外源性胆绿素对中波紫外线诱导的HaCaT细胞光损伤的保护作用

目的 探讨外源性胆绿素对中波紫外线（UVB）照射的HaCaT细胞的保护作用及其机制。方法 将培养的HaCaT细胞分为对照组（不加胆绿素，不照射UVB）、UVB组（30 mJ/cm2 UVB照射）和100 nmol/L、1 μmol/L、10 μmol/L胆绿素 + UVB组（分别于30 mJ/cm2 UVB照射前1 h加入相应浓度胆绿素），处理完成后继续培养24 h，观察HaCaT细胞形态变化，CCK8法检测各实验组细胞生存率。Western 印迹检测抗氧化信号分子Nrf?2蛋白及光损伤信号分子基质金属蛋白酶1（MMP?1）和MMP?3蛋白表达。结果 CCK8法结果显示，UVB组HaCaT细胞活力低于对照组（P < 0.05），在加入100 nmol/L、1 μmol/L、10 μmol/L 胆绿素预处理后，细胞生存率逐渐升高，与UVB组比较，差异有统计学意义（均P < 0.05）。Western印迹显示，UVB组MMP?1（1.150 ± 0.187）、MMP?3（0.979 ± 0.054）蛋白表达较对照组（0.116 ± 0.018、0.636 ± 0.035）升高（均P < 0.01），而100 nmol/L、1 μmol/L、10 μmol/L胆绿素 + UVB组MMP?1（0.825 ± 0.139、0.313 ± 0.047和0.286 ± 0.036）、MMP?3（0.888 ± 0.017、0.672 ± 0.042和0.569 ± 0.037）蛋白表达较UVB组降低（均P < 0.05）。UVB组Nrf?2蛋白（0.906 ± 0.034）较对照组（1.242 ± 0.141）表达降低（P < 0.05），100 nmol/L、1 μmol/L、10 μmol/L胆绿素 + UVB组Nrf?2蛋白表达（1.556 ± 0.112、1.897 ± 0.234和2.035 ± 0.274）较UVB组升高（均P < 0.01）。结论 外源性胆绿素对UVB诱导的HaCaT细胞损伤起保护作用，该作用可能与Nrf?2抗氧化信号通路有关。

Protective effect of exogenous biliverdin against ultraviolet B-induced photodamage in HaCaT cells

Liu Yingdi, Bai Bingxue, Ren Jing, Ma LiangjuanDepartment of Dermatology, Chifeng Municipal Hospital, Chifeng 024000, Inner Mongolia, China （Liu YD）; Department of Dermatology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150081, China （Bai BX, Ren J, Ma LJ）Corresponding author: Ma Liangjuan, Email: maliangjuan@163.com【Abstract】 Objective To evaluate the protective effect of exogenous biliverdin on ultraviolet B （UVB）-radiated HaCaT cells, and to explore its mechanism. Methods Cultured HaCaT cells were divided into 5 groups: control group receiving no treatment, UVB group irradiated with 30 mJ/cm2 UVB, 3 biliverdin + UVB groups treated with 100 nmol/L, 1 μmol/L and 10 μmol/L biliverdin respectively for 1 hour followed by 30 mJ/cm2 UVB radiation. After 24-hour treatment, changes in the morphology of HaCaT cells were observed, and cell counting kit 8 （CCK8） assay was performed to determine cell survival rates in the above groups. Western blot analysis was conducted to measure the protein of antioxidant signaling molecule NF-E2-related factor-2 （Nrf-2） and the photodamage signaling molecules matrix metalloproteinase-1 （MMP-1） and MMP-3. Results CCK8 assay showed that the survival rate of HaCaT cells was significantly lower in the UVB group than in the control group （P < 0.05）, but significantly higher in the 100-nmol/L, 1-μmol/L and 10-μmol/L biliverdin + UVB groups than in the UVB group （all P < 0.05）. Western blot analysis showed that the protein of MMP-1 and MMP-3 was significantly higher in the UVB group （1.150 ± 0.187, 0.979 ± 0.054 respectively） than in the control group （0.116 ± 0.018, 0.636 ± 0.035 respectively; both P < 0.01）, but was significantly lower in the 100-nmol/L, 1-μmol/L and 10-μmol/L biliverdin + UVB groups （MMP-1: 0.825 ± 0.139, 0.313 ± 0.047 and 0.286 ± 0.036 respectively; MMP-3: 0.888 ± 0.017, 0.672 ± 0.042 and 0.569 ± 0.037 respectively） than in the UVB group （all P < 0.05）. Moreover, the protein of Nrf-2 was significantly lower in the UVB group （0.906 ± 0.034） than in the control group （1.242 ± 0.141, P < 0.05）, but significantly higher in the 100-nmol/L, 1-μmol/L and 10-μmol/L biliverdin + UVB groups （1.556 ± 0.112, 1.897 ± 0.234 and 2.035 ± 0.274） than in the UVB group （all P < 0.01）. Conclusion Exogenous biliverdin protects against UVB-induced photodamage in HaCaT cells, which may be associated with Nrf-2 antioxidant signaling pathway.