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Gu F, Liu X, Liang J, Chen J, Chen F, Li F. Bitter taste receptor mTas2r105 is expressed in small intestinal villus and crypts. Biochem Biophys Res Commun 2015; 463:934-41. [PMID: 26071358 DOI: 10.1016/j.bbrc.2015.06.038] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 06/04/2015] [Indexed: 12/30/2022]
Abstract
The small intestine is the most important digestion and absorption organ in the body. Taste receptors and taste signal transduction cascades were detected in a variety of non-lingual tissues including testis, kidney, nasal cavity, lung, heart and gastrointestinal (GI) tract. Though the expression of bitter taste receptors and taste signal transduction cascades has been reported in the gut for a decade, the evidence revealing the expression of Tas2rs in the gut remain unbelievable. Here, the amplification of 35 bitter taste receptors from small intestine cDNA revealed that all transcripts are present in duodenum, jejunum and ileum, except Tas2r117. In addition, Tas2Rs and taste-related signaling transduction cascades are also observed in mouse small intestine including duodenum, jejunum and ileum by RT-PCR and Western Blot. On the other hand, three types of transgenic system were used to investigate the expression of the bitter taste receptor Tas2r105 in mouse intestine (Tas2r105-GFP/Cre, Tas2r105-GFP/Cre-DTA and Tas2r105-GFP/Cre-LacZ). With the bitter taste receptor mTas2r105 transgenic mice, the expression of mTas2r105 is showed in the villus and crypts of small intestine. mTas2r105 positive cells are also observed at the connective tissue of villus. DTA expression in mTas2r105 + cells completely ablate the expression of mTas2r105 in intestinal epithelia, but did not ablate mTas1r3 expression in intestine epithelia. LacZ staining further reveals that bitter taste receptor mTas2r105 is expressed in crypt base cells.
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Affiliation(s)
- Fu Gu
- School of Life Science, Shanghai University, Shanghai, PR China
| | - Xin Liu
- School of Life Science, Shanghai University, Shanghai, PR China
| | - Jie Liang
- School of Life Science, Shanghai University, Shanghai, PR China
| | - Jiaying Chen
- School of Life Science, Shanghai University, Shanghai, PR China
| | - Fuxue Chen
- School of Life Science, Shanghai University, Shanghai, PR China.
| | - Feng Li
- School of Medicine, Shanghai Jiao Tong University, Shanghai, PR China.
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Krasteva-Christ G, Soultanova A, Schütz B, Papadakis T, Weiss C, Deckmann K, Chubanov V, Gudermann T, Voigt A, Meyerhof W, Boehm U, Weihe E, Kummer W. Identification of cholinergic chemosensory cells in mouse tracheal and laryngeal glandular ducts. Int Immunopharmacol 2015; 29:158-65. [PMID: 26033492 DOI: 10.1016/j.intimp.2015.05.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/27/2015] [Accepted: 05/18/2015] [Indexed: 11/19/2022]
Abstract
Specialized epithelial cells in the respiratory tract such as solitary chemosensory cells and brush cells sense the luminal content and initiate protective reflexes in response to the detection of potentially harmful substances. The majority of these cells are cholinergic and utilize the canonical taste signal transduction cascade to detect "bitter" substances such as bacterial quorum sensing molecules. Utilizing two different mouse strains reporting expression of choline acetyltransferase (ChAT), the synthesizing enzyme of acetylcholine (ACh), we detected cholinergic cells in the submucosal glands of the murine larynx and trachea. These cells were localized in the ciliated glandular ducts and were neither found in the collecting ducts nor in alveolar or tubular segments of the glands. ChAT expression in tracheal gland ducts was confirmed by in situ hybridization. The cholinergic duct cells expressed the brush cell marker proteins, villin and cytokeratin-18, and were immunoreactive for components of the taste signal transduction cascade (Gα-gustducin, transient receptor potential melastatin-like subtype 5 channel = TRPM5, phospholipase C(β2)), but not for carbonic anhydrase IV. Furthermore, these cells expressed the bitter taste receptor Tas2r131, as demonstrated utilizing an appropriate reporter mouse strain. Our study identified a previously unrecognized presumptive chemosensory cell type in the duct of the airway submucosal glands that likely utilizes ACh for paracrine signaling. We propose that these cells participate in infection-sensing mechanisms and initiate responses assisting bacterial clearance from the lower airways.
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Affiliation(s)
- G Krasteva-Christ
- Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany; Institute of Anatomy and Cell Biology, Julius-Maximilians-University, Wuerzburg, Germany.
| | - A Soultanova
- Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany
| | - B Schütz
- Institute for Anatomy and Cell Biology, Philipps-University, Marburg, Germany
| | - T Papadakis
- Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany
| | - C Weiss
- Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany
| | - K Deckmann
- Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany
| | - V Chubanov
- Walter-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilian-University, Munich, Germany
| | - T Gudermann
- Walter-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilian-University, Munich, Germany
| | - A Voigt
- Dept. Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - W Meyerhof
- Dept. Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - U Boehm
- Department of Pharmacology and Toxicology, University of Saarland School of Medicine, Homburg, Germany
| | - E Weihe
- Institute for Anatomy and Cell Biology, Philipps-University, Marburg, Germany
| | - W Kummer
- Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany
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