To investigate the effect of adipose-derived stem cells (ADSCs) on radiation-induced skin injury in SD rats. Methods: Radioactive particles 192Ir were used to irradiate the left medial thigh skin of SD rats, and the irradiation dose was at 90 Gy. Then, the rats were randomly allocated into a control group and a treatment group (each n=9). After the irradiation, the control group was injected with 60 μL PBS and the treatment group was injected with 60 μL ADSCs in irradiated skin. The progress of skin damage and healing was observed and photographed every day. Twenty-eighth days after the irradiation, the irradiated skin tissue was taken from the left thigh, and then fixed with formaldehyde fixative solution. At the same time, the skin tissue of the corresponding part of the normal group (n=9) that was not irradiated was also taken. After sampling, embedding and slicing, immunohistochemical staining was used to compare the levels of α-smooth muscle actin (α-SMA), and HE staining was used to compare pathological features of the skin. Results: Radioactive particle 192Ir caused the development of III or IV radioactive skin damage. The score of the treatment group was significantly lower than that of the control group. The wounds of the treatment group were basically healed at 28 days, while the ulcer of the control group was unhealed. So, the healing time was shorter in the treatment group. The expression of α-SMA in the skin of the two groups was increased after the radiotherapy. By analyzing the pathological microstructure image, we found that the thickness of epidermis in the control group was greater than that in the treatment group, while the vascular density in the treatment group was greater than that in the control group (all P<0.05). Conclusion: Radioactive particles 192Ir can cause skin damage, while the adipose-derived stem cells might alleviate radiation-induced skin injury and promote ulcer healing by promoting angiogenesis.
目的：研究脂肪干细胞(adipose derived stem cells，ADSCs)在SD大鼠放射性皮肤损伤中的干预作用。方法：采用剂量为90 Gy的192Ir放射源，对SD大鼠左侧大腿内侧皮肤进行单次近距离照射，建立放射性皮肤损伤动物模型，并随机将其分为实验组和对照组(n=9)。照射后24 h，实验组大鼠照射处注射60 μL(5×105个)脂肪干细胞，对照组注射等体积的PBS。每隔3~4 d观察大鼠照射处皮肤损伤及愈合情况。照射后第28天，处死所有SD大鼠，取照射处皮肤组织，同时取未照射的正常组(n=9)相应部位的皮肤组织切片，采用免疫组织化学法比较3组皮肤组织中α-平滑肌肌动蛋白(α-smooth muscle actin，α-SMA)表达情况；HE染色观察皮肤组织病理学表现。结果：SD大鼠在受照射后出现III或IV度放射性皮肤损伤；实验组的创面评级明显低于对照组，愈合时间明显短于对照组；正常组皮肤组织中不表达α-SMA，实验组较对照组皮肤组织中的α-SMA表达增强；实验组表皮厚度低于对照组，而血管密度明显增加(均P<0.05)。 结论：192Ir放射剂量为90 Gy时可以导致大鼠皮肤损伤，而ADSCs可以减轻放射性皮肤损伤，并通过增加微血管新生促进溃疡愈合。.