基于底物的髓过氧化物酶活性在气道上皮细胞中的代谢组学特征:对早期囊性纤维化肺病的影响。
Substrate-dependent metabolomic signatures of myeloperoxidase activity in airway epithelial cells: Implications for early cystic fibrosis lung disease.
机构信息
Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University, Atlanta, GA, USA.
Respiratory and Sleep Medicine, Royal Children's Hospital, Parkville, VIC, Australia; Respiratory Diseases, Murdoch Children's Research Institute, Parkville, VIC, Australia; Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia.
出版信息
Free Radic Biol Med. 2023 Sep;206:180-190. doi: 10.1016/j.freeradbiomed.2023.06.021. Epub 2023 Jun 23.
Myeloperoxidase (MPO) is released by neutrophils in inflamed tissues. MPO oxidizes chloride, bromide, and thiocyanate to produce hypochlorous acid (HOCl), hypobromous acid (HOBr), and hypothiocyanous acid (HOSCN), respectively. These oxidants are toxic to pathogens, but may also react with host cells to elicit biological activity and potential toxicity. In cystic fibrosis (CF) and related diseases, increased neutrophil inflammation leads to increased airway MPO and airway epithelial cell (AEC) exposure to its oxidants. In this study, we investigated how equal dose-rate exposures of MPO-derived oxidants differentially impact the metabolome of human AECs (BEAS-2B cells). We utilized enzymatic oxidant production with rate-limiting glucose oxidase (GOX) coupled to MPO, and chloride, bromide (Br), or thiocyanate (SCN) as substrates. AECs exposed to GOX/MPO/SCN (favoring HOSCN) were viable after 24 h, while exposure to GOX/MPO (favoring HOCl) or GOX/MPO/Br (favoring HOBr) developed cytotoxicity after 6 h. Cell glutathione and peroxiredoxin-3 oxidation were insufficient to explain these differences. However, untargeted metabolomics revealed GOX/MPO and GOX/MPO/Br diverged significantly from GOX/MPO/SCN for dozens of metabolites. We noted methionine sulfoxide and dehydromethionine were significantly increased in GOX/MPO- or GOX/MPO/Br-treated cells, and analyzed them as potential biomarkers of lung damage in bronchoalveolar lavage fluid from 5-year-olds with CF (n = 27). Both metabolites were associated with increasing bronchiectasis, neutrophils, and MPO activity. This suggests MPO production of HOCl and/or HOBr may contribute to inflammatory lung damage in early CF. In summary, our in vitro model enabled unbiased identification of exposure-specific metabolite products which may serve as biomarkers of lung damage in vivo. Continued research with this exposure model may yield additional oxidant-specific biomarkers and reveal explicit mechanisms of oxidant byproduct formation and cellular redox signaling.
髓过氧化物酶 (MPO) 由炎症组织中的中性粒细胞释放。MPO 可将氯、溴和硫氰酸盐分别氧化为次氯酸 (HOCl)、次溴酸 (HOBr) 和次硫氰酸 (HOSCN)。这些氧化剂对病原体有毒,但也可能与宿主细胞反应产生生物活性和潜在毒性。在囊性纤维化 (CF) 和相关疾病中,中性粒细胞炎症增加导致气道 MPO 增加和气道上皮细胞 (AEC) 暴露于其氧化剂。在这项研究中,我们研究了 MPO 衍生氧化剂的等剂量率暴露如何差异影响人 AEC(BEAS-2B 细胞)的代谢组。我们利用酶促氧化剂产生,限速葡萄糖氧化酶 (GOX) 与 MPO 偶联,并以氯、溴 (Br) 或硫氰酸盐 (SCN) 作为底物。暴露于 GOX/MPO/SCN(有利于 HOSCN)的 AEC 在 24 小时后仍具有活力,而暴露于 GOX/MPO(有利于 HOCl)或 GOX/MPO/Br(有利于 HOBr)的 AEC 在 6 小时后出现细胞毒性。细胞谷胱甘肽和过氧化物还原酶 3 的氧化不足以解释这些差异。然而,非靶向代谢组学显示,GOX/MPO 和 GOX/MPO/Br 与 GOX/MPO/SCN 相比,数十种代谢物明显不同。我们注意到甲硫氨酸亚砜和去甲硫氨酸在 GOX/MPO 或 GOX/MPO/Br 处理的细胞中显著增加,并将它们分析为 CF 五岁儿童支气管肺泡灌洗液中肺损伤的潜在生物标志物(n=27)。这两种代谢物都与支气管扩张、中性粒细胞和 MPO 活性的增加有关。这表明 MPO 产生的 HOCl 和/或 HOBr 可能导致 CF 早期的炎症性肺损伤。总之,我们的体外模型能够对特定暴露的代谢产物进行无偏识别,这些产物可能作为体内肺损伤的生物标志物。使用这种暴露模型的进一步研究可能会产生额外的氧化剂特异性生物标志物,并揭示氧化剂副产物形成和细胞氧化还原信号的明确机制。