Autophagy regulates cellular turnover by disassembling unnecessary or dysfunctional constituents. Recent studies demonstrated that autophagy and its regulators play a wide variety of roles in melanocyte biology. Activation of autophagy is known to induce melanogenesis and regulate melanosome biogenesis in melanocytes. Also, autophagy induction was reported to regulate physiologic skin color via melanosome degradation, although the downstream effectors are not yet clarified. To determine the role of autophagy as a melanosome degradation machinery, we administered several autophagy inducers in human keratinocytes and melanocytes. Our results showed that the synthetic autophagy inducer PTPD-12 stimulated autophagic flux in human melanocytes and in keratinocytes containing transferred melanosomes. Increased autophagic flux led to melanosome degradation without affecting the expression of MITF. Furthermore, the color of cell pellets of both melanocytes and keratinocytes was visibly lightened. Inhibition of autophagic flux by chloroquine resulted in marked attenuation of PTPD-12-induced melanosome degradation, whereas the expression of melanogenesis pathway genes and proteins remained unaffected. Taken together, our results suggest that the modulation of autophagy can contribute to the regulation of melanocyte biology and skin pigmentation.

中文翻译：

---

自噬诱导可以通过引起角质形成细胞和黑素细胞中黑素体降解来调节皮肤色素沉着。

自噬通过分解不必要或功能失调的成分来调节细胞更新。最近的研究表明自噬及其调节剂在黑素细胞生物学中起着各种各样的作用。已知自噬的激活可诱导黑素细胞中黑素生成并调节黑素体的生物生成。此外，据报道自噬诱导通过黑素体降解来调节生理皮肤的颜色，尽管下游效应子尚未阐明。为了确定自噬作为黑素体降解机制的作用，我们在人角质形成细胞和黑素细胞中施用了几种自噬诱导剂。我们的结果表明，合成的自噬诱导物PTPD-12刺激人黑素细胞和含有转移的黑素体的角质形成细胞中的自噬通量。自噬通量的增加导致黑素体降解而不影响MITF的表达。此外，可见地淡化了黑素细胞和角质形成细胞的细胞沉淀的颜色。氯喹抑制自噬通量导致PTPD-12诱导的黑素体降解显着减弱，而黑色素生成途径基因和蛋白质的表达仍然不受影响。两者合计，我们的结果表明自噬的调节可以有助于调节黑色素细胞生物学和皮肤色素沉着。而黑色素生成途径基因和蛋白质的表达仍然不受影响。两者合计，我们的结果表明自噬的调节可以有助于调节黑色素细胞生物学和皮肤色素沉着。而黑色素生成途径基因和蛋白质的表达仍然不受影响。两者合计，我们的结果表明自噬的调节可以有助于调节黑色素细胞生物学和皮肤色素沉着。