miR-126-5p Targets SP1 to Inhibit the Progression of Parkinson's Disease.

Background: At present, symptomatic treatment may improve the life quality of Parkinson's disease (PD) patients to a certain extent but cannot completely cure PD. Therefore, it is urgent medical problem to be solved for improving the efficacy and safety of PD treatment.

Methods: SH-SY5Y and SK-N-SH cells were treated with 1-methyl-4-phenylpyridinium (MPP+) to establish PD model cells. miR-126-5p and specific protein-1 (SP1) expression levels were detected by quantitative Real-Time PCR (qRT-PCR). Western blot was applied to measure protein levels of SP1, Bax, and Bcl-2. The viabilities and apoptosis rates of treated cells were measured using cell counting kit-8 assay and flow cytometry analysis. Enzyme-linked immunosorbent assay was performed to measure TNF-α and IL-1β releases. Interaction between miR-126-5p and SP1 was examined by dual-luciferase reporter assay.

Results: MPP+ treatment greatly downregulated miR-126-5p expression while upregulated SP1 expression in SH-SY5Y and SK-N-SH cells in a time- and does-dependent manner. Overexpression of miR-126-5p facilitated cell viability, while reduced cell apoptosis and inflammatory responses induced by MPP+ treatment. Moreover, SP1 was a target of miR-126-5p and could be negatively regulated by miR-126-5p. Overexpression of SP1 could reverse the effects of miR-126-5p on MPP+-administrated cells.

Conclusion: Our results suggested that miR-126-5p attenuated the neurotoxicity induced by MPP+ in vitro through targeting SP1 (Graphical abstract), which further enhanced our understanding of the pathological mechanism of PD.