In this study, we investigated the effects of lysophosphatidic acid (LPA) on melanogenesis in Mel-Ab cells. We found that LPA significantly attenuates melanin synthesis, and reduces the activity of tyrosinase, the rate-limiting melanogenic enzyme. Interestingly, LPA was also found to induce the activation of a 90 kDa ribosomal S6 kinase (RSK-1), which is known to phosphorylate microphthalmia-associated transcription factor (MITF) at serine 409. Though it has been previously reported that the phosphorylation of MITF is followed by the degradation of MITF, we found that LPA significantly inhibited MITF promoter activity, and that this reduced MITF and tyrosinase protein production. Our results indicate that LPA contributes to reduced melanin synthesis via the down-regulation of MITF.

中文翻译：

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溶血磷脂酸对黑色素生成的影响。

在这项研究中，我们调查了溶血磷脂酸（LPA）对Mel-Ab细胞黑色素生成的影响。我们发现，LPA会显着减弱黑色素的合成，并降低酪氨酸酶（限速黑色素生成酶）的活性。有趣的是，还发现LPA可以诱导90 kDa核糖体S6激酶（RSK-1）的活化，已知该酶在丝氨酸409处磷酸化与小眼科相关的转录因子（MITF）。 MITF之后是MITF的降解，我们发现LPA显着抑制了MITF启动子的活性，并降低了MITF和酪氨酸酶蛋白的产生。我们的结果表明，LPA通过下调MITF有助于减少黑色素的合成。