IL-33在小鼠皮肤创伤后损伤时间推断中的作用

目的通过观察白细胞介素-33(interleukin-33,IL-33)在皮肤创伤后的时序性变化规律,探讨IL-33在法医学实践中用于损伤时间推断的应用价值。方法利用直径为5mm的圆形锉刀在小鼠背部建造皮肤损伤模型,于伤后1h、3h、6h、12h、1d、3d、5d、7d、10d取损伤处组织,对照组在与创伤组小鼠相同部位取同等大小的皮肤样本。采用苏木精-伊红(hematoxylin-eosin,HE)染色法观察皮肤创伤后愈合过程中的形态学变化,通过Western印迹法、免疫组织化学染色和双重免疫荧光染色法检测皮肤创伤样本IL-33的表达变化。结果Western印迹法结果显示,伤后3h,IL-33蛋白表达稍有下降,6h后IL-33蛋白表达逐渐增加,于伤后3d达峰值,随后逐渐减少。免疫组织化学染色结果显示,在对照组皮肤的表皮、毛囊、皮脂腺及真皮中固有细胞有少量IL-33阳性表达,伤后3h,IL-33阳性细胞率开始增加,伤后3d达到峰值,随后逐渐减少。双重免疫荧光染色结果显示,伤后1~3d,IL-33阳性表达细胞主要为巨噬细胞,伤后5~7d,IL-33阳性表达细胞主要为肌成纤维细胞。HE染色结果显示该皮肤损伤模型创口愈合过程符合炎症的病理学发展规律。结论IL-33有望成为法医学推断皮肤损伤时间的参考指标。

Function of IL-33 in Wound Age Estimation of Skin Wounds in Mice

Objective To explore the application value of interleukin-33(IL-33)in wound age estimation in forensic practice by observing the sequential changes of IL-33 after skin wound.Methods Skin wound models were generated on the back of mice with a round file of 5 mm in diameter.Skin samples of the same size were taken from the same parts of mice in control group and injury group 1 h,3 h,6 h,12 h,1 d,3 d,5 d,7 d and 10 d after skin wound.Hematoxylin-eosin(HE)staining method was applied to observe the morphological changes in the recovering process after skin wound.Western blotting,immunohistochemistry staining and double immunofluorescence staining methods were applied to detect the expression changes of IL-33 in the skin wound samples.Results The results of Western blotting showed that the expression of IL-33 protein decreased slightly at 3 h after skin wound,increased gradually at 6 h after skin wound,and reached the peak value at 3 d,then decreased gradually.Immunohistochemistry staining results showed that faint positive expression of IL-33 was observed in epidermis,hair follicles,sebaceous glands and dermal resident cells of the control group skin.The positive cell rate of IL-33 increased at 3h after skin wound and reached the peak value at 3 d,then decreased gradually.The results of double immunofluorescence staining showed that the majority of IL-33 positive cells from 1d to 3d after wound were macrophages,while the majority of IL-33 positive cells from 5 d to 7 d after wound were myofibroblasts.In addition,the results of HE staining showed that the wound healing process of the skin wound model was consistent with the pathological development law of inflammation.Conclusion IL-33 could become a reference index for wound age estimation of skin wound in forensic practice.