消旋山莨菪碱减轻小鼠放射性肺损伤的作用及分子机制研究

Mechanism of racanisodamine on alleviating radiation-induced lung injury in mice

目的探讨消旋山莨菪碱对X射线致放射性肺损伤的保护作用及机制。方法将20只C57BL/6小鼠按随机数表法分为对照组、模型组(照射)、给药组(消旋山莨菪碱)、治疗组(照射+消旋山莨菪碱),每组5只。给药组、治疗组照射前3天给予消旋山莨菪碱注射液腹腔注射(5 mg/kg),模型组、治疗组给予6 MV X射线,18 Gy单次全胸腔照射,构建放射性肺损伤小鼠模型,辐照后治疗组采取每隔1天给药,连续给药6周后处死小鼠并取材。HE染色检测肺组织病理形态;酶联免疫吸附法(ELISA)检测肺泡灌洗液和血清中肿瘤坏死因子α(TNF-α)、白介素6(IL-6)、白介素1β(IL-1β)细胞因子表达;细胞衰老β-半乳糖苷酶(SA-β-Gal)染色检测肺组织细胞衰老情况;Western blot检测核因子E2相关因子2(Nrf2)、磷酸化NRF2(p-Nrf2)、p62蛋白表达。结果与模型组相比,治疗组肺组织HE病理评分减低(t=8.66,P<0.01);肺泡灌洗液中炎性细胞数量减少(t=10.70,P<0.01)、蛋白浓度降低(t=6.75,P<0.01),血清TNF-α、IL-1β、IL-6表达减少(t=8.17、4.58、6.54,P<0.01);肺组织SA-β-gal活性降低,且肺组织Nrf2、磷酸化Nrf2表达增强(t=6.42、7.30,P<0.01),而p62表达减少(t=4.62,P<0.01)。结论消旋山莨菪碱可通过减轻炎症等途径发挥对X射线致放射性肺损伤的保护作用,其保护机制可能与激活Nrf2通路,逆转辐照所致的细胞衰老有关。

Objective To investigate the protective effect of racanisodamine on lung injury in mice exposed to irradiation.Methods C57BL/6 mice were randomly divided into control group,racanisodamine group,18 Gy irradiation group(model group)and racanisodamine combined with 18 Gy irradiation group(treatment group),with 5 mice in each group.The mice in the treatment group received racanisodamine(5 mg/kg)intraperitoneally 3 d before irradiation and contained the whole experiments.Then,single chest irradiation of 18 Gy X-rays was performed both in the model and treatment groups.The racanisodamine group and treatment group received racanisodamine intraperitoneally once a day until 6 weeks after irradiation.The mice were killed at 6 weeks after irradiation.The lung histopathology was observed by HE staining.Serum and bronchial alveolar lavage fluid(BALF)inflammatory cytokines such as TNF-α,IL-1βand IL-6 were determined by ELISA method.Cell senescence was detected by SA-β-Gal staining.The expressions of Nrf2,p-Nrf2 and p62 in lung tissue were performed by immunehistochemistry and Western blot assays.Results Compared with the model group,the scores of HE staining were decreased(t=8.66,P<0.01),the number of infiltrated inflammatory cells in BALF were decreased(t=10.70,P<0.01),and protein concentration in BALF had lower levels(t=6.75,P<0.01),the serum TNF-α,IL-1βand IL-6 were decreased significantly(t=8.17,4.58,6.54,P<0.01),the activity of SA-β-gal was decreased,and the expressions of Nrf2,p-Nrf2 were enhanced(t=6.42,7.30,P<0.01),while the expression of p62 was reduced(t=4.62,P<0.01)in the treatment group.Conclusions Racanisodamine plays the protective effect of radiation-induced lung injury by alleviating inflammation associating with the activating of Nrf2-related pathway,which reversed radiation-induced cell senescence.