A型肉毒毒素对紫外线诱导光老化大鼠HMGB1/RAGE通路及皮肤损伤的影响

Effect of botulinum toxin type A on HMGB1/RAGE pathway and skin damage in ultraviolet-induced photoaging rats

目的 探究A型肉毒毒素(botulinum toxin type-A, BTX-A)对紫外线诱导光老化大鼠皮肤损伤的影响及其作用机制。方法 自2020年7月至2021年2月,河北工程大学附属医院将40只大鼠分为正常组、模型组、1.5 U BTX-A组、3.0 U BTX-A组、6.0 U BTX-A组。观察HE染色、Masson染色观察组织形态,SA-β-Gal半乳糖染色观察细胞衰老,TUNEL染色检测细胞凋亡;试剂盒检测皮肤组织中超氧化物歧化酶(superoxide dismutase, SOD)、羟脯氨酸(hydroxyproline, HYP)、丙二醛(malondialdehyde, MDA)水平;蛋白质免疫印迹法检测皮肤组织中老化标志物(细胞周期调控因子p16、p21、p53)、细胞凋亡相关蛋白(抗凋亡bcl-2蛋白、促凋亡bax蛋白)、高迁移率族蛋白B1(high mobility group protein B1, HMGB1)、晚期糖基化终产物受体(receptor of advanced glycation end products, RAGE)、核因子κB亚基p65(NF-κB p65)表达水平。结果 正常组表皮结构完整,胶原纤维排列致密;模型组表皮增厚,出现炎性细胞浸润,胶原纤维排列疏松;1.5、3.0、6.0 U BTX-A组较模型组有所改善,表皮少量增厚,胶原纤维排列分散程度变小。相较于正常组,模型组和BTX-A各剂量组p16、p21、p53、HMGB1、RAGE、NF-κB p65表达以及MDA含量均显著升高,Bcl-2/Bax水平以及SOD、HYP活性显著降低(P<0.05);相较于模型组,1.5、3.0、6.0 U BTX-A组p16、p21、p53、HMGB1、RAGE、NF-κB p65表达以及MDA含量显著降低,Bcl-2/Bax水平以及SOD、HYP活性显著升高(P<0.05)。结论 BTX-A对紫外线诱导光老化大鼠皮肤损伤具有保护作用,可能是通过HMGB1/RAGE通路发挥作用的。

Objective To explore the effect of botulinum toxin type A(BTX-A) on skin damage in ultraviolet-induced photoaging rats and its mechanism. Methods From July 2020 to February 2021, the experiment was divided 40 rats into normal group, model group,1.5 U, 3.0 U and 6.0 U BTX-A group. Hematoxylin and eosin(HE) staining and Masson’s trichrome staining were used to observe the tissue morphology of skin tissue section, SA-β-Gal staining was used to observe cell senescence and TUNEL staining was used to detect apoptosis. The level of superoxide dismutase(SOD), hydroxyproline(HYP) and malondialdehyde(MDA) in skin tissue was detected by kit. The expression level of aging markers(cell cycle regulation factors p16, p21, p53), apoptosis related proteins(B-cell lymphoma-2,Bcl2-associated X protein), high mobility group protein B1(HMGB1), receptor of advanced glycation end products(RAGE) and nuclear factor-κB subunit p65(NF-κB p65) in skin tissue was detected by western blotting. Results In the normal group, the epidermal structure was intact and the collagen fibers were arranged compactly. In the model group, the thickened epidermis was found, inflammatory cells was infiltrated and collagen fibers arranged loosely. Compared with the model group, the 1.5 U, 3.0 U and 6.0 U BTX-A group was improved. The slightly thickened epidermis was found, and the arrangement and dispersion of collagen fibers were reduced. Compared with the normal group, the expression of p16, p21, p53, HMGB1, RAGE, NF-κB p65 and the content of MDA in the model group and the 1.5U, 3.0 U and 6.0 U BTX-A group were significantly increased, while the level of Bcl-2/Bax and the activity of SOD and HYP were significantly decreased(P<0.05). Compared with the model group, the expression of p16, p21, p53, HMGB1, RAGE, NF-κB p65 and the content of MDA in the 1.5 U, 3.0 U and 6.0 U BTX-A group were significantly decreased, while the level of Bcl-2/Bax and the activity of SOD and HYP were significantly increased(P<0.05). Conclusion BTX-A has protective effect on skin damage in ultraviolet-induced photoaging rats, which may play a role through HMGB1/RAGE pathway.