不同温度凝胶对大鼠寒区皮肤放射损伤修复的研究

Effect of different temperature hydrogel on repairing radiation-induced skin injury of SD rats in cold region

摘要:

目的 探讨不同温度凝胶对寒区皮肤放射损伤修复的影响。方法 将20只SD大鼠随机分为4 ℃凝胶组和37 ℃凝胶组。大鼠于-20 ℃低温环境下饲养1周后，通过自身对照，于背部两侧采用锶-90照射10 min复制SD大鼠寒区皮肤放射损伤模型。伤后不同时间点观察皮肤修复情况；苏木精-伊红染色观察皮肤病理改变；Western blotting检测血管生成和胶原生成相关蛋白血管内皮生长因子（VEGF）、α-平滑肌肌动蛋白（α-SMA）、胶原蛋白Ⅰ（CollagenⅠ）和胶原蛋白Ⅲ（Collagen Ⅲ）表达；酶联免疫吸附试验（ELISA）检测相关生长因子人血小板衍生生长因子D（PDGFD）和转化生长因子-β（TGF-β）水平。结果 4 ℃凝胶组和37 ℃凝胶组大鼠体重比较，差异无统计学意义（P >0.05）。与自身对照比较，照射后大鼠出现皮肤损伤，呈红斑溃疡状态，随着时间推移皮肤损伤先加重后逐步减轻，在照射后第21天皮肤损伤最重；不同温度凝胶干预后，大鼠不同时间点的皮肤损伤程度均有所减轻，与自身对照比较，37 ℃凝胶组大鼠促创面愈合效果最显著。HE染色结果显示，照射后大鼠表皮增厚，真皮层伴有淋巴细胞浸润；凝胶干预后皮肤组织损伤减轻，37 ℃凝胶组上皮恢复最为明显。Western blotting检测结果显示，自身对照、4 ℃凝胶组和37 ℃凝胶组大鼠皮肤组织的VEGF、α-SMA、CollagenⅠ和CollagenⅢ蛋白相对表达量比较，差异有统计学意义（P <0.05）；凝胶干预后，37 ℃凝胶组大鼠皮肤组织的VEGF、α-SMA、CollagenⅠ和CollagenⅢ蛋白相对表达量显著升高。ELISA检测结果显示，37 ℃凝胶组皮肤组织的PDGFD和TGF-β水平显著升高（P <0.05）。结论 低温环境下，锶-90照射能够造成大鼠皮肤损伤；37 ℃凝胶相比于4 ℃凝胶更有益于寒区皮肤放射损伤愈合。

Abstract:

Objective To investigate the effects of different temperature gels on the repair of cold-region skin radiation injury.Methods Twenty SD rats were randomly divided into a 4 °C gel group and a 37 °C gel group. After one week of rearing in a -20 °C low-temperature environment, a cold-region skin radiation injury model in SD rats was replicated by strontium-90 irradiation on both sides of the back for 10 minutes. The skin repair was observed at different time points after injury, and histopathological changes were observed using hematoxylin-eosin (HE) staining. Western blotting was performed to detect the expression of vascular endothelial growth factor (VEGF), alpha-smooth muscle actin (α-SMA), collagen I, and collagen Ⅲ. Enzyme-linked immunosorbent assay (ELISA) was used to measure platelet-derived growth factor D (PDGFD) and transforming growth factor-beta (TGF-β) levels.Results There was no significant difference in body weight between the 4 °C gel group and the 37 °C gel group (P > 0.05). Compared with self-control, rats showed skin damage after irradiation, presenting as erythema and ulceration. The severity of skin damage increased first and then gradually decreased over time, with the most severe damage observed on day 21 after irradiation. After gel intervention at different temperatures, the degree of skin damage in rats was reduced at different time points. Compared with self-control, the 37 °C gel group showed the most significant promotion of wound healing. HE staining results showed that the epidermis thickened, and the dermis was infiltrated with lymphocytes after irradiation. Gel intervention reduced skin tissue damage, and epithelial recovery was most pronounced in the 37 °C gel group. Western blotting results showed that the relative expression levels of VEGF, α-SMA, Collagen I, and Collagen Ⅲ proteins in skin tissues of rats in the self-control, 4°C gel, and 37 °C gel groups were statistically different (P < 0.05). After gel intervention, the relative expression levels of VEGF, α-SMA, Collagen I, and Collagen Ⅲ proteins in skin tissues of rats in the 37 °C gel group were significantly increased. ELISA results showed that the levels of PDGFD and TGF-β in skin tissues of the 37 °C gel group were significantly increased (P < 0.05).Conclusion Under low-temperature conditions, strontium-90 irradiation can cause skin damage in rats. A 37 °C gel is more beneficial for the healing of cold-region skin radiation injury compared to a 4 °C gel.