摘要目的 通过光化性角化病(AK)皮肤组织块干扰模型探讨转化生长因子( TGF) β1/Smads对p53的调控作用.方法 培养人AK组织块,分为5个组,第1组对照组,第2组TGF β1培养24 h组,第3组SB431542培养24 h组,第4组TGFβ1培养48 h组,第5组SB431542培养48 h组,取材后实时PCR和Western印迹分别检测p53 mRNA和蛋白表达及Smad2磷酸化水平.结果 在TGFβ1培养24 h后,与对照相比,p53 mRNA表达增加(13.4968±0.9903,P＜ 0.05),Smad2磷酸化增多(0.700±0.023,P＜0.05)；培养48 h后,p53 mRNA为13.3882±1.6772,蛋白为1.009±0.001,均增加(P＜0.05),Smad2磷酸化增多(0.646±0.120,P＜0.05)；TGFβ1培养24 h和48 h相比,p53蛋白由0.634±0.040增加至1.009±0.001(P＜0.05)；在SB431542培养24 h后,与对照相比Smad2磷酸化变化不明显,当SB431542培养48 h后,与对照相比Smad2磷酸化水平明显减少(0.116±0.003,P＜0.05),其余没有明显变化.结论 人AK皮肤组织块培养可作为一种信号通路的干扰模型,TGFβ1在AK中可通过Smads通路调控p53表达.

abstractsObjective To evaluate the performance of actinic keratosis (AK) tissue as a culture model for the study of interference in transduction pathway,and to explore the mechanism underlying the p53 regulation though TGFβ1/Smads pathway by using the tissue culture model.Methods Twenty-five skin samples from the lesions of patients with AK were cultured,and divided into 5 groups to be treated with TGFβ1 of 10 μg/L for 24 and 48 hours,the tran sforming growth factor (TGF) β1 receptor kinase inhibitor SB431542 of 10 μmol/L for 24 and 48 hours,respectively,or remain untreated.Real time PCR and Western blot were performed to quantify the mRNA expression of p53 and protein expression of p53 and phosphorylated Smad2 in these tissue specimens respectively.Results A significant elevation was observed in the expressions of p53 mRNA ( 13.4968 ± 0.9903 vs.1,P ＜ 0.05) and phosphorylated Smad2 (0.700 ± 0.023 vs.1,P ＜ 0.05) in AK tissues after treatment with TGFβ1 for 24 hours,and in the expressions of p53 mRNA (13.3882 ± 1.6772 vs.1,P ＜ 0.05) and protein (1.009 ± 0.001 vs.0.512 ± 0.005,P ＜ 0.05) after treatment with TGFβ1 for 48 hours,compared with the untreated AK tissues.No significant differences were observed in the expression of p53 protein between the AK tissues treated with TGFβ1 for 24 hours and 48 hours (P ＞ 0.05).SB431542 induced a statistical reduction in the level of phosphorylated Smad2 at 48 hours (0.116 ± 0.003 vs.0.306 ± 0.023,P ＜ 0.05),but no significant changes were observed in the expression of p53 mRNA or protein after SB431542 treatment for 24 or 48 hours.Conclusions AK tissue cultures can serve as a model for the study of interference in signal transduction pathway.TGFβ1 might regulate the expression of p53 protien through Smads pathway in AK.