Abstract: FR-PO0292
AXL Disrupts the Integrity of the Slit Diaphragm by Inhibiting ZO-1 Phase Separation and Aggravates Podocyte Injury in Diabetic Nephropathy
Session Information
- Diabetic Kidney Disease: Basic and Translational Science Advances - 1
November 07, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Diabetic Kidney Disease
- 701 Diabetic Kidney Disease: Basic
Authors
- Wu, Danfeng, Guangdong Provincial People's Hospital, Guangzhou, Guangdong, China
- Zhang, Ting, Guangdong Provincial People's Hospital, Guangzhou, Guangdong, China
- Liu, Peimin, Guangdong Provincial People's Hospital, Guangzhou, Guangdong, China
- Xu, Haosen, Guangdong Provincial People's Hospital, Guangzhou, Guangdong, China
- Yang, Shanzhi, Guangdong Provincial People's Hospital, Guangzhou, Guangdong, China
- Jiang, Huan, Guangdong Provincial People's Hospital, Guangzhou, Guangdong, China
- Li, Jiaoqing, Guangdong Provincial People's Hospital, Guangzhou, Guangdong, China
- Bai, Xiaoyan, Guangdong Provincial People's Hospital, Guangzhou, Guangdong, China
Background
SD injury of podocyte hiatal septum is an important cause of podocyte lesions and proteinuria in diabetic nephropathy. ZO tight junction protein (Zonula occludens - 1, 1) is an important link protein, SD area in maintaining normal cell structure and biological function plays a key role. However, how ZO-1 is regulated and its mechanism remain unclear.
Methods
The expression level and localization of AXL in renal tissues from DKD patients and diabetic mice were examined by analyzing the database, single-cell sequencing and molecular biology techniques. The potential binding partners of AXL were screened and confirmed by mass spectrometry and Co-IP analysis. FRAP was used to detect the effect of AXL on ZO-1 phase separation. The role of AXL on the phenotype of diabetic nephropathy was investigated using podocyte-specific AXL-KO mice.
Results
We found that AXL expression level was upregulated in podocytes of DKD patients and mice, causing podocyte injuries and proteinuria. AXL up-regulation in renal tissues of DKD patients was associated with increased albumiuria and deteriorated renal function. In db/db diabetic mice in vivo, overexpression of AXL worsened podocyte injury, whereas AXL inhibitor R428 significantly alleviated this effect. Podocyte-specific AXL-KO diabetic mice showed aggravated albuminuria and podocyte injury. AXL was expressed in podocytes and localized at the slit diaphragm. In cultured podocytes in vitro, AXL and ZO-1 were co-localized in a bead-like pattern along the cell membrane. High glucose up-regulated the expression level of AXL and reduced ZO-1 phase separation and membrane expression level. Knocking down AXL, however, restored ZO-1 membrane localization and alleviated podocyte injury. ZO-1 protein formed phase separation droplets, and AXL disrupted its phase separation by binding to the SH3 domain of ZO-1.
Conclusion
Our results suggest that AXL disrupts the integrity of the slit diaphragm by inhibiting the ZO-1 phase separation, causing the loosening of tight junctions, thereby disrupting the SD integrity and exacerbating podocyte injury and proteinuria. AXL may serve as a potentially new target for podocyte-specific therapeutics in regulating the slit diaphragm, providing a novel direction for the treatment of diabetic nephropathy.