Biomedical Research

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The role of miR-21 and its predicted target gene, PTEN, in the development of ventilator associated pneumonia

Aims: This study is to analyse the role and mechanism of PTEN in patients with Ventilator-Associated Pneumonia (VAP).

Methods: Alveolar Macrophages (AMs), serum and peripheral blood monocytes were collected from 69 patients with hospital-acquired VAP during the treatment of lung trauma between June, 2012 and July, 2015. Normal samples from 53 healthy people were collected as control group. The levels of PTEN mRNA expression in these samples were examined by quantitative Real-time PCR, while PTEN protein levels were analysed by Western Blot and ELISA. MiRNAs that regulate PTEN expression was predicted by bioinformatics analysis, and the expression of predicted miRNA was measured by quantitative Real-time PCR.

Results: Compared with healthy controls, PTEN was significantly downregulated at both mRNA and protein levels in AMs, serum and peripheral blood monocytes from patients with VAP (P<0.05). MiR-21 was predicted to bind to the 3’UTR of PTEN mRNA, and miR-21 expression was significantly upregulated in samples from SAP patients (P<0.05).

Conclusion: The downregulation of PTEN expression in VAP patients may be directly regulated by the upregulation of miR-21. MiR-21 might affect the function of macrophages by regulating the expression of PTEN, and therefore contribute to the development of VAP.

Author(s): Zhen Wang, Yisheng Zheng, Zhenjian Fang, Yuan Zhang