SP-A在矽肺中的作用研究  

The role of surfactant associated protein-A in silicosis

作　　者：苏文瑶 陈铿铿[2] 张碧珠[2] 金佳纯[2] 农骐郢 赵娜 SU Wenyao;CHEN Kengkeng;ZHANG Bizhu;JIN Jiachun;NONG Qiying;ZHAO Na(School of Public Health,Guangzhou Medical University,Guangzhou,Guangdong 511436,China;不详)

机构地区：[1]广州医科大学公共卫生学院,广东广州511436 [2]广东省职业病防治院,广东广州510300

出　　处：《中国职业医学》2023年第1期38-45,共8页China Occupational Medicine

基　　金：广东省自然科学基金(2021A1515010081,2021A1515011546,2021A1515012205,2023A1515012756,2023A1515010085);广东省医学科学技术研究基金(B2021134,A2022038,A2022013);广州市科技计划项目(202102080005);广东省职业病防治院重点科研项目(Z2022-11,Z2022-12);广东省职业健康工程技术研究中心(D:2019A069)。

摘　　要：目的探讨表面活性物质相关蛋白-A(SP-A)在矽肺发生发展中的作用与机制。方法将无特定病原体(SPF)级SP-A基因敲除的纯合子和杂合子小鼠进行配种繁殖,选择基因型为SP-A^(-/-)的小鼠进行后续实验。选择SPF级野生型(SP-A+/+)小鼠与SP-A^(-/-)小鼠各12只,采用随机数字表法,将小鼠分为SP-A^(+/+)对照组、SP-A^(-/-)对照组、SP-A^(+/+)矽肺组、SP-A^(-/-)矽肺组,每组6只。2个矽肺组小鼠均通过气管暴露法一次性予20.0μL的250 g/L的游离二氧化硅混悬液,2个对照组小鼠注射等体积0.9%氯化钠溶液。于建模后第28天处死小鼠,观察其肺组织病理学改变情况,采用TUNEL法检测小鼠肺泡Ⅱ型上皮细胞凋亡情况,采用荧光定量聚合酶链式反应检测小鼠肺组织中凋亡因子B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、半胱氨酸蛋白酶(Caspase)-3和Caspase-9的mRNA表达。结果肺组织病理学结果显示,在二氧化硅暴露后,SP-A^(+/+)矽肺组小鼠肺内可见肺泡间隔增厚、散在矽结节和胶原纤维形成,矽肺结节内可见大量炎性细胞浸润;SP-A^(-/-)矽肺组小鼠肺部炎症和间质纤维化程度较SP-A^(+/+)矽肺组严重。与2个对照组比较,2个矽肺组小鼠肺泡Ⅱ型上皮细胞凋亡率和肺组织中Bax、Caspase-3、Caspase-9 mRNA相对表达水平均升高(P值均<0.05);而SP-A^(-/-)矽肺组小鼠上述4个指标均高于SP-A^(+/+)矽肺组(P值均<0.05)。4组小鼠肺组织中Bcl-2 mRNA相对表达水平比较,差异无统计学意义(P>0.05)。结论敲除SP-A可加重矽肺模型小鼠炎症和肺纤维化程度,促进肺泡Ⅱ型上皮细胞凋亡;其机制可能与SP-A影响线粒体途径细胞凋亡的Bcl-2/Bax/Caspase-3信号通路有关。Objective To investigate the role of surfactant associated protein-A(SP-A) in the development and progression of silicosis,and its mechanism.Methods Homozygous and heterozygous mice of SP-A knockout of specific pathogen free(SPF) grade were selected for mating,and mice with SP-A^(-/-) genotype were selected for subsequent experiments.SP-A wild-type(SP-A^(+/+)) and SP-A^(-/-) mice were divided into SP-A^(+/+) control group,SP-A^(-/-) control group,SP-A^(+/+) silicosis group and SP-A^(-/-) silicosis group with six mice in each group by random number table method.Mice in both silicosis groups were given 20.0 μL 250 g/L silica suspension by tracheal exposure,and mice in both control groups were injected with 0.9% sodium chloride solution at the same volume.On the 28th day after modeling,mice were sacrificed.Lung tissues were used for lung histopathology examination.The apoptosis of alveolar type Ⅱ epithelial cells of mice was detected by TUNEL method.The mRNA expression of B-lymphoblastoma 2(Bcl-2),Bcl-2 associated X protein(Bax),cysteinyl aspartate specific proteinase(Caspase)-3 and Caspase-9 in lung tissues of mice was detected by quantitative real-time polymerase chain reaction.Results The histopathological result of mice showed that thickened alveolar septum,scattered silicon nodule and collagen fiber formation were observed in the mice lungs of SP-A^(+/+) silicosis group,and a large number of inflammatory cells were observed in silicosis nodule,after exposure to silica dust.SP-A^(-/-) silicosis group resulted in a more severe pulmonary inflammation and interstitial fibrosis compared to SP-A^(+/+) silicosis group.The apoptosis of alveolar type Ⅱ epithelial cells and the mRNA relative expression levels of Bax,Caspase-3 and Caspase-9 in lung tissues of mice in each silicosis groups were increased compared with their control groups(all P<0.05).The above four indexes of mice in SP-A^(-/-) silicosis group were higher than those in SP-A^(+/+) silicosis group(all P<0.05).There was no significant difference in the e

关 键 词：表面活性蛋白A 矽肺 炎症 纤维化 上皮细胞 凋亡 小鼠 

分 类 号：R135.2[医药卫生—劳动卫生]