Bone marrow stromal and vascular smooth muscle cells have chemosensory capacity via bitter taste receptor expression

• Published in: PloS one 2013-03, Vol.8 (3), p.e58945-e58945
• Main Authors: Lund, Troy C, Kobs, Amanda J, Kramer, Ashley, Nyquist, Mick, Kuroki, Marcos T, Osborn, John, Lidke, Diane S, Low-Nam, Shalini T, Blazar, Bruce R, Tolar, Jakub
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Animals; Biology; Bitter taste; Blood pressure; Blood Pressure - drug effects; Blood Pressure - physiology; Bone marrow; Bone Marrow Cells - cytology; Bone Marrow Cells - metabolism; Calcium; Calcium (intracellular); Calcium - metabolism; Cells, Cultured; Change detection; Chemoreception; Child; Child, Preschool; Cyclic adenosine monophosphate; Female; Flow cytometry; Gene expression; Humans; Infant; Male; Medical research; Mice; Microenvironments; Muscle, Smooth, Vascular - cytology; Muscle, Smooth, Vascular - metabolism; Muscles; Myocytes, Smooth Muscle - cytology; Myocytes, Smooth Muscle - metabolism; Pediatrics; Physiology; Proteomics; Quaternary Ammonium Compounds - pharmacology; Rats, Sprague-Dawley; Receptors; Receptors, G-Protein-Coupled - agonists; Receptors, G-Protein-Coupled - metabolism; Rodents; Scientific imaging; Signaling; Smooth muscle; Stem cells; Stromal Cells - cytology; Stromal Cells - metabolism; Taste; Taste (Sense); Taste receptors
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0058945

The ability of cells to detect changes in the microenvironment is important in cell signaling and responsiveness to environmental fluctuations. Our interest is in understanding how human bone marrow stromal-derived cells (MSC) and their relatives, vascular smooth muscle cells (VSMC), interact with their environment through novel receptors. We found, through a proteomics screen, that MSC express the bitter taste receptor, TAS2R46, a protein more typically localized to the taste bud. Expression was also confirmed in VSMCs. A prototypical bitter compound that binds to the bitter taste receptor class, denatonium, increased intracellular calcium release and decreased cAMP levels as well as increased the extracellular release of ATP in human MSC. Denatonium also bound and activated rodent VSMC with a change in morphology upon compound exposure. Finally, rodents given denatonium in vivo had a significant drop in blood pressure indicating a vasodilator response. This is the first description of chemosensory detection by MSC and VSMCs via a taste receptor. These data open a new avenue of research into discovering novel compounds that operate through taste receptors expressed by cells in the marrow and vascular microenvironments.