Figure 7. Sp1 overexpression inhibits the neural protective function of shXIST and aggravates MPP+-induced neurodegeneration. SH-SY5Y and PC-12 cells were transfected with shNC, shXIST or the Sp1 overexpression vector and treated with 1 mM MPP+. The expression of (A) XIST, (B) miR-199a-3p, (C) Sp1 and LRRK2 mRNA was determined by qPCR analysis. (D) Western blot analysis was performed to analyse the protein expression of Sp1, LRRK2 and α-synuclein under the specific conditions. (E) Flow cytometry analysis of apoptosis was performed after the cells were transfected with shXIST and/or Sp1. (F) Comparison of apoptotic cells in the indicated groups. (G) TUNEL staining was performed to measure the apoptosis rate of the SH-SY5Y and PC-12 cells after they were transfected with shXIST alone or co-transfected with Sp1. (H) The CCK-8 assay was performed to assess cell viability. (I) MES23.5 cells were transfected with shNC, shXIST or Sp1 and treated with 1 mM MPP+. The localization of TUBB3 in MES23.5 cells is shown in the representative images. (J) Cell cycle phases were determined by propidium iodide staining and flow cytometry after the cells were transfected with shXIST alone or co-transfected with Sp1. (K) The cell cycle results for the different groups were compared. The data are representative of three experiments. *p <0.05, **p <0.01 and ***p <0.001.