Peptidomimetics Activating the Proteasome: A New Perspective for Parkinson's Treatment.

The development of age-related neurodegenerative diseases is associated with the accumulation of damaged and misfolded proteins. Such proteins are eliminated from cells by proteolytic systems, mainly by 20S proteasomes, whose activity declines with age. Its stimulation has been recognized as a promising approach to delay the onset or ameliorate the symptoms of neurodegenerative disorders. Here we present peptidomimetics that are very effective in stimulating the proteasome in biochemical assays and in cell culture. They are stable in human plasma and capable of penetrating the cell membranes. The activators demonstrated the ability to enhance h20S degradation of α-synuclein and tau, whose aggregates are involved in the development of Parkinson's and Alzheimer's diseases, respectively. The peptidomimetics did not show cytotoxicity to HEK293T and primary hippocampal cells. Additionally, these compounds were highly effective in reducing the amount of phosphorylated α-synuclein aggregates in hippocampal neurons in a mouse embryonic cell model.