and intravenous self‐administration (rats). In mice, MDPV concentrations sufficient to produce locomotor stimulation (0.1 and 0.3 mg/ml) and lethality (1 mg/ml) were consumed when the alternative fluid was 0.1 mg/ml quinine. However, when water was available as an alternative to MDPV, very little MDPV consumption occurred at the concentrations which previously elicited biological effects. In subsequent studies, mice were implanted with radiotelemetry probes to simultaneously measure core temperature and locomotor activity, and provided with MDPV solutions to drink (0.03, 0.1, 0.3, and 1 mg/ml). Separate groups of mice were trained to respond under an FR5 schedule reinforced by milk presentations. In pairing sessions, MDPV (0, 1 or 10 mg/kg) was administered IP in the presence of a novel light+tone stimulus complex. The light+tone stimulus complex was contingently available under a PR schedule after 0, 3 or 6 pairings with MDPV, but no apparent reinforcing effects were observed. In contrast, MDPV was an effective intravenous reinforcer across a wide range of unit doses (0.003, 0.01, 0.03, 0.1, and 0.3 mg/kg/infusion) in rats previously trained to self‐administer phencyclidine (PCP) and its analogue methoxetamine (MXE). Possible explanations for the discrepancy in apparent reinforcing effects of MDPV may be related to route of administration or species differences and will be discussed.Grant Funding Source: Supported by RR020146 and RR029884
The insecticides carbaryl and carbofuran show high affinity for hMT2 melatonin receptors (662.12)
Authors: Popovska‐Gorevski Marina , Dubocovich Margarita , Rajnarayanan Rajendram 
Published: June 2021

Carbaryl (1‐naphthyl methylcarbamate) and carbofuran (2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl methylcarbamate) are among the most toxic insecticides, known to increase diabetes risk. Using an integrated pharmacoinformatics‐molecular docking approach, we found carbaryl and carbofuran to be structurally similar to melatonin. These compounds docked into our predictive 3D model of the MT2 melatonin receptor with relatively high binding affinity scores. Carbaryl and carbofuran then were tested for competition with 2‐[125I]‐iodomelatonin (300nM) binding to hMT1 or hMT2 receptors stably expressed in CHO cells. Biphasic competition curves suggest that carbaryl binds to two affinity states of the hMT1 (IC50Hi=6.8nM, IC50Lo=22µM) and hMT2 (IC50Hi=16nM, IC50Lo= 0.9μM) receptors while carbofuran binds two sites on the hMT2 (IC50Hi=27nM, IC50Lo=11μM) receptor. Compared to carbaryl, carbofuran affinity for hMT2 was lower, but it showed selectivity, as it did not compete for hMT1 binding. GTP (100 mM) did not affect binding affinity of carbaryl for either hMT1 or hMT2 receptors. However, GTP significantly decreased the affinity of carbofuran for hMT2 receptors suggesting potential agonist efficacy. These data support the utility of molecular modeling for screening potential melatonin ligands and suggest that carbaryl and carbofuran could interact with pancreatic MT2 receptors, known to affect glucose homeostasis and insulin secretion.Grant Funding Source: Supported by UB Funds
Probing the structural determinants of the central region of third intracellular loop of human dopamine D1‐class receptor subtypes (662.9)
Authors: Albaker Awatif , Yang Xiaodi , Liang Binhui , Charette Andrew , Tiberi Mario 
Published: June 2021

Dopamine D1‐class receptors (D1, D5) are seven transmembrane receptors and play a major role in regulating important physiological effects in the brain and in the periphery. The first and the second intracellular loops are highly conserved between D1R and D5R while the third intracellular loop is the most divergent. The alpha‐helical of the amino and the carboxyl ends of the third intracellular loop (IL3) of GPCRs play a pivotal role in receptor activation and G proteins coupling. Meanwhile, it remains unclear whether the central region of IL3 linking the cytoplasmic extension of TM5 and TM6 significantly contributes to GPCR activation and G protein coupling. Here, we address this issue using either deletions of the conserved N‐terminal moiety or divergent C‐terminal moiety of the central region of IL3 of human D1‐class receptors (D1ΔN and D5ΔN; D1ΔC and D5ΔC). Also, we test the effect of agonist‐induced desensitization on these mutants. The agonist affinities were significantly increased and decreased at D1ΔN and D5ΔN, respectively. However, D1ΔC and D5ΔC displayed drastically increased agonist affinity. We also observed full abolition of constitutive activity of D1ΔN and D5ΔN, and a severe blunting in agonist‐induced cAMP formation. In contrast, constitutive and agonist‐dependent activity of D1ΔC and D5ΔC were considerably increased. Overall, our study strongly suggests a critical role of the central region of IL3 in subtype‐specific activation of D1‐class dopaminergic signaling. Potentially, this may be achieved through distinct motifs located in the N‐ and C‐terminal moiety of the central region of IL3Grant Funding Source: supported by a Graduate Scholarship from King Saud University (to AB) and OMHF grant (to MT)
Mitochondrial reactive oxygen species induce hyperexcitability in nociceptive airway sensory nerves via PKC activation (663.5)
Authors: Taylor‐Clark Thomas , Hadley Stephen , Bahia Parmvir 
Published: June 2021

Activation of airway nociceptive C‐fibers evokes cough and parasympathetic reflexes. Nociceptor excitability is increased by inflammation, worsening symptoms in asthma. Airway C‐fiber terminals are packed with mitochondria. Inflammatory signaling modulates mitochondrial function, causing reactive oxygen species (ROS) production. We hypothesize that these ROS increase nociceptor excitability. We recorded action potentials in single C‐fibers using an ex vivo mouse lung‐ganglia preparation. “Nociceptors” are slow fibers, sensitive to capsaicin (via TRPV1). Antimycin A, a mitochondrial complex III inhibitor that evokes ROS, had no effect on the excitability of non‐nociceptive nerves. Ten minutes after antimycin A, nociceptive nerves developed hyperexcitability to chemical and mechanical stimuli. Antimycin‐induced hyperexcitability was blocked by N‐acetyl cysteine and dithiothreitol but not by TRPV1 knockout. ROS can activate protein kinase C independently of Ca2+. Here, the PKC inhibitor bisindolylmaleimide I (BIM I), but not the inactive analogue BIM V, abolished antimycin‐induced hyperexcitability. Antimycin A also caused PKC translocation via ROS. Lastly, exogenous H2O2 induced nociceptor hyperexcitability, which was blocked by BIM I. We conclude that acute modulation of nerve terminal mitochondria can induce airway nociceptor hyperexcitability via ROS‐activated PKC pathways.Grant Funding Source: Supported by R01HL119802‐01
In humans with type 2 diabetes, prostacyclin receptor expression increases as hemoglobin A1c levels increase (664.6)
Authors: Stephenson Alan , Knebel Stephanie , Sprague Randy 
Published: June 2021

In healthy humans (HH), exposure of erythrocytes to reduced O2 tension stimulates the release of O2 as well as the potent vasodilator adenosine triphosphate (ATP). Erythrocytes of humans with type 2 diabetes (DM2) fail to release ATP when exposed to reduced O2 tension. However, iloprost (1 µM)‐induced stimulation of the prostacyclin receptor (IPR) activates a signaling pathway distinct from the low O2 pathway resulting in increased cAMP and ATP release in erythrocytes of HH and humans with DM2. In fact, as glycemic control worsens (indicated by increases in HbA1c) IPR‐mediated ATP release increases. We hypothesized that with DM2, the increased ATP release may result from increased IPR expression or decreased phosphodiesterase (PDE) 3 activity. Previously, we reported that when PDE3 activity was inhibited with cilostazol, a selective PDE3 inhibitor, iloprost (1 µM)‐induced ATP release was not different between HH and DM2, indicating that PDE3 activity is decreased in erythrocytes from humans with DM2. Here, using Western blot analysis, we found that expression of IPR monomeric (40, 50, and 65 kD, n=8, P<0.05) and dimeric isoforms (MW greater than 65 kD, n=8, P<0.02) was directly correlated with levels of HbA1c. Taken together with the PDE studies, when compared to HH erythrocytes, decreased PDE3 activity and increased expression of the IPR as glycemic control worsens may explain the increased iloprost‐induced ATP release in erythrocytes from humans with DM2.Grant Funding Source: ADA and NIH
Ionizing radiation promotes the acquisition of a senescence‐associated secretory phenotype and impairs angiogenic capacity in cerebromicrovascular endothelial cells: role of increased DNA damage and decreased DNA repair capacity in microvascular radiosens (665.3)
Authors: Ungvari Zoltan , Podlutsky Andrej , Sosnowska Danuta , Tucsek Zsuzsanna , Toth Peter , Deak Ferenc , Gautam Tripti , Csiszar Anna , Sonntag William 
Published: June 2021

Cerebromicrovascular rarefaction is believed to play a central role in cognitive impairment in patients receiving whole‐brain irradiation therapy. To elucidate the mechanism underlying the deleterious effects of γ‐irradiation on the cerebral microcirculation, rat primary cerebromicrovascular endothelial cells (CMVECs) were irradiated in vitro. We found that in CMVECs, γ‐irradiation (2‐8 Gy) elicited increased DNA damage, which was repaired less efficiently in CMVECs compared with neurons, microglia, and astrocytes. Increased genomic injury in CMVECs associated with increased apoptotic cell death. In the surviving cells, γ‐irradiation promotes premature senescence (indicated by SA‐β‐galactosidase positivity and upregulation of p16 (INK4a)), which was associated with impaired angiogenic capacity (decreased proliferation and tube‐forming capacity). γ‐Irradiated CMVECs acquired a senescence‐associated secretory phenotype, characterized by upregulation of proinflammatory cytokines and chemokines (including IL‐6, IL‐1α, and MCP‐1). Collectively, increased vulnerability of γ‐irradiated CMVECs and their impaired angiogenic capacity likely contribute to cerebromicrovascular rarefaction and prevent regeneration of the microvasculature postirradiation. The acquisition of a senescence‐associated secretory phenotype in irradiated CMVECs is biologically highly significant as changes in the cytokine microenvironment in the hippocampus may affect diverse biological processes relevant for normal neuronal function (including regulation of neurogenesis and the maintenance of the blood brain barrier).Grant Funding Source: Supported by NIH and the Ellison Medical Foundation
Functional consequences of chronic mast cell activation by aged mesenteric lymphatic vessels (666.1)
Authors: Gashev Anatoliy , Chatterjee Victor , Tobin Richard , Newell Rogers M. Karen 
Published: June 2021

Here we present novel data related to interactions between lymphatic vessels, mast cells (MCs), eosinophils, and immune cells. MCs are known to inhabit in greater density the tissue near mesenteric lymphatic vessels (MLVs). Acute activation induces MC degranulation with subsequent recruitment of eosinophils and of MHC class II+ cells towards MLVs. Aging permanently influences mesenteric MCs by inducing chronic basal activation, thereby influencing contractility of aged MLVs. At the same time, the number of intact MCs available to react acutely to inflammatory stimuli decreases with age. The diminished number and activity of MCs in aged tissues also diminishes traffic and activation of eosinophils and other immune cells that are attracted to aged MLVs. Concurrently, MCs can function as helper cells for B cells that can produce IgE. IgE has a relatively short half‐life in the absence of chronic MC activation. We propose that a key component of aging‐associated alterations of “mesenteric lymphatic system‐mast cells/eosinophils‐inflammatory cells” system is the increased basal activation of resident MCs and eosinophils in aged mesentery that promote chronic inflammation while being insufficient to recruit enough anti‐inflammatory MHC class II+ cells and eosinophils, resulting in the inability to prevent a smooth transition from acute inflammation to specific immune cell activation. NIH R01 AG030578.Grant Funding Source: NIH R01 AG030578
Visualizing the endothelium from inside intact arteries at physiological pressures reveals pulsatile linear, circular and spiral Ca2+ waves (668.1)
Authors: Wilson Calum , Saunter Christopher , Zagnoni Michele , Girkin John , McCarron John 
Published: June 2021

Ca2+ signalling in the endothelium is central to the control of vascular function and to the changes that occur in vascular disease. However, visualizing Ca2+ signals in endothelial cells in intact, pressurised arteries is difficult (particularly in the larger arteries where atherosclerosis and re‐stenosis occurs), due to medial and adventitial thickness. A novel wide‐field, epi‐fluorescent microscope with subcellular resolution, that enables endothelium imaging from the inside of large pressurised arteries, has been developed. A side‐viewing Gradient Index (GRIN) relay lens, inserted into the lumen of pressurised arteries, permits the endothelium to be imaged with a 350 µm diameter field of view ‐ an area encompassing approximately 200 cells. Acetylcholine‐activation of the endothelium evoked pulsatile, repetitive Ca2+ waves that initiated at several sites (measured by fluorescent indicators). Waves progressed through the endothelium linearly, in expanding circles and in spiral forms. The Ca2+ waves show properties of excitable systems i.e. regenerative propagation and annihilation of colliding wavefronts. The GRIN lens approach offers a new level of understanding in the study of endothelial Ca2+ signalling and we propose the endothelium, via Ca2+ signals, behaves as an excitable medium in physiological conditions.Grant Funding Source: Wellcome Trust; British Heart Foundation; EPSRC