Document Detail

Oxidation of hydrogen sulfide remains a priority in mammalian cells and causes reverse electron transfer in colonocytes.
MedLine Citation:
PMID:  20398623     Owner:  NLM     Status:  MEDLINE    
Sulfide (H2S) is an inhibitor of mitochondrial cytochrome oxidase comparable to cyanide. In this study, poisoning of cells was observed with sulfide concentrations above 20 microM. Sulfide oxidation has been shown to take place in organisms/cells naturally exposed to sulfide. Sulfide is released as a result of metabolism of sulfur containing amino acids. Although in mammals sulfide exposure is not thought to be quantitatively important outside the colonic mucosa, our study shows that a majority of mammalian cells, by means of the mitochondrial sulfide quinone reductase (SQR), avidly consume sulfide as a fuel. The SQR activity was found in mitochondria isolated from mouse kidneys, liver, and heart. We demonstrate the precedence of the SQR over the mitochondrial complex I. This explains why the oxidation of the mineral substrate sulfide takes precedence over the oxidation of other (carbon-based) mitochondrial substrates. Consequently, if sulfide delivery rate remains lower than the SQR activity, cells maintain a non-toxic sulfide concentration (<1 microM) in their external environment. In the colonocyte cell line HT-29, sulfide oxidation provided the first example of reverse electron transfer in living cells, such a transfer increasing sulfide tolerance. However, SQR activity was not detected in brain mitochondria and neuroblastoma cells. Consequently, the neural tissue would be more sensitive to sulfide poisoning. Our data disclose new constraints concerning the emerging signaling role of sulfide.
Emilie Lagoutte; Sabria Mimoun; Mireille Andriamihaja; Catherine Chaumontet; François Blachier; Frédéric Bouillaud
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-04-14
Journal Detail:
Title:  Biochimica et biophysica acta     Volume:  1797     ISSN:  0006-3002     ISO Abbreviation:  Biochim. Biophys. Acta     Publication Date:  2010 Aug 
Date Detail:
Created Date:  2010-06-28     Completed Date:  2010-08-19     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0217513     Medline TA:  Biochim Biophys Acta     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  1500-11     Citation Subset:  IM    
Copyright Information:
Copyright (c) 2010 Elsevier B.V. All rights reserved.
CNRS-FRE3210, Université René Descartes, Site Necker 156 rue de Vaugirard, 75730 Paris cedex15, France.
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MeSH Terms
CHO Cells
Colon / metabolism*
Electron Transport
HT29 Cells
Hydrogen Sulfide / metabolism*
Mitochondria / metabolism
NAD / metabolism
Quinone Reductases / genetics,  physiology
Rotenone / pharmacology
Signal Transduction
Reg. No./Substance:
53-84-9/NAD; 7783-06-4/Hydrogen Sulfide; 83-79-4/Rotenone; EC 1.6.99.-/Quinone Reductases; EC 1.8.5.-/sulfide quinone reductase

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