以人自发性永生化角质形成细胞系(HaCaT)细胞为材料, 通过CCK8和蛋白印迹法分别测定不同剂量长波紫外线(ultraviolet A, UVA)、不同浓度丹参酮ⅡA(tanshinone ⅡA,TSⅡA), 以及UVA和TSⅡA共同作用下的细胞活力和促分裂素原活化蛋白激酶(mitogenactivatedprotein kinase, MAPK)信号通路蛋白(p38, JNK和Erk)磷酸化水平. 结果表明:在10 J/cm2的UVA照射下, 细胞活力为对照组的70%左右, 在20 J/cm²的UVA照射下, 细胞活力仅为对照组的55%左右; 低浓度的TSⅡA在正常情况下对细胞活力无影响, 高浓度(85 μmol/L) TSⅡA处理组的细胞活力约为对照组的70%左右. 与TSⅡA或UVA单独处理相比, 二者共同作用下细胞活力大大降低且差异极其显著. UVA照射提高了MAPK信号通路中的p38和JNK磷酸化水平, 但是对Erk磷酸化水平没有影响; 而TSⅡA可以显著提高低辐射剂量(2 J/cm²)UVA诱导下的p38和JNK的磷酸化水平. 这说明UVA促进HaCaT细胞凋亡是通过提高p38和JNK磷酸化水平来实现的; 而TSⅡA可以提高p38和JNK磷酸化水平,进一步加速UVA诱导的HaCaT细胞凋亡.

Human immortalized keratinocytes (HaCaT) were used as materials and effects of ultraviolet A (UVA), tanshinone ⅡA (TS ⅡA), and combination of UVA and TS ⅡA on cell viability and mitogen-activated protein kinase (MAPK) signaling protein phosphorylation were studied using CCK8 and Western blot respectively. The results showed that UVA at 10 J/cm² lowered cell viability to about 70% of that of control, while 20 J/cm² dose led to further reduction to about 55%. Low concentration TSⅡA had no impact on cell viability, and high concentration TSⅡA (85 μmol/L) could decrease cell viability to 75%. When combined together, UVA and TS ⅡA significantly exhibited together inhibitory effect on cell viability compared to their individual effects. UVA irradiation elevated the phosphorylation level of p38 and JNK in MAPK cascade, but had no effect on phosphorylation of Erk. TS ⅡA could promote phosphorylation of p38 and JNK induced by low dose UVA (2 J/cm²). The above results indicate that UVA induces HaCaT apoptosis by promoting phosphorylation of p38 and JNK, and in turn, TS ⅡA further promotes its phosphorylation and accelerated HaCaT apoptosis