Coenzyme Q and the regulation of intracellular steady-state levels of superoxide in HL-60 cells.

Abstract

The present work was set to study how CoQ concentrations affected steady-state levels of superoxide in a cellular model of partial CoQ(10) deficiency in cultured human myeloid leukemia HL-60 cells. Culturing HL-60 cells in the presence of p-aminobenzoate, a competitive inhibitor of polyprenyl-4-hydroxybenzoate transferase (Coq2p), produced a significant decrease of CoQ(10) levels without affecting cell viability. Concomitant decreases in CoQ-dependent electron transport activity and mitochondrial membrane potential were observed under these conditions. Intracellular superoxide was significantly elevated in cells treated with p-aminobenzoate, both under serum-containing and serum-free conditions, and this effect was reversed by exogenous CoQ(10). A slight increase of superoxide was also observed in CoQ(10)-supplemented cells in the absence of serum. Our results support a requirement for CoQ(10) to control superoxide levels in HL-60 cells. The importance of extramitochondrial sources of superoxide in cells with impaired CoQ(10) biosynthesis is discussed.

• Authors: David González-Aragón, María I Burón, Guillermo López-Lluch, María D Hermán, Consuelo Gómez-Díaz, Plácido Navas, José M Villalba
• Journal: BioFactors (Oxford, England) (Biofactors) Vol. 25 Issue 1-4 Pg. 31-41 ( 2005) ISSN: 0951-6433 [Print] Netherlands
• PMID: 16873928 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Coenzymes
• Phenanthridines
• Superoxides
• Ubiquinone
• hydroethidine
• Succinate Cytochrome c Oxidoreductase
• Alkyl and Aryl Transferases
• 4-hydroxybenzoate polyprenyltransferase
• coenzyme Q10
• 4-Aminobenzoic Acid

Topics

• 4-Aminobenzoic Acid (pharmacology)
• Alkyl and Aryl Transferases (antagonists & inhibitors)
• Coenzymes
• HL-60 Cells
• Humans
• Phenanthridines (metabolism)
• Succinate Cytochrome c Oxidoreductase (metabolism)
• Superoxides (metabolism)
• Ubiquinone (analogs & derivatives, deficiency, physiology)