Fig. 5.

Overexpression of Pur α suppresses rGGGGCC repeat-mediated neurodegeneration. (A) Pur α overexpression attenuates rGGGGCC repeat-mediated cell death in Neuro-2a cells. Neuro-2a cells were cotransfected using GGGGCC repeat-expressing constructs and Pur α or hnRNP A2/B1 expression vectors. A significant reduction in cell viability was seen for Neuro-2a cells transfected with the (GGGGCC)₃₀ construct and pcDNA control vector compared with cells transfected with the (GGGGCC)₃ construct or control EGFP expression vector (P < 0.0001, t test). Pur α overexpression in the presence of (GGGGCC)₃₀ construct resulted in significantly greater cell viability (P = 0.0041, t test). (B) Light (top) and electron (middle and bottom) microscopy of flies overexpressing Pur α and rGGGGCC repeats in the fly eye. (Left) Flies expressing (GGGGCC)₃₀-EGFP. (Right) Flies expressing (GGGGCC)₃₀-EGFP and Pur α. (C) Knockdown of Pur α induces cell death in Neuro-2a cells. Transient transfection of siRNA against Pur α significantly reduced Pur α mRNA levels (Left) (P < 0.0001, t test), as detected by qRT-PCR, and cell viability (Right) (P = 0.0022, t test).