Affinity-Based Protein Profiling Revealed that HIGD1A is a Direct Target Protein of Aristolochic Acids.

Exposure to aristolochic acids (AA) via the ingestion of AA-containing medicine or food is a significant risk factor for severe nephropathy. Despite decades of research, the direct molecular targets underlying AA toxicity remain elusive. In this study, a map of the AA-binding protein atlas in kidney tissues is constructed via the design and synthesis of an AA-based affinity probe. Among the AA-binding proteins, HIGD1A is identified as a high-affinity AA target (SPR: 59.6 nm; ITC: 195 nm) with significant thermostability changes upon AA binding. Furthermore, AA disrupted the HIGD1A-TFAM interaction, triggering TFAM degradation via the autophagy-lysosome pathway. This led to the accumulation of cytosolic mitochondrial DNA. This study also suggested that HIGD1A also contributed to AA-induced inflammation by increasing the cytosolic levels of oxidized mitochondrial DNA to activate the MAPK and NF-κB pathways. This study not only reveals an important target protein of AA but also provides novel inspiration and ideas for toxicology and chemical biology research.