过氧化氢对培养白癜风黑素细胞超微结构的影响

目的 探讨白癜风黑素细胞对外源性氧化剂的敏感性及氧化应激在白癜风发病中的作用.方法 以0.5mmol/L过氧化氢分别处理4例白癜风患者外观正常皮肤及6例正常对照皮肤培养的黑素细胞,采用透射电镜观察细胞的形态学变化,并应用图像分析技术和形态计量学方法,测定线粒体、粗面内质网及黑素小体的超微结构变化.结果 0.5mmol/L过氧化氢对正常人黑素细胞形态学及主要细胞器超微结构无明显影响.过氧化氢处理后的白癜风黑素细胞线粒体、内质网分别与处理前及正常对照处理后比较,数量明显减少,差异均有统计学意义(P<0.01).线粒体局部空化,内质网扩张.部分黑素小体体积显著增大,但黑素小体数量与过氧化氢处理前及正常对照处理后比较,差异无统计学意义(P>0.05).结论 过氧化氢可能通过破坏细胞的能量代谢和蛋白合成系统,使黑素细胞功能逐渐减退,促使白癜风的发生.

Influence of hydrogen peroxide on the ultrastructure of cultured vitiligo melanocytes

Objective To analyze the sensitivity of vitiligo melanocytes to external oxidants and the role of oxidative stress in the pathogenesis ofvitiligo.Methods Melanocytes were isolated from the epidermis of normal-appearing skin of 4 vitiligo patients and from that of 6 normal human controls,and subjected to primary culture.The cultured melanocytes were exposed to 0.5 mmol/L hydrogen peroxide for 1 h.The cell ultrastructural characteristics were observed by transmission electron microscopy.Stereological image analysis was also performed to assess the ultrastructural changes of mitochondria,rough endoplasmic reticulum and melanosome.Results The 0.5 mmol/L hydrogen peroxide had no significant effect on the morphology or ultrastructure of cell organelles of the normal control melanocytes,whereas the number of mitochondria and rough endoplasmic reticulum were significantly decreased in melanocytes after the treatment compared with the melanocytes without any treatment(P<0.05) and the control melanocytes(P<0.01). Partial vacuolization of mitochondria and dilation of endoplasmic reticulum were observed in vitiligo melanocytes treated with hydrogen peroxide.No significant difference was found in the number of melanosomes among the vitiligo melanocytes with and without treatment as well as the control melanocytes (P>0.05),even though the volume increase was found in some melanosomes.Conclusion Our results suggest that hydrogen peroxide could impair the function of melanocytes and induce the development of vitiligo, likely by interfering with the energy metabolism and protein synthesis in these cells.