中文摘要：

目的：探讨长波紫外线引起皮肤光老化、皱纹形成的机制。方法：以7.2J/cm2长波紫外线单次或多次照射培养真皮成纤维细胞,光镜、电镜观察细胞的形态学变化,原位杂交和免疫组化的方法检测基质金属蛋白酶中的间质胶原酶（MMP-1）、间质溶解素-1（MMP-3）mRNA及其共同的组织抑制因子（TIMP-1）蛋白在各实验组成纤维细胞的表达并进行定量分析。结果：在长波紫外线累积剂量达57.6J/cm2后,培养真皮成纤维细胞开始出现具有细胞衰老特征性的形态改变,但仅经两次7.2J/cm2 UVA照射,培养成纤维细胞就出现MMP-1、MMP-3 mRNA的表达并随累积照射剂量增加逐渐增强,但各照射组的TIMP-1蛋白均仅在照射后48h内呈一过性轻度表达。结论：皮肤光老化皱纹形成可能与长波紫外线照射引起真皮成纤维细胞基质金属蛋白酶及其组织抑制剂表达失衡密切相关。

英文摘要：

Objective To investigate the mechanism of skin photoaging induced by UVA. Methods Cultured dermalfibroblast was irradiated by single or repetitive low dose 7.2J/cm2 UVA, alterations of cellular morphology were observedby light microscope and electron microscope, in situ hybridization histochemistry and immunocytochemistry were usedto detect the expression of matrix metallo proteinases interstitial collagenase （MMP-1）,stromelysin-1 （MMP-3） mRNA and their major tissue inhibitor TIMP-1 protein of dermal fibroblasts of all the experimental groups. Results Aftertreatment with a cumulative dose of 57.6J/cm2 UVA, fibroblasts displayed morphological changes of cell senescence,however, after twice 7.2J/cm2 UVA radiation,dermal fibroblasts were continuous up-regulation of mRNA of MMP-1 and MMP-3 were increasing with dose-dependence.The protein of TIMP-1 was only slightly induced within short period of 48 hours in all UVA radiation groups. Conclusions Wrinkle formation of skin photoaging were likely correlated todisequilibrium of expression of matrix metallo proteinases and their tissue inhibitor of dermal fibroblasts induced byrepeated UVA radiation.