Myoglobin-dependent O2 consumption of the hypoxic trout heart

Helbo, Signe; Fago, Angela; Gesser, H.

doi:10.1016/j.cbpa.2013.01.020

Cited by 4 publications

(4 citation statements)

References 48 publications

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“…Even though the physiological importance of Mb for cardiac and skeletal muscles is well established, Mb has been considered to be cellular O 2 storage and supply, the literature lacks on mechanisms which control its expression. Recently, Helbo and coworkers showed that hypoxia increases Mb expression in skeletal muscle, which would be a compensatory mechanism to the decrease of oxygen in the tissue, as in high altitude regions, depending on the low atmospheric pressure (Helbo et al, ). It was also suggested that increased muscle activity generates several degrees of hypoxia that could be one of the factors responsible for the increased expression of Mb protein in the chronic exercise (Farrell & Clutterham, ).…”

Section: Discussionmentioning

confidence: 99%

“…The responses obtained in the initial periods of the study suggest that the SSCS increases the gene expression of Mb in cardiac muscle as it is the most abundant protein that ensures an adequate oxygen supply to the heart. The SSCS may be promoting hypoxia, which increases the hypoxia induced factor 1‐alpha (HIF1‐alpha) (Helbo et al, ). As a consequence, this would increase the expression of Mb and later on, with an extended exposure time to SSCS (4 weeks).…”

Section: Discussionmentioning

confidence: 99%

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Evaluation of globins expression in brain, heart, and lung in rats exposed to side stream cigarette smoke

Tae

Oliveira

Conceição

et al. 2016

Environmental Toxicology

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The side stream cigarette smoke (SSCS) is a contributing factor in the pathogenesis of cigarette smoking-induced toxicity. Hemoglobin (Hb), myoglobin (Mb), neuroglobin (Ngb), and cytoglobin (Cygb) are globins with different distributions and functions in the tissues and have similar actions by providing O (oxygen) for respiratory chain, detoxification of ROS and nitric oxide (NO), and protect tissues against irreversible lesions. We aimed to investigate the effects of SSCS exposure on gene and protein expression of Ngb, Cygb, and Mb in different tissue. The Ngb and Cygb gene and protein expression in the cerebral cortex increased after 1 week of rat exposure to SSCS. In hippocampus, the Ngb gene and protein expression increased after 1 week or more of exposure and no change was observed in Cygb gene and protein expression. In myocardium, Mb and Cygb gene expression increased at 1 and 4 weeks of exposure, while protein expression of both increased at 1, 2, 3, and 4 weeks. In lung, observed an increase in Cygb gene and protein expression after 2, 3, and 4 weeks of exposure. The findings suggest that SSCS modulates Ngb, Cygb, and Mb in central and peripheral tissue © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1252-1261, 2017.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Evaluation of globins expression in brain, heart, and lung in rats exposed to side stream cigarette smoke

Tae

Oliveira

Conceição

et al. 2016

Environmental Toxicology

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“…Intracellular O 2 carrier and nitrite reductase activity. Mb is a monomeric globin protein involved in facilitating O 2 diffusion and O 2 storage in the skeletal and heart muscle, where it is normally expressed at high levels in most vertebrates (29,34,100). Notable exceptions of vertebrates lacking Mb are some Antarctic icefish, the stickleback, and frogs (6,49).…”

Section: Myoglobinmentioning

confidence: 99%

Functional roles of globin proteins in hypoxia-tolerant ectothermic vertebrates

Fago

2017

Journal of Applied Physiology

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Globins are heme-containing proteins ubiquitously expressed in vertebrates, where they serve a broad range of biological functions, directly or indirectly related to the tight control of oxygen levels and its toxic products in vivo. Perhaps the most investigated of all proteins, hemoglobin and myoglobin are primarily involved in oxygen transport and storage, but also in facilitating arterial vasodilation, suppressing mitochondrial respiration, and preventing tissue oxidative damage via accessory redox enzymatic activities during hypoxia. By contrast, the more recently discovered neuroglobin and cytoglobin do not seem to function as reversible oxygen carriers and are instead involved in redox activities, although their exact biological roles remain to be clarified. In this context, hypoxia-tolerant ectotherms, such as freshwater turtles and members of the carp family that survive winter in extreme hypoxia, have proven as excellent models to appreciate the diversity of biological functions of globin proteins. Unraveling physiological roles of globin proteins in these extreme animals will clarify an important part of the adaptive mechanisms for surviving extreme fluctuations of oxygen availability that are prohibitive to mammals.

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“…Thus, interactions between NO and the protein moiety of Mb may improve NO-dependent myocardial efficiency and fine-tune the balance between O 2 demand and aerobic availability in the fish heart [11]. In addition, the extent of NO scavenging by deoxy heme appears to be limited in the hypoxic myocardium of trout, suggesting a role of endogenously produced NO in the regulation of myocardial O 2 consumption [12].…”

Section: Introductionmentioning

confidence: 99%

Oxygen-Linked S-Nitrosation in Fish Myoglobins: A Cysteine-Specific Tertiary Allosteric Effect

et al. 2014

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The discovery that cysteine (Cys) S-nitrosation of trout myoglobin (Mb) increases heme O2 affinity has revealed a novel allosteric effect that may promote hypoxia-induced nitric oxide (NO) delivery in the trout heart and improve myocardial efficiency. To better understand this allosteric effect, we investigated the functional effects and structural origin of S-nitrosation in selected fish Mbs differing by content and position of reactive cysteine (Cys) residues. The Mbs from the Atlantic salmon and the yellowfin tuna, containing two and one reactive Cys, respectively, were S-nitrosated in vitro by reaction with Cys-NO to generate Mb-SNO to a similar yield (∼0.50 SH/heme), suggesting reaction at a specific Cys residue. As found for trout, salmon Mb showed a low O2 affinity (P 50 = 2.7 torr) that was increased by S-nitrosation (P 50 = 1.7 torr), whereas in tuna Mb, O2 affinity (P 50 = 0.9 torr) was independent of S-nitrosation. O2 dissociation rates (k off) of trout and salmon Mbs were not altered when Cys were in the SNO or N-ethylmaleimide (NEM) forms, suggesting that S-nitrosation should affect O2 affinity by raising the O2 association rate (k on). Taken together, these results indicate that O2-linked S-nitrosation may occur specifically at Cys107, present in salmon and trout Mb but not in tuna Mb, and that it may relieve protein constraints that limit O2 entry to the heme pocket of the unmodified Mb by a yet unknown mechanism. UV-Vis and resonance Raman spectra of the NEM-derivative of trout Mb (functionally equivalent to Mb-SNO and not photolabile) were identical to those of the unmodified Mb, indicating that S-nitrosation does not affect the extent or nature of heme-ligand stabilization of the fully ligated protein. The importance of S-nitrosation of Mb in vivo is confirmed by the observation that Mb-SNO is present in trout hearts and that its level can be significantly reduced by anoxic conditions.

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Myoglobin-dependent O2 consumption of the hypoxic trout heart

Cited by 4 publications

References 48 publications

Evaluation of globins expression in brain, heart, and lung in rats exposed to side stream cigarette smoke

Evaluation of globins expression in brain, heart, and lung in rats exposed to side stream cigarette smoke

Functional roles of globin proteins in hypoxia-tolerant ectothermic vertebrates

Oxygen-Linked S-Nitrosation in Fish Myoglobins: A Cysteine-Specific Tertiary Allosteric Effect

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