Identification of miRNAs Potentially Involved in Bronchiolitis Obliterans Syndrome: A Computational Study

The pathogenesis of Bronchiolitis Obliterans Syndrome (BOS), the main clinical phenotype of chronic lung allograft dysfunction, is poorly understood. Recent studies suggest that epigenetic regulation of microRNAs might play a role in its development. In this paper we present the application of a complex computational pipeline to perform enrichment analysis of miRNAs in pathways applied to the study of BOS. The analysis considered the full set of miRNAs annotated in miRBase (version 21), and applied a sequence of filtering approaches and statistical analyses to reduce this set and to score the candidate miRNAs according to their potential involvement in BOS development. Dysregulation of two of the selected candidate miRNAs–miR-34a and miR-21 –was clearly shown in in-situ hybridization (ISH) on five explanted human BOS lungs and on a rat model of acute and chronic lung rejection, thus definitely identifying miR-34a and miR-21 as pathogenic factors in BOS and confirming the effectiveness of the computational pipeline.

闭塞性细支气管炎综合征（Bronchiolitis Obliterans Syndrome, BOS）是慢性肺移植功能障碍的主要临床表型，其发病机制迄今尚未完全阐明。近期研究表明，微小核糖核酸（microRNAs, miRNAs）的表观遗传调控可能参与其发病进程。本文介绍了一套复杂计算流程的应用，该流程针对闭塞性细支气管炎综合征的研究开展通路层面的微小核糖核酸富集分析。本次分析以miRBase（版本21）数据库中注释的全部微小核糖核酸作为初始数据集，通过一系列筛选方法与统计学分析对其进行筛选缩减，并依据候选微小核糖核酸参与闭塞性细支气管炎综合征发病的潜在可能性进行评分。通过对5例移植后发生闭塞性细支气管炎综合征的人类离体肺组织以及急性与慢性肺排斥反应大鼠模型进行原位杂交（in-situ hybridization, ISH）实验，明确观察到筛选出的2种候选微小核糖核酸——miR-34a与miR-21——存在表达失调现象，从而确凿证实miR-34a与miR-21为闭塞性细支气管炎综合征的致病因子，并验证了该计算流程的有效性。