title: Expression, regulation and putative nutrient-sensing function of taste GPCRs in the heart.
abstract: G protein-coupled receptors (GPCRs) are critical for cardiovascular physiology. Cardiac cells express >100 nonchemosensory GPCRs, indicating that important physiological and potential therapeutic targets remain to be discovered. Moreover, there is a growing appreciation that members of the large, distinct taste and odorant GPCR families have specific functions in tissues beyond the oronasal cavity, including in the brain, gastrointestinal tract and respiratory system. To date, these chemosensory GPCRs have not been systematically studied in the heart. We performed RT-qPCR taste receptor screens in rodent and human heart tissues that revealed discrete subsets of type 2 taste receptors (TAS2/Tas2) as well as Tas1r1 and Tas1r3 (comprising the umami receptor) are expressed. These taste GPCRs are present in cultured cardiac myocytes and fibroblasts, and by in situ hybridization can be visualized across the myocardium in isolated cardiac cells. Tas1r1 gene-targeted mice (Tas1r1(Cre)/Rosa26(tdRFP)) strikingly recapitulated these data. In vivo taste receptor expression levels were developmentally regulated in the postnatal period. Intriguingly, several Tas2rs were upregulated in cultured rat myocytes and in mouse heart in vivo following starvation. The discovery of taste GPCRs in the heart opens an exciting new field of cardiac research. We predict that these taste receptors may function as nutrient sensors in the heart.
authors.affiliation: University of Queensland, School of Biomedical Sciences, Brisbane, Australia.
authors.forename: Simon R
authors.initials: SR
authors.lastname: Foster
authors.forename: Enzo R
authors.initials: ER
authors.lastname: Porrello
authors.forename: Brooke
authors.initials: B
authors.lastname: Purdue
authors.forename: Hsiu-Wen
authors.initials: HW
authors.lastname: Chan
authors.forename: Anja
authors.initials: A
authors.lastname: Voigt
authors.forename: Sabine
authors.initials: S
authors.lastname: Frenzel
authors.forename: Ross D
authors.initials: RD
authors.lastname: Hannan
authors.forename: Karen M
authors.initials: KM
authors.lastname: Moritz
authors.forename: David G
authors.initials: DG
authors.lastname: Simmons
authors.forename: Peter
authors.initials: P
authors.lastname: Molenaar
authors.forename: Eugeni
authors.initials: E
authors.lastname: Roura
authors.forename: Ulrich
authors.initials: U
authors.lastname: Boehm
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Meyerhof
authors.forename: Walter G
authors.initials: WG
authors.lastname: Thomas
mesh_terms: D000818:Animals; D005347:Fibroblasts / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D009206:Myocardium / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000378:metabolism; D020161:Physical Chromosome Mapping; D051381:Rats; D043562:Receptors, G-Protein-Coupled / Q000235:genetics* / Q000378:metabolism*; D013217:Starvation / Q000235:genetics; D013649:Taste / Q000235:genetics*; D000098706:Taste Receptors, Type 2
chemical_list: D043562:Receptors, G-Protein-Coupled; D000098706:Taste Receptors, Type 2