TPI Df is a devastating untreatable childhood metabolic disease resulting in anemia, paralysis, irreversible
brain damage and premature death. Numerous single amino acid substitutions in Triosephosphate
Isomerase (TPI) are pathogenic and result in rapidly progressing multisystem disease. Importantly, all
known pathogenic TPI Df mutations result in a protein that retains function and pathogenesis is known to
result from increased turnover of the functioning protein by Protein Quality Control pathways (PQC). We
have developed a human cellular TPI Df assay based on a cellular model of the “common” E104D mutation
and implemented it for high-content, high-throughput imaging. We have used this model in a pilot screen
and validated its utility to identify novel compounds that modulate mutant TPI protein levels in human cells.
We propose to develop the assay to full HTS standards, conduct a screen of several relevant compound
libraries, and identify first-in-class TPI Df small molecule therapies. We will validate hits in secondary
assays for TPI stability and activity in TPI Df patient cells, prioritize them in a panel of in vitro toxicology
and metabolic stability assays, examine structure activity relationships (SARs) of the lead compounds and
substantially validate them in vivo using a recently developed mouse TPI Df model. Overall this project will
discover and validate the first ever treatments for TPI Df that will provide the basis for clinical trials.