LncRNA XIST, miR-199a-3p, Sp1 and LRRK2 expression in an in vitro model of PD. (A) MPP+ was added to the cells to final concentrations of 0, 0.1, 0.2, 0.4, 0.6, 0.8 or 1 mM. Cell viability was determined using the CCK-8 assay after 24 and 48 h. (B) Flow cytometry analysis was performed to measure the apoptosis of SH-SY5Y and PC-12 cells, which were treated with 0, 0.2, 0.6, or 1 mM of MPP+. (C) Comparison of apoptotic cells in different groups. (D–G) Relative expression of (D) XIST, (E) miR-199a-3p, (F) Sp1 mRNA and (G) LRRK2 mRNA in the above groups of cells were determined by qPCR analysis. (H) Western blot results showed that the protein levels of Sp1, LRRK2 were elevated when the cells were treated with MPP+. GAPDH was used as a loading control. The data are representative of three experiments. *p <0.05, **p <0.01 and ***p <0.001.