Wang Y, Zhang Y, Zhang L, Li M, Zhu P, Ji W, Liang R, Qiin L, Wu W, Feng F, Jin Y
Department of epidemiology, School of Public Health, Zhengzhou University, Zhengzhou 450001, China.
Department of Toxicology, School of Public Health, Zhengzhou University, Zhengzhou 450001, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2022 Jun 20;42(6):860-867. doi: 10.12122/j.issn.1673-4254.2022.06.09.
To investigate the roles of angiotensin-converting enzyme 2 (ACE2) in ozone-induced pulmonary inflammation and airway remodeling in mice.
Sixteen wild-type (WT) C57BL/6J mice and 16 ACE2 knock-out (KO) mice were exposed to either filtered air or ozone (0.8 ppm) for 3 h per day for 5 consecutive days. Masson's staining and HE staining were used to observe lung pathologies. Bronchoalveolar lavage fluid (BALF) was collected and the total cell count was determined. The total proteins and cytokines in BALF were determined by BCA and ELISA method. The transcription levels of airway remodeling-related indicators in the lung tissues were detected using real-time quantitative PCR. The airway resistance of the mice was measured using a small animal ventilator with methacholine stimulation.
Following ozoneexposure ACE2 KO mice had significantly higher lung pathological scores than WT mice ( < 0.05). Masson staining results showed that compared with ozone-exposed WT mice, ozone-exposed ACE2 KO mice presented with significantly larger area of collagen deposition in the bronchi [(19.62±3.16)% (6.49±1.34)%, < 0.05] and alveoli [(21.63±3.78)% (4.44±0.99)%, < 0.05]. The total cell count and total protein contents in the BALF were both higher in ozone-exposed ACE2 KO mice than in WT mice, but these differences were not statistically significant ( > 0.05). The concentrations of IL-6, IL-1β, TNF-, CXCL1/KC and MCP-1 in the BALF were all higher in ozone-exposed ACE2 KO mice than in ozone-exposed WT mice, but only the difference in IL-1β was statistically significant ( < 0.05). The transcription levels of MMP-9, MMP-13, TIMP 4, COL1A1, and TGF-β in the lung tissues were all significantly higher in ozone-exposed ACE2 KO mice ( < 0.01). No significant difference was found in airway resistance between ozone-exposed ACE KO mice and WT mice after challenge with 0, 10, 25, or 100 mg/mL of methacholine.
ACE2 participates in ozone-induced lung inflammation and airway remodeling in mice.
探讨血管紧张素转换酶2（ACE2）在臭氧诱导的小鼠肺部炎症和气道重塑中的作用。
将16只野生型（WT）C57BL/6J小鼠和16只ACE2基因敲除（KO）小鼠，每天暴露于过滤空气或臭氧（0.8 ppm）中3小时，连续5天。采用Masson染色和苏木精-伊红（HE）染色观察肺部病理变化。收集支气管肺泡灌洗液（BALF）并测定总细胞数。采用BCA法和酶联免疫吸附测定（ELISA）法测定BALF中的总蛋白和细胞因子。使用实时定量聚合酶链反应（PCR）检测肺组织中气道重塑相关指标的转录水平。使用配备乙酰甲胆碱刺激装置的小动物呼吸机测量小鼠的气道阻力。
臭氧暴露后，ACE2基因敲除小鼠的肺部病理评分显著高于野生型小鼠（P<0.05）。Masson染色结果显示，与臭氧暴露的野生型小鼠相比，臭氧暴露的ACE2基因敲除小鼠支气管中的胶原沉积面积显著更大[（19.62±3.16）% 对（6.49±1.34）%，P<0.05]，肺泡中的胶原沉积面积也显著更大[（21.63±3.78）% 对（4.44±0.99）%，P<0.05]。臭氧暴露的ACE2基因敲除小鼠BALF中的总细胞数和总蛋白含量均高于野生型小鼠，但差异无统计学意义（P>0.05）。臭氧暴露的ACE2基因敲除小鼠BALF中白细胞介素-6（IL-6）、白细胞介素-1β（IL-1β）、肿瘤坏死因子-α（TNF-α）、趋化因子CXCL1/KC和单核细胞趋化蛋白-1（MCP-1）的浓度均高于臭氧暴露的野生型小鼠，但只有IL-1β的差异具有统计学意义（P<0.05）。臭氧暴露的ACE2基因敲除小鼠肺组织中基质金属蛋白酶-9（MMP-9）、基质金属蛋白酶-13（MMP-13）、金属蛋白酶组织抑制剂4（TIMP 4）、Ⅰ型胶原α1链（COL1A1）和转化生长因子-β（TGF-β）的转录水平均显著升高（P<0.01）。用0、10、25或100 mg/mL乙酰甲胆碱激发后，臭氧暴露的ACE基因敲除小鼠与野生型小鼠的气道阻力无显著差异。
ACE2参与臭氧诱导的小鼠肺部炎症和气道重塑。
