miR-424 protects PC-12 cells from OGD-induced injury by negatively regulating MKP-1

Y.-X. Cao, Z.-Q. Wang, J.-X. Kang, K. Liu, C.-F. Zhao, Y.-X. Guo, B.-H. Jiao

Department of Neurosurgery, The Second Hospital of Hebei Medical University, Shijiazhuang, China. jiaobaohua456@126.com

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• Neurology

OBJECTIVE: It’s of great significance to investigate the novel targets of drugs for the treatment of stroke. In this study, we explored the neuroprotective role of miR-424 in oxygen glucose deprivation (OGD)-induced injuries in PC-12 cells.

MATERIALS AND METHODS: PC-12 cells were subjected to OGD stimulation to mimic ischemic injury. The expressions of miR-424 and mitogen-activated protein kinase phosphatase-1 (MKP-1) were altered by transient transfection with miR-424 mimic, miR-424 inhibitor, pEX-MKP-1, or sh-MKP-1. Cell counting kit-8 (CCK-8) assay, flow cytometry, and quantitative reverse transcription polymerase chain reaction (qRT-PCR), were conducted to respectively detect cell viability, apoptotic cells, and the expression of miR-424 and MKP-1. The protein expressions of several factors were determined by Western blot. Meanwhile, relative luciferase activity assay was done to verify the predicted targets association.

RESULTS: OGD induced injury in PC-12 cells by suppressing cell viability and inducing apoptosis. OGD also induced the expression of miR-424 in PC-12 cells. Overexpression of miR-424 protected PC-12 cells from OGD-induced injury by increasing cell viability and decreasing apoptosis. MKP-1 was a direct target of miR-424, and its expression was negatively regulated by miR-424. Up-regulation of expression of MKP-1 aggravated OGD-induced cell injury by inhibiting the expression of hypoxia-inducible factor 1α (HIF-1α), thus inhibiting the PI3K/AKT/mTOR pathways.

CONCLUSIONS: miR-424 protected PC-12 cells from OGD-induced injury through direct suppression of MKP-1 expression, as MKP-1 promoted OGD-induced cell injury by inhibiting the expression of HIF-1α and PI3K/AKT/mTOR pathways.

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