Expression of Vesicular Nucleotide Transporter in Rat Odontoblasts.
Expression of Vesicular Nucleotide Transporter in Rat Odontoblasts.
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DOI：
10.1267/ahc.15022
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发表时间：
2016-02-27
影响因子：
2.4
通讯作者：
Kawamoto T
中科院分区：
文献类型：
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作者：
Ikeda E;Goto T;Gunjigake K;Kuroishi K;Ueda M;Kataoka S;Toyono T;Nakatomi M;Seta Y;Kitamura C;Nishihara T;Kawamoto T
已经提出了几种关于牙齿疼痛传递机制的理论。然而，从成牙本质细胞到牙髓神经的确切信号传导机制仍有待阐明。最近有报道称 ATP 相关的疼痛传递，但尚不清楚 ATP 是否参与牙痛传递。在本研究中，我们重点关注囊泡核苷酸转运蛋白（VNUT）（一种将 ATP 转运至囊泡的蛋白），并检查 VNUT 是否参与成牙本质细胞的 ATP 释放。我们通过 RT-PCR 和免疫染色检查了大鼠牙髓中 VNUT 的表达。使用 ATP 荧光素酶方法评估热刺激下培养的成牙本质细胞样细胞的 ATP 释放。 VNUT 在牙髓组织中表达，并且在成牙本质细胞中证实了 VNUT 免疫阳性囊泡的分布。在成牙本质细胞中，一些 VNUT 免疫阳性囊泡与膜融合蛋白共定位。此外，P2X3（一种 ATP 受体）、免疫阳性轴突分布在成牙本质细胞之间。添加 VNUT 的 siRNA 可以抑制成牙本质细胞样细胞通过热刺激释放 ATP。这些发现表明，胞质 ATP 由 VNUT 转运，然后囊泡中的 ATP 从成牙本质细胞释放到轴突上的 ATP 受体。成牙本质细胞中的 ATP 囊泡运输似乎是从成牙本质细胞到牙髓中轴突信号转导的关键机制。
Several theories have been proposed regarding pain transmission mechanisms in tooth. However, the exact signaling mechanism from odontoblasts to pulp nerves remains to be clarified. Recently, ATP-associated pain transmission has been reported, but it is unclear whether ATP is involved in tooth pain transmission. In the present study, we focused on the vesicular nucleotide transporter (VNUT), a transporter of ATP into vesicles, and examined whether VNUT was involved in ATP release from odontoblasts. We examined the expression of VNUT in rat pulp by RT-PCR and immunostaining. ATP release from cultured odontoblast-like cells with heat stimulation was evaluated using ATP luciferase methods. VNUT was expressed in pulp tissue, and the distribution of VNUT-immunopositive vesicles was confirmed in odontoblasts. In odontoblasts, some VNUT-immunopositive vesicles were colocalized with membrane fusion proteins. Additionally P2X3, an ATP receptor, immunopositive axons were distributed between odontoblasts. The ATP release by thermal stimulation from odontoblast-like cells was inhibited by the addition of siRNA for VNUT. These findings suggest that cytosolic ATP is transported by VNUT and that the ATP in the vesicles is then released from odontoblasts to ATP receptors on axons. ATP vesicle transport in odontoblasts seems to be a key mechanism for signal transduction from odontoblasts to axons in the pulp.