[Expression and function prediction of miR-618 in sputa and sera of patients with pulmonary tuberculosis]

To measure the level of miR-618 in sputa and sera from the patients with pulmonary tuberculosis, determine the concentration of IL-13 which is a cytokine encoded by target gene of miR-618, and predict the function of miR-618 with bioinformatics.

Sputum and serum samples were collected from the healthy controls and the patients with active pulmonary tuberculosis, respectively. Level of miR-618 was measured by nucleic acid hybridization and real-time quantitative RT-PCR(qRT-PCR). Concentration of IL-13 was determined by ELISA. Target genes of miR-618 were predicted with TargetSean, and GO annotation and biological pathway of the target genes were analyzed with DAVID database and BINGO of Cytoscape.

Both hybridization and qRT-PCR results showed that level of miR-618 in both sputa and sera obviously decreased in the tuberculosis group compared to the control group (P<0.05). There was no statistical difference in IL-13 concentration between the tuberculosis group and the control group, however, it had an increasing tendency in the former. GO annotation of predicted target genes of miR-618 was enriched in biological processes such as regulation of transcription and molecular functions such as DNA binding (P<0.05). In KEGG pathway, the predicted target genes mostly existed in TGF-β signaling pathway (P<0.05).

Level of miR-618 in both sputa and sera was significantly lower in the tuberculosis group than that in the control group and predicted target genes of miR-618 were mainly involved in biological processes such as regulation of transcription and RNA metabolism.