Elevated constitutive expression of Hsp40 chaperone Sis1 reduces TDP-43 aggregation-induced oxidative stress in Ire1 pathway dependent-manner in yeast TDP-43 proteinopathy model of amyotrophic lateral sclerosis

Oxidative stress is a therapeutic target in TDP-43 proteinopathies like amyotrophic lateral sclerosis (ALS) and FTLD-TDP. TDP-43 over-expression causes oxidative stress in yeast model of ALS. Previously, we developed a red/white color conversion reporter assay using ade1 or ade2 mutant yeast to examine oxidative stress induced by expression of amyloidogenic proteins. Also, a previous study showed that overexpression of yeast Hsp40 chaperone Sis1 could mitigate the toxicity and proteosomal blockage induced by TDP-43 over-expression. Here, using the red/white reporter yeast assay and also by CellROXstaining, we found that an elevated expression of Sis1 mitigates the TDP-43-induced oxidative stress. Furthermore, as redox signalling and the ER stress response pathways cross-talk, we checked if the Sis1mediated mitigation of the TDP-43-induced oxidative stress can also be observed in yeast deleted for ER stress response gene, IRE1. We find that in the yeast deleted for the IRE1 gene, the elevated expression of Sis1 fails to neutralize the TDP-43-induced oxidative stress. Taken together, Hsp40 chaperone modulation can be further examined towards therapeutic research on the TDP-43 proteinopathies. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study found that the elevated expression of Hsp40 chaperone Sis1 can mitigate the oxidative stress induced by TDP-43 proteinopathy in a yeast model. The mitigation effect of Sis1 on oxidative stress is dependent on the ER stress response pathway.