Abstract: FR-PO1061
Daphnepedunin A, a Natural Small Molecule, Targets Cdc42-Mediated GSK-3β/β-Catenin Signaling to Combat Renal Fibrosis
Session Information
- CKD Mechanisms: Progression, Fibrosis, and Beyond
November 03, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 2303 CKD (Non-Dialysis): Mechanisms
Authors
- Hu, Xinrong, Department of Nephrology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Zhou, Yi, Department of Nephrology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
Background
Renal fibrosis is a common fate in various chronic kidney diseases (CKD), eventually leading to renal dysfunction. So far there is no effective treatment for this pathological process. Wikstroemia chamaedaphne, a shrub endemic in China, is a medicinal plant that have been used in folk medicines to treat edema, but its application and mechanism in kidney-related diseases are unknown.
Methods
The inhibitory effects of ethanolic extracts of Wikstroemia chamaedaphne on the activation of renal fibroblasts were detected in the in vitro model of rat renal fibroblast cell line stimulated by transforming growth factor-β1. A phenotypic screening was conducted to identify the most potent diterpenoid isolated from Wikstroemia chamaedaphne on the in vitro model of renal fibroblast activation. Unilateral uretera obstruction mouse model of renal fibrosis was utilized to confirm the anti-renal fibrotic activity of the diterpenoid. The drug efficacy of the diterpenoid was compared with pirfenidone, the anti-renal fibrotic drug undergoing clinical phase 2 trial. RNA-sequencing was employed to explore the underlying pharmacological mechanism. By incorporating cellular thermal shift assay with quantitative mass spectrometry (MS-CETSA), the direct target of the diterpenoid was identified. Surface plasmon resonance and active GTP-binding cdc42 pull-down experiments was performed to verify the target protein. Small interfering RNA was used to knock down the target protein in NRK-49F cells and the drug efficacy of the diterpenoid was testified.
Results
In our bioassay-guided chemical investigation on the medicinal plant Wikstroemia chamaedaphne, the daphne diterpenoid daphnepedunin A (15) was identified as a promising anti-renal fibrotic lead. 15 showed significant anti-renal fibrosis effects both in vitro and in vivo, much more potent than the clinical trial drug pirfenidone. Leveraging MS-CETSA, we identified cell division cycle 42 (cdc42), a GTPase, as the direct target of 15. Mechanistically, 15 inhibited the activity of cdc42, disrupting cdc42-dependent glycogen synthase kinase-3β (GSK-3β) serine 9 phosphorylation, which in turn activates GSK-3β and downregulates downstream β-catenin profibrotic signaling.
Conclusion
Our findings suggest that cdc42 is a potential therapeutic target for renal fibrosis, and 15 has great potential as a cdc42 inhibitor for the treatment of CKD.
Funding
- Government Support – Non-U.S.