H2O2 metabolism in liver and heart mitochondria: Low emitting-high scavenging and high emitting-low scavenging systems

Kamunde, Collins; Sharaf, Mahmoud S.; MacDonald, Nicole

doi:10.1016/j.freeradbiomed.2018.05.064

Cited by 28 publications

(12 citation statements)

References 56 publications

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“…Catalase was measured using Purpald (4-amino-3-hydrazino-5-mercapto-1,2,4-triazole) based on [35] as we recently described for fish mitochondria [36]. Briefly catalase reacts with methanol in the presence of hydrogen peroxide to produce formaldehyde which upon binding to Purpald changes from colorless to purple.…”

Section: Methodsmentioning

confidence: 99%

“…For SOD, superoxide anion radical (O 2 •– ) generated by a xanthine oxidase-hypoxanthine system was detected using water-soluble tetrazolium, WST-1 (sodium salt of 4-[3-(4iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate) according to [37] as recently described for fish mitochondria [36]. Here, WST-1 produces a water soluble dye upon reduction of the O 2 •– and the rate of reduction of WST-1 is linear to xanthine oxidase activity and is inhibited by SOD.…”

Section: Methodsmentioning

confidence: 99%

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Brown seaweed (AquaArom) supplementation increases food intake and improves growth, antioxidant status and resistance to temperature stress in Atlantic salmon, Salmo salar

2019

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Seaweeds represent a vast resource that remains underutilized as an ingredient in aquafeeds. Here we probed the effect of addition of AquaArom, a seaweed meal derived from brown seaweeds (Laminaria sp., kelp), to fish feed on growth performance, antioxidant capacity and temperature responsiveness of mitochondrial respiration. A commercial salmonid feed was mixed with 0 (control), 3, 6 and 10% seaweed and fed to Atlantic salmon ( Salmo salar ) smolts for 30 days. The smolts consumed more of the seaweed-supplemented food relative to the control and there were no mortalities. Compared with the control, the final fish weight, standard length, weight gain and SGR were higher in fish fed diets supplemented with the 3 and 10% seaweed, while growth performance for fish maintained on 6% seaweed remained neutral. Importantly, seaweed supplementation increased protein efficiency ratio (PER) and tended to improve food conversion ratio (FCR). Although the hepatosomatic and visceral indices did not change, whole gut and intestinal weights and lengths were higher in fish maintained on seaweed-supplemented diets suggesting increased retention time and a larger surface area for food digestion and nutrient absorption. Measurement of antioxidant status revealed that seaweed supplementation dose-dependently increased plasma total antioxidant capacity as well as the level of glutathione, and activities of catalase and superoxide dismutase in liver mitochondria. Moreover, seaweed supplementation reduced the effect of acute temperature rise on mitochondrial respiration and proton leak. Overall, these data suggest that AquaArom can be mixed with fish food up to 10% to increase food consumption and enhance growth performance, as well as to improve antioxidant capacity and alleviate adverse effects of stressors such as temperature in fish.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Brown seaweed (AquaArom) supplementation increases food intake and improves growth, antioxidant status and resistance to temperature stress in Atlantic salmon, Salmo salar

2019

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“…In support of this, there is increasing evidence that mitochondria can also act as net sinks of ROS and this is linked to lifespan. For instance mitochondria from the long lived naked mole rat (NMR) produce less ROS than comparable shorter lived animals [ 139 , 140 ]. Furthermore the mitochondria in NMR, and bats, also appear to be able to maintain a depolarisation of the inner membrane for much longer during their life cycle, which is a key mechanism to reduce ROS production during ageing [ 141 ].…”

Section: The Immune System Hormesis and Mitochondriamentioning

confidence: 99%

SARS-CoV-2 and mitochondrial health: implications of lifestyle and ageing

Nunn

Guy²,

Brysch

et al. 2020

Immun Ageing

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Infection with SARs-COV-2 displays increasing fatality with age and underlying co-morbidity, in particular, with markers of the metabolic syndrome and diabetes, which seems to be associated with a “cytokine storm” and an altered immune response. This suggests that a key contributory factor could be immunosenescence that is both age-related and lifestyle-induced. As the immune system itself is heavily reliant on mitochondrial function, then maintaining a healthy mitochondrial system may play a key role in resisting the virus, both directly, and indirectly by ensuring a good vaccine response. Furthermore, as viruses in general, and quite possibly this new virus, have also evolved to modulate immunometabolism and thus mitochondrial function to ensure their replication, this could further stress cellular bioenergetics. Unlike most sedentary modern humans, one of the natural hosts for the virus, the bat, has to “exercise” regularly to find food, which continually provides a powerful adaptive stimulus to maintain functional muscle and mitochondria. In effect the bat is exposed to regular hormetic stimuli, which could provide clues on how to resist this virus. In this paper we review the data that might support the idea that mitochondrial health, induced by a healthy lifestyle, could be a key factor in resisting the virus, and for those people who are perhaps not in optimal health, treatments that could support mitochondrial function might be pivotal to their long-term recovery.

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“…Although mitochondria have long been recognized as one of the many cellular sites of H 2 O 2 formation [15] , [21] , [6] mitochondria also have a substantial capacity to eliminate H 2 O 2 . Indeed, mitochondria from several tissues, including brain, liver, heart and skeletal muscle appear to have far greater maximal capacity to consume H 2 O 2 than to produce it; however, in all tissues other than liver the rate of H 2 O 2 consumption requires respiratory substrate to be maximized [10] , [16] , [24] , [25] , [30] , [32] , [35] . The respiration-dependency of mitochondrial H 2 O 2 consumption comes largely from the GSH-peroxidase and thioredoxin-dependent peroxiredoxin pathways, both of which require a supply of electrons, via NADPH, to remain active [2] .…”

Section: Introductionmentioning

confidence: 99%

“…Although the maximal capacity to consume H 2 O 2 can be much higher in mitochondria than the production rates, the consumption of H 2 O 2 becomes limited as the concentration of H 2 O 2 declines [10] , [16] , [3] , [30] , [32] . Recently Starkov and colleagues [30] combined this concentration-dependent capacity for mitochondrial H 2 O 2 consumption into an elegantly simple model to describe H 2 O 2 metabolism in mouse brain mitochondria.…”

Section: Introductionmentioning

confidence: 99%

Mitochondria can act as energy-sensing regulators of hydrogen peroxide availability

2019

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Mitochondria are widely recognized as sources of reactive oxygen species in animal cells, with H2O2 being of particular note because it can act not only in oxidative stress but also is important to several signalling pathways. Lesser recognized is that mitochondria can have far greater capacity to consume H2O2 than to produce it; however, the consumption of H2O2 may be kinetically constrained by H2O2 availability especially at the low nanomolar (or lower) concentrations that occur in vivo. The production of H2O2 is a function of many factors, not the least of which are respiratory substrate availability and the protonmotive force (Δp). The Δp, which is predominantly membrane potential (ΔΨ), can be a strong indicator of mitochondrial energy status, particularly if respiratory substrate supply is either not meeting or exceeding demand. The notion that mitochondria may functionally act in regulating H2O2 concentrations may be somewhat implicit but little evidence demonstrating this is available. Here we demonstrate key assumptions that are required for mitochondria to act as regulators of H2O2 by an integrated system of production and concomitant consumption. In particular we show the steady-state level of H2O2 mitochondria approach is a function of both mitochondrial H2O2 consumption and production capacity, the latter of which is strongly influenced by ΔΨ. Our results are consistent with mitochondria being able to manipulate extramitochondrial H2O2 as a means of signalling mitochondrial energetic status, in particular the Δp or ΔΨ. Such a redox-based signal could operate with some independence from other energy sensing mechanisms such as those that transmit information using the cytosolic adenylate pool.

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H2O2 metabolism in liver and heart mitochondria: Low emitting-high scavenging and high emitting-low scavenging systems

Cited by 28 publications

References 56 publications

Brown seaweed (AquaArom) supplementation increases food intake and improves growth, antioxidant status and resistance to temperature stress in Atlantic salmon, Salmo salar

Brown seaweed (AquaArom) supplementation increases food intake and improves growth, antioxidant status and resistance to temperature stress in Atlantic salmon, Salmo salar

SARS-CoV-2 and mitochondrial health: implications of lifestyle and ageing

Mitochondria can act as energy-sensing regulators of hydrogen peroxide availability

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