Objectives: Adenosine is known to induce a bronchospasm in asthma- and COPD patients. The role of A(2B) receptors was investigated with respect to several parameters of the respiratory tract: tonus of smooth muscle, ciliary beat frequency as measured by high-speed video camera connected to a microscope (both in rats) and mucociliary clearance (MCC; transport of a fluorescent dye using a microdialysis procedure) in mice.
Key Findings: NECA (5'-N-ethylcarboxamidoadenosine) (a non-selective adenosine receptor agonist) was able to acutely induce a contraction, which was reversed to a relaxation after repeated dosing. This relaxation was completely abolished by PSB-1115, an A(2B) receptor antagonist. IL-13 (cytokine) was not involved mediating acute contractility effects. MCC was increased by BAY 60-6583 (A(2B) receptor agonist) and NECA (counteracted by the A(2B) receptor antagonist PSB-1115). Activation of A(2B) adenosine receptors by BAY 60-6583 induced an increase of the ciliary beat frequency, which could be reduced by administration of PSB-1115. Several cytokines were increased by NECA although only some are relevant because they are not blocked by A(2B) receptor antagonism.
Conclusions: The A(2B) receptors are involved in airway relaxation, MCC improvement and ciliary beat frequency. A(2B) receptor agonists may be of therapeutic value and should be developed.
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http://dx.doi.org/10.1111/j.2042-7158.2012.01580.x | DOI Listing |
Int J Mol Sci
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Atherothrombosis Research Centre/Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, 451 10 Ioannina, Greece.
Ticagrelor, a reversible platelet P2Y receptor antagonist, exerts various pleiotropic actions, some of which are at least partially mediated through adenosine. We studied the ticagrelor and adenosine effect on the angiogenic properties of progenitor CD34-derived endothelial colony-forming cells (ECFCs). Angiogenesis studies were performed in vitro using capillary-like tube formation and spheroid-based angiogenesis assays.
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December 2024
Department of Pharmacy, Al-Zahrawi University College, Karbala, Iraq.
Netrin-1, an essential extracellular protein, has gained significant attention due to its pivotal role in guiding axon and cell migration during embryonic development. The fundamental significance of netrin-1 in developmental biology is reflected in its high conservation across different species as a part of the netrin family. The bifunctional nature of netrin-1 demonstrates its functional versatility, as it can function as either a repellent or an attractant according to the context and the expressed receptors on the target cells including the deleted in colorectal cancer (DCC), the uncoordinated-5 (UNC5), DSCAM, Neogenin-1, Adenosine A2b and Draxin receptors.
View Article and Find Full Text PDFActivation of PLCβ enzymes by G and G proteins is a common mechanism to trigger cytosolic Ca increase. We and others reported that G inhibitor FR900358 (FR) can inhibit both and G- and, surprisingly, G-mediated intracellular Ca mobilization. Thus, the G-G-PLCβ-Ca signaling axis depends entirely on the presence of active G, which reasonably explained FR-inhibited G-induced Ca release.
View Article and Find Full Text PDFCancer Sci
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Department of Personalized Cancer Immunotherapy/Center for Comprehensive Cancer Immunotherapy, Mie University Graduate School of Medicine, Tsu, Japan.
Melanoma-associated antigen (MAGE)-A4, a cancer testis antigen, presents a promising target for chimeric antigen receptor T cell therapy in refractory solid tumors, including breast cancer (BC). However, the lack of highly specific Abs against MAGE-A4 is a major challenge for the development of MAGE-A4-targeted immunotherapies. This study aimed to validate the specificity of a novel MAGE-A4 Ab (E701U) and examine MAGE-A4 expression in clinical BC samples.
View Article and Find Full Text PDFAndrology
December 2024
Faculty of Medicine, Department of Obstetrics, Gynecology and Reproduction, Centre Hospitalier Universitaire de Québec - Research Centre, and Centre de Recherche en Reproduction, Développement et Santé Intergénérationnelle - Université Laval, Québec, QC, Canada.
Introduction: The epididymis creates an optimal acidic luminal environment for sperm maturation and storage. In epididymal principal cells (PCs), proton secretion is activated by the accumulation of the sodium-proton exchanger type 3, NHE3 (SLC9A3), in apical stereocilia. PCs also secrete ATP, which is hydrolyzed into adenosine by ectonucleotidases.
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