长波紫外线照射对硬皮病鼠模型皮肤硬化程度的影响

目的 探讨长波紫外线照射对硬皮病鼠模型皮肤硬化程度的影响。方法 小鼠局部注射博来霉素建立硬皮病鼠模型后，随机分成三组，每组3只小鼠，其中一组小鼠不照射UVA1，另外两组小鼠分别每次照射UVA1 12 min（5.32 J/cm2）、25 min（11.1 J/cm2），连续20次，累积剂量分别为106.4和222 J/cm2。另一批小鼠随机分两组，每组3只小鼠，每日注射博来霉素同时每日照射UVA1剂量分别为5.32 J/cm2和11.1 J/cm2，连续20次，累积剂量分别为106.4和222 J/cm2。结果 和未经UVA1照射的硬皮病鼠模型比较，接受不同剂量UVA1照射后的两组硬皮病小鼠皮损区表真皮厚度显著降低（P ＜ 0.05），羟脯氨酸含量显著降低（P ＜ 0.05）， 真皮中转化生长因子β（TGF-β）表达降低（P ＜ 0.05），基质金属蛋白酶1（MMP-1）表达升高（P ＜ 0.05）。两组小鼠注射博来霉素同时接受不同剂量UVA1照射后皮损处表真皮厚度、TGF-β表达、MMP-1表达差异均无统计学意义（P ＞ 0.05）。结论 UVA1照射博来霉素诱导的硬皮病小鼠模型均可导致皮损处能分解胶原纤维的MMP-1表达增加，促进胶原合成的TGF-β表达降低，胶原含量降低，表真皮厚度降低。

Effects of ultraviolet A1 irradiation on the severity of sclerosis in a mouse model of scleroderma

Objective To investigate the effects of ultraviolet 1 （UVA1） irradiation on the severity of sclerosis in a mouse model of scleroderma. Methods Mouse model of scleroderma was created by injec-tion of bleomycin for 3 weeks. Nine of these mice were equally divided into three groups: bleomycin group receiving no irradiation, U1 group and U2 group receiving 12 minutes （5.32 J/cm2） and 25 minutes（11.1 J/cm2） of irradiation, respectively, for 20 sessions. Another 6 mice were equally divided into 2 groups, to simultane-ously receive the injection of bleomycin and irradiation of UVA1 at a dose of 5.32 J/cm2 （U/B1 group）, or 11.1 J/cm2 （U/B2 group） for 20 sessions. All the studied mice were sacrified at 2 days after the last irradia-tion or injection. Skin specimens were obtained from the back of these mice. Measurements of skin （epider-mis and dermis） thickness, hydroxyproline content, transforming growth factor beta （TGF-β） and matrix metalloproteinases （MMP-1） expression were done using histologic and immunohistochemical methods, etc. Results Compared with the mice in bleomycin group, the skin thickness, hydroxyproline content, and expression of TGF-β were all significantly decreased（all P < 0.05）, while the expression of MMP-1 was significantly increased （P < 0.05） in the mice of U1 and U2 groups. However, there was no significant differ-ence in any of the above parameters when the bleomycin group was compared with the U/B1 group or U/B2 group, or when the U/B1 and U/B2 groups were compared （all P > 0.05）. Conclusions UVA1 irradiation could induce the elevation of MMP-1 expression, as well as the reduction in TGF-β expression, collagen content and skin thickness in a mouse model of scleroderma.