Role of plasma membrane coenzyme Q on the regulation of apoptosis

Article type: Research Article

Authors: López‐Lluch, G. | Barroso, M.P. | Martín, S.F. | Fernández‐Ayala, D.J.M. | Gómez‐Díaz, C. | Villalba, J.M. | Navas, P.^;

Affiliations: Laboratorio Andaluz de Biología, Universidad Pablo de Olavide, 41013 Sevilla, Spain | Departamento de Biología Celular, Facultad de Ciencias, Universidad de Córdoba, Córdoba, Spain

Note: [] Correspondence to: Prof. P. Navas, Laboratorio Andaluz de Biología, Universidad Pablo de Olavide, Carretera de Utrera Km. 1, 41013 Sevilla, Spain.

Abstract: Serum withdrawal is a model to study the mechanisms involved in the induction of apoptosis caused by mild oxidative stress. Apoptosis induced by growth factors removal was prevented by the external addition of antioxidants such as ascorbate, \alpha‐tocopherol and coenzyme Q (CoQ). CoQ is a lipophilic antioxidant which prevents oxidative stress and participates in the regeneration of \alpha‐tocopherol and ascorbate in the plasma membrane. We have found an inverse relationship between CoQ content in plasma membrane and lipid peroxidation rates in leukaemic cells. CoQ_{10} addition to serum‐free culture media prevented both lipid peroxidation and cell death. Also, CoQ_{10} addition decreased ceramide release after serum withdrawal by inhibition of magnesium‐dependent plasma membrane neutral‐sphingomyelinase. Moreover, CoQ_{10} addition partially blocked activation of CPP32/caspase‐3. These results suggest CoQ of the plasma membrane as a regulator of initiation phase of oxidative stress‐mediated serum withdrawal‐induced apoptosis.

Journal: Biofactors, vol. 9, no. 2-4, pp. 171-177, 1999