title: G protein-coupled receptors mediate coronary flow- and agonist-induced responses via lectin-oligosaccharide interactions.
abstract: Blood flow acts parallel to the coronary luminal endothelial surface layer (LESL) and modulates multiple parenchymal functions via the release of paracrine agents. Evidence indicates that the LESL may be a flow-sensing organelle and that perhaps through flow-induced lectin (L)·oligosaccharide (O) complex formation (L·O) participates in this process. LESL integrins and selectins are both lectinic and flow sensitive, but the L properties of flow-sensitive G protein-coupled receptors (GPCRs) are unknown. Therefore, we investigated the presence of L in the LESL and hypothesized that if flow-sensitive GPCRs are L, flow and O will determine their response to receptor activation. The LESL protein fraction isolated from guinea pig hearts was passed through an affinity chromatography column made of three sugars, mannose, galactose, and N-acetylglucosamine, and the lectinic fraction was eluted. Immune dot blot was used to identify L proteins in the LESL fraction. Our results indicate the following. 1) Two-dimensional SDS-PAGE (2D-SDS-PAGE) of the LESL lectinic fraction revealed at least 167 Ls. 2) Among these Ls, we identified three selectins and the GPCRs: angiotensin II, bradykinin (B2-R), adenosine A1 and A2, prolactin, endothelin, α1-adrenergic (α1A-R), thromboxane A2, β1-adrenergic, β3-adrenergic, and insulin receptors; the first six GPCRs are known to be flow sensitive. 3) The amplitude of receptor-induced vascular responses by α1A-R and B2-R activation (phenylephrine or bradykinin, respectively) was a function of flow and O (hyaluronidate). Our results support a novel mechanism of GPCR-mediated responses to flow via L·O interaction.
authors.affiliation: Departamento de Fisiología, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico;
authors.forename: Sandra
authors.initials: S
authors.lastname: Perez-Aguilar
authors.forename: David
authors.initials: D
authors.lastname: Torres-Tirado
authors.forename: Guadalupe
authors.initials: G
authors.lastname: Martell-Gallegos
authors.forename: Jimena
authors.initials: J
authors.lastname: Velarde-Salcedo
authors.forename: Ana Paulina
authors.initials: AP
authors.lastname: Barba-de la Rosa
authors.forename: Maureen
authors.initials: M
authors.lastname: Knabb
authors.forename: Rafael
authors.initials: R
authors.lastname: Rubio
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism; D000818:Animals; D002317:Cardiovascular Agents / Q000494:pharmacology; D002846:Chromatography, Affinity; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D005690:Galactose / Q000378:metabolism; D037161:Galectins / Q000378:metabolism; D019276:Glycocalyx / Q000378:metabolism; D006168:Guinea Pigs; D037102:Lectins / Q000378:metabolism*; D008024:Ligands; D008358:Mannose / Q000378:metabolism; D037601:Mannose-Binding Lectin / Q000378:metabolism; D040542:Mechanotransduction, Cellular / Q000187:drug effects; D008955:Models, Cardiovascular; D009844:Oligosaccharides / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D043562:Receptors, G-Protein-Coupled / Q000819:agonists / Q000378:metabolism*; D034781:Receptors, N-Acetylglucosamine / Q000378:metabolism; D012039:Regional Blood Flow; D013997:Time Factors
chemical_list: D002317:Cardiovascular Agents; D037161:Galectins; D037102:Lectins; D008024:Ligands; D037601:Mannose-Binding Lectin; D009844:Oligosaccharides; D043562:Receptors, G-Protein-Coupled; D034781:Receptors, N-Acetylglucosamine; D008358:Mannose; D000117:Acetylglucosamine; D005690:Galactose
keywords: G protein-coupled receptors; flow sensitivity requirements; lectins and sugars of glycocalyx; mechanosensors; regulatory extracellular matrix