title: Analysis of the expression of human bitter taste receptors in extraoral tissues.
abstract: The 25 bitter taste receptors (T2Rs) in humans perform a chemosensory function. However, very little is known about the level of expression of these receptors in different tissues. In this study, using nCounter gene expression we analyzed the expression patterns of human TAS2R transcripts in cystic fibrosis bronchial epithelial (CuFi-1), normal bronchial epithelial (NuLi-1), airway smooth muscle (ASM), pulmonary artery smooth muscle (PASM), mammary epithelial, and breast cancer cells. Our results suggest a specific pattern of TAS2R expression with TAS2R3, 4, 5, 10, 13, 19, and 50 transcripts expressed at moderate levels and TAS2R14 and TAS2R20 (or TASR49) at high levels in the various tissues analyzed. This pattern of expression is mostly independent of tissue origin and the pathological state, except in cancer cells. To elucidate the expression at the protein level, we pursued flow cytometry analysis of select T2Rs from CuFi-1 and NuLi-1 cells. The expression levels observed at the gene level by nCounter analysis correlate with the protein levels for the T2Rs analyzed. Next, to assess the functionality of the expressed T2Rs in these cells, we pursued functional assays measuring intracellular calcium mobilization after stimulation with the bitter compound quinine. Using PLC inhibitor, U-73122, we show that the calcium mobilized in these cells predominantly takes place through the Quinine-T2R-Gαβγ-PLC pathway. This report will accelerate studies aimed at analyzing the pathophysiological function of T2Rs in different extraoral tissues.
authors.affiliation: Manitoba Chemosensory Biology (MCSB) Research Group, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.|Department of Oral Biology, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.
authors.forename: Appalaraju
authors.initials: A
authors.lastname: Jaggupilli
authors.affiliation: Manitoba Chemosensory Biology (MCSB) Research Group, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.|Department of Oral Biology, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.
authors.forename: Nisha
authors.initials: N
authors.lastname: Singh
authors.affiliation: Manitoba Chemosensory Biology (MCSB) Research Group, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.|Department of Oral Biology, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.
authors.forename: Jasbir
authors.initials: J
authors.lastname: Upadhyaya
authors.affiliation: Manitoba Chemosensory Biology (MCSB) Research Group, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.|Department of Oral Biology, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.
authors.forename: Anurag S
authors.initials: AS
authors.lastname: Sikarwar
authors.affiliation: Manitoba Chemosensory Biology (MCSB) Research Group, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.|Department of Oral Biology, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.|Department of Dental Hygiene, Chiba Prefectural University of Health Sciences, Winnipeg, Canada.
authors.forename: Makoto
authors.initials: M
authors.lastname: Arakawa
authors.affiliation: Manitoba Chemosensory Biology (MCSB) Research Group, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.|Departments of Pediatrics, Physiology, University of Manitoba, Winnipeg, Canada.|Biology of Breathing, Children's Hospital Research Institute of Manitoba (CHRIM), Winnipeg, Canada.
authors.forename: Shyamala
authors.initials: S
authors.lastname: Dakshinamurti
authors.affiliation: Manitoba Chemosensory Biology (MCSB) Research Group, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.|Department of Oral Biology, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.
authors.forename: Rajinder P
authors.initials: RP
authors.lastname: Bhullar
authors.affiliation: Manitoba Chemosensory Biology (MCSB) Research Group, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.|Department of Oral Biology, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada.|Biology of Breathing, Children's Hospital Research Institute of Manitoba (CHRIM), Winnipeg, Canada.
authors.forename: Kangmin
authors.initials: K
authors.lastname: Duan
authors.affiliation: Manitoba Chemosensory Biology (MCSB) Research Group, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada. Prashen.Chelikani@umanitoba.ca.|Department of Oral Biology, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada. Prashen.Chelikani@umanitoba.ca.|Biology of Breathing, Children's Hospital Research Institute of Manitoba (CHRIM), Winnipeg, Canada. Prashen.Chelikani@umanitoba.ca.|Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, R3E 0W4, Canada. Prashen.Chelikani@umanitoba.ca.
authors.forename: Prashen
authors.initials: P
authors.lastname: Chelikani
mesh_terms: D001980:Bronchi / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D009130:Muscle, Smooth / Q000378:metabolism*; D009928:Organ Specificity / Q000502:physiology; D043562:Receptors, G-Protein-Coupled / Q000096:biosynthesis*; D020545:Respiratory Mucosa / Q000378:metabolism*; D000098706:Taste Receptors, Type 2
chemical_list: D043562:Receptors, G-Protein-Coupled; D000098706:Taste Receptors, Type 2
keywords: Airway smooth muscle cells (ASMCs); Bitter taste receptor gene (TAS2R); Bitter taste receptor protein (T2R); Breast cancer cells (MDA-MB-231); Cystic fibrosis bronchial epithelial cells (CuFi-1); G protein-coupled receptor (GPCR); Normal bronchial epithelial cells (NuLi-1); nCounter® gene sequencing