Upregulation and Mitochondrial Sequestration of Hemoglobin Occur in Circulating Leukocytes during Critical Illness, Conferring a Cytoprotective Phenotype

Brunyánszki, Attila; Erdélyi, Katalin; Szczesny, Bartosz; Oláh, Gabor; Salomão, Reinaldo; Herndon, David N.; Szabó, Csaba

doi:10.2119/molmed.2015.00187

Cited by 27 publications

(26 citation statements)

References 39 publications

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“…24h after CLP, which, to our knowledge, is the longest delay in the administration of a H 2 S donor, relative to the initiation of circulatory shock/sepsis in an animal model), as well as the positive findings with H 2 S in murine models of CLP on survival, as well as the positive effects of NaHS on bacterial clearance and antibacterial defenses (18,19) would suggest that H 2 S donation may be a translationally relevant therapeutic approach for sepsis. This conclusion may be further supported by several additional preclinical studies in various models of sepsis, endotoxemia and inflammation (27–31) as well as by clinical observations showing H 2 S levels are elevated in various forms of critical illness (7,32). However, we must point out that the survival experiment was terminated 48 hours after the start of the CLP, so we do not know if the animals that were alive at 48 hours could be considered "permanent" survivors, or, alternatively, the NaHS treatment only delayed the onset of death.…”

Section: Discussionmentioning

confidence: 66%

Delayed Treatment with Sodium Hydrosulfide Improves Regional Blood Flow and Alleviates Cecal Ligation and Puncture (CLP)-Induced Septic Shock

Ahmad

Druzhyna

Szabó³

2016

Shock

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Cecal ligation and puncture (CLP) induced sepsis is a serious medical condition, caused by a severe systemic infection resulting in a systemic inflammatory response. Recent studies have suggested the therapeutic potential of donors of hydrogen sulfide (H2S), a novel endogenous gasotransmitter and biological mediator in various diseases. The aim of the present study was to assess the effect of H2S supplementation in sepsis, with special reference to its effect on the modulation of regional blood flow. We infused sodium hydrosulfide (NaHS), a compound that produces H2S in aqueous solution (1, 3 or 10 mg/kg/h, for 1 hour at each dose level) in control rats or rats 24 hours after CLP, and measured blood flow using fluorescent microspheres. In normal control animals, NaHS induced a characteristic redistribution of blood flow, and reduced cardiac, hepatic and renal blood flow in a dose-dependent fashion. In contrast, in rats subjected to CLP, cardiac, hepatic and renal blood flow was significantly reduced; infusion of NaHS (1 mg/kg/h and 3 mg/kg/h) significantly increased organ blood flow. In other words, the effect of H2S on regional blood flow is dependent on the status of the animals (i.e. a decrease in blood flow in normal controls, but an increase in blood flow in CLP). We have also evaluated the effect of delayed treatment with NaHS on organ dysfunction and the inflammatory response by treating the animals with NaHS (3 mg/kg) intraperitoneally (i.p) at 24 h after the start of the CLP procedure; plasma levels of various cytokines and tissue indicators of inflammatory cell infiltration and oxidative stress were measured 6 hours later. After 24 h of CLP, glomerular function was significantly impaired, as evidenced by markedly increased (over 4-fold over baseline) blood urea nitrogen and creatinine levels; this increase was also significantly reduced by treatment with NaHS. NaHS also attenuated the CLP-induced increases in malondialdehyde levels (an index of oxidative stress) in heart as well as in liver and myeloperoxidase levels (an index of neutrophil infiltration) in heart and lung. Plasma levels of IL-1β, IL-5, IL-6, TNF-α and HMGB1 were attenuated by NaHS. Treatment of NaHS at 3 mg/kg i.p, (but not 1 mg/kg or 6 mg/kg), starting 24 hours post-CLP, with dosing repeated every 6 h, improved the survival rate in CLP animals. In summary, treatment with 3 mg/kg H2S - when started in a delayed manner, when CLP-induced organ injury, inflammation and blood flow redistribution have already ensued - improves blood flow to several organs, protects against multiple organ failure, and reduces the plasma levels of multiple pro-inflammatory mediators. These findings support the view that H2S donation may have therapeutic potential in sepsis.

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Section: Discussionmentioning

confidence: 66%

Delayed Treatment with Sodium Hydrosulfide Improves Regional Blood Flow and Alleviates Cecal Ligation and Puncture (CLP)-Induced Septic Shock

Ahmad

Druzhyna

Szabó³

2016

Shock

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“…Recent studies demonstrate that CSE is upregulated and H 2 S plasma levels are increased in mice subjected to burn injury [44,45]. In liver homogenates obtained from mice subjected to burn injury, increased S -sulfhydration of ATP5A1 was detected at the early time points, followed by a return to baseline over time (Fig.…”

Section: Resultsmentioning

confidence: 81%

S- Sulfhydration of ATP synthase by hydrogen sulfide stimulates mitochondrial bioenergetics

Módis

Ahmad

et al. 2016

Pharmacological Research

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113

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Mammalian cells can utilize hydrogen sulfide (H2S) to support mitochondrial respiration. The aim of our study was to explore the potential role of S-sulfhydration (a H2S-induced posttranslational modification, also known as S-persulfidation) of the mitochondrial inner membrane protein ATP synthase (F1F0 ATP synthase/Complex V) in the regulation of mitochondrial bioenergetics. Using a biotin switch assay, we have detected S-sulfhydration of the α subunit (ATP5A1) of ATP synthase in response to exposure to H2S in vitro. The H2S generator compound NaHS induced S-sulfhydration of ATP5A1 in HepG2 and HEK293 cell lysates in a concentration-dependent manner (50–300 μM). The activity of immunocaptured mitochondrial ATP synthase enzyme isolated from HepG2 and HEK293 cells was stimulated by NaHS at low concentrations (10–100 nM). Site-directed mutagenesis of ATP5A1 in HEK293 cells demonstrated that cysteine residues at positions 244 and 294 are subject to S-sulfhydration. The double mutant ATP synthase protein (C244S/C294S) showed a significantly reduced enzyme activity compared to control and the single-cysteine-mutated recombinant proteins (C244S or C294S). To determine whether endogenous H2S plays a role in the basal S-sulfhydration of ATP synthase in vivo, we compared liver tissues harvested from wild-type mice and mice deficient in cystathionine-gamma-lyase (CSE, one of the three principal mammalian H2S-producing enzymes). Significantly reduced S-sulfhydration of ATP5A1 was observed in liver homogenates of CSE−/− mice, compared to wild-type mice, suggesting a physiological role for CSE-derived endogenous H2S production in the S-sulfhydration of ATP synthase. Various forms of critical illness (including burn injury) upregulate H2S-producing enzymes and stimulate H2S biosynthesis. In liver tissues collected from mice subjected to burn injury, we detected an increased S-sulfhydration of ATP5A1 at the early time points post-burn. At later time points (when systemic H2S levels decrease) S-sulfhydration of ATP5A1 decreased as well. In conclusion, H2S induces S-sulfhydration of ATP5A1 at C244 and C294. This post-translational modification may be a physiological mechanism to maintain ATP synthase in a physiologically activated state, thereby supporting mitochondrial bioenergetics. The sulfhydration of ATP synthase may be a dynamic process, which may be regulated by endogenous H2S levels under various pathophysiological conditions.

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“…Thus, the ultimate outcome parameters may depend on the relative importance of the various pathways affected by H 2 S in the particular experimental model studied. The outcome of the experiment may also depend on the changes in endogenous H 2 S biosynthesis; for instance, in some (but not all) models of critical illness, H 2 S levels can be elevated; these elevated H 2 S levels may serve cytoprotective as well as deleterious roles, dependent on the type of critical illness, and perhaps the stage and the severity of the disease as well [reviewed in (6,8,33,34)]. Similarly, H 2 S has been demonstrated to affect the production of various pro- and anti-inflammatory cytokines (6,8,11,12–16,19); both stimulatory and inhibitory effects have been reported; the direction of the effect is dependent on the concentration of H 2 S used, as well as the experimental model and cell type used, and it has been shown to involve a variety of signaling pathways including NF-κB, MAP kinases and histone deacetylases (14,19,20,35–39).…”

Section: Discussionmentioning

confidence: 99%

Effect of endotoxemia in mice genetically deficient in cystathionine-γ-lyase, cystathionine-β-synthase or 3-mercaptopyruvate sulfurtransferase

Ahmad¹,

Gerö²,

Oláh³

et al. 2016

International Journal of Molecular Medicine

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Hydrogen sulfide (H2S) has been proposed to exert pro- as well as anti-inflammatory effects in various models of critical illness. In this study, we compared bacterial lipopolysaccharide (LPS)-induced changes in inflammatory mediator production, indices of multiple organ injury and survival in wild-type (WT) mice and in mice with reduced expression of one of the three H2S-producing enzymes, cystathionine-γ-lyase (CSE), cystathionine-β-synthase (CBS) or 3-mercaptopyruvate sulfurtransferase (3MST). Mice were injected intraperitoneally (i.p.) with LPS (10 mg/kg). After 6 h, the animals were sacrificed, blood and organs were collected and the following parameters were evaluated: blood urea nitrogen (BUN) levels in blood, myeloperoxidase (MPO) and malondialdehyde (MDA) in the lung, cytokine levels in plasma and the expression of the three H2S-producing enzymes (CBS, CSE and 3MST) in the spleen, lung, liver and kidney. LPS induced a tissue-dependent upregulation of some of the H2S-producing enzymes in WT mice (upregulation of CBS in the spleen, upregulation of 3MST in the liver and upregulation of CBS, CSE and 3MST in the lung). Moreover, LPS impaired glomerular function, as evidenced by increased BUN levels. Renal impairment was comparable in the CSE−/− and Δ3MST mice after LPS challenge; however, it was attenuated in the CBS+/− mice. MPO levels (an index of neutrophil infiltration) and MDA levels (an index of oxidative stress) in lung homogenates were significantly increased in response to LPS; these effects were similar in the WT, CBS+/−, CSE−/− and Δ3MST mice; however, the MDA levels tended to be lower in the CBS+/− and CSE−/− mice. LPS induced significant increases in the plasma levels of multiple cytokines [tumor necrosis factor (TNF)α, interleukin (IL)-1β, IL-6, IL-10, IL-12 and interferon (IFN)γ] in plasma; TNFα, IL-10 and IL-12 levels tended to be lower in all three groups of animals expressing lower levels of H2S-producing enzymes. The survival rates after the LPS challenge did not show any significant differences between the four animal groups tested. Thus, the findings of this study indicate that a deficiency in 3MST does not significantly affect endotoxemia, while a deficiency in CBS or CSE slightly ameliorates the outcome of LPS-induced endotoxemia in vivo.

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Upregulation and Mitochondrial Sequestration of Hemoglobin Occur in Circulating Leukocytes during Critical Illness, Conferring a Cytoprotective Phenotype

Cited by 27 publications

References 39 publications

Delayed Treatment with Sodium Hydrosulfide Improves Regional Blood Flow and Alleviates Cecal Ligation and Puncture (CLP)-Induced Septic Shock

Delayed Treatment with Sodium Hydrosulfide Improves Regional Blood Flow and Alleviates Cecal Ligation and Puncture (CLP)-Induced Septic Shock

S- Sulfhydration of ATP synthase by hydrogen sulfide stimulates mitochondrial bioenergetics

Effect of endotoxemia in mice genetically deficient in cystathionine-γ-lyase, cystathionine-β-synthase or 3-mercaptopyruvate sulfurtransferase

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