p53相关的细胞周期调控在UVB诱导的皮肤成纤维细胞早衰中的作用

p53-related Cell Cycle Regulation in UVB-induced Premature Senescent Human Skin Fibroblasts

目的探讨中波紫外线(UVB)诱导皮肤成纤维细胞(HSF)应激诱导的早衰(SIPS)后细胞周期调控的变化。探讨p53相关的生长停滞、细胞凋亡相关基因表达在UVB诱导的SIPS中的变化情况。方法对UVB诱导发生SIPS的HSF,流式细胞仪检测细胞周期;Western blot法检测衰老信号通路中p53,p21,p16的表达;实时荧光定量PCR芯片检测与p53相关的生长停滞(p53,p21,p16,p19)、凋亡(bax,bcl-2)基因的mRNA表达水平。结果流式细胞仪对UVB诱导的SIPS模型进行细胞周期检测发现,大部分细胞发生了G1期阻滞;衰老通路中p53,p21和p16的表达都明显增加;实时荧光定量PCR芯片检测发现,与生长停滞相关的抑癌基因p53,p21,p16,p19的表达均上调;p53下游的凋亡相关基因中的抑凋亡基因bcl-2表达稍上调,而凋亡基因bax表达下调。结论G1期阻滞和衰老信号通路蛋白表达增加进一步印证了UVB诱导HSF发生的SIPS。p53信号通路相关基因的表达变化提示UVB诱导的SIPS可能具有与p53相关的抗凋亡作用,但其中p53信号通路所起的作用还需更进一步的实验探索。

Objective To explore the effects of UVB-induced SIPS on cell cycle regulation in HSF. Methods In UVB- stressed premature senescent HSF, cell cycle assay was analyzed with fluorescence-activated cell sorting （FACS） by flow cytometer. Protein expressions of p53, p21 and p16 in senescence pathways were determined by western immunoblot. A real time PCR array was performed to investigate mRNA level of a number of genes involved in growth arrest （ p53, p21, p16, p19 ）, apoptosis （bax, bcl-2） induced by UVB. Results FACS analysis showed that UVB-strcssed HSF were blocked mostly in G1 phase of the cell cycle. Protein expressions of p53, p21 and p16 in senescence pathways were increased significantly. PCR array indicated some genes were differentially expressed in UVB-induced SIPS. First, anti-oncogenes involved in growth arrest p53, p21, p16, p19 were all overexpressed . Second, among genes involved in p53-dependent apoptosis, bax was downregulatcd while bcl-2 was up-regulated slightly. Conclusions G1 stage arrest and expression of proteins involved in senescence pathways further confirm L UVB-induccd SIPS in HSF. Expression of p53-related genes suggest that UVB-induced SIPS may play an important role in p53-related apoptosis resistance activity. The role of p53 pathwys in related mechanisms should be further explored.