摘要
目的探讨低剂量长波紫外线(UVA)诱导培养人皮肤黑素细胞适应性反应的程度及特点。方法以具有致死作用的86.4 J/cm2UVA照射经7.2 J/cm2低剂量UVA单次或多次预照射的培养人皮肤黑素细胞.光镜、电镜观察细胞形态学变化,流式细胞仪检测细胞凋亡的比例,单细胞凝胶电泳检测DNA 损伤的程度。结果单次或多次7.2 J/cm2 UVA预照射处理后的培养皮肤黑素细胞使随后86.4 J/cm2 UVA 照射诱导的形态学上的毒性反应减轻,细胞凋亡的比例下降,DNA链断裂减少及修复加快,与未经预处理86.4 J/cm2 UVA照射的相应细胞比较差异有统计学意义(P<0.01或P<0.05);单次7.2 J/cm2 UVA预照射诱导培养皮肤黑素细胞的适应性反应在预照射12 h后消失,而当低剂量UVA预照射的累积剂量达到28.8 J/cm2以上时,预照射的培养细胞即使是14 d后对86.4 J/cm2UVA照射仍有明显的防护作用。结论低剂量UVA照射可诱导培养的皮肤黑素细胞出现对随后高剂量UVA照射的适应性反应,其效应滞留期及强度与低剂量UVA的累积剂量有关。
Objective To investigate the extent and features of adaptation reaction of melanocytes induced by low dose UVA radiation. Methods Cultured skin melanocytes were irradiated by a lethal dose of 86.4 J/cm2 UVA with or without pre-irradiation of single or repetitive low dose 7.2 J/cm2 UVA. Alterations of cellular morphology were observed by light and electron microscopy. Proportions of apoptosis were assayed by flow cytometry. The extent of DNA damage was determined by single cell gel electrophoresis (SCGE). Results In cultured skin melanocytes, pretreatment with single or repetitive irradiation of 7.2 J/cm2 UVA could alleviate toxic reaction of cellular morphology, decrease apoptosis ratio, reduce DNA chain breakages and enhance repair of DNA damage caused by subsequent 86.4 J/cm2 UVA irradiations, compared to those without pretreatment (P < 0.01 or P < 0.05). The adaptation reaction induced by a single pretreatment of 7.2 J/cm2 UVA disappeared 12 h after irradiation, however, the accumulated dosage of 28.8 J/cm2 by repeated low dose UVA pre-treatments could prevent damage by 86.4 J/cm2 UVA irradiation even after 14 d. Conclusions Low dose U-VA irradiation could induce adaptation reaction which protects cultured skin melanocytes from damages by subsequent challenged dose of UVA. The period the adaptation reaction lasts and protective extents are clearly related to the accumulated dosage of repeated low dose UVA irradiations and intervals.
出处
《中华皮肤科杂志》
CAS
CSCD
北大核心
2005年第7期432-434,共3页
Chinese Journal of Dermatology
基金
博士后基金资助课题(2002224)
