A cell state specific metabolic vulnerability to GPX4-dependent ferroptosis in glioblastoma
Ontology highlight
ABSTRACT: Glioma cells hijack developmental transcriptional programs to control cell state. During neural development, lineage trajectories rely on specialized metabolic pathways. However, the link between tumor cell state and metabolic programs is poorly understood in glioma. Here we uncover a glioma cell state-specific metabolic liability that can be leveraged therapeutically. To model the diversity of glioma cell states, we generated genetically-engineered murine gliomas, induced by deletion of p53 alone (p53) or with constitutively active Notch signaling (N1IC), a pathway critical in controlling CNS cell fate. N1IC tumors harbored quiescent astrocyte-like transformed cell states while p53 tumors were comprised of proliferating progenitor-like cell states. N1IC cells exhibit distinct metabolic alterations, with mitochondrial uncoupling and increased ROS production rendering them more sensitive to inhibition of the lipid hydroperoxidase GPX4 and induction of ferroptosis. Importantly, treating patient-derived organotypic slices with a GPX4 inhibitor induced selective depletion of quiescent AC-like glioma cell populations with similar metabolic profiles.
Project description:Comparative analysis of gene expression in cultured primary keratinocytes isolated from newborn control (K14-cre; GPx4fl/+) and knockout (K14-cre; GPx4fl/fl) mice. Selenoproteins are essential for skin function, as targeted abolition of selenoproteins in epidermal tissue results in newborn mice manifesting gross abnormalities of skin and hair, accompanied by retarded growth and premature death. To investigate whether lack of a single selenoprotein could induce similar phenotypic effect in mice, we generated keratinocyte-specific knockout mice lacking glutathione peroxidase 4 (GPx4), an essential selenoprotein in skin, to examine phenotypic changes resulting from the lack of GPx4 in skin. Ablation of GPx4 results in focal alopecia and disturbed hair follicle morphogenesis, with GPx4 being essential during early stages of hair follicle morphogenesis as well as for keratinocyte adhesion and proliferation in culture. We have generated mice with selective removal of the GPx4 gene in keratinocytes under the control of Keratin-14-cre (K14-cre) promoter. Comparative microarray analysis was performed on RNA samples taken from pooled primary keratinocytes from knockout and control mice from the same litter. Array replicates were performed using RNA samples from three different litters.
Project description:Ferroptosis is an iron-dependent programmed cell death associated with severe kidney diseases, linked to decreased glutathione peroxidase 4 (GPX4). However, the spatial distribution of renal GPX4-mediated ferroptosis and the molecular events causing GPX4 reduction during ischemia-reperfusion (I/R) remain largely unknown. Using spatial transcriptomics, we identify that GPX4 is situated at the interface of the inner cortex and outer medulla, a hyperactive ferroptosis site post-I/R injury. We show that OTU deubiquitinase 5 (OTUD5) is a GPX4-binding protein that confers ferroptosis resistance by stabilizing GPX4. During I/R, ferroptosis is induced by mTORC1-mediated autophagy, causing OTUD5 degradation and subsequent GPX4 decay. Functionally, OTUD5 deletion intensifies renal tubular cell ferroptosis and exacerbates acute kidney injury, while AAV-mediated OTUD5 delivery mitigates ferroptosis and promotes renal function recovery from I/R injury. In this work, our study highlights a new autophagy-dependent ferroptosis module: hypoxia/ischemia-induced OTUD5 autophagy triggers GPX4 degradation, offering a potential therapeutic avenue for I/R-related kidney diseases.
Project description:Invariant natural killer T (iNKT) cells are a group of innate like T cells that plays important roles in immune homeostasis and activation. We found that iNKT cells, compared to CD4+ T cells, have significantly higher levels of lipid peroxidation in both mice and humans. Proteomic analysis also demonstrated that iNKT cells express higher levels of Glutathione peroxidase 4 (Gpx4), a major antioxidant enzyme that reduces lipid peroxidation and prevents ferroptosis. T cell specific deletion of Gpx4 reduces iNKT cell population, most prominently the IFNg producing NKT1 subset. RNAseq analysis revealed IFNg signaling, cell cycle regulation, as well as mitochondrial function are perturbed by Gpx4 deletion in iNKT cells. Consistently, we detected impaired cytokine production, elevated cell proliferation and cell death, and accumulation of lipid peroxides and mitochondrial ROS in Gpx4 KO iNKT cells. Ferroptosis inhibitor, iron chelator, vitamin E and vitamin K2 can prevent ferroptosis induced by Gpx4 deficiency in iNKT cells and ameliorate the impaired function of iNKT cells due to Gpx4 inhibition. Lastly, vitamin E rescued iNKT cell population in Gpx4 KO mice. Altogether, our findings reveal the critical role of Gpx4 in regulating iNKT cell homeostasis and function, through controlling lipid peroxidation and ferroptosis.
Project description:Osteoarthritis (OA) is the most common joint disease and is the leading cause of chronic disability among older people. Chondrocyte death was involved in OA pathogenesis. Ferroptosis is an iron-dependent cell death associated with peroxidation of lipids. Expression of GPX4 in the OA cartilage from OA patients were significantly lower than normal cartilage.In order to analyze the mechanism of GPX4, we conducted RNA-sequencing in mouse chondrocytes with or without GPX4 knockdown.Our results showed that Gpx4 downregulation could increase the sensitivity of chondrocytes to oxidative stress and aggravate ECM degradation in chondrocytes.
Project description:Comparative analysis of gene expression in cultured primary keratinocytes isolated from newborn control (K14-cre; GPx4fl/+) and knockout (K14-cre; GPx4fl/fl) mice. Selenoproteins are essential for skin function, as targeted abolition of selenoproteins in epidermal tissue results in newborn mice manifesting gross abnormalities of skin and hair, accompanied by retarded growth and premature death. To investigate whether lack of a single selenoprotein could induce similar phenotypic effect in mice, we generated keratinocyte-specific knockout mice lacking glutathione peroxidase 4 (GPx4), an essential selenoprotein in skin, to examine phenotypic changes resulting from the lack of GPx4 in skin. Ablation of GPx4 results in focal alopecia and disturbed hair follicle morphogenesis, with GPx4 being essential during early stages of hair follicle morphogenesis as well as for keratinocyte adhesion and proliferation in culture.
Project description:Knockout or inhibition of glutathione peroxidase 4 (GPX4) induces ferroptosis which has been proposed as a potential therapeutic strategy for cancer. Here we unexpectedly found that inducible knockout of GPX4 in tumor cells significantly promotes non-small cell lung cancer (NSCLC) progression in the autochthonous KrasLSL-G12D/+Lkb1fl/fl (KL) and KrasLSL-G12D/+Tp53fl/fl (KP) mouse models, whereas inducible overexpression of GPX4 in tumor cells had an opposite effect. Mechanistically, knockout of GPX4 in tumor cells results in the accumulation of triacylglycerol (TAG) that was stored in lipid droplets in tumor cells and the efflux of TAG that induces ferroptosis of macrophages in the tumor microenvironment (TME), thereby igniting an immunoinhibitory TME characterized by the dysfunction of anti-tumor T cells and the decrease of antigen-presenting macrophages. Consistently, treatment with liprostatin-1 or inducible overexpression of GPX4 in tumor cells significantly rescues the ferroptosis of macrophages and ignites the activation of T cells in the TME, thereby inhibiting NSCLC progression. These findings highlight a previously uncharacterized role of tumor cell-specific GPX4 in NSCLC progression by modulating TAG metabolism in the TME and provide potential therapeutic strategies for NSCLC.
Project description:Analysis of proteins interacting with GPX4 in A375 and 293T cells infected with lentiviruses encoding empty vector or Flag-GPX4, using anti-Flag magnetic beads enrichment and LC-MS/MS.
Project description:CDK4/6 inhibition is the standard of care for estrogen receptor positive (ER+) breast cancer, although cytostasis is frequently observed, and new treatment strategies that enhance efficacy are required. We performed a genome-wide CRISPR screen to identify genetic determinants of CDK4/6 inhibitors sensitivity. Multiple genes involved in oxidative stress and ferroptosis modulated palbociclib sensitivity. Depletion or inhibition of GPX4 increased sensitivity to palbociclib in ER+ breast cancer models, and sensitised triple negative breast cancer models to palbociclib, with GPX4 null xenografts being highly sensitive to palbociclib. Palbociclib induced oxidative stress and disordered lipid metabolism with lipid peroxidation, leading to a ferroptosis-sensitive state. Lipid peroxidation relied on a peroxisome AGPAT3-dependent pathway in ER+ breast cancer models, rather than the classical ACSL4 pathway. Our data demonstrate that CDK4/6 inhibition creates vulnerability to ferroptosis that could be exploited through combination with GPX4 inhibitors, enhancing sensitivity to CDK4/6 inhibition in breast cancer.
Project description:Glioblastoma is an aggressive diffusely infiltrating neoplasm that spreads beyond surgical resection margins, where it intermingles with non-neoplastic brain cells. This complex microenvironment harbouring infiltrating glioma and non-neoplastic brain cells is the origin of tumor recurrence. Thus, understanding the cellular and molecular features of the glioma microenvironment is therapeutically and prognostically important. Here, we used single-nucleus RNA sequencing (snRNAseq) of primary and recurrent glioma to define three compositional ‘tissue-states’ rooted in cohabitation of cell-types and transcriptional states. These comprise a state featuring A) minimally infiltrated-brain, B) reactive inflamed infiltrated tissue, and C) cellular tumor. Spatial transcriptomics confirmed that the cell-types and transcriptomics states which compositionally cohabitate indeed do colocalize in space. Tissue states are clinically significant because they correlate with radiographic, histopathologic, and prognostic features. We found that in addition to enrichment of tissue state B signature, enrichment of both neoplastic and non-neoplastic cell-type gene signatures in tissue state B correlated with decreased survival. Importantly, we found that our compositionally defined tissue states are enriched in distinct metabolic pathways. One such pathway is fatty acid biosynthesis, which was enriched in tissue state B – a state enriched in recurrent glioblastoma and composed of astrocyte-like/mesenchymal glioma cells, reactive astrocytes resembling those seen in neurodegeneration, and monocyte-like myeloid cells. We discovered that targeting fatty acid synthesis was sufficient to deplete the transcriptional signature of tissue state B. Our findings define a novel compositional approach to the glioma infiltrated tissue which allows us to discover prognostic and targetable features, paving the way to new mechanistic and therapeutic discoveries.