维A酸衍生物ECPIRM对维A酸核受体的影响及小鼠皮肤刺激反应

目的 探讨维A酸衍生物ECPIRM对维A酸核受体的影响,评估ECPIRM对小鼠皮肤的红斑、脱屑等刺激反应.方法 10μmol/L ECPIRM和全反式维A酸(ATRA)作用于SCL-1细胞24 h,用蛋白免疫印迹法和实时荧光定量PCR法分别检测维A酸受体(RARα 、RARβ、RARγ和RXRα)的蛋白和mRNA表达变化.用实时荧光定量PCR检测维A酸受体RAR激活通路的靶基因细胞色素P450家族成员26A1和他扎罗汀诱导基因1 (TIG1)的mRNA表达变化.BALB/c小鼠剃毛后外涂ECPIRM凝胶,以等摩尔浓度的全反式维A酸乳膏为对照,观察小鼠皮肤刺激反应.结果 ATRA作用后,RARα、RARβ、RARγ的蛋白和mRNA表达明显增高,与对照组比较差异有统计学意义(P＜0.05).CYP26A1和TIG1的mRNA表达分别增加到25.49倍和3.88倍,差异有统计学意义(P＜0.01).但ECPIRM作用后并不增加核受体RARα、RARβ、RARγ及RXRα的蛋白表达;RARα、RARβ、RARγ的mRNA表达变化差异无统计学意义(P＞0.05);RAR靶基因CYP26A1和TIG1的mRNA表达变化差异无统计学意义(P＞0.05).BALB/c小鼠外用全反式维A酸乳膏后2d出现明显的红斑、脱屑反应,用药5d达高峰.而连续外用0.075％ECPIRM凝胶21d,小鼠一直未出现红斑、脱屑反应.结论 ECPIRM不激活经典的维A酸受体通路,未出现ATRA样皮肤刺激反应.

Effect of a tretinoin derivative ECPIRM on retinoic acid receptors and skin irritation responses to it in mice

Objective To estimate the effect of a tretinoin derivative ECPIRM on retinoic acid receptors (RARs),and to observe skin irritation responses to it in mice.Methods Cultured SCL-1 cells were divided into 2 groups to be treated with culture medium containing 10 μmol/L ECPIRM (ECPIRM group) or 10 μmol/L all-trans retinoic acid (ATRA) (ATRA group) for 24 hours,and those treated with drug-free culture medium served as the control group.Western blot analysis and real-time fluorescence-based quantitative PCR were performed to quantify the protein and mRNA expressions of RARs (RARα,RARβ,RARγ and RXRα) respectively.In addition,real-time fluorescence-based quantitative PCR was conducted to measure the mRNA expressions of two target genes of the activated RAR signaling pathway,i.e.,cytochrome P450 26A1 (CYP26A1) and tazarotene-induced gene 1 (TIG1).Eight BALB/c mice were equally divided into 2 groups to be topically treated with 0.075％ ECPIRM gel or 0.05％ ATRA cream at equal molar concentrations on the shaved skin once daily for 21 successive days.Skin irritation reactions were assessed in these mice.Results Compared with the control group,the ATRA group showed significantly increased protein and mRNA expressions of RARα,RARβ and RARγ (all P ＜ 0.05).The mRNA expressions of CYP26A1 and TIG1 genes in the ATRA group were 25.49 and 3.88 times that in the control group respectively (both P ＜ 0.01).However,there was no significant difference in the protein expressions of RARα,RARβ,RARγ and RXRα,or mRNA expressions of RARα,RARβ,RARγ CYP26A1 and TIG1 between the ECPIRM group and control group (all P ＞ 0.05).Obvious Skin irritation reactions such as erythema and desquamation were observed in BALB/c mice after 2-day topical treatment with ATRA cream,and their degree peaked after 5-day treatment.However,neither erythema nor desquamation was observed in BALB/c mice during 21-day treatment with 0.075％ ECPIRM gel.Conclusion Unlike ATRA,ECPIRM cannot activate the canonical RAR signaling pathway or cause skin irritation reactions.