Abstract: TH-PO1157
Role of Zinc Protoporphyrin-Regulated Ferroptosis in the Pathogenesis of CKD
Session Information
- CKD: Mechanisms, AKI, and Beyond - 1
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 2303 CKD (Non-Dialysis): Mechanisms
Authors
- Liu, Shing-Hwa, National Taiwan University College of Medicine, Taipei City, Taiwan, Taiwan
- Tsai, Li Ting, National Taiwan University College of Medicine, Taipei City, Taiwan, Taiwan
- Liu, Chieh-Yun, National Taiwan University College of Medicine, Taipei City, Taiwan, Taiwan
- Wu, Cheng-Tien, China Medical University Hospital, Taichung, Taichung City, Taiwan
- Chiang, Chih-Kang, National Taiwan University College of Medicine, Taipei City, Taiwan, Taiwan
Background
Zinc protoporphyrin (ZnPP), a naturally occurring metalloporphyrin formed during heme biosynthesis when zinc is incorporated into the protoporphyrin ring instead of iron, which process is particularly enhanced during periods of iron deficiency or impaired iron utilization. ZnPP can be elevated in patients with renal failure. However, its role in renal pathology remains unclear. Here, we investigated the role of ZnPP in chronic kidney disease (CKD) pathogenesis using an adenine-induced CKD mouse model and the renal tubular cell models.
Methods
Human renal proximal tubular epithelial cell HK-2 and normal rat kidney tubular epithelial cell NRK-52E were used. Six-week-old male C57BL/6 mice were treated with adenine to induce CKD. In some experiments, CKD mice were treated with the N,N,N′,N′-tetrakis (2-pyridinylmethyl)-1,2-ethanediamine (TPEN), a potent zinc chelator as a ZnPP inhibitor. Serum biochemical analysis, renal histological examination, and protein expression for ferroptosis-related signaling molecules in the kidney were determined.
Results
ZnPP (5 and 10 μM) decreased cell viability in HK-2 and NRK-52E cells (p<0.05, n=6). ZnPP altered iron metabolism by elevating labile iron through the upregulation of transferrin and divalent metal transporter 1, which facilitated iron uptake, while reducing iron storage and export due to the downregulation of ferroportin and ferritin (p<0.05, n=6). ZnPP-treated renal tubular cells exhibited a significant downregulation of glutathione peroxidase 4 (GPX4) and SLC7A11/xCT protein levels and the increase in reactive oxygen species (ROS) generation (ferroptosis markers; p<0.05, n=6), which could be reversed by iron scavenger deferoxamine (p<0.05, n=6). In vivo model showed that ZnPP substantially accumulated in the kidneys of CKD mice, contributing to ferroptosis and renal fibrosis (p<0.05, n=6). Notably, zinc chelator TPEN treatment effectively reduced ZnPP accumulation and mitigated ZnPP-induced ferroptosis and renal injury in CKD mice, indicating its potential as a promising therapeutic target for kidney disease (p<0.05, n=6).
Conclusion
These findings demonstrate for the first time that ZnPP drives ferroptosis in vitro and in vivo, suggesting a possible treatment approach that targets this mechanism to prevent ferroptosis and offering new insights into the pathogenesis of CKD.
Funding
- Government Support – Non-U.S.