Activation of TRPV4 Strengthens the Tight-Junction Barrier in Human Epidermal Keratinocytes
Activation of TRPV4 Strengthens the Tight-Junction Barrier in Human Epidermal Keratinocytes
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DOI：
10.1159/000343173
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发表时间：
2013-01-01
影响因子：
2.7
通讯作者：
Inoue, S.
中科院分区：
文献类型：
--
作者：
Akazawa, Y.;Yuki, T.;Inoue, S.
瞬时受体电位阳离子通道V亚家族(TRPV)在表皮中表达，被认为是对外界刺激如温度和其他物理或化学因素的敏感。在这项研究中，我们研究了激动剂激活TRPVs是否改变了培养的人表皮角质形成细胞的表皮紧密连接(TJ)功能。逆转录-聚合酶链式反应(RT-PCR)分析表明，在分化的角质形成细胞中有TRPV1、3和4mRNA的表达。用TRPV4激动剂(4α-佛波醇12，13-十二酸，4α-PDD)刺激角质形成细胞，通过跨上皮电阻测量和细胞旁示踪剂流量测量分析，增强了TJ相关屏障。用TRPV1和TRPV3激动剂刺激则没有相同的结果。同时，4个α-PDD刺激的角质形成细胞表达TJ结构蛋白occludin和claudin-4，上调TJ调节因子磷酸化非典型PKC Zeta/L，并观察到4个α-PDD刺激的角质形成细胞表达阻滞素和磷酸化非典型PKC Zeta/L复合体。综上所述，我们证明了TRPV4的激活增强了表皮细胞的TJ相关屏障。也有人认为，TJ结构蛋白的上调和/或非典型的磷酸化PKC Zeta/L对TJ结构蛋白的翻译后修饰是TJ功能增强的原因。我们的研究支持这样的假设，即TJ通过TRPV感受到的外部环境的变化会改变他们的功能。版权所有(C)2012 S.Karger AG，巴塞尔
The transient receptor potential cation channel, subfamily V (TRPV), is expressed in the epidermis and considered to be a sensor of extrinsic stimuli such as temperature and other physical or chemical factors. In this study, we examined whether or not the activation of TRPVs by their agonists alters the epidermal tight junction (TJ) function in cultured human epidermal keratinocytes. Reverse transcription-polymerase chain reaction (RT-PCR) analyses showed that mRNA for TRPV1, 3 and 4 were expressed in differentiated keratinocytes in which TJs had formed. Stimulation of the keratinocytes with a TRPV4 agonist (4 alpha-phorbol 12, 13-didecanoate, 4 alpha-PDD) strengthened the TJ-associated barrier, analyzed by means of transepithelial electric resistance measurements and flux measurements of the paracellular tracer. Stimulation with TRPV1 and TRPV3 agonists did not have the same result. Simultaneously, the 4 alpha-PDD-stimulated keratinocytes showed an upregulation of TJ structural proteins, occludin and claudin-4, and TJ regulatory factors, phosphoatypical PKC zeta/L. It was also observed that the amounts of occludin and phospho-atypical PKC zeta/L, complex were higher in 4 alpha-PDD stimulated keratinocytes. In conclusion, we demonstrated that the activation of TRPV4 strengthened the TJ-associated barrier of epidermal cells. It was also suggested that the upregulation of TJ structural proteins and/or the post-translational modification of TJ structural proteins by phospho-atypical PKC zeta/L, are responsible for the enhancement of TJ function. Our study supports the hypothesis that TJs change their function in response to a change in the external environment sensed through TRPVs. Copyright (C) 2012 S. Karger AG, Basel