RESUMO
<p><b>OBJECTIVE</b>To Investigate the biological effects of miR-144 in rats' pulmanory injury induced by nanosized SiO₂preliminarily.</p><p><b>METHOD</b>150 healthy SD rats were divided into five groups randomly: the control group, the nanosized SiO₂groups of 6.25, 12.5, 25.0 mg/ml, and the microsized SiO₂group of 25.0 mg/ml, 30 rats each group. Six rats were sacrificed for their pathological change on the 7th, 15th, 30th, 60th and 90th day after exposure. The expression levels of mature miR-144 in lung tissue of the rats after instilled intracheally nanosized SiO₂at 90d was detected by Quantitative Reverse Transcription PCR. Target prediction for miR-144 was conducted by databases of Target-scan, microRNA.org and miRDB. Function-significant enrichment analysis and signal pathway analysis for predicted target genes were respectively conducted by the Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes, then target genes related to pulmonary fibrosis were screened out.</p><p><b>RESULTS</b>The expression of miR-144 was up-regulated in lung tissue of rats exposed to nanosized SiO₂. The result was consistent with the results of high-throughput sequencing Hiseq 2000. The target genes of miR-144 related to fibrosis or signal pathway involved in fibrosis were screened out.They are SMAD4, SMAD5, ADAMTS3, ADAMTS15 and ADAMTS19.</p><p><b>CONCLUSION</b>MiR-144 probably participate in the regulation of fibrosis, which may play an important role in pulmonary injury induced by nanosized SiO₂.</p>