In Vitro and In Vivo Antagonism of a G Protein-Coupled Receptor (S1P3) with a Novel Blocking Monoclonal Antibody

Background: S1P 3 is a lipid-activated G protein-couple receptor (GPCR) that has been implicated in the pathological processes of a number of diseases, including sepsis and cancer. Currently, there are no available high-affinity, subtypeselective drug compounds that can block activation of S1P3. We have developed a monoclonal antibody (7H9) that specifically recognizes S1P3 and acts as a functional antagonist. Methodology/Principal Findings: Specific binding of 7H9 was demonstrated by immunocytochemistry using cells that over-express individual members of the S1P receptor family. We show, in vitro, that 7H9 can inhibit the activation of S1P3mediated cellular processes, including arrestin translocation, receptor internalization, adenylate cyclase inhibiton, and calcium mobilization. We also demonstrate that 7H9 blocks activation of S1P3 in vivo, 1) by preventing lethality due to systemic inflammation, and 2) by altering the progression of breast tumor xenografts. Conclusions/Significance: We have developed the first-reported monoclonal antibody that selectively recognizes a lipidactivated GPCR and blocks functional activity. In addition to serving as a lead drug compound for the treatment of sepsi

The Concise Guide to PHARMACOLOGY 2023/24: G protein-coupled receptors.

peer reviewedThe Concise Guide to PHARMACOLOGY 2023/24 is the sixth in this series of biennial publications. The Concise Guide provides concise overviews, mostly in tabular format, of the key properties of approximately 1800 drug targets, and about 6000 interactions with about 3900 ligands. There is an emphasis on selective pharmacology (where available), plus links to the open access knowledgebase source of drug targets and their ligands (https://www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. Although the Concise Guide constitutes almost 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.16177. G protein-coupled receptors are one of the six major pharmacological targets into which the Guide is divided, with the others being: ion channels, 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-2023, and supersedes data presented in the 2021/22, 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

Pleotropic Roles of Autotaxin in the Nervous System Present Opportunities for the Development of Novel Therapeutics for Neurological Diseases

10.1007/s12035-019-01719-1MOLECULAR NEUROBIOLOGY571372-39

Sphingolipidomics analysis of large clinical cohorts. Part 1: Technical notes and practical considerations

10.1016/j.bbrc.2018.04.076BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS5043596-60

7H9 blocks activation of S1P₃.

<p>(A-D) 7H9 blocks S1P₃-mediated arrestin translocation. β-arrestin (green) is cytosolic in quiescent cells and appears as diffuse labeling (A). Following stimulation with 1 µM S1P (B), arrestin translocates to the plasma membrane and is rapidly internalized into intracellular vesicles (arrows). In contrast, when cells are pre-treated with 1 µg/ml 7H9 arrestin localization is diffuse and cytoplasmic in both the absence (C) and presence (D) of 1 µM S1P. (E-H) 7H9 blocks S1P-dependent internalization of S1P₃. Epitope-tagged S1P₃ is normally abundant on the plasma membrane (E, arrows), but is internalized into intracellular vesicles (arrowheads) upon stimulation with 1 µM S1P (F). Following pre-treatment of cells with 7H9, S1P₃ remains localized to the plasma membrane in the absence (G) or presence (H) of 1 µM S1P. (I) 7H9 blocks S1P₃-dependent calcium mobilization. S1P₃-expressing cells exhibited increased intracellular [Ca²⁺] upon stimulation with 100 nM S1P (blue, antibody control). Cells within the same culture that did not express S1P₃-EGFP (green, receptor control) showed no change in [Ca_i²⁺]. Similarly, cells expressing S1P₃ that were pre-treated with 7H9 (red, 7H9) also showed no response to 100 nM and 1 µM S1P, but gave a partial response at 5 µM. (J) 7H9 blocks S1P₃-dependent inhibition of AC. cAMP was measured in S1P₃-expressing cells by ELISA and normalized to controls. The graph represents the change in cAMP content from unstimulated cells, relative to the change observed in stimulated cells with no 7H9 pre-treatment. *p<0.05, **p<0.01. Error bars  =  S.E.M.</p

Sphingosine kinase inhibition ameliorates chronic hypoperfusion-induced white matter lesions

10.1016/j.neuint.2016.02.012NEUROCHEMISTRY INTERNATIONAL9490-97UNITED KINGDO

Biological Effects of Naturally Occurring Sphingolipids, Uncommon Variants, and Their Analogs

10.1007/s12017-016-8424-8NEUROMOLECULAR MEDICINE183396-414United State

S1P signaling.

<p>S1P is an extracellular signaling molecule, generated by the phosphorylation of sphingosine, that exerts a variety of effects on a family of 5 cognate GPCRs.</p

7H9 prevents lethality caused by LPS administration.

<p>Survival curve of mice treated with LPS (8 mg/kg, i.p.) on day 0. Mice were pre-treated with vehicle (PBS), IgG (normal mouse IgG), or 7H9.</p