The potential role of microRNAs in lung allograft rejection.

Lung transplantation (LT) has proven to be successful in carefully selected individuals with end-stage lung disease. However, long-term graft survival post-LT is often hindered by the development of the bronchiolitis obliterans syndrome (BOS). Because BOS represents is a major problem for all LT centers, early identification and prediction of progressive loss of lung function is a major goal. MicroRNAs (miRNAs) play a major role in regulating many cellular functions, including epithelial-to-mesenchymal transition. miRNAs are emerging not only as biomarkers but also as potential therapy. The recognized importance of injured human bronchial epithelium in lung allograft dysfunction indicates that there is a need for research into the potential role of miRNAs. In this we review we summarize published findings in miRNAs implicated in lung and other types of allograft dysfunction and their role in maintaining the phenotype of epithelial cells after transplant injury. We also address potential clinical interventions that involve manipulating miRNA expression that may promote long-term airway integrity and graft survival.