Ultraviolet radiation stimulates a biphasic pattern of 1,2-diacylglycerol formation in cultured human melanocytes and keratinocytes by activation of phospholipases C and D.
Ultraviolet radiation stimulates a biphasic pattern of 1,2-diacylglycerol formation in cultured human melanocytes and keratinocytes by activation of phospholipases C and D.
复制标题
紫外线辐射通过激活磷脂酶 C 和 D，刺激培养的人黑素细胞和角质形成细胞中 1,2-二酰甘油形成的双相模式。
作者：
C. Carsberg;J. Ohanian;P. Friedmann
紫外线辐射（UVR）诱导人表皮黑素细胞合成黑色素，磷脂衍生的1，2-二酰基甘油（DAGs）参与介导这一反应。在先前的实验中，向培养的色素细胞中加入合成的DAG 1-油酰基-2-乙酰基甘油刺激黑素生成。本研究的目的是分析紫外线辐射（UVR）对内源DAGs产生的影响。结果发现，在许多培养的细胞类型，包括人黑素细胞和B16小鼠黑色素瘤细胞，但也人角质形成细胞和瑞士3 T3成纤维细胞，暴露于单剂量的紫外线照射刺激内源性DAG形成的双相增加。在几秒钟内的早期短暂上升之后，是几分钟内更持续的延迟上升。DAG水平的早期升高伴随着三磷酸肌醇形成的短暂升高，表明磷脂酰肌醇特异性磷脂酶C的激活。延迟的上升伴随着磷脂酶D的激活。色素细胞的这种内源性DAG形成是DAGs参与UVR诱导的表皮黑色素合成的进一步证据。由于DAG的形成也见于其他细胞类型，因此DAG可能参与了一系列UVR诱导的反应。
Ultraviolet radiation (UVR) induces melanin synthesis by human epidermal melanocytes, and phospholipid-derived 1,2-diacylglycerols (DAGs) have been implicated in mediating this response. In previous experiments, addition of the synthetic DAG 1-oleoyl-2-acetylglycerol to cultured pigment cells stimulated melanogenesis. The purpose of the present study was to analyse the effects of UVR on the endogenous generation of DAGs. It was found that in a number of cultured cell types, including human melanocytes and B16 mouse melanoma cells, but also human keratinocytes and Swiss 3T3 fibroblasts, exposure to a single dose of UVR stimulated a biphasic increase in endogenous DAG formation. An early transient rise, over seconds, was followed by a more sustained delayed rise over minutes. The early rise in DAG levels was accompanied by a transient rise in inositol trisphosphate formation, indicating activation of phosphatidylinositol-specific phospholipase C. The delayed rise was accompanied by activation of phospholipase D. This endogenous DAG formation by pigment cells is further evidence for the involvement of DAGs in UVR-induced epidermal melanin synthesis. Since DAG formation is also seen in other cells types, it is possible that DAGs may be involved in an array of UVR-induced responses.