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Yamamoto T, Koyama Y, Imai Y, Sawada E, Kishimoto N, Seo K. SARS-CoV-2 recombinant proteins-induced degeneration of taste buds in rat circumvallate papillae. J Dent Sci 2022; 17:1450-1453. [PMID: 35371412 PMCID: PMC8958135 DOI: 10.1016/j.jds.2022.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 03/21/2022] [Indexed: 12/02/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections cause loss or alteration of taste and smell as early symptoms and sequelae, but the detailed mechanism remains unclear. This study investigated whether coronavirus disease 2019-induced taste disorders are caused by direct effects on taste bud cells. SARS-CoV-2 recombinant spike and nucleocapsid proteins were applied to circumvallate papillae of male Sprague–Dawley rats. Immunohistochemistry and image analysis were used to compare the number of taste buds, and taste bud cells and area, together with confirmation of angiotensin-converting enzyme 2 (ACE2) expression. Immunohistochemical analysis revealed ACE2 expression in the taste buds of rat circumvallate papillae. Decreases in the number of taste buds, taste bud cells, and their area were observed at 12 days after application of SARS-CoV-2 recombinant spike and nucleocapsid proteins. These data suggest that SARS-CoV-2 proteins induce degeneration of taste buds.
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Affiliation(s)
- Toru Yamamoto
- Corresponding author. Division of Dental Anesthesiology, Faculty of Dentistry & Graduate School of Medicine and Dental Sciences, Niigata University, 2-5274 Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan. Fax: +81 25 227 0812.
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Saraf S, Jain S, Sahoo RN, Mallick S. Present Scenario of M-Cell Targeting Ligands for Oral Mucosal Immunization. Curr Drug Targets 2020; 21:1276-1284. [DOI: 10.2174/1389450121666200609113252] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 04/18/2020] [Accepted: 04/23/2020] [Indexed: 02/07/2023]
Abstract
The immune system plays an important role in the prevention of infection and forms the
first line of defense against pathogen attack. Delivering of antigen through mucosal route may elicit
mucosal immune system as the mucosal surface is the most common site of pathogen entry. Mucosal
immune system will be capable to counter pathogen at mucosal surface. Oral mucosal immunization
opens the ways to deliver antigens at gut-associated lymphoid tissue. This can elicit both local and
systemic immune response. Mucosal vaccines are economical, highly accessible, non parenteral delivery
and capacity to produce mass immunization at the time of pandemics. To deliver antigens on the
mucosal surface of the gastrointestinal tract, the immune system relies on specialized epithelial cell
i.e. Microfold (M)-cell. An approach to exploit the targeting specific receptors on M-cell for entry of
antigens has made a breakthrough in vaccine development. In this review, various strategies have been
discussed for the possible entry of antigens through M-cells and an approach to increase the uptake
and efficacy of vaccines for oral mucosal immunization.
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Affiliation(s)
- Surendra Saraf
- School of Pharmaceutical Sciences, Siksha ‘O’ Anusandhan (Deemed to be University), Bhubaneswar-751030, Orissa, India
| | - Shailesh Jain
- Dean, Faculty of Pharmacy and Pharmaceutical Sciences at Madhyanchal Professional University Bhopal (MP), India
| | - Rudra Narayan Sahoo
- School of Pharmaceutical Sciences, Siksha ‘O’ Anusandhan (Deemed to be University), Bhubaneswar-751030, Orissa, India
| | - Subrata Mallick
- School of Pharmaceutical Sciences, Siksha ‘O’ Anusandhan (Deemed to be University), Bhubaneswar-751030, Orissa, India
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Maeda N, Narukawa M, Ishimaru Y, Yamamoto K, Misaka T, Abe K. A large increase of sour taste receptor cells in Skn-1-deficient mice does not alter the number of their sour taste signal-transmitting gustatory neurons. Neurosci Lett 2017; 648:53-58. [PMID: 28359935 DOI: 10.1016/j.neulet.2017.03.046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 03/01/2017] [Accepted: 03/26/2017] [Indexed: 11/19/2022]
Abstract
The connections between taste receptor cells (TRCs) and innervating gustatory neurons are formed in a mutually dependent manner during development. To investigate whether a change in the ratio of cell types that compose taste buds influences the number of innervating gustatory neurons, we analyzed the proportion of gustatory neurons that transmit sour taste signals in adult Skn-1a-/- mice in which the number of sour TRCs is greatly increased. We generated polycystic kidney disease 1 like 3-wheat germ agglutinin (pkd1l3-WGA)/Skn-1a+/+ and pkd1l3-WGA/Skn-1a-/- mice by crossing Skn-1a-/- mice and pkd1l3-WGA transgenic mice, in which neural pathways of sour taste signals can be visualized. The number of WGA-positive cells in the circumvallate papillae is 3-fold higher in taste buds of pkd1l3-WGA/Skn-1a-/- mice relative to pkd1l3-WGA/Skn-1a+/+ mice. Intriguingly, the ratio of WGA-positive neurons to P2X2-expressing gustatory neurons in nodose/petrosal ganglia was similar between pkd1l3-WGA/Skn-1a+/+ and pkd1l3-WGA/Skn-1a-/- mice. In conclusion, an alteration in the ratio of cell types that compose taste buds does not influence the number of gustatory neurons that transmit sour taste signals.
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Affiliation(s)
- Naohiro Maeda
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Masataka Narukawa
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yoshiro Ishimaru
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan; Department of Agricultural Chemistry, Faculty of Agriculture, Meiji University, Tama-ku, Kawasaki-shi, Kanagawa, Japan
| | - Kurumi Yamamoto
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Takumi Misaka
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Keiko Abe
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan; Kanagawa Academy of Science and Technology, Takatsu-ku, Kawasaki-shi, Kanagawa, Japan.
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