目的 分析咖啡酸对UVB损伤人角质形成细胞HaCaT的保护作用机制。方法 采用UVB灯照射建立HaCaT细胞UVB损伤模型。HaCaT细胞中分别加入浓度梯度为0（对照组）、5、10、20、40、80、160µ；mol/L的咖啡酸，计算细胞存活率，选择最佳浓度进行后续试验。将处于对数生长期HaCaT分为对照组、模型组、咖啡酸（10µ；mol/L）组，进行苏木精–伊红（HE）染色，显微镜观察细胞形态。按照试剂盒说明书操作，采用样本蛋白浓度计算方法，测定细胞中过氧化氢酶（CAT）、超氧化物歧化酶（SOD）的含量。蛋白免疫印记检测促分裂原活化蛋白激酶（MAPK）通路相关蛋白的表达。结果 咖啡酸10µ；mol/L组能够减轻UVB对HaCaT细胞造成的损伤，修复HaCaT的细胞形态，增加抗凋亡蛋白Bcl-2在HaCaT细胞中的表达，减少细胞的凋亡。咖啡酸10µ；mol/L组能够显著升高HaCaT中SOD、CAT含量，增强细胞中的抗氧化能力，降低MAPK亚族p38信号通路p-p38和p53蛋白在细胞中的表达。结论 咖啡酸可以抑制UVB对细胞的损伤，修复细胞的形态结构，减少细胞的凋亡和增强细胞的抗氧化性，且可能通过MAPK信号通路的调控来减弱UVB对HaCaT细胞的损伤，而对UVB损伤后的HaCaT细胞具有保护作用。

Objective To analyze the protective mechanism of caffeic acid on HaCaT cells after UVB injury. Method UVB injury model of HaCaT cells was established by irradiation with UVB lamp. Caffeic acid was added to HaCaT cells with concentration gradients of 0 (control group), 5, 10, 20, 40, 80, and 160 µmol/L, respectively, to calculate the cell survival rate and select the final concentration for subsequent tests. HaCaT cells in logarithmic growth phase were divided into control group, model group, and caffeic acid 10 µmol/L group. Hematoxylin and eosin (HE) staining was performed to observe the cell morphology under microscope. Results The 10 µmol/L caffeic acid group could repair the damage caused by UVB to HaCaT cells, repair the cell morphology of HaCaT cells, increase the expression of anti-apoptotic protein Bcl-2 in HaCaT cells, and reduce cell apoptosis. Caffeic acid 10 µmol/L group can significantly increase the contents of SOD and CAT in HaCaT cells, enhance the antioxidant capacity of cells, and reduce the expression of p-P38 and P53 proteins in MAPK subgroup P38 signaling pathway in cells. Conclusion Caffeic acid can inhibit the damage of UVB to cells, repair the morphological structure of cells, reduce cell apoptosis and enhance the antioxidant capacity of cells. It may weaken the damage of UVB to HaCaT cells through the regulation of MAPK signal pathway, and have a protective effect on HaCaT cells damaged by UVB.

R966

云南中烟工业有限责任公司科技项目（2020CP02.2020539200340205）