Minsoo Kwon1, Sang Hoon Baek1, Chul-Kyu Park2, Gehoon Chung3, Seog Bae Oh4. 1. Dental Research Institute and Department of Neurobiology and Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea. 2. Department of Physiology, Graduate School of Medicine, Gachon University, Incheon 406-799, Republic of Korea. 3. Dental Research Institute and Department of Neurobiology and Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea; Pain Cognitive Function Research Center, Seoul National University, Seoul, Republic of Korea. Electronic address: gehoon@snu.ac.kr. 4. Dental Research Institute and Department of Neurobiology and Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea; Pain Cognitive Function Research Center, Seoul National University, Seoul, Republic of Korea; Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea. Electronic address: odolbae@snu.ac.kr.
Abstract
OBJECTIVE: Hydrostatic force applied to tooth pulp has long been suspected to be the direct cause of dental pain. However, the molecular and cellular identity of the transducer of the mechanical force in teeth is not clear. Growing number of literatures suggested that odontoblasts, secondary to its primary role as formation of tooth structure, might function as a cellular mechanical transducer in teeth. DESIGN: In order to determine whether odontoblasts could play a crucial role in transduction of hydrostatic force applied to dental pulp into electrical impulses, current study investigated the expression of stretch-activated transient receptor potential (TRP) channels in acutely isolated odontoblasts from adult rats by single cell reverse transcriptase polymerase chain reaction and immunocytochemical analysis. RESULTS: As the result, expression of TRPM7 (melastatin 7) was observed in majority (87%) of odontoblasts while mRNAs for TRPC1 (canonical 1), TRPC6 (canonical 6) and TRPV4 (vanilloid 4) were detected in small subpopulations of odontoblasts. TRPM3 (melastatin 3) was not detected in our experimental set-up. Immunocytochemical analysis further revealed TRPM7 expression at protein level. CONCLUSION: Expression of the mechanosensitive TRP channels provides additional evidence that supports the sensory roles of odontoblasts. Given that TRPM7 is a mechanosensitive ion channel with a kinase activity that plays a role in Mg(2+) homeostasis, it is possible that TRPM7 expressed in odontoblasts might play a central role in mineralization during dentin formation.
OBJECTIVE: Hydrostatic force applied to tooth pulp has long been suspected to be the direct cause of dental pain. However, the molecular and cellular identity of the transducer of the mechanical force in teeth is not clear. Growing number of literatures suggested that odontoblasts, secondary to its primary role as formation of tooth structure, might function as a cellular mechanical transducer in teeth. DESIGN: In order to determine whether odontoblasts could play a crucial role in transduction of hydrostatic force applied to dental pulp into electrical impulses, current study investigated the expression of stretch-activated transient receptor potential (TRP) channels in acutely isolated odontoblasts from adult rats by single cell reverse transcriptase polymerase chain reaction and immunocytochemical analysis. RESULTS: As the result, expression of TRPM7 (melastatin 7) was observed in majority (87%) of odontoblasts while mRNAs for TRPC1 (canonical 1), TRPC6 (canonical 6) and TRPV4 (vanilloid 4) were detected in small subpopulations of odontoblasts. TRPM3 (melastatin 3) was not detected in our experimental set-up. Immunocytochemical analysis further revealed TRPM7 expression at protein level. CONCLUSION: Expression of the mechanosensitive TRP channels provides additional evidence that supports the sensory roles of odontoblasts. Given that TRPM7 is a mechanosensitive ion channel with a kinase activity that plays a role in Mg(2+) homeostasis, it is possible that TRPM7 expressed in odontoblasts might play a central role in mineralization during dentin formation.
Authors: Sara J Bonvini; Mark A Birrell; Jaclyn A Smith; Maria G Belvisi Journal: Naunyn Schmiedebergs Arch Pharmacol Date: 2015-01-10 Impact factor: 3.000