TRPV6 is a Ca2+ entry channel essential for Ca2+-induced differentiation of human keratinocytes
TRPV6 is a Ca2+ entry channel essential for Ca2+-induced differentiation of human keratinocytes
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DOI：
10.1074/jbc.m611398200
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发表时间：
2007-08-03
影响因子：
4.8
通讯作者：
Prevarskaya, Natalia
中科院分区：
文献类型：
--
作者：
Lehen'kyi, V'yacheslav;Beck, Benjamin;Prevarskaya, Natalia
由于皮肤中的天然Ca 2+梯度，Ca 2+是诱导角质形成细胞分化的重要因素。然而，介导钙离子进入和触发角质形成细胞分化的膜机制尚未阐明。在这项研究中，我们证明，钙诱导分化上调瞬时受体电位高钙选择性通道，TRPV 6的mRNA和蛋白质表达。后者介导Ca 2+摄取并占人角质形成细胞中的基础[Ca 2 +]（i）。我们的研究结果表明，TRPV 6是角质形成细胞进入分化的先决条件，因为TRPV 6在人原代角质形成细胞中的沉默导致由Ca 2+触发的受损分化表型的发展。与分化的对照细胞相比，小干扰RNA-TRPV 6显著抑制了分化标记物如外皮蛋白、转氨酶-1和细胞角蛋白-10的表达。TRPV 6沉默影响细胞形态和细胞间接触的发展，以及细胞分层的能力。1，25-二羟基维生素D3是一种分化辅助因子，可剂量依赖性地增加人角质形成细胞中TRPV 6 mRNA和蛋白的表达。这种TRPV 6上调导致未分化和分化的角质形成细胞中Ca 2+摄取的显著增加。我们的结论是TRPV 6介导，至少部分，促分化的影响，1，25-二羟维生素D3通过增加Ca 2+进入，从而促进分化。总之，这些数据表明TRPV 6通道是Ca 2 +/1，25-二羟维生素D3诱导的人角质形成细胞分化的关键因素。
Ca2+ is an essential factor inducing keratinocyte differentiation due to the natural Ca2+ gradient in the skin. However, the membrane mechanisms that mediate calcium entry and trigger keratinocyte differentiation had not previously been elucidated. In this study we demonstrate that Ca2+-induced differentiation up-regulates both mRNA and protein expression of a transient receptor potential highly Ca2+-selective channel, TRPV6. The latter mediates Ca2+ uptake and accounts for the basal [Ca2+] (i) in human keratinocytes. Our results show that TRPV6 is a prerequisite for keratinocyte entry into differentiation, because the silencing of TRPV6 in human primary keratinocytes led to the development of impaired differentiated phenotype triggered by Ca2+. The expression of such differentiation markers as involucrin, transglutaminase-1, and cytokeratin-10 was significantly inhibited by small interfering RNA-TRPV6 as compared with differentiated control cells. TRPV6 silencing affected cell morphology and the development of intercellular contacts, as well as the ability of cells to stratify. 1,25-Dihydroxyvitamin D3, a cofactor of differentiation, dose-dependently increased TRPV6 mRNA and protein expression in human keratinocytes. This TRPV6 up-regulation led to a significant increase in Ca2+ uptake in both undifferentiated and differentiated keratinocytes. We conclude that TRPV6 mediates, at least in part, the pro-differentiating effects of 1,25-dihydroxyvitamin D3 by increasing Ca2+ entry, thereby promoting differentiation. Taken together, these data suggest that the TRPV6 channel is a key element in Ca2+/1,25-dihydroxyvitamin D3-induced differentiation of human keratinocytes.