Aristolochic acid nephropathy (AAN) is characterized by acute proximal tubule necrosis and immune cell infiltration, contributing to the global burden of chronic kidney disease and urothelial cancer. Although the proximal tubule has been defined as the primary target of aristolochic acids I (AAI), the mechanistic underpinning of gross renal deterioration caused by AAI has not been explicitly explained, prohibiting effective therapeutic intervention. To this point, we employed integrated single-cell RNA-sequencing, bulk RNA-sequencing, and mass spectrometry-based proteomics to analyze mouse kidney post-acute AAI exposure. Our results revealed a dramatic reduction of proximal tubule epithelial cells, associated with apoptotic and inflammatory pathways, indicating permanent damage beyond repair. We found the enriched development pathways in other nephron segments, suggesting activation of reparative programs triggered by AAI. The divergent response may be attributed to the segment-specific distribution of organic anions channels along the nephron, including OAT1 and OAT3. Moreover, we observed dramatic activation and recruitment of cytotoxic T and macrophage M1 cells, highlighting inflammation as a principal contributor to permanent renal injury. Ligand-receptor pairing revealed critical intercellular crosstalk underpins damage-induced activation of immune cells. These results provide novel insight into AAI-induced kidney injury and point out potential pathways for future therapeutic intervention.
Jiayun Chen, Piao Luo, Chen Wang, Chuanbin Yang, Yunmeng Bai, Xueling He, Qian Zhang, Junzhe Zhang, Jing Yang, Shuang Wang, Jigang Wang