[Expression of miR-29a in serum of patients with pulmonary tuberculosis and prediction of its function with bioinformatics analysis].

Objective: To analyze the expression of miR-29a in serum of patients with pulmonary tuberculosis, and to predict and analyze function of its target genes for further studying of its biological function and regulatory mechanism in tuberculosis (TB).

Methods: Fasting venous blood samples were collected from 65 untreated patients with active pulmonary TB (case group) and 45 healthy controls (control group) in the morning, respectively, and then sera were isolated. Total RNA was extracted with TRIzol reagent and was further purified. RNA quality was measured by gel electrophoresis and ultraviolet spectrophotometer. Nucleic acid hybridization and real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were performed to investigate expression of miR-29a in serum. Both TargetSean and PicTar software were used to predict comprehensively target genes of miR-29a and their intersection was regarded as target genes of miR-29a. Gene ontology of target genes was analyzed with DAVID database and three category annotations were extracted, respectively. GO overrepresentation was further analyzed by BINGO of Cytoscape. Enriched pathways of target genes were analyzed.

Results: The hybridization result showed that miR-29a was increased in serum of the case group (854 ± 93) compared to the control group (80 ± 22) (t = 3.541, P < 0.05). The PCR result showed that compared to the control group (0.18 ± 0.07), miR-29a was increased in serum of the case group (1.35 ± 0.62) (t = 2.987, P < 0.05). The target genes were mainly involved in biological processes including regulation of transcription, molecular function including metal ion binding, and cellular components including extracellular matrix, respectively. In the KEGG pathway, the target gene set was significantly enriched in the 7 signaling pathways including adhesion, ECM-receptor interaction and so on. In the PANTHER pathway, the gene set mostly existed in integrin signaling pathway, cadherin signaling pathway and Wnt signaling pathway.

Conclusions: Level of miR-29a was increased significantly in serum of patients with active pulmonary tuberculosis. Target genes of miR-29a were mainly involved in biological processes including cell adhesion, regulation of transcription and so on.