近红外线、紫外线及二者共同作用对小鼠皮肤光老化的影响
Effects of IRA and UV alone or in combination on skin photoaging in mice

摘要：目的 研究近红外线(IRA)、紫外线(UV)对小鼠皮肤光老化及皮肤MMP-13表达的影响，观察IRA、UV在光老化中的作用及其相互关系，探索IRA引起光老化的分子机制。方法 ICR雄性小鼠随机分为5组，即空白组、IRA组、UV组、IRA/UV组、UV/IRA组。后4组小鼠接受光照不同且顺序各异。用HE染色、免疫组化、实时定量PCR、Western blot测定MMP-13表达。结果 目测及HE染色显示，较之空白组小鼠，4组实验组小鼠均出现光老化表现；与空白组比较，UV联合IRA组均能上调MMP-13蛋白和mRNA的表达(P<0.05)，并且IRA/UV组比UV/IRA组上调更加显著(P<0.05)。结论 ①IRA可引起小鼠皮肤光老化；②IRA和UV可上调MMP-13表达，并加速光老化过程；③IRA和UV共同作用于皮肤时，作用顺序不同对皮肤老化所产生影响不同。因此，在预防小鼠皮肤皱纹形成及治疗其光老化中，防止IRA辐射，避免MMP-13形成可能发挥重要作用。
ABSTRACT: Objective To detect the expression of MMP-13 in the skin of mice treated by near-infrared (IRA) and ultraviolet (UV) so as to observe their effects on skin photoaging and their interrelation and explore molecular mechanisms in IRA-induced skin photoaging. Methods Male ICR mice were randomly divided into five groups: control group (without ray exposure), IRA group, UV group, IRA/UV group, and UV/IRA group. The mice in the latter four groups had their dorsal skin exposed to different radiated ray respectively. The levels of MMP-13 protein and mRNA in the exposed skin were detected by HE, immunohistochemical method, Western blot and real-time PCR. Results Both skin lesions by visual inspection and H&E staining results showed that mice in the other four groups had skin photoaging in the exposed skin area compared with the control group. The levels of MMP-13 protein and mRNA in the exposed skin in IRA/UV and UV/IRA groups were significantly higher than those in the control mice (P<0.05). In addition, mice in IRA/UV group showed higher levels of MMP-13 protein and mRNA than those in UV/IRA group (P<0.05). Conclusion ① IRA causes skin photoaging in mice. ② UV and IRA interact with each other, up-regulate the expression of MMP-13, and promote each other in the process of photoaging. ③ The effects of IRA and UV in combination on skin photoaging are closely related to order of exposure. Taken together, avoiding IRA exposure and the expression of MMP-13 play an important role in preventing skin wrinkle formation and treatment of photoaging in mice