The Role of Short-Chain Fatty Acids, Produced by Anaerobic Bacteria, in the Cystic Fibrosis Airway
The Role of Short-Chain Fatty Acids, Produced by Anaerobic Bacteria, in the Cystic Fibrosis Airway
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DOI：
10.1164/rccm.201505-0943oc
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发表时间：
2015-12-01
影响因子：
24.7
通讯作者：
McElvaney, Noel G.
中科院分区：
文献类型：
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作者：
Mirkovic, Bojana;Murray, Michelle A.;McElvaney, Noel G.
理论基础：囊性纤维症(PWCF)患者的呼吸道中存在大量厌氧细菌。在肠道中，厌氧菌产生短链脂肪酸(SCFA)，调节免疫和炎症过程。目的：探讨厌氧菌通过短链脂肪酸(SCFA)在囊性纤维化(CF)气道发病中的作用。方法：对109例PWCF标本进行厌氧微生物培养，16S RNA测序鉴定细菌。用气相色谱法测定厌氧上清液和支气管肺泡灌洗液(BAL)中单链脂肪酸的含量。应用逆转录聚合酶链式反应、Western印迹分析、激光扫描细胞术和激光共聚焦显微镜检测SCFA受体GPr41和GPR43在CF和非CF支气管刷及16HBE14o(-)和CFBE41o(-)细胞中的表达。用ELISA检测SCFA诱导的IL-8分泌。检测和主要结果：109例PWCF中57例(52.3%)厌氧菌阳性。患病率随着年龄的增长而增加，6岁以下(n=24)和年龄(n=85)的PWCF患病率从33.3%上升到57.7%。所有被评估的厌氧菌都能产生毫摩尔浓度的单链脂肪酸，包括醋酸、丙酸和丁酸。成人BAL样本中SCFA水平高于儿童。CFBE41o(-)细胞、CFHBE14o(-)细胞、CFHBE14o(-)细胞经囊性纤维化跨膜传导调节抑制剂CFTR(Inh)-172、CFBAL或内质网应激诱导剂处理后，Gpr41水平均升高。SCFAs可诱导呼吸道上皮细胞产生剂量依赖性和百日咳毒素敏感的IL-8，CFBE41o细胞产生的IL-8高于16HBE14O(-)细胞。结论：SCFAs通过上调Gpr41的表达，导致CFBE14O(-)细胞过度分泌IL-8。
Rationale: Anaerobic bacteria are present in large numbers in the airways of people with cystic fibrosis (PWCF). In the gut, anaerobes produce short-chain fatty acids (SCFAs) that modulate immune and inflammatory processes.Objectives: To investigate the capacity of anaerobes to contribute to cystic fibrosis (CF) airway pathogenesis via SCFAs.Methods: Samples of 109 PWCF were processed using anaerobic microbiological culture with bacteria present identified by 16S RNA sequencing. SCFA levels in anaerobic supernatants and bronchoalveolar lavage (BAL) were determined by gas chromatography. The mRNA and/or protein expression of two SCFA receptors, GPR41 and GPR43, in CF and non-CF bronchial brushings and 16HBE14o(-) and CFBE41o(-) cells were evaluated using reverse transcription polymerase chain reaction, Western blot analysis, laser scanning cytometry, and confocal microscopy. SCFA-induced IL-8 secretion was monitored by ELISA.Measurements and Main Results: Fifty-seven (52.3%) of 109 PWCF were anaerobe positive. Prevalence increased with age, from 33.3% to 57.7% in PWCF younger (n = 24) and older (n = 85) than 6 years of age. All evaluated anaerobes produced millimolar concentrations of SCFAs, including acetic, propionic, and butyric acids. SCFA levels were higher in BAL samples of adults than in those of children. GPR41 levels were elevated in CFBE41o(-) versus 16HBE14o(-) cells; CF versus non-CF bronchial brushings; and 16HBE14o(-) cells after treatment with cystic fibrosis transmembrane conductance regulator inhibitor CFTR(inh)-172, CF BAL, or inducers of endoplasmic reticulum stress. SCFAs induced a dose-dependent and pertussis toxin-sensitive IL-8 response in bronchial epithelial cells, with a higher production of IL-8 in CFBE41o than in 16HBE14o(-) cells.Conclusions: This study illustrates that SCFAs contribute to excessive production of IL-8 in CF airways colonized with anaerobes via up-regulated GPR41.