Ohguchi Kenji, Banno Yoshiko, Akao Yukihiro, Nozawa Yoshinori
Gifu International Institute of Biotechnology, 1-1 Naka-Fudogaoka, Kakamigahara, Gifu 504-0838, Japan.
Biochem Biophys Res Commun. 2006 Oct 6;348(4):1398-402. doi: 10.1016/j.bbrc.2006.08.002. Epub 2006 Aug 10.
In the current study, the involvement of phospholipase D (PLD) in the regulation of collagen type I production was examined using human dermal fibroblasts. Procollagen I production in the cells overexpressing PLD1, but not PLD2, was found to be increased compared with those in the vector control cells. To investigate the role of PLD1, we examined the effect of knockdown of endogenous PLD1 by small interference RNA (siRNA) on collagen production. The reduction of expression levels of PLD1 by siRNA transfection was accompanied by diminution of procollagen biosynthesis and also ribosomal S6 kinase 1 (S6K1) phosphorylation. The activity of mammalian target of rapamycin (mTOR) is essential for phosphorylation of S6K1 and the treatment of dermal fibroblasts with rapamycin, a potent inhibitor of mTOR abolished procollagen I production. These results suggest that PLD1 plays a crucial role in collagen type I production through mTOR signaling in human dermal fibroblast.
在本研究中，利用人皮肤成纤维细胞检测了磷脂酶D（PLD）在I型胶原蛋白生成调节中的作用。与载体对照细胞相比，发现过表达PLD1而非PLD2的细胞中前胶原I的生成增加。为了研究PLD1的作用，我们检测了小干扰RNA（siRNA）敲低内源性PLD1对胶原蛋白生成的影响。siRNA转染导致PLD1表达水平降低，同时前胶原生物合成减少，核糖体S6激酶1（S6K1）磷酸化也减少。雷帕霉素靶蛋白（mTOR）的活性对于S6K1的磷酸化至关重要，用雷帕霉素（一种有效的mTOR抑制剂）处理皮肤成纤维细胞可消除前胶原I的生成。这些结果表明，PLD1通过mTOR信号通路在人皮肤成纤维细胞I型胶原蛋白生成中起关键作用。
