Sies, H. et al. Defining roles of specific reactive oxygen species (ROS) in cell biology and physiology. Nat. Rev. Mol. Cell Biol. 23, 499–515 (2022).
Brand, M. D. Mitochondrial generation of superoxide and hydrogen peroxide as the source of mitochondrial redox signaling. Free Radic. Biol. Med. 100, 14–31 (2016).
Fazakerley, D. J., Krycer, J. R., Kearney, A. L., Hocking, S. L. & James, D. E. Muscle and adipose tissue insulin resistance: malady without mechanism? J. Lipid Res. 60, 1720–1732 (2019).
Fisher-Wellman, K. H. & Neufer, P. D. Linking mitochondrial bioenergetics to insulin resistance via redox biology. Trends Endocrinol. Metab. 23, 142–153 (2012).
Hotamisligil, G. S. Foundations of immunometabolism and implications for metabolic health and disease. Immunity 47, 406–420 (2017).
Fazakerley, D. J. et al. Mitochondrial CoQ deficiency is a common driver of mitochondrial oxidants and insulin resistance. eLife 7, e32111 (2018).
Anderson, E. J. et al. Mitochondrial H2O2 emission and cellular redox state link excess fat intake to insulin resistance in both rodents and humans. J. Clin. Invest. 119, 573–581 (2009).
Houstis, N., Rosen, E. D. & Lander, E. S. Reactive oxygen species have a causal role in multiple forms of insulin resistance. Nature 440, 944–948 (2006).
Barazzoni, R. et al. Fatty acids acutely enhance insulin-induced oxidative stress and cause insulin resistance by increasing mitochondrial reactive oxygen species (ROS) generation and nuclear factor-κB inhibitor (IκB)–nuclear factor-κB (NFκB) activation in rat muscle, in the absence of mitochondrial dysfunction. Diabetologia 55, 773–782 (2012).
Nakamura, S. et al. Palmitate induces insulin resistance in H4IIEC3 hepatocytes through reactive oxygen species produced by mitochondria. J. Biol. Chem. 284, 14809–14818 (2009).
Lonn, E. et al. Effects of vitamin E on cardiovascular and microvascular outcomes in high-risk patients with diabetes. Diabetes Care 25, 1919–1927 (2002).
Heart Outcomes Prevention Evaluation Study Investigators. Vitamin E supplementation and cardiovascular events in high-risk patients. N. Engl. J. Med. 342, 154–160 (2000).
Johansen, J. S., Harris, A. K., Rychly, D. J. & Ergul, A. Oxidative stress and the use of antioxidants in diabetes: linking basic science to clinical practice. Cardiovasc. Diabetol. 4, 5 (2005).
Feillet-Coudray, C. et al. The mitochondrial-targeted antioxidant MitoQ ameliorates metabolic syndrome features in obesogenic diet-fed rats better than apocynin or allopurinol. Free Radic. Res. 48, 1232–1246 (2014).
Pryde, K. R. & Hirst, J. Superoxide is produced by the reduced flavin in mitochondrial complex I. J. Biol. Chem. 286, 18056–18065 (2011).
Treberg, J. R., Quinlan, C. L. & Brand, M. D. Evidence for two sites of superoxide production by mitochondrial NADH–ubiquinone oxidoreductase (complex I). J. Biol. Chem. 286, 27103–27110 (2011).
Hinkle, P. C., Butow, R. A., Racker, E. & Chance, B. Partial resolution of the enzymes catalyzing oxidative phosphorylation. J. Biol. Chem. 242, 5169–5173 (1967).
Chouchani, E. T. et al. Ischaemic accumulation of succinate controls reperfusion injury through mitochondrial ROS. Nature 515, 431–435 (2014).
Mills, E. L. et al. Succinate dehydrogenase supports metabolic repurposing of mitochondria to drive inflammatory macrophages. Cell 167, 457–470 (2016).
Scialò, F. et al. Mitochondrial ROS produced via reverse electron transport extend animal lifespan. Cell Metab. 23, 725–734 (2016).
Fernández-Agüera, M. C. et al. Oxygen sensing by arterial chemoreceptors depends on mitochondrial complex I signaling. Cell Metab. 22, 825–837 (2015).
Arias-Mayenco, I. et al. Acute O2 sensing: role of coenzyme QH2/Q ratio and mitochondrial ROS compartmentalization. Cell Metab. 28, 145–158 (2018).
Ojha, R. et al. Regulation of reverse electron transfer at mitochondrial complex I by unconventional Notch action in cancer stem cells. Dev. Cell 57, 260–276 (2022).
Casey, A. M. et al. Pro-inflammatory macrophages produce mitochondria-derived superoxide by reverse electron transport at complex I that regulates IL-1β release during NLRP3 inflammasome activation. Nat. Metab. 7, 493–507 (2025).
Murphy, M. P. How mitochondria produce reactive oxygen species. Biochem. J. 417, 1–13 (2009).
Langston, P. K. et al. Glycerol phosphate shuttle enzyme GPD2 regulates macrophage inflammatory responses. Nat. Immunol. 20, 1186–1195 (2019).
Roca, F. J., Whitworth, L. J., Prag, H. A., Murphy, M. P. & Ramakrishnan, L. Tumor necrosis factor induces pathogenic mitochondrial ROS in tuberculosis through reverse electron transport. Science 376, eabh2841 (2022).
Polyzos, S. A., Kountouras, J. & Mantzoros, C. S. Obesity and nonalcoholic fatty liver disease: from pathophysiology to therapeutics. Metabolism 92, 82–97 (2019).
Hotamisligil, G. S. Inflammation, metaflammation and immunometabolic disorders. Nature 542, 177–185 (2017).
Cochemé, H. M. et al. Using the mitochondria-targeted ratiometric mass spectrometry probe MitoB to measure H2O2 in living Drosophila. Nat. Protoc. 7, 946–958 (2012).
Murphy, M. P. et al. Guidelines for measuring reactive oxygen species and oxidative damage in cells and in vivo. Nat. Metab. 4, 651–662 (2022).
Arruda, A. P. et al. Chronic enrichment of hepatic endoplasmic reticulum–mitochondria contact leads to mitochondrial dysfunction in obesity. Nat. Med. 20, 1427–1435 (2014).
Kushnareva, Y., Murphy, A. N. & Andreyev, A. Complex I-mediated reactive oxygen species generation: modulation by cytochrome c and NAD(P)+ oxidation–reduction state. Biochem. J. 368, 545–553 (2002).
Lambert, A. J. & Brand, M. D. Inhibitors of the quinone-binding site allow rapid superoxide production from mitochondrial NADH:ubiquinone oxidoreductase (complex I). J. Biol. Chem. 279, 39414–39420 (2004).
Hirst, J., King, M. S. & Pryde, K. R. The production of reactive oxygen species by complex I. Biochem. Soc. Trans. 36, 976–980 (2008).
Quinlan, C. L. et al. The 2-oxoacid dehydrogenase complexes in mitochondria can produce superoxide/hydrogen peroxide at much higher rates than complex I. J. Biol. Chem. 289, 8312–8325 (2014).
Brand, M. D. et al. Suppressors of superoxide-H2O2 production at site IQ of mitochondrial complex I protect against stem cell hyperplasia and ischemia–reperfusion injury. Cell Metab. 24, 582–592 (2016).
Watson, M. A. et al. Suppression of superoxide/hydrogen peroxide production at mitochondrial site IQ decreases fat accumulation, improves glucose tolerance and normalizes fasting insulin concentration in mice fed a high-fat diet. Free Radic. Biol. Med. 204, 276–286 (2023).
Robb, E. L. et al. Control of mitochondrial superoxide production by reverse electron transport at complex I. J. Biol. Chem. 293, 9869–9879 (2018).
Yin, Z. et al. Structural basis for a complex I mutation that blocks pathological ROS production. Nat. Commun. 12, 707 (2021).
Villalba, J. M. & Navas, P. Regulation of coenzyme Q biosynthesis pathway in eukaryotes. Free Radic. Biol. Med. 165, 312–323 (2021).
Matsura, T., Yamada, K. & Kawasaki, T. Changes in the content and intracellular distribution of coenzyme Q homologs in rabbit liver during growth. Biochim. Biophys. 1083, 277–282 (1991).
Matsura, T., Yamada, K. & Kawasaki, T. Difference in antioxidant activity between reduced coenzyme Q9 and reduced coenzyme Q10 in the cell: studies with isolated rat and guinea pig hepatocytes treated with a water-soluble radical initiator. Biochim. Biophys. Acta 1123, 309–315 (1992).
Burger, N. et al. A sensitive mass spectrometric assay for mitochondrial CoQ pool redox state in vivo. Free Radic. Biol. Med. 147, 37–47 (2020).
Guerra, R. M. & Pagliarini, D. J. Coenzyme Q biochemistry and biosynthesis. Trends Biochem. Sci. 48, 463–476 (2023).
Awad, A. M. et al. Coenzyme Q10 deficiencies: pathways in yeast and humans. Essays Biochem. 62, 361–376 (2018).
Casey, J. & Threlfall, D. R. Formation of 3-hexaprenyl-4-hydroxybenzoate by matrix-free mitochondrial membrane-rich preparations of yeast. Biochim. Biophys. Acta 530, 487–502 (1978).
Robb, E. L. et al. Selective superoxide generation within mitochondria by the targeted redox cycler MitoParaquat. Free Radic. Biol. Med. 89, 883–894 (2015).
Gray, L. R. et al. Hepatic mitochondrial pyruvate carrier 1 is required for efficient regulation of gluconeogenesis and whole-body glucose homeostasis. Cell Metab. 22, 669–681 (2015).
Peng, M. et al. Primary coenzyme Q deficiency in Pdss2 mutant mice causes isolated renal disease. PLoS Genet. 4, e1000061 (2008).
El-Khoury, R. et al. Alternative oxidase expression in the mouse enables bypassing cytochrome c oxidase blockade and limits mitochondrial ROS overproduction. PLoS Genet. 9, e1003182 (2013).
Szibor, M. et al. Bioenergetic consequences from xenotopic expression of a tunicate AOX in mouse mitochondria: switch from RET and ROS to FET. Biochim. Biophys. Acta 1861, 148137 (2020).
Lin, C. S. et al. Mouse mtDNA mutant model of Leber hereditary optic neuropathy. Proc. Natl Acad. Sci. USA 109, 20065–20070 (2012).
Sattar, N. et al. Statins and risk of incident diabetes: a collaborative meta-analysis of randomised statin trials. Lancet 375, 735–742 (2010).
Mills, E. J. et al. Efficacy and safety of statin treatment for cardiovascular disease: a network meta-analysis of 170 255 patients from 76 randomized trials. QJM 104, 109–124 (2011).
Deshwal, S. et al. Mitochondria regulate intracellular coenzyme Q transport and ferroptotic resistance via STARD7. Nat. Cell Biol. 25, 246–257 (2023).
Kemmerer, Z. A. et al. UbiB proteins regulate cellular CoQ distribution in Saccharomyces cerevisiae. Nat. Commun. 12, 4769 (2021).
Bersuker, K. et al. The CoQ oxidoreductase FSP1 acts parallel to GPX4 to inhibit ferroptosis. Nature 575, 688–692 (2019).
Doll, S. et al. FSP1 is a glutathione-independent ferroptosis suppressor. Nature 575, 693–698 (2019).
Goncalves, R. L. S., Schlame, M., Bartelt, A., Brand, M. D. & Hotamışlıgil, G. S. Cardiolipin deficiency in Barth syndrome is not associated with increased superoxide/H2 O2 production in heart and skeletal muscle mitochondria. FEBS Lett. 595, 415–432 (2021).
Affourtit, C., Quinlan, C. L. & Brand, M. D. Measurement of proton leak and electron leak in isolated mitochondria. Methods Mol. Biol. 810, 165–182 (2012).
Miwa, S. et al. Carboxylesterase converts Amplex red to resorufin: implications for mitochondrial H2O2 release assays. Free Radic. Biol. Med. 90, 173–183 (2016).
Sud, M. et al. Metabolomics Workbench: an international repository for metabolomics data and metadata, metabolite standards, protocols, tutorials and training, and analysis tools. Nucleic Acids Res. 44, D463–D470 (2016).
Hu, C. et al. Blood clearance kinetics and organ delivery of medium-chain triglyceride and fish oil-containing lipid emulsions: comparing different animal species. Clin. Nutr. 40, 987–996 (2021).
European Association for the Study of the Liver (EASL), European Association for the Study of Diabetes (EASD) and European Association for the Study of Obesity (EASO). EASL–EASD–EASO Clinical Practice Guidelines for the management of non-alcoholic fatty liver disease. Diabetologia 59, 1121–1140 (2016).
Chalasani, N. et al. The diagnosis and management of nonalcoholic fatty liver disease: practice guidance from the American Association for the Study of Liver Diseases. Hepatology 67, 328–357 (2018).
Kleiner, D. E. et al. Design and validation of a histological scoring system for nonalcoholic fatty liver disease. Hepatology 41, 1313–1321 (2005).
Goncalves, R. Ubiquinone deficiency drives reverse electron transport to disrupt hepatic metabolic homeostasis in obesity. Figshare https://figshare.com/s/0b856e078932282d73d4 (2025).
