Induction of cytosolic TDP-43 accumulation and SGs by paraquat in SH-SY5Y cells. Cells were exposed overnight to 1 mM paraquat and TDP-43 localization was examined by immunofluorescence. A-C: untreated, D-I: paraquat treated. Arrows show loss of nuclear TDP-43. Arrowheads show diffuse cytosolic TDP-43. Green = TDP-43, blue = DAPI. Right-hand panels = merged images. J-Q: Cells were exposed to 1 mM paraquat overnight and TDP-43 and HuR localization was measured by immunofluorescence. J-M: untreated, N-Q: paraquat treated. Green = TDP-43, Red = HuR, Blue = DAPI. M and Q are merged images from TDP-43 and HuR panels. Arrows indicate stress granules. Inset shows higher magnification of TDP-43 and HuR positive SGs. Bar = 10 μm. Representative images from four separate experiments performed in duplicate or triplicate.