(a) Transgenic yeast which overexpresses the TDP-43 peptide. NoTox = low expression, TDP-43; IntTox = intermediate expression, TDP-43 aggregation seen as clumps of GFP-TDP43; HiTox = high expression, TDP-43 in larger clumps and increased death of yeast. Arrows demarcate the inclusion granules of TDP-43 (Susan Lindquist, MIT). (b) OPP significantly reduces the cytotoxicity of the aggregated neuropeptides in the transgenic yeast rescue assay. Bar heights represent percent growth relative to control strain. OPP doubles the growth for β-amyloid-producing yeast from 20% (without OPP) to 40% (with OPP); more than doubles the growth for Huntingtin-producing yeast from 25% (without OPP) to 60% (with OPP). OPP increases the growth of TDP-43-producing yeast more than 6-fold from 25% (without OPP) to 190% (with OPP). There is no significant change in the growth of the α-synuclein-producing yeast with or without OPP. OPP dose was 10 μg/ml for the 4 peptide-producing transgenic yeasts.