Difference between revisions of "Malagrino 2019 Oxid Med Cell Longev"

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|journal=Oxid Med Cell Longev
 
|journal=Oxid Med Cell Longev
 
|abstract=Hydrogen sulfide (H<sub>2</sub>S), a known inhibitor of cytochrome c oxidase (CcOX), plays a key signaling role in human (patho)physiology. H<sub>2</sub>S is synthesized endogenously and mainly metabolized by a mitochondrial sulfide-oxidizing pathway including sulfide:quinone oxidoreductase (SQR), whereby H<sub>2</sub>S-derived electrons are injected into the respiratory chain stimulating O<sub>2</sub> consumption and ATP synthesis. Under hypoxic conditions, H<sub>2</sub>S has higher stability and is synthesized at higher levels with protective effects for the cell. Herein, working on SW480 colon cancer cells, we evaluated the effect of hypoxia on the ability of cells to metabolize H<sub>2</sub>S. The sulfide-oxidizing activity was assessed by high-resolution respirometry, measuring the stimulatory effect of sulfide on rotenone-inhibited cell respiration in the absence or presence of antimycin A. Compared to cells grown under normoxic conditions (air O<sub>2</sub>), cells exposed for 24 h to hypoxia (1% O<sub>2</sub>) displayed a 1.3-fold reduction in maximal sulfide-oxidizing activity and 2.7-fold lower basal O<sub>2</sub> respiration. Based on citrate synthase activity assays, mitochondria of hypoxia-treated cells were 1.8-fold less abundant and displayed 1.4-fold higher maximal sulfide-oxidizing activity and 2.6-fold enrichment in SQR as evaluated by immunoblotting. We speculate that under hypoxic conditions mitochondria undergo these adaptive changes to protect cell respiration from H<sub>2</sub>S poisoning.
 
|abstract=Hydrogen sulfide (H<sub>2</sub>S), a known inhibitor of cytochrome c oxidase (CcOX), plays a key signaling role in human (patho)physiology. H<sub>2</sub>S is synthesized endogenously and mainly metabolized by a mitochondrial sulfide-oxidizing pathway including sulfide:quinone oxidoreductase (SQR), whereby H<sub>2</sub>S-derived electrons are injected into the respiratory chain stimulating O<sub>2</sub> consumption and ATP synthesis. Under hypoxic conditions, H<sub>2</sub>S has higher stability and is synthesized at higher levels with protective effects for the cell. Herein, working on SW480 colon cancer cells, we evaluated the effect of hypoxia on the ability of cells to metabolize H<sub>2</sub>S. The sulfide-oxidizing activity was assessed by high-resolution respirometry, measuring the stimulatory effect of sulfide on rotenone-inhibited cell respiration in the absence or presence of antimycin A. Compared to cells grown under normoxic conditions (air O<sub>2</sub>), cells exposed for 24 h to hypoxia (1% O<sub>2</sub>) displayed a 1.3-fold reduction in maximal sulfide-oxidizing activity and 2.7-fold lower basal O<sub>2</sub> respiration. Based on citrate synthase activity assays, mitochondria of hypoxia-treated cells were 1.8-fold less abundant and displayed 1.4-fold higher maximal sulfide-oxidizing activity and 2.6-fold enrichment in SQR as evaluated by immunoblotting. We speculate that under hypoxic conditions mitochondria undergo these adaptive changes to protect cell respiration from H<sub>2</sub>S poisoning.
 +
|keywords=H2S-oxidizing activity
 
|editor=[[Plangger M]],
 
|editor=[[Plangger M]],
 
|mipnetlab=IT Roma Sarti P
 
|mipnetlab=IT Roma Sarti P
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|preparations=Intact cells
 
|preparations=Intact cells
 
|topics=Inhibitor
 
|topics=Inhibitor
 +
|couplingstates=ROUTINE
 
|pathways=ROX
 
|pathways=ROX
|instruments=Oxygraph-2k
+
|instruments=Oxygraph-2k, TIP2k
|additional=Labels, 2019-02,
+
|additional=2019-02,
 
}}
 
}}

Latest revision as of 11:05, 16 August 2019

Publications in the MiPMap
Malagrinò F, Zuhra K, Mascolo L, Mastronicola D, Vicente JB, Forte E, Giuffrè A (2019) Hydrogen sulfide oxidation: adaptive changes in mitochondria of SW480 colorectal cancer cells upon exposure to hypoxia. Oxid Med Cell Longev 2019:8102936.

» Open Access

Malagrino F, Zuhra K, Mascolo L, Mastronicola D, Vicente JB, Forte E, Giuffre A (2019) Oxid Med Cell Longev

Abstract: Hydrogen sulfide (H2S), a known inhibitor of cytochrome c oxidase (CcOX), plays a key signaling role in human (patho)physiology. H2S is synthesized endogenously and mainly metabolized by a mitochondrial sulfide-oxidizing pathway including sulfide:quinone oxidoreductase (SQR), whereby H2S-derived electrons are injected into the respiratory chain stimulating O2 consumption and ATP synthesis. Under hypoxic conditions, H2S has higher stability and is synthesized at higher levels with protective effects for the cell. Herein, working on SW480 colon cancer cells, we evaluated the effect of hypoxia on the ability of cells to metabolize H2S. The sulfide-oxidizing activity was assessed by high-resolution respirometry, measuring the stimulatory effect of sulfide on rotenone-inhibited cell respiration in the absence or presence of antimycin A. Compared to cells grown under normoxic conditions (air O2), cells exposed for 24 h to hypoxia (1% O2) displayed a 1.3-fold reduction in maximal sulfide-oxidizing activity and 2.7-fold lower basal O2 respiration. Based on citrate synthase activity assays, mitochondria of hypoxia-treated cells were 1.8-fold less abundant and displayed 1.4-fold higher maximal sulfide-oxidizing activity and 2.6-fold enrichment in SQR as evaluated by immunoblotting. We speculate that under hypoxic conditions mitochondria undergo these adaptive changes to protect cell respiration from H2S poisoning.

Keywords: H2S-oxidizing activity Bioblast editor: Plangger M O2k-Network Lab: IT Roma Sarti P


Labels: MiParea: Respiration, Pharmacology;toxicology  Pathology: Cancer  Stress:Hypoxia  Organism: Human  Tissue;cell: Endothelial;epithelial;mesothelial cell  Preparation: Intact cells 

Regulation: Inhibitor  Coupling state: ROUTINE  Pathway: ROX  HRR: Oxygraph-2k, TIP2k 

2019-02