高能蓝光辐照致皮肤屏障损伤的表型特征

Phenotypic characteristics of skin barrier damage caused by high-energy blue light irradiation

目的:本文通过人体临床试验、小鼠实验和细胞实验观察蓝光致皮肤屏障损伤的表型特征,初步揭示高能蓝光对皮肤屏障损伤的影响。方法:纳入40名健康受试者,测量背部皮肤辐照蓝光(120 J/cm2)前后的经皮水分丢失(TEWL)值。将12只背部事先脱毛的清洁级C57BL/6小鼠随机分成对照组与照光组,照光组连续2周进行每日200 J/cm2的蓝光辐照后,观察小鼠背部皮肤的变化情况,苏木精-伊红(HE)染色检测小鼠皮肤表皮的厚度变化;免疫组化染色检测皮肤屏障功能蛋白的表达变化:丝聚蛋白(FLG)、角蛋白(KRT)1及KRT10。实时荧光定量聚合酶链式反应(qPCR)检测蓝光辐照后人皮肤角质形成细胞HaCat细胞中皮肤屏障功能基因的表达变化:KRT1、KRT10、KRT14、FLG、内披蛋白(IVL)及兜甲蛋白(LOR)。结果 :蓝光辐照24 h后,受试者皮肤TEWL值是辐照前的1.2倍,差异有统计学意义(P<0.05)。连续2周的蓝光辐照期间观察到小鼠背部皮肤出现粗糙、脱屑及瘙痒等皮肤屏障损伤的相关特征表型;辐照2周后小鼠背部皮肤的免疫组化结果显示照光组的皮肤屏障功能蛋白(FLG、KRT1、KRT10)均上调,且蛋白定位异常;HE染色结果显示照光组的表皮厚度(22.49±3.96 nm)及表皮的角质层厚度(6.55±2.49 nm)相比于对照组的表皮厚度(7.59±1.94 nm)及对照组的角质层厚度(2.46±0.99 nm)均有增厚,差异均有统计学意义(P<0.05)。照光组HaCat细胞中的皮肤屏障功能基因(KRT1、KRT10、KRT14、FLG、IVL、LOR)的表达均上调(P<0.05),差异均有统计学意义(P<0.05)。结论:高能蓝光损伤皮肤屏障,该损伤可能与蓝光诱发的皮肤屏障功能相关蛋白表达的升高有关。

Objective: In this study, the phenotypic characteristics of blue light-induced skin barrier damage were observed through human clinical trials, mouse experiments and cell experiments, and the effects of high-energy blue light on skin barrier were initially revealed. Methods: Transepidermal water loss(TEWL) values were measured on the back skin of 40 healthy subjects before and after exposure to blue light(120 J/cm^(2)). Twelve clean-grade C57BL/6 mice whose backs were depilated in advance were randomly divided into two groups: the control group and the illumination group. The mice of the illumination group were irradiated with 200 J/cm^(2) of blue light every day for two consecutive weeks, and the changes of the back skin were observed. Hematoxylin-eosin(HE) staining was used to detect the thickness changes of mouse skin epidermis, and immunohistochemistry(IHC) staining was used to detect the expression changes of skin barrier function proteins: filaggrin(FLG), keratin(KRT)1, and KRT10. Quantitative real-time PCR(qPCR) was employed to detect the expression changes of skin barrier function genes in human skin keratinocytes(HaCat) after blue light irradiation: KRT1, KRT10, KRT14, FLG, involucrin(IVL), and loricrin(LOR). Results: The TEWL value of the subjects’ skin at 24 h after blue light irradiation was 1.2 times greater than that of the subjects before blue light irradiation, and the difference was statistically significant(P<0.05). Characteristic phenotypes associated with skin barrier damage, such as roughness, scaling, and itching, were observed in the back skin of mice during the two consecutive weeks of blue light exposure. The immunohistochemical staining of the back skin of mice after the two-week exposure revealed significantly up-regulated skin barrier function proteins(FLG, KRT1, KRT10) in the illumination group(P<0.05) and abnormal protein localization. The results of HE staining of mouse skin sections showed the illumination group had significantly thicker epidermis(22.49±3.96 nm vs. 7.59±1.94 nm) and the stratum corneum of the epidermis(6.55±2.49nm vs. 2.46±0.99 nm) than the control group, with statistically significant differences(P<0.05). The expressions of skin barrier function genes(KRT1, KRT10, KRT14, FLG, IVL, LOR) in HaCat cells of the illumination group were significantly up-regulated(P<0.05). Conclusion: High-energy blue light damages the skin barrier, which may be related to the blue light-induced increase of skin barrier function proteins.