MiR-7 inhibits MPP+-induced cell death by targeting RelA. A, Silencing RelA expression protects against MPP+-induced cell death, but not against A23817. SH-SY5Y cells were transfected with either siRNA-NT or siRNA-RelA and treated with 2 mm MPP+ or 2 μm A23187 for 24 h, and cell survival was measured. Silencing RelA expression by siRNA-RelA was confirmed by Western blot analysis. B, Knockdown of RelA expression protects against MPP+-induced cell death in differentiated ReNcell VM cells. Cells infected with lenti-shRNA-RelA or lenti-shRNA-control were challenged with MPP+, and survival was measured. Knocking down RelA expression by lenti-shRNA-RelA was confirmed by Western blot analysis. C, Overexpression of RelA mRNA without its 3′-UTR prevents miR-7-mediated cytoprotection. SH-SY5Y cells were cotransfected with Flag-RelA (without 3′-UTR) in the presence of miR-7 or miR-SC. Cell survival after treatment with 2 mm MPP+ for 24 h was assessed. Repression of RelA expression by miR-7 and its overexpression by transfection were confirmed by Western blot analysis. *p < 0.05, **p < 0.01.