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The Concise Guide to PHARMACOLOGY 2021/22 is the fifth in this series of biennial publications. The Concise Guide provides concise overviews, mostly in tabular format, of the key properties of nearly 1900 human drug targets with an emphasis on selective pharmacology (where available), plus links to the open access knowledgebase source of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. Although the Concise Guide constitutes over 500 pages, the material presented is substantially reduced compared to information and links presented on the website. It provides a permanent, citable, point-in-time record that will survive database updates. The full contents of this section can be found at http://onlinelibrary.wiley.com/doi/bph.15539. Ion channels are one of the six major pharmacological targets into which the Guide is divided, with the others being: G protein-coupled receptors, nuclear hormone receptors, catalytic receptors, enzymes and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. The landscape format of the Concise Guide is designed to facilitate comparison of related targets from material contemporary to mid-2021, and supersedes data presented in the 2019/20, 2017/18, 2015/16 and 2013/14 Concise Guides and previous Guides to Receptors and Channels. It is produced in close conjunction with the Nomenclature and Standards Committee of the International Union of Basic and Clinical Pharmacology (NC-IUPHAR), therefore, providing official IUPHAR classification and nomenclature for human drug targets, where appropriate.

Administration of extracellular ATP to lymphoblastoid cell lines in normal subjects and Duchenne muscular dystrophy patients to analyze their response to ATP reveals that normal and dystrophic cell lines respond differently to extracellular ATP and that dystrophy patients are more sensitive to extracellular ATP. Extracellular ATP induces a rise in plasma membrane depolarization and cytoplasmic Ca2+ levels and causes swelling, rounding and lysing of the cells in dystrophy patients, indicating the presence of an ATP-gated membrane channel which is permeable to Ca2+ and Na+.

The nucleotide adenosine-5'-monophosphate (AMP) can be released by various cell types and has been shown to elicit different cellular responses. In the extracellular space AMP is dephosphorylated to the nucleoside adenosine which can then bind to adenosine receptors. However, it has been shown that AMP can also activate A1 and A2a receptors directly. Here we show that AMP is a potent modulator of mouse and human dendritic cell (DC) function. AMP increased intracellular Ca2+ concentration in a time and dose dependent manner. Furthermore, AMP stimulated actin-polymerization in human DCs and induced migration of immature human and bone marrow derived mouse DCs, both via direct activation of A1 receptors. AMP strongly inhibited secretion of TNF-α and IL-12p70, while it enhanced production of IL-10 both via activation of A2a receptors. Consequently, DCs matured in the presence of AMP and co-cultivated with naive CD4+CD45RA+ T cells inhibited IFN-α production whereas secretion of IL-5 and IL-13 was up-regulated. An enhancement of Th2-driven immune response could also be observed when OVA-pulsed murine DCs were pretreated with AMP prior to co-culture with OVA-transgenic naïve OTII T cells. An effect due to the enzymatic degradation of AMP to adenosine could be ruled out, as AMP still elicited migration and changes in cytokine secretion in bone-marrow derived DCs generated from CD73-deficient animals and in human DCs pretreated with the ecto-nucleotidase inhibitor 5'-(alpha,beta-methylene) diphosphate (APCP). Finally, the influence of contaminating adenosine could be excluded, as AMP admixed with adenosine desaminase (ADA) was still able to influence DC function. In summary our data show that AMP when present during maturation is a potent regulator of dendritic cell function and point out the role for AMP in the pathogenesis of inflammatory disorders. [ABSTRACT FROM AUTHOR]

Beside its well described role in the central and peripheral nervous system 5-hydroxytryptamine (5-HT), commonly known as serotonin, is also a potent immuno-modulator. Serotoninergic receptors (5-HTR) are expressed by a broad range of inflammatory cell types, including dendritic cells (DCs). In this study, we aimed to further characterize the immunobiological properties of serotoninergic receptors on human monocyte-derived DCs. 5-HT was able to induce oriented migration in immature but not in LPS-matured DCs via activation of 5-HTR1 and 5-HTR2 receptor subtypes. Accordingly, 5- HT also increased migration of pulmonary DCs to draining lymph nodes in vivo. By binding to 5-HTR3, 5-HTR4 and 5-HTR7 receptors, 5-HT up-regulated production of the pro-inflammatory cytokine IL-6. Additionally, 5-HT influenced chemokine release by human monocyte-derived DCs: production of the potent Th1 chemoattractant IP-10/CXCL10 was inhibited in mature DCs, whereas CCL22/MDC secretion was up-regulated in both immature and mature DCs. Furthermore, DCs matured in the presence of 5-HT switched to a high IL-10 and low IL-12p70 secreting phenotype. Consistently, 5-HT favoured the outcome of a Th2 immune response both in vitro and in vivo. In summary, our study shows that 5-HT is a potent regulator of human dendritic cell function, and that targeting serotoninergic receptors might be a promising approach for the treatment of inflammatory disorders. [ABSTRACT FROM AUTHOR]

Receptors for extracellular nucleotides are the focus of increasing attention for their ability to cause release of plasma membrane vesicles (microparticles, MPs). Here, we show that monocyte-derived human dendritic cells (DCs) stimulated with a P2X7 receptor (P2X7R) agonist undergo a large release of MPs endowed with procoagulant activity. Functional and Western blot studies revealed that MPs contain the membrane-bound form of tissue factor (TF), a glycoprotein acting as essential cofactor of activated factor VII and triggering blood coagulation. Quiescent DCs express the membrane-bound (full length), as well as truncated alternatively spliced TF forms. DC reactivity to anti-TF Abs disappeared almost completely on stimulation with ATP or benzoyl ATP (BzATP), as shown by immunoblot and confocal microscopy analysis. Concurrently, TF reactivity and activity appeared in the vesicular fraction, indicating that MPs are important carriers for the dissemination of full-length TF form. Activity of MP-bound TF, comparable to that of relipidated recombinant TF, was dose dependently inhibited by the addition of a specific anti-human TF antibody. We infer that a large fraction of this protein, and its procoagulant potential, are "deliverable" after physiological or pathological stimuli. These findings might have implications for triggering and propagating coagulation in healthy and atherosclerotic vessels. [ABSTRACT FROM AUTHOR]