Functional Expression of IP, 5-HT4, D1, A2A, and VIP Receptors in Human Odontoblast Cell Line

Eri Kitayama; Maki Kimura; Takehito Ouchi; Masahiro Furusawa; Yoshiyuki Shibukawa

doi:10.3390/biom13060879

Functional Expression of IP, 5-HT₄, D₁, A_2A, and VIP Receptors in Human Odontoblast Cell Line

Biomolecules. 2023 May 23;13(6):879. doi: 10.3390/biom13060879.

Authors

Eri Kitayama^{1

2}, Maki Kimura¹, Takehito Ouchi¹, Masahiro Furusawa², Yoshiyuki Shibukawa¹

Affiliations

¹ Department of Physiology, Tokyo Dental College, 2-9-18, Kanda-Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan.
² Department of Endodontics, Tokyo Dental College, 2-9-18, Kanda-Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan.

Abstract

Odontoblasts are involved in sensory generation as sensory receptor cells and in dentin formation. We previously reported that an increase in intracellular cAMP levels by cannabinoid 1 receptor activation induces Ca²⁺ influx via transient receptor potential vanilloid subfamily member 1 channels in odontoblasts, indicating that intracellular cAMP/Ca²⁺ signal coupling is involved in dentinal pain generation and reactionary dentin formation. Here, intracellular cAMP dynamics in cultured human odontoblasts were investigated to understand the detailed expression patterns of the intracellular cAMP signaling pathway activated by the G_s protein-coupled receptor and to clarify its role in cellular functions. The presence of plasma membrane Gα_s as well as prostaglandin I₂ (IP), 5-hydroxytryptamine 5-HT₄ (5-HT₄), dopamine D₁ (D₁), adenosine A_2A (A_2A), and vasoactive intestinal polypeptide (VIP) receptor immunoreactivity was observed in human odontoblasts. In the presence of extracellular Ca²⁺, the application of agonists for the IP (beraprost), 5-HT₄ (BIMU8), D₁ (SKF83959), A_2A (PSB0777), and VIP (VIP) receptors increased intracellular cAMP levels. This increase in cAMP levels was inhibited by the application of the adenylyl cyclase (AC) inhibitor SQ22536 and each receptor antagonist, dose-dependently. These results suggested that odontoblasts express G_s protein-coupled IP, 5-HT₄, D₁, A_2A, and VIP receptors. In addition, activation of these receptors increased intracellular cAMP levels by activating AC in odontoblasts.

Keywords: Gs protein-coupled receptor; adenylyl cyclase; cAMP dynamics; human; immunofluorescence; odontoblasts.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cell Line
Humans
Odontoblasts
Receptors, Cannabinoid / metabolism
Receptors, G-Protein-Coupled / metabolism
Receptors, Vasoactive Intestinal Peptide* / metabolism
Serotonin* / metabolism
Serotonin* / pharmacology
Signal Transduction

Substances

Serotonin
Receptors, Vasoactive Intestinal Peptide
Receptors, G-Protein-Coupled
Receptors, Cannabinoid

Grants and funding

This study was supported by JSPS KAKENHI (Grant Numbers 19H03833, 19K10117, 22K09972, and 22K17025) and the Tokyo Dental College Research Branding Project (Multidisciplinary Research Center for Jaw Disease (MRCJD): Achieving Longevity and Sustainability by Comprehensive Reconstruction of Oral and Maxillofacial Functions).