Altered microRNAs expression profiling in experimental silicosis rats.

MicroRNAs (miRNAs) are 19~24 nt non-coding RNA molecules that regulate expression of target genes at the post-transcriptional level. Evidence indicates that miRNAs play an essential role in physiological and pathological conditions including pulmonary development, inflammation, fibrosis and cancer. The aim of the present study is to investigate the altered miRNAs expression profile in rats with experimental silicosis. We duplicated silicosis rat model, and identify the miRNA expression pattern of silicosis rat with miRNA microarray. Compared with normal lung tissue, fourteen miRNAs were found significantly up-regulated while the other twenty-five down-regulated in silicosis samples. The differential expression of two selected miRNAs was confirmed by stem-loop real-time reverse transcription-polymerase chain reaction. Our results indicate that the 39 altered miRNAs may be involved in lung fibrosis of rats that were exposed to silica dust. Furthermore, the microarray results provide a solid basis for further validation, such as identification of other miRNAs that may be related to inflammation and fibrosis. The findings are paving way for silicosis early prevention, prognosis and possible therapy.