ZDHHC18 promotes renal fibrosis development by regulating HRAS palmitoylation
Di Lu, … , Yuhang Jiang, Qi Wang
Di Lu, … , Yuhang Jiang, Qi Wang
Published February 6, 2025
Citation Information: J Clin Invest. 2025;135(6):e180242. https://doi.org/10.1172/JCI180242.
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ZDHHC18 promotes renal fibrosis development by regulating HRAS palmitoylation

Abstract

Fibrosis is the final common pathway leading to end-stage chronic kidney disease (CKD). However, the function of protein palmitoylation in renal fibrosis and the underlying mechanisms remain unclear. In this study, we observed that expression of the palmitoyltransferase ZDHHC18 was significantly elevated in unilateral ureteral obstruction (UUO) and folic acid–induced (FA-induced) renal fibrosis mouse models and was significantly upregulated in fibrotic kidneys of patients with CKD. Functionally, tubule-specific deletion of ZDHHC18 attenuated tubular epithelial cells’ partial epithelial-mesenchymal transition (EMT) and then reduced the production of profibrotic cytokines and alleviated tubulointerstitial fibrosis. In contrast, ZDHHC18 overexpression exacerbated progressive renal fibrosis. Mechanistically, ZDHHC18 catalyzed the palmitoylation of HRAS, which was pivotal for its translocation to the plasma membrane and subsequent activation. HRAS palmitoylation promoted downstream phosphorylation of MEK/ERK and further activated Ras-responsive element–binding protein 1 (RREB1), enhancing SMAD binding to the Snai1 cis-regulatory regions. Taken together, our findings suggest that ZDHHC18 plays a crucial role in renal fibrogenesis and represents a potential therapeutic target for combating kidney fibrosis.

Authors

Di Lu, Gulibositan Aji, Guanyu Li, Yue Li, Wenlin Fang, Shuai Zhang, Ruiqi Yu, Sheng Jiang, Xia Gao, Yuhang Jiang, Qi Wang

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Figure 6

ZDHHC18-mediated HRAS palmitoylation regulates its plasma membrane localization.

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ZDHHC18-mediated HRAS palmitoylation regulates its plasma membrane local...
(A) Molecular docking simulations were performed on human ZDHHC18/HRAS to determine the strength of the interaction. (B) HK-2 cells were transfected with HA-ZDHHC18 and the Flag-RAS isoform for 48 hours. Cell lysates were collected for the ABE assay and immunoblot analysis. (C) HK-2 cells overexpressing ZDHHCs were subjected to an ABE assay and immunoblot analysis. (D) HRAS palmitoylation levels in the kidneys of WT and Zdhhc18-CKO mice were analyzed using ABE and immunoblot assays 10 days after UUO. (E) HRAS palmitoylation levels in the kidneys of WT and Zdhhc18-CKO mice were analyzed using ABE and immunoblot assays 28 days after FA. (F) HK-2 cells with ZDHHC18 knockdown were treated with TGF-β1 for 48 hours. The palmitoylation status of HRAS was assessed using ABE and immunoblot assays. (G) HK-2 cells were treated with 2 μM 2BP for 48 hours and then stimulated with TGF-β1 for 48 hours. The palmitoylation status of HRAS was assessed using ABE and immunoblot assays. (H) Representative fluorescence images of GFP-HRAS staining in HK-2 cells transfected with siZDHHC18 or siCtrl. Scale bar: 50 μm. (I) Subcellular fractionation was performed on HK-2 cells transfected with siCtrl or siZDHHC18, followed by immunoblot analysis using the indicated antibodies. For C–G, the results are representative of 3 independent biological experiments. HRAS palmitoylation levels were quantified using ImageJ software (C–G). WCL, whole-cell lysate; Palm, palmitoylation. Data are presented as the mean ± SD. **P < 0.01 and ***P < 0.001, by 2-way ANOVA with Tukey’s multiple-comparison test (D–G).