Department of Oral and Craniofacial Sciences, Faculty of Dentistry, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan.
Arch Oral Biol. 2018 May;89:94-98. doi: 10.1016/j.archoralbio.2018.02.011. Epub 2018 Feb 21.
Transient receptor potential vanilloid 4 (TRPV4) has been considered as a mechano-, thermo- and osmo-receptor. Under inflammatory conditions in dental pulp, teeth can become sensitive upon exposure to a variety of innocuous stimuli. The objective of the present study was to investigate the expression of the TRPV4 channel on nerve fibers in human dental pulp of non-symptomatic and symptomatic teeth associated with inflammatory conditions.
Dental pulp from extracted human permanent teeth was processed for fluorescence immunohistochemistry. Ten asymptomatic (normal) and 10 symptomatic (symptoms associated with pulpitis) teeth were used in this study. Nerve fibers were identified by immunostaining for a marker, protein gene product 9.5, and the cells were counterstained with 4',6-diamidino-2-phenylindole. An anti-TRPV4 antibody was used to trace TRPV4 expression.
TRPV4 expression was co-localized with the nerve fiber marker. Immunoreactivity for TRPV4 was more intense (p < 0.05) in the nerves of symptomatic teeth than those of normal teeth. The number of co-localization spots was increased significantly (p < 0.05) in the dental pulp of symptomatic teeth compared with that of asymptomatic (normal) teeth.
There is expression of TRPV4 channels on the nerve fibers of human dental pulp. Our findings suggest upregulation of TRPV4 expression under inflammatory conditions in the pulp. The upregulation of TRPV4 channels may be associated with the exaggerated response of dental pulp to innocuous mechanical, thermal and osmotic stimuli under inflammatory conditions.
瞬时受体电位香草酸 4 型（TRPV4）被认为是一种机械、热和渗透感受器。在牙髓的炎症状态下，牙齿在接触各种无害刺激时会变得敏感。本研究的目的是研究与炎症状态相关的无症状和有症状牙齿的牙髓神经纤维中 TRPV4 通道的表达。
从提取的人恒牙牙髓中处理荧光免疫组织化学。本研究使用了 10 颗无症状（正常）和 10 颗有症状（与牙髓炎相关的症状）的牙齿。神经纤维通过免疫染色标记蛋白基因产物 9.5 进行鉴定，并用 4'，6-二脒基-2-苯吲哚对细胞进行复染。使用抗 TRPV4 抗体追踪 TRPV4 的表达。
TRPV4 表达与神经纤维标记物共定位。与正常牙齿相比，症状性牙齿的神经中 TRPV4 免疫反应性更强（p<0.05）。与无症状（正常）牙齿相比，症状性牙齿牙髓中共定位点的数量显著增加（p<0.05）。
人牙髓神经纤维上有 TRPV4 通道的表达。我们的发现表明，在牙髓炎症状态下 TRPV4 表达上调。TRPV4 通道的上调可能与炎症状态下牙髓对无害机械、热和渗透刺激的过度反应有关。
