Figure 3

The Oxidoreductase Activity of PDI Is Protective against TDP-43 Mislocalization to the Cytoplasm

(A) Neuro-2a cells expressing EGFP-tagged TDP-WT (row 1), TDP-M337V with empty vector (row 2), co-expressing PDI-WT or PDI-QUAD, or treated with BMC (rows 3, 4, 5), arrows repesent mislocalised TDP-43.

(B) Expression of PDI-WT (∗∗p < 0.01) or administration of BMC (∗p < 0.05) to mutant TDP-M337V-expressing cells significantly reduced the proportion of cells displaying cytoplasmic TDP-43. A significant difference in cells expressing cytoplasmic TDP-43 was observed between PDI-WT and PDI-QUAD (∗∗p < 0.01), and between PDI-QUAD and BMC (∗p < 0.05).

(C) Primary neurons expressing TDP-WT (row 1), TDP-M337V with empty vector (row 2), co-expressing PDI-WT or PDI-QUAD, or treated with BMC (rows 3, 4, 5), arrows repesent mislocalised TDP-43.

(D) Over-expression of PDI-WT (∗∗p < 0.01) or BMC treatment (∗p < 0.05) in mutant TDP-M337V-expressing cells significantly reduced the proportion of cells displaying cytoplasmic TDP-43. There was also a significant difference between TDP-M337V cells co-expressing PDI-WT and those co-expressing PDI-QUAD (∗p < 0.05).

(E) Neuro-2a cells expressing mCherry-tagged TDP-WT (row 1), TDP-Q331K (row 2), or co-expressing PDI-WT or PDI-QUAD, or treated with BMC (rows 3, 4, 5), arrows repesent mislocalised TDP-43

(F) Expression of PDI-WT or treatment with BMC (∗∗∗p < 0.001) in mutant TDP-Q331K-expressing cells significantly reduced the proportion of cells displaying cytoplasmic TDP-43, compared with cells expressing empty vector only. A significant difference was observed between PDI-WT and PDI-QUAD, and between PDI-QUAD and BMC treated cells (∗p < 0.05).

Scale bars: 10 μm in (A) and (E), 5 μm in (C).