N-乙酰半胱氨酸对博莱霉素致小鼠肺间质纤维化形成及NF-κB、IL-4表达的影响

Effects of N-acetylcysteine on expressions of NF-κB and IL-4 in mice with pulmonary fibrosis

目的:探讨N-乙酰半胱氨酸(NAC)对博莱霉素(BLM)致小鼠肺间质纤维化形成及核转录因子-κB(NF-κB)、白细胞介素-4(IL-4)表达的影响。方法:75只雌性C57BL/6小鼠随机分为3组:BLM组25只,气管注射BLM5mg/kg制作肺间质纤维化模型;NAC组25只,于注射BLM前5天开始,每天给予NAC250mg/kg直至取材;对照组25只,气管注射生理盐水。第1、3、7、14、28天处死小鼠,取右肺组织行HE染色和Masson染色,左肺组织测羟脯氨酸(HYP)含量;分别采用ELISA法和SP免疫组化染色检测支气管肺泡灌洗液中IL-4的含量和灌洗细胞中NF-κBp65的表达。结果:第7、14、28天,BLM组肺组织病理可见实变及胶原沉积,而NAC组明显减轻;3组小鼠肺组织HYP含量差异有统计学意义,NAC组HYP含量低于BLM组(P<0.05);第1、3、7天,3组小鼠支气管肺泡灌洗细胞NF-κBp65的表达水平及支气管肺泡灌洗液中IL-4的含量差异有统计学意义,且NAC组2指标均低于BLM组(P均<0.05)。结论:NAC可能通过抑制NF-κB的活化,减少致纤维化相关细胞因子IL-4的产生,进而减轻BLM所致小鼠肺间质纤维化。

Aim：To investigate the effects of N-acetylcysteine（NAC）on expressions of nuclear factor-kappa B（NF-κB）and interleukin-4（IL-4）in mice with bleomycin（BLM）-induced pulmonary fibrosis.Methods：A total of 75 C57BL/6 mice were randomly allocated into three groups.BLM group（n=25）and control group（n=25）received intratracheal instillation of BLM and normal saline,respectively.NAC group（n=25）administrated NAC once a day via esophagus 5 days before BLM treatment till sampling.On days 1,3,7,14,and 28,the right lung tissue was collected for HE and Masson staining,and left lung tissue for detecting the content of hydroxyproline（HYP）.The content of IL-4 in bronchoalveolar lavage fluid of the right lung and the NF-κB p65 expression in bronchoalveolar lavage cells were detected by ELISA and immunohistochemical SP staining.Results：On days 7,14,and 28,BLM group had excessive lung solidation and collagen sediment,which was milder in NAC group.There were significant differences in HYP contents in lung tissue on days 7,14,and 28,level of NF-κB p65 expression in the bronchoalveolar lavage cells,and concentration of IL-4 in bronchoalveolar lavage fluid on days 1,3,and 7 among the 3 groups,and they were lower in NAC group than those in BLM group（P0.05）.Conclusion：NAC may alleviate the pulmonary fibrosis induced by BLM through inhibiting the activation of NF-κB and reducing the produce of IL-4.