[miR-199a-5p inhibits the proliferation of rat airway smooth muscle cells and the expression of hypoxia inducible factor 1 alpha under hypoxia conditions].

OBJECTIVE

To investigate the expression of miR-199a-5p in airway smooth muscle cells (ASMCs) of rats in normoxia and hypoxia and its role in the regulation of proliferation and the expression of hypoxia inducible factor 1 alpha (HIF-1α) of ASMCs.

METHODS

ASMCs were prepared by means of adherent culture in vitro. After ASMCs were cultured under normoxia and hypoxia conditions for 24 hours, the content of miR-199a-5p was detected by real-time quantitative PCR (qRT-PCR). The mimic or inhibitor of miR-199a-5p were artificially synthesized and transferred into ASMCs in hypoxia via liposomes. The expressions of miR-199a-5p and HIF-1α mRNA were detected by qRT-PCR. Western blotting and CCK-8 assay were applied to detect the expression levels of HIF-1α protein and the proliferation of ASMCs, respectively.

RESULTS

Compared with the normoxia group, hypoxia significantly promoted cell proliferation and increased the levels of HIF-1α mRNA and protein. The level of miR-199a-5p decreased in the hypoxia group compared with the normoxia group. The proliferation rate of ASMCs under hypoxia conditions was significantly attenuated by transfection of miR-199a-5p mimic, while it was significantly lifted by transfection of miR-199a-5p inhibitor. Compared with control group, the expression of HIF-1α protein was reduced in the mimic group and raised in the inhibitor group. There was no significant difference in the content of HIF-1α mRNA among groups under hypoxia conditions.

CONCLUSION

miR-199a-5p can inhibit the proliferation of ASMCs and the expression of HIF-1α protein in vitro under hypoxia conditions.