- 作者列表："Spence CD","Vanaudenaerde B","Einarsson GG","Mcdonough J","Lee AJ","Johnston E","Verleden GM","Elborn JS","Dupont LJ","Van Herck A","Gilpin DF","Vos R","Tunney MM","Verleden SE
BACKGROUND:Alterations in the lung microbiota may drive disease development and progression in patients with chronic respiratory diseases. Following lung transplantation (LTx), azithromycin is used to both treat and prevent chronic lung allograft dysfunction (CLAD). The objective of this study was to determine the association between azithromycin use, CLAD, acute rejection, airway inflammation, and bacterial microbiota composition and structure after LTx. METHODS:Bronchoalveolar lavage samples (n = 219) from 69 LTx recipients (azithromycin, n = 32; placebo, n = 37) from a previously conducted randomized placebo-controlled trial with azithromycin were analyzed. Samples were collected at discharge, 1, and 2 years following randomization and at CLAD diagnosis. Bacterial microbial community composition and structure was determined using 16S ribosomal RNA gene sequencing and associated with clinically important variables. RESULTS:At discharge and following 1 and 2 years of azithromycin therapy, no clear differences in microbial community composition or overall diversity were observed. Moreover, no changes in microbiota composition were observed in CLAD phenotypes. However, acute rejection was associated with a reduction in community diversity (p = 0.0009). Significant correlations were observed between microbiota composition, overall diversity, and levels of inflammatory cytokines in bronchoalveolar lavage, particularly CXCL8. CONCLUSIONS:Chronic azithromycin usage did not disturb the bacterial microbiota. However, acute rejection episodes were associated with bacterial dysbiosis.
背景: 在慢性呼吸系统疾病患者中，肺部微生物群的改变可能会推动疾病的发展和进展。肺移植 (LTx) 后，阿奇霉素被用于治疗和预防慢性移植肺功能障碍。本研究的目的是确定阿奇霉素使用、包被、急性排斥反应、气道炎症与 LTx 后细菌菌群组成和结构之间的相关性。 方法: 来自 69 例 LTx 受者 (阿奇霉素，n = 32; 安慰剂，n = 37) 的支气管肺泡灌洗样本 (n = 219) 从以前进行的随机安慰剂对照试验与阿奇霉素进行了分析。在出院时、随机化后 1 年和 2 年和包被诊断时收集样本。使用 16 S 核糖体 RNA 基因测序确定细菌微生物群落组成和结构，并与临床重要变量相关。 结果: 出院时以及阿奇霉素治疗 1 年和 2 年后，未观察到微生物群落组成或总体多样性的明显差异。此外，在复合表型中未观察到微生物组成的变化。然而，急性排斥反应与社区多样性降低相关 (p = 0.0009)。在微生物群组成、总体多样性和支气管肺泡灌洗中炎性细胞因子水平之间观察到显著的相关性，特别是 cxcl8。 结论: 慢性使用阿奇霉素对细菌菌群无影响。然而，急性排斥反应发作与细菌生态失调有关。
METHODS:BACKGROUND AND PURPOSE:A critical role for sphingosine kinase/sphingosine-1-phosphate (S1P) pathway in the control of airway function has been demonstrated in respiratory diseases. Here, we address S1P contribution in a mouse model of mild chronic obstructive pulmonary disease (COPD). EXPERIMENTAL APPROACH:C57BL/6J mice have been exposed to room air or cigarette smoke up to 11 months and killed at different time points. Functional and molecular studies have been performed. KEY RESULTS:Cigarette smoke caused emphysematous changes throughout the lung parenchyma coupled to a progressive collagen deposition in both peribronchiolar and peribronchial areas. The high and low airways showed an increased reactivity to cholinergic stimulation and α-smooth muscle actin overexpression. Similarly, an increase in airway reactivity and lung resistances following S1P challenge occurred in smoking mice. A high expression of S1P, Sph-K2 , and S1P receptors (S1P2 and S1P3 ) has been detected in the lung of smoking mice. Sphingosine kinases inhibition reversed the increased cholinergic response in airways of smoking mice. CONCLUSIONS AND IMPLICATIONS:S1P signalling up-regulation follows the disease progression in smoking mice and is involved in the development of airway hyperresponsiveness. Our study defines a therapeutic potential for S1P inhibitors in management of airways hyperresponsiveness associated to emphysema in smokers with both asthma and COPD.
METHODS::The interim results from this 90-day multi-dose, inhalation toxicology study with life-time post-exposure observation has shown an important fundamental difference in persistence and pathological response in the lung between brake dust derived from brake-pads manufactured with chrysotile, TiO2 or chrysotile alone in comparison to the amphiboles, crocidolite and amosite asbestos. In the brake dust exposure groups no significant pathological response was observed at any time. Slight macrophage accumulation of particles was noted. Wagner-scores, were from 1 to 2 (1 = air-control group) and were similar to the TiO2 group. Chrysotile being biodegradable, shows a weakening of its matrix and breaking into short fibers & particles that can be cleared by alveolar macrophages and continued dissolution. In the chrysotile exposure groups, particle laden macrophage accumulation was noted leading to a slight interstitial inflammatory response (Wagner-score 1-3). There was no peribronchiolar inflammation and occasional very slight interstitial fibrosis. The histopathology and the confocal analyses clearly differentiate the pathological response from amphibole asbestos, crocidolite and amosite, compared to that from the brake dust and chrysotile. Both crocidolite and amosite induced persistent inflammation, microgranulomas, and fibrosis (Wagner-scores 4), which persisted through the post exposure period. The confocal microscopy of the lung and snap-frozen chestwalls quantified the extensive inflammatory response and collagen development in the lung and on the visceral and parietal surfaces. The interim results reported here, provide a clear basis for differentiating the effects from brake dust exposure from those following amphibole asbestos exposure. The subsequent results through life-time post-exposure will follow.
METHODS::The respiratory tract is lined by a pseudo-stratified epithelium from the nose to terminal bronchioles. This first line of defense of the lung against external stress includes five main cell types: basal, suprabasal, club, goblet and multiciliated cells, as well as rare cells such as ionocytes, neuroendocrine and tuft/brush cells. At homeostasis, this epithelium self-renews at low rate but is able of fast regeneration upon damage. Airway epithelial cell lineages during regeneration have been investigated in the mouse by genetic labeling, mainly after injuring the epithelium with noxious agents. From these approaches, basal cells have been identified as progenitors of club, goblet and multiciliated cells, but also of ionocytes and neuroendocrine cells. Single-cell RNA sequencing, coupled to lineage inference algorithms, has independently allowed the establishment of comprehensive pictures of cell lineage relationships in both mouse and human. In line with genetic tracing experiments in mouse trachea, studies using single-cell RNA sequencing (RNAseq) have shown that basal cells first differentiate into club cells, which in turn mature into goblet cells or differentiate into multiciliated cells. In the human airway epithelium, single-cell RNAseq has identified novel intermediate populations such as deuterosomal cells, 'hybrid' mucous-multiciliated cells and progenitors of rare cells. Novel differentiation dynamics, such as a transition from goblet to multiciliated cells have also been discovered. The future of cell lineage relationships in the respiratory tract now resides in the combination of genetic labeling approaches with single-cell RNAseq to establish, in a definitive manner, the hallmarks of cellular lineages in normal and pathological situations.