Fluorescence Probes to Detect Lipid-Derived Radicals

Yamada, Kenichi; Mito, Fumiya; Matsuoka, Yuta; Ide, Satsuki; Shikimachi, Kazushige; Fujiki, Ayano; Kusakabe, Daiki; Ishida, Yuma; Enoki, Masataka; Tada, Arisa; Ariyoshi, Miyuki; Yamasaki, Toshihide; Yamato, Masayuki

doi:10.1016/j.freeradbiomed.2016.10.182

Cited by 8 publications

(8 citation statements)

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“…Lipid peroxyl radicals generated by arachidonic acids (AAs)/ LOX system were detected with the NBD-Pen fluorescence probe. 20 Mixtures of 160 ml PBS pH 7.4 (PBS) containing AAs (final 500 mM; Sigma-Aldrich [.95.0%]) and the compounds were prepared in a black-walled 96-well plate. Aliquots of 20 ml NBD-Pen (final 5 mM) and 20 ml LOX solution (final 10 mg/ml, LOX from Glycine max; Sigma-Aldrich) were added, and the fluorescence intensity (ex 470 nm, em 530 nm) was measured at 37°C using a Spectra Max M2e (Molecular Devices).…”

Section: Lipid Peroxyl Radical-scavenging Analysismentioning

confidence: 99%

“…The only currently established method to monitor lipid radicals uses electron spin resonance (ESR)-spin trapping techniques, 19 but we recently developed a specific fluorescence probe for lipid radicals, 2,2,6-trimethyl-4-(4-nitrobenzo [1,2,5]oxadiazol-7-ylamino)-6-pentylpiperidine-1-oxyl (NBD-Pen), which enabled us to directly detect lipid-derived radicals with high sensitivity and selectivity. 20 Cytochrome P450 families (CYP) contain key enzymes of drug metabolism and steroid hormone synthesis that can also convert lipophilic substrates to hydrophilic products. 21 Some CYP-catalyzed reactions are involved in ROS production and lipid peroxidation.…”

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confidence: 99%

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Drugs Repurposed as Antiferroptosis Agents Suppress Organ Damage, Including AKI, by Functioning as Lipid Peroxyl Radical Scavengers

Mishima

Sato

Ito

et al. 2019

JASN

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127

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BackgroundFerroptosis, nonapoptotic cell death mediated by free radical reactions and driven by the oxidative degradation of lipids, is a therapeutic target because of its role in organ damage, including AKI. Ferroptosis-causing radicals that are targeted by ferroptosis suppressors have not been unequivocally identified. Because certain cytochrome P450 substrate drugs can prevent lipid peroxidation via obscure mechanisms, we evaluated their antiferroptotic potential and used them to identify ferroptosis-causing radicals.MethodsUsing a cell-based assay, we screened cytochrome P450 substrate compounds to identify drugs with antiferroptotic activity and investigated the underlying mechanism. To evaluate radical-scavenging activity, we used electron paramagnetic resonance–spin trapping methods and a fluorescence probe for lipid radicals, NBD-Pen, that we had developed. We then assessed the therapeutic potency of these drugs in mouse models of cisplatin-induced AKI and LPS/galactosamine-induced liver injury.ResultsWe identified various US Food and Drug Administration–approved drugs and hormones that have antiferroptotic properties, including rifampicin, promethazine, omeprazole, indole-3-carbinol, carvedilol, propranolol, estradiol, and thyroid hormones. The antiferroptotic drug effects were closely associated with the scavenging of lipid peroxyl radicals but not significantly related to interactions with other radicals. The elevated lipid peroxyl radical levels were associated with ferroptosis onset, and known ferroptosis suppressors, such as ferrostatin-1, also functioned as lipid peroxyl radical scavengers. The drugs exerted antiferroptotic activities in various cell types, including tubules, podocytes, and renal fibroblasts. Moreover, in mice, the drugs ameliorated AKI and liver injury, with suppression of tissue lipid peroxidation and decreased cell death.ConclusionsAlthough elevated lipid peroxyl radical levels can trigger ferroptosis onset, some drugs that scavenge lipid peroxyl radicals can help control ferroptosis-related disorders, including AKI.

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Section: Lipid Peroxyl Radical-scavenging Analysismentioning

confidence: 99%

mentioning

confidence: 99%

Drugs Repurposed as Antiferroptosis Agents Suppress Organ Damage, Including AKI, by Functioning as Lipid Peroxyl Radical Scavengers

Mishima

Sato

Ito

et al. 2019

JASN

Self Cite

127

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“…33 This quenching process means that when an ORCA is MRI/EPR active, adjacent fluorophores are typically quenched. While this has been elegantly exploited, 32,33,40,41 a true ratiometric sensor capable of assessing the probe concentration by fluorescence and the relative ROS levels by EPR/MRI signal would require a constant fluorescence emission regardless of the oxidation state of the ORCA.…”

Section: ■ Introductionmentioning

confidence: 99%

Nitroxyl Modified Tobacco Mosaic Virus as a Metal-Free High-Relaxivity MRI and EPR Active Superoxide Sensor

Dharmarwardana¹,

Chen²,

Palacios

et al. 2018

Mol. Pharmaceutics

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Superoxide overproduction is known to occur in multiple disease states requiring critical care; yet, noninvasive detection of superoxide in deep tissue remains a challenge. Herein, we report a metal-free magnetic resonance imaging (MRI) and electron paramagnetic resonance (EPR) active contrast agent prepared by "click conjugating" paramagnetic organic radical contrast agents (ORCAs) to the surface of tobacco mosaic virus (TMV). While ORCAs are known to be reduced in vivo to an MRI/EPR silent state, their oxidation is facilitated specifically by reactive oxygen species-in particular, superoxide-and are largely unaffected by peroxides and molecular oxygen. Unfortunately, single molecule ORCAs typically offer weak MRI contrast. In contrast, our data confirm that the macromolecular ORCA-TMV conjugates show marked enhancement for T contrast at low field (<3.0 T) and T contrast at high field (9.4 T). Additionally, we demonstrated that the unique topology of TMV allows for a "quenchless fluorescent" bimodal probe for concurrent fluorescence and MRI/EPR imaging, which was made possible by exploiting the unique inner and outer surface of the TMV nanoparticle. Finally, we show TMV-ORCAs do not respond to normal cellular respiration, minimizing the likelihood for background, yet still respond to enzymatically produced superoxide in complicated biological fluids like serum.

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“…Recently, it has been shown that the onset and progress of liver cancer can be markedly suppressed by preadministration of a compound that captures lipid carbon-centered radicals in a liver cancer animal model, established by using a nitrosamine carcinogen. 5 Similarly, with regard to age-related macular degeneration (AMD), it has been reported that pretreatment with a lipid carbon radical-scavenging compound could suppress retinal damage by light exposure, reduce lipid peroxides, and delay disease progression. 6 These studies suggest that lipid carbon-centered radicals contribute to the onset and progress of various diseases.…”

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confidence: 99%

“…TEMPO (2,2,6,6-tetramethylpiperidin-N-oxyl), as the one used for the treatment of liver cancer and AMD in a previous study. 5,6 TEMPO has a chemically modifiable substituent at the 4-position of the piperidine ring. Some of these derivatives are commercially available.…”

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confidence: 99%

Radioiodinated Nitroxide Derivative for the Detection of Lipid Radicals

Yamasaki

Azuma

Sano

et al. 2019

ACS Med. Chem. Lett.

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Thus far, no accurate measurement technology has been developed to detect lipid alkyl radicals (lipid radicals), which cause lipid peroxidation. Therefore, we aimed to develop a nuclear medical imaging probe that can be taken up in the lipophilic site in cells such as biological membranes, by reacting specifically with the lipid radicals generated there. We designed and synthesized 4-(4-[ 125 I]iodobenzamido)-2,2,6,6-tetramethylpiperidine-1-oxyl, which shows high reactivity to lipid radicals with a high radiochemical yield and purity. Intracellular retention was found to increase significantly when lipid radicals were produced.

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Fluorescence Probes to Detect Lipid-Derived Radicals

Cited by 8 publications

References 0 publications

Drugs Repurposed as Antiferroptosis Agents Suppress Organ Damage, Including AKI, by Functioning as Lipid Peroxyl Radical Scavengers

Drugs Repurposed as Antiferroptosis Agents Suppress Organ Damage, Including AKI, by Functioning as Lipid Peroxyl Radical Scavengers

Nitroxyl Modified Tobacco Mosaic Virus as a Metal-Free High-Relaxivity MRI and EPR Active Superoxide Sensor

Radioiodinated Nitroxide Derivative for the Detection of Lipid Radicals

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