肺细胞外基质水凝胶治疗大鼠 放射性肺损伤的实验研究

Therapeutic effect of lung ECM hydrogel on radiation-induced lung injury in rats

摘要:

目的 探讨气管内注射肺细胞外基质（ECM）水凝胶对大鼠放射性肺损伤的疗效。方法 脱细 胞法制备肺ECM 水凝胶, 单次全肺20 Gy 照射复制放射性肺损伤模型。实验一：照射后30 min 将24 只大鼠 随机分为4 组，分别注射肺ECM 水凝胶0、300、500 及800μl，比较注射后30 min 的死亡率、动脉血氧分 压（PaO2），免疫荧光染色观察水凝胶分布。实验二：将18 只大鼠分为对照组（正常大鼠）、照射组（照射+ 气管内注射生理盐水）及ECM 组（照射+ 气管内注射肺ECM 水凝胶），注射时间为照射后30 min，剂量 500μl，照射7 d 后行肺病理学检查，ELISA 法检测血清中肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6） 水平。结果 气管内注射肺ECM 水凝胶300 或500μl 不会影响大鼠PaO2（P >0.05），而800μl 则会影响大 鼠PaO2（P <0.05），300、500 及800μl 组均能在肺泡表面观察到绿色荧光，其中800μl 分布最均匀；照射组 及ECM 组大鼠血清中TNF-α、IL-6 水平较对照组升高（P <0.05），ECM 组大鼠血清中TNF-α、IL-6 水平 较照射组降低（P <0.05）。结论 肺ECM 水凝胶能减轻放射性肺损伤早期的炎症反应，可作为一种新的治疗策略。

Abstract:

Objective To investigate the therapeutic effect of intratracheal injection of extracellular matrix (ECM) hydrogel on radiation-induced lung injury (RILI) in rats. Methods Lung ECM hydrogel was prepared by decellularization and RILI model was established by single whole lung 20Gy irradiation. Experiment 1: 24 rats were injected with lung ECM hydrogel half an hour after radiation and randomly divided into 4 groups (0 μl group, 300 μl group, 500 μl group and 800 μl group) according to the doses of lung ECM hydrogel. The mortality, PaO2 and material distribution observed by immunofluorescence staining of each group were compared half an hour after injection. Experiment 2: 18 rats were divided into control group, irradiation group and ECM group. 500 μl or equivalent saline of ECM hydrogel was injected half an hour after irradiation. Lung pathology was performed 7 days after irradiation and TNF-α and IL-6 level in serum was detected by Elisa method. Results Intratracheal injection of lung ECM hydrogel 300 μl and 500 μl did not affect the PaO2 in rats(P > 0.05), while 800 μl affected the PaO2 in rats (P < 0.05). The green fluorescence distribution was observed on the alveolar surface in 300 μl, 500 μl, and 800 μl groups, and distribution was the most uniform in 800 μl group. The serum levels of TNF-α and IL-6 in ECM group and irradiation group were higher than those in control group, and the serum levels of TNF-α and IL-6 in ECM group were lower than those in irradiation group (P < 0.05). Conclusions Lung ECM hydrogel can alleviate the early inflammatory response of RILI and can be used as a new treatment strategy for RILI.