Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan.
Division of Biological Sciences, Department of Environmental Biochemistry, Kyoto Pharmaceutical University, Kyoto, Japan.
Sci Rep. 2019 Apr 30;9(1):6686. doi: 10.1038/s41598-019-43254-y.
Taste buds are comprised of taste cells, which are classified into types I to IV. Transient receptor potential (TRP) channels play a significant role in taste perception. TRP vanilloid 4 (TRPV4) is a non-selective cation channel that responds to mechanical, thermal, and chemical stimuli. The present study aimed to define the function and expression of TRPV4 in taste buds using Trpv4-deficient mice. In circumvallate papillae, TRPV4 colocalized with a type IV cell and epithelial cell marker but not type I, II, or III markers. Behavioural studies showed that Trpv4 deficiency reduced sensitivity to sourness but not to sweet, umami, salty, and bitter tastes. Trpv4 deficiency significantly reduced the expression of type III cells compared with that in wild type (WT) mice in vivo and in taste bud organoid experiments. Trpv4 deficiency also significantly reduced Ki67-positive cells and β-catenin expression compared with those in WT circumvallate papillae. Together, the present results suggest that TRPV4 contributes to sour taste sensing by regulating type III taste cell differentiation in mice.
味蕾由味觉细胞组成，味觉细胞可分为 I 型至 IV 型。瞬时受体电位 (TRP) 通道在味觉感知中发挥重要作用。TRP 香草素 4 (TRPV4) 是一种非选择性阳离子通道，可响应机械、热和化学刺激。本研究旨在使用 TRPV4 缺陷小鼠来定义 TRPV4 在味蕾中的功能和表达。在轮廓乳头中，TRPV4 与 IV 型细胞和上皮细胞标志物共定位，但与 I、II 或 III 型标志物不共定位。行为研究表明，Trpv4 缺陷小鼠降低了对酸味的敏感性，但对甜味、鲜味、咸味和苦味的敏感性没有影响。与野生型 (WT) 小鼠相比，Trpv4 缺陷显著降低了体内和味觉器官样体实验中 III 型细胞的表达。Trpv4 缺陷还显著降低了 Ki67 阳性细胞和 β-连环蛋白的表达，与 WT 轮廓乳头相比。综上所述，本研究结果表明，TRPV4 通过调节小鼠 III 型味觉细胞分化来参与酸味感知。
