Jia Guohua, Yu Siwang, Sun Wanlu, Yang Jin, Wang Ying, Qi Yongfen, Chen Yahong
Department of Pulmonary and Critical Care Medicine, Peking University Third Hospital, Beijing, China.
State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China.
Front Pharmacol. 2020 Feb 7;11:29. doi: 10.3389/fphar.2020.00029. eCollection 2020.
To investigate whether hydrogen sulfide provide protective effects on atmosphere particulate matter (PM)-induced emphysema and airway inflammation and its mechanism.
Wild type C57BL/6 and Nrf2 knockout mice were exposed to PM (200 g per mouse). Hydrogen sulfide or propargylglycine were administered by intraperitoneal injection respectively 30 min before PM exposure, mice were anesthetized 29th day after administration. Mice emphysema, airway inflammation, and oxidative stress were evaluated, the expression of NLRP3, active caspase-1, and active caspase-3 were detected. Alveolar epithelial A549 cells line were transfected with control small interfering RNA (siRNA) or Nrf2 siRNA and then incubated with or without hydrogen sulfide for 30 min before exposed to fine particulate matter for 24 h, cell viability, terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling (TUNEL) assay, the secretion of interleukin (IL)-1, ASC speck formation, the expression level of NLRP3, active caspase-1, and active caspase-3 were measured.
PM significantly increased mice emphysema and airway inflammation measured by mean linear intercept, alveolar destroy index and total cell, neutrophil counts, cytokines IL-6, tumor necrosis factor (TNF)-, CXCL1, IL-1 in bronchoalveolar lavage fluid. PM-induced mice emphysema and airway inflammation was greatly attenuated by hydrogen sulfide, while propargylglycine aggravated that. PM-induced oxidative stress was reduced by hydrogen sulfide as evaluated by 8-OHdG concentrations in lung tissues. The expression of NLRP3, active caspase-1, and active caspase-3 enhanced by PM were also downregulated by hydrogen sulfide in mice lung. The protective effect of hydrogen sulfide on emphysema, airway inflammation, inhibiting oxidative stress, NLRP3 inflammasome formation, and anti-apoptosis was inhibited by Nrf2 knockout in mice. Similarly, hydrogen sulfide attenuated the secretion of IL-1, NLRP3 expression, caspase-1 activation, ASC speck formation, and apoptosis caused by fine particulate matter exposure in A549 cells but not in Nrf2 silenced cells.
Hydrogen sulfide played a protect role in PM-induced mice emphysema and airway inflammation by inhibiting NLRP3 inflammasome formation and apoptosis Nrf2-dependent pathway.
探讨硫化氢是否对大气颗粒物（PM）诱导的肺气肿和气道炎症具有保护作用及其机制。
将野生型C57BL/6和Nrf2基因敲除小鼠暴露于PM（每只小鼠200μg）。在暴露于PM前30分钟分别腹腔注射硫化氢或炔丙基甘氨酸，给药后第29天对小鼠进行麻醉。评估小鼠的肺气肿、气道炎症和氧化应激，检测NLRP3、活化的半胱天冬酶-1和活化的半胱天冬酶-3的表达。用对照小干扰RNA（siRNA）或Nrf2 siRNA转染肺泡上皮A549细胞系，然后在暴露于细颗粒物24小时前，在有或无硫化氢的情况下孵育30分钟，检测细胞活力、末端脱氧核苷酸转移酶脱氧尿苷三磷酸缺口末端标记（TUNEL）试验、白细胞介素（IL）-1的分泌、ASC斑点形成、NLRP3、活化的半胱天冬酶-1和活化的半胱天冬酶-3的表达水平。
通过平均线性截距、肺泡破坏指数以及支气管肺泡灌洗液中的总细胞数、中性粒细胞计数、细胞因子IL-6、肿瘤坏死因子（TNF）-、CXCL1、IL-1测定，PM显著增加了小鼠的肺气肿和气道炎症。硫化氢可显著减轻PM诱导的小鼠肺气肿和气道炎症，而炔丙基甘氨酸则加重了这种炎症。通过肺组织中8-羟基脱氧鸟苷浓度评估，硫化氢可降低PM诱导的氧化应激。PM增强的NLRP3、活化的半胱天冬酶-1和活化的半胱天冬酶-3在小鼠肺中的表达也被硫化氢下调。小鼠中Nrf2基因敲除抑制了硫化氢对肺气肿、气道炎症、抑制氧化应激、NLRP3炎性小体形成和抗凋亡的保护作用。同样，硫化氢减轻了细颗粒物暴露在A549细胞中引起的IL-1分泌、NLRP3表达、半胱天冬酶-1活化、ASC斑点形成和凋亡，但在Nrf2沉默的细胞中则没有这种作用。
硫化氢通过抑制NLRP3炎性小体形成和凋亡的Nrf2依赖性途径，对PM诱导的小鼠肺气肿和气道炎症发挥保护作用。
