Abstract: TH-PO002
Caspase-11-Mediated Tubular Epithelial Pyroptosis Underlies Contrast-Induced AKI
Session Information
- AKI: Mechanisms - Primary Injury and Repair - I
November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 103 AKI: Mechanisms
Authors
- Zhang, Zhen, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shao, Xinghua, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Ni, Zhaohui, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
Background
Contrast-induced acute kidney injury (CI-AKI) is a serious complication in patients after administration of iodinated contrast media. Pyroptosis is a form of programmed lytic cell death that is triggered by inflammatory caspases (caspase-11), but little is known about its role in tubular epithelial cells (TECs) death and CI-AKI.
Methods
1. The primary mouse and human renal TECs were treated with iohexol and isosmotic mannitol in separate experiments. Experiments were performed in triplicate. The protein expression of Caspase-4/5/11, IL-1β and Gsdmd in cells by assessed by Western Blot, respectively. Caspase-4/5, and IL-1β mRNA expression in cells detected by real-time PCR. ELISA was used to detected the concentration of IL-1β in cell culture supernatants and a CytoTox 96 Non-Radioactive Cytotoxicity Assay measured cell death.
2. The model of CI-AKI mice was established. Mice were killed 24 hours after iohexol or other drugs injection, and blood and kidney tissue specimens of mice were collected. Scr and blood BUN was assessed by an automatic biochemical analyzer; the protein expression of Caspase-11, IL-1β and Gsdmd in mouse kidney was assessed by Western Blot; Acute kidney injury biomarkers (KIM-1, IL-18) and inflammatory cytokines IL-6 mRNA expression was detected by real-time PCR. H&E staining and immunolabelling were used to evaluate degree of renal tubular injury and expression of caspase-11, and IL-1β in kidneys, respectively.
Results
Here, we show that systemic exposure to contrast media causes severe tubular epithelial pyroptosis that is mediated by the inflammatory caspases, caspases 4/5 in human TECs, or the murine homolog caspase-11 in mice in vivo and in mouse TECs in vitro. Knockdown of caspase-4/5 preserved human TECs from cell death and reduced the release of mature IL-1β, and in caspase-11-deficient mice, contrast-induced acute kidney injury was abrogated, indicating a central role for caspase-11 in acute kidney injury. Additionally, deletion of caspase-11 in TECs reduced Gsdmd cleavage, which is the key process for execution of pyroptosis.
Conclusion
These results establish the requisite role of caspase-11–mediated epithelial pyroptosis in CI-AKI and suggest that epithelial inflammatory caspases are an important therapeutic target for AKI.
Funding
- Other NIH Support