TRAF3 loss protects glioblastoma cells from lipid peroxidation and immune elimination via dysregulated lipid metabolism
Yu Zeng, … , Ye Song, Aidong Zhou
Yu Zeng, … , Ye Song, Aidong Zhou
Published February 11, 2025
Citation Information: J Clin Invest. 2025;135(7):e178550. https://doi.org/10.1172/JCI178550.
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Research Article Cell biology Metabolism

TRAF3 loss protects glioblastoma cells from lipid peroxidation and immune elimination via dysregulated lipid metabolism

Abstract

Glioblastoma (GBM) is a highly aggressive form of brain tumor characterized by dysregulated metabolism. Increased fatty acid oxidation (FAO) protects tumor cells from lipid peroxidation–induced cell death, although the precise mechanisms involved remain unclear. Here, we report that loss of TNF receptor–associated factor 3 (TRAF3) in GBM critically regulated lipid peroxidation and tumorigenesis by controlling the oxidation of polyunsaturated fatty acids (PUFAs). TRAF3 was frequently repressed in GBM due to promoter hypermethylation. TRAF3 interacted with enoyl-CoA hydratase 1 (ECH1), an enzyme that catalyzes the isomerization of unsaturated FAs (UFAs) and mediates K63-linked ubiquitination of ECH1 at Lys214. ECH1 ubiquitination impeded TOMM20-dependent mitochondrial translocation of ECH1, which otherwise promoted the oxidation of UFAs, preferentially the PUFAs, and limited lipid peroxidation. Overexpression of TRAF3 enhanced the sensitivity of GBM to ferroptosis and anti–programmed death–ligand 1 (anti–PD-L1) immunotherapy in mice. Thus, the TRAF3/ECH1 axis played a key role in the metabolism of PUFAs and was crucial for lipid peroxidation damage and immune elimination in GBM.

Authors

Yu Zeng, Liqian Zhao, Kunlin Zeng, Ziling Zhan, Zhengming Zhan, Shangbiao Li, Hongchao Zhan, Peng Chai, Cheng Xie, Shengfeng Ding, Yuxin Xie, Li Wang, Cuiying Li, Xiaoxia Chen, Daogang Guan, Enguang Bi, Jianyou Liao, Fan Deng, Xiaochun Bai, Ye Song, Aidong Zhou

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Figure 5

Depletion of ECH1 induces accumulation of PUFAs and lipid peroxidation.

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Depletion of ECH1 induces accumulation of PUFAs and lipid peroxidation. ...
(A) ECH1 catalyzes the isomerization of a 3-trans, 5-cis dienoyl-CoA substrate to a 2-trans, 4-trans dienoyl-CoA product, enabling UFAs oxidation. (B) OCR time series in shECH1 GBM0709 cells treated or not with ETO by Seahorse assay. (C and D) Quantification of basal and maximum respiration (C) and ATP production (D) in GBM0709 cells. (E) OCR time series in shECH1 GBM0709 cells treated or not with BSA-conjugated linoleic acid (LA). (F and G) Quantification of basal and maximum respiration (F) and ATP production (G) in GBM0709 cells. Data are expressed as the mean ± SD of 4 independent assays (B–G). (H) Acetyl-CoA levels in GBM0709 cells expressing shECH1 compared with control shRNA (n = 3). (I) Lipidomics analysis shows the relative content of SFAs, MUFAs, and PUFAs in GBM0709 cells expressing shECH1 compared with control shRNA (n = 3). (J) Enrichment analysis of upregulated lipid species in GBM0709 cells expressing shECH1-1 compared with control shRNA. (K) Biosynthetic analysis of lipid species in GBM0709 cells expressing shECH1-1 compared with control shRNA. (L) Relative content of SFAs, MUFAs, and PUFAs in CL in GBM0709 cells expressing ECH1 shRNAs compared with control (n = 3). (M) Analysis of the specific FA branches in CL in GBM0709 cells expressing shECH1 compared with control shRNAs (n = 3). (N) MDA levels were detected in GBM0709 cells expressing shECH1 (n = 3). (O) BODIPY 581/591 staining of GBM0709 cells expressing shECH1. Scale bar: 100 μm. The proportion of oxidized cells was calculated (n = 6). Statistical significance was determined by 1-way ANOVA with Tukey’s post hoc test (C, D, F–I, and L–O). Oligo, oligonucleotide; Rote, rotenone. Data are expressed as the mean ± SD. *P < 0.05, **P < 0.01, and ***P < 0.001.