RESUMEN
Objective To investigate the relationship between expression of matrix metalloproteinases of dermal fibroblasts and wrinkle formation in photoaging skin.Methods In situ hybridization histochemistry and immunocytochemistry were used to detect the expression of matrix metalloproteinases MMP-1,MMP-3mRNA and the expression of tissue inhibitor of MMP-1at(TIMP-1)protein in dermal fibroblasts from non-lesional skin of psoriatic patients during and after PUVA treatment.Results The expression of MMP-1and MMP-3mRNA of dermal fibroblasts from non-lesional skin was persistently up-regulated during PUVA thera-py,and lasted more than6months after treatment;while the expression of TIMP-1protein was only slightly expressed for a short period during PUVA therapy.Conclusion Wrinkle formation in photoaging skin after PUVA therapy is correlated with the imbalance of expression of matrix metalloproteinases and their inhibitors of dermal fibroblasts.