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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Research Article Nephrology

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 8

Palmitoylated HRAS–activated RREB1 recruits SMAD2/3 to the cis-regulatory regions of Snai1 and Has2.

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Palmitoylated HRAS–activated RREB1 recruits SMAD2/3 to the cis-regulator...
(A) Immunoblot analysis of p-MEK, p-ERK, MEK, and ERK in WT and Zdhhc18-CKO mice after UUO. (B) p-ERK staining and quantification for UUO mice (n = 8). (C) Immunoblot analysis of p-MEK, p-ERK, MEK, and ERK after FA (n = 8). (D) p-ERK staining and quantification for FA mice (n = 8). (E) p-ERK staining for NRF and RF patients and Pearson’s correlation analysis between ZDHHC18 and p-ERK staining (n = 15). (F and G) PTECs were isolated from WT mice with Rreb1 knockdown and treated with TGF-β1. (F) Confocal microscopy shows phalloidin (green) and DAPI (blue). Quantitative analysis of the major/minor axis of cells. (G) Immunoblotting for E-cadherin and vimentin expression in cells. (H) RREB1 immunoblot for WT and Zdhhc18-CKO mice after UUO and FA. (I–M) PTECs from WT and Zdhhc18-CKO mice were transfected with HA-RREB1 and treated with PBS/TGF-β1. (J) ChIP-PCR analysis of RREB1 binding to the enhancer regions of Snai1 and Has2. (K) Cell lysates were collected for immunoprecipitation and immunoblot analysis. (L) ChIP-PCR analysis of SMAD2/3 binding to the enhancer regions of Snai1 and Has2. (M) mRNA levels of Snai1 and Has2. (N–R) PTECs were isolated from Cdh16 Cre+ Hrasfl/fl mice and overexpressed HrasWT, HrasC181S, and HrasC184S, followed by transfection with HA-RREB1 for 48 hours, with PBS or TGF-β1 stimulation. (O) ChIP-PCR analysis of RREB1 binding to the enhancer regions of Snai1 and Has2. (P) Cell lysates were collected for immunoprecipitation and immunoblot analysis. (Q) ChIP-PCR analysis of SMAD2/3 binding to the enhancer regions of Snai1 and Has2. (R) mRNA levels of Snai1 and Has2. (S) Schematic of ZDHHC18-mediated RAS and TGF-β1 signaling. Scale bars: 20 μm (B, D, and E) and 50 μm (F). Data indicate the mean ± SD. *P < 0.05, **P < 0.01, and ***P < 0.001, by 1-way ANOVA with Tukey’s multiple-comparison test (O), by 2-way ANOVA with Tukey’s multiple-comparison test (B, D, F, L, M, Q, and R), and 2-tailed Student’s t test (J).