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Kuganesan N, Dlamini S, McDaniel J, Tillekeratne VLM, Taylor WR. Identification and initial characterization of a potent inhibitor of ferroptosis. J Cell Biochem 2020; 122:413-424. [PMID: 33377232 DOI: 10.1002/jcb.29870] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 10/12/2020] [Accepted: 11/03/2020] [Indexed: 01/17/2023]
Abstract
Ferroptosis is a form of iron-dependent cell death characterized by elevated lipid peroxides and reactive oxygen species (ROS). Glutathione (GSH) plays an essential role in scavenging ROS to maintain cell viability and acts as a cofactor of GSH peroxidase 4 (GPX4) that protects lipids from oxidation. We have previously described a novel class of small molecules that induce ferroptosis in certain types of cancer cells. These compounds induce ferroptosis by blocking the uptake of cystine required for GSH synthesis. Even though ferroptosis is a well-established form of cell death, signaling pathways that modulate this process are not known. Therefore, we used a panel of growth factors/kinase inhibitors to test effects on ferroptosis induced by our lead compound. We discovered that BMS536924, a dual inhibitor of insulin-like growth and insulin receptors, is a potent inhibitor of ferroptosis. Further investigation indicated that the anti-ferroptotic activity of BMS536924 does not lie in its ability to inhibit insulin signal transduction. Instead, we provide evidence that BMS536924 binds iron, an essential cofactor in ferroptosis. Our results suggest caution in interpreting the effects of BMS536924 in investigations of insulin signaling and uncover a novel ferroptosis inhibitor.
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Affiliation(s)
- Nishanth Kuganesan
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, USA
| | - Samkeliso Dlamini
- Department of Medicinal and Biological Chemistry, University of Toledo, Toledo, Ohio, USA
| | - Jade McDaniel
- Department of Medicinal and Biological Chemistry, University of Toledo, Toledo, Ohio, USA
| | | | - William R Taylor
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, USA
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Hoehne A, James ML, Alam IS, Ronald JA, Schneider B, D'Souza A, Witney TH, Andrews LE, Cropper HC, Behera D, Gowrishankar G, Ding Z, Wyss-Coray T, Chin FT, Biswal S, Gambhir SS. [ 18F]FSPG-PET reveals increased cystine/glutamate antiporter ( xc-) activity in a mouse model of multiple sclerosis. J Neuroinflammation 2018; 15:55. [PMID: 29471880 PMCID: PMC5822551 DOI: 10.1186/s12974-018-1080-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 01/24/2018] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The cystine/glutamate antiporter (xc-) has been implicated in several neurological disorders and, specifically, in multiple sclerosis (MS) as a mediator of glutamate excitotoxicity and proinflammatory immune responses. We aimed to evaluate an xc-specific positron emission tomography (PET) radiotracer, (4S)-4-(3-[18F]fluoropropyl)-L-glutamate ([18F]FSPG), for its ability to allow non-invasive monitoring of xc- activity in a mouse model of MS. METHODS Experimental autoimmune encephalomyelitis (EAE) was induced in C57BL/6 mice by subcutaneous injection of myelin oligodendrocyte glycoprotein (MOG35-55) peptide in complete Freund's adjuvant (CFA) followed by pertussis toxin. Control mice received CFA emulsion and pertussis toxin without MOG peptide, while a separate cohort of naïve mice received no treatment. PET studies were performed to investigate the kinetics and distribution of [18F]FSPG in naïve, control, pre-symptomatic, and symptomatic EAE mice, compared to 18F-fluorodeoxyglucose ([18F]FDG). After final PET scans, each mouse was perfused and radioactivity in dissected tissues was measured using a gamma counter. Central nervous system (CNS) tissues were further analyzed using ex vivo autoradiography or western blot. [18F]FSPG uptake in human monocytes, and T cells pre- and post-activation was investigated in vitro. RESULTS [18F]FSPG was found to be more sensitive than [18F]FDG at detecting pathological changes in the spinal cord and brain of EAE mice. Even before clinical signs of disease, a small but significant increase in [18F]FSPG signal was observed in the spinal cord of EAE mice compared to controls. This increase in PET signal became more pronounced in symptomatic EAE mice and was confirmed by ex vivo biodistribution and autoradiography. Likewise, in the brain of symptomatic EAE mice, [18F]FSPG uptake was significantly higher than controls, with the largest changes observed in the cerebellum. Western blot analyses of CNS tissues revealed a significant correlation between light chain of xc- (xCT) protein levels, the subunit of xc- credited with its transporter activity, and [18F]FSPG-PET signal. In vitro [18F]FSPG uptake studies suggest that both activated monocytes and T cells contribute to the observed in vivo PET signal. CONCLUSION These data highlight the promise of [18F]FSPG-PET as a technique to provide insights into neuroimmune interactions in MS and the in vivo role of xc- in the development and progression of this disease, thus warranting further investigation.
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Affiliation(s)
- Aileen Hoehne
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Michelle L James
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA.,Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, 94305, USA
| | - Israt S Alam
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - John A Ronald
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Bernadette Schneider
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Aloma D'Souza
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Timothy H Witney
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Lauren E Andrews
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Haley C Cropper
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Deepak Behera
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Gayatri Gowrishankar
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Zhaoqing Ding
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, 94305, USA
| | - Tony Wyss-Coray
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, 94305, USA
| | - Frederick T Chin
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Sandip Biswal
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Sanjiv S Gambhir
- Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Stanford University, Stanford, CA, 94305, USA. .,Department of Bioengineering, Department of Materials Science & Engineering, Stanford University, Stanford, CA, 94305, USA.
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