Telethon Kids Institute, Centre for Health Research, The University of Western Australia, Perth, WA, Australia.
Advanced Lung Disease Unit, Fiona Stanley Hospital, Perth, WA, Australia.
Transplantation. 2020 Jun;104(6):1166-1176. doi: 10.1097/TP.0000000000003134.
Dysregulated airway epithelial repair following injury is a proposed mechanism driving posttransplant bronchiolitis obliterans (BO), and its clinical correlate bronchiolitis obliterans syndrome (BOS). This study compared gene and cellular characteristics of injury and repair in large (LAEC) and small (SAEC) airway epithelial cells of transplant patients.
Subjects were recruited at the time of routine bronchoscopy posttransplantation and included patients with and without BOS. Airway epithelial cells were obtained from bronchial and bronchiolar brushing performed under radiological guidance from these patients. In addition, bronchial brushings were also obtained from healthy control subjects comprising of adolescents admitted for elective surgery for nonrespiratory-related conditions. Primary cultures were established, monolayers wounded, and repair assessed (±) azithromycin (1 µg/mL). In addition, proliferative capacity as well as markers of injury and dysregulated repair were also assessed.
SAEC had a significantly dysregulated repair process postinjury, despite having a higher proliferative capacity than large airway epithelial cells. Addition of azithromycin significantly induced repair in these cells; however, full restitution was not achieved. Expression of several genes associated with epithelial barrier repair (matrix metalloproteinase 7, matrix metalloproteinase 3, the integrins β6 and β8, and β-catenin) were significantly different in epithelial cells obtained from patients with BOS compared to transplant patients without BOS and controls, suggesting an intrinsic defect.
Chronic airway injury and dysregulated repair programs are evident in airway epithelium obtained from patients with BOS, particularly with SAEC. We also show that azithromycin partially mitigates this pathology.
损伤后气道上皮修复失调被认为是导致移植后细支气管炎性细支气管闭塞（BO）及其临床相关疾病闭塞性细支气管炎综合征（BOS）的一种机制。本研究比较了移植患者大（LAEC）和小（SAEC）气道上皮细胞损伤和修复的基因和细胞特征。
在移植后常规支气管镜检查时招募受试者，包括有和没有 BOS 的患者。通过影像学引导从这些患者的支气管和细支气管刷检中获得气道上皮细胞。此外，还从因非呼吸系统相关疾病接受择期手术的青少年健康对照者的支气管刷检中获得支气管刷检。建立原代培养物，单层细胞划痕，评估（±）阿奇霉素（1μg/ml）修复情况。此外，还评估了增殖能力以及损伤和失调修复的标志物。
尽管 SAEC 的增殖能力高于大气道上皮细胞，但在损伤后其修复过程明显失调。加入阿奇霉素可显著诱导这些细胞的修复，但未完全恢复。与无 BOS 的移植患者和对照组相比，来自 BOS 患者的上皮细胞中，与上皮屏障修复相关的几个基因（基质金属蛋白酶 7、基质金属蛋白酶 3、整合素β6 和β8 以及β-连环蛋白）的表达明显不同，提示存在固有缺陷。
在来自 BOS 患者的气道上皮细胞中，可明显观察到慢性气道损伤和失调的修复程序，特别是在 SAEC 中。我们还表明，阿奇霉素部分减轻了这种病理。
