Figure 2. MiR-199a-3p overexpression prevents MPP+-induced cellular toxicity. (A) The flow cytometry assay was performed to evaluate the apoptosis of SH-SY5Y and PC-12 cells that were treated with 1 mM MPP+ and transfected with the miR-199a-3p mimics, miR-199a-3p inhibitor, mimics NC or inhibitor NC. (B) Apoptotic cells in the different groups were compared. (C) The CCK-8 assay was performed to evaluate the viability of SH-SY5Y and PC-12 cells. (D) The cell cycle phases were determined by propidium iodide staining and flow cytometry. (E) Comparison of the cell cycle analysis results for the different groups. (F) TUNEL staining was conducted to assess SH-SY5Y and PC-12 cell apoptosis. (G) Immunofluorescence staining was performed to monitor the distribution of TUBB3 in MES23.5 cells. (H) Western blot and (I) qPCR results showed that miR-199a-3p overexpression reduced LRRK2 and α-synuclein expression at both the protein and mRNA levels, which were promoted by MPP+ treatment. The data are representative of three experiments. *p <0.05, **p <0.01 and ***p <0.001.