Endogenous MIF inhibits the association of misfolded SOD1 with spinal cord intracellular membranes. (A) Schematic drawing of the protocol used to test whether the deletion of endogenous MIF in SOD1G85R mice enhances the association of the mutant SOD1G85R with mitochondria and ER membranes. (B, D, E, and G) Immunoblotting of spinal cord mitochondria (B), spinal cord ER (E), liver mitochondria (D), and liver ER (G) recovered from SOD1G85R/MIF+/+ (WT) or SOD1G85R/MIF−/− (KO) mice, as detailed in A, and assayed for the presence of mutant SOD1 in these fractions at disease onset or in its symptomatic stages. Immunoblots were probed with an anti-hSOD1 antibody. Immunoblotting for VDAC1 was used to verify the amount of mitochondria added/recovered. Ponceau staining was used to verify the amount of ER membranes recovered. (C and F) Quantitative analysis of mutant SOD1 associated with spinal cord mitochondria and ER performed from triplicates analyzed from two or three different mice (for each genotype at each disease stage) using ImageJ software and Student’s t test. *P < 0.05.