Abstract:

Zheng Yue, Chen Haiyan, Xu Qingfang, Ye Congxiu, Liu Huixian, Yi Jinling, Lai Wei. Department of Dermatovenereology, Third Affiliated Hospital, Sun Yat-sen University, Guangzhou 510630, China Corresponding author: Lai Wei, Email: drlaiwei@163.com 【Abstract】 Objective To evaluate the performance of transfection with a complex plasmid encoding green fluorescent protein tagged CatD （GFP-CatD） in researches on chronic photodamaged fibroblasts. Methods Human dermal fibroblasts （HSFs） were irradiated with ultraviolet A （UVA） at 25 J/cm2 once a day for 21 consecutive days to establish a chronic photodamaged cell model. A plasmid encoding GFP-CatD was constructed and transfected into some chronic photodamaged fibroblasts （experimental group）. The photodamaged HSFs receiving no treatment served as the blank control group, and those transfected with the negative plasmid encoding GFP only as the negative control group. After additional culture, fluorescence microscopy and Western-blot analysis were performed to observe and measure the expression of GFP-CatD in HSFs respectively, flow cytometry and methyl thiazolyl tetrazolium （MTT） assay to evaluate the apoptosis and proliferation of chronic photodamaged fibroblasts respectively. Results Fluorescence microscopy showed the expression of GFP-CatD in cytoplasm of chronic photodamaged fibroblasts at 96 hours after transfection with the GFP-CatD-encoding plasmid. Western-blot analysis revealed that the expression of CatD in the experimental group was 1.28 times that in the blank control group. There were no significant differences in the apoptosis rate （4.29% ± 1.30% vs. 3.03% ± 1.70%, P > 0.05） or proliferative rate （45.20% ± 4.70% vs. 43.60 ± 3.90%, P > 0.05） between the experimental group and blank control group. Conclusion CatD could be traced in chronic photodamaged fibroblasts with no changes in biological activity or cell cycle after transfection with the GFP-CatD-encoding complex plasmid.