The antiestrogen 4-hydroxytamoxifen protects against isotretinoin-induced permeability transition and bioenergetic dysfunction of liver mitochondria: comparison with tamoxifen

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Filomena S G Silva (Author) Other; Mariana P C Ribeiro (Author) Other; Maria S Santos (Author) Other; Petronila Rocha Pereira (Author) Other; Alice Santos Silva (Author) FFUP; Jose B A Custodio (Author) Other

Journal

Title: Journal of Bioenergetics and Biomembranes

Vol. 45

Pages: 383-396

ISSN: 0145-479X

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 3 Citations

Scopus - 2 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-006-8Q9

DOI: 10.1007/s10863-013-9517-9

Abstract (EN): The combination of isotretinoin (13-cis-retinoic acid) with antiestrogens seems to be a promising strategy for cancer chemotherapy. The aim of the study was to evaluate the effects of isotretinoin alone or in combination with 4-hydroxytamoxifen (OHTAM) and with its prodrug tamoxifen (TAM), on the functions of rat liver mitochondria, i.e., mitochondrial permeability transition (MPT), bioenergetic functions and adenine nucleotide translocase (ANT). Isotretinoin (5 nmol/mg protein) induced the Ca2+-dependent MPT pore opening in mitochondria energized with succinate, which was prevented by OHTAM, cyclosporine A, TAM and ANT ligands. When mitochondria were energized with glutamate/malate and in the absence of added Ca2+ isotretinoin decreased the state 3 respiration, the ATP levels, the active ANT content and increased the lag phase of the phosphorylation cycle, demonstrating that isotretinoin decreased the mitochondrial phosphorylation efficiency. These changes of isotretinoin in bioenergetic parameters were not significant in the presence of succinate. The effects of isotretinoin at 5 nmol/mg protein on the Ca2+-dependent MPT and phosphorylative efficacy may be related with interactions with the ANT. Above 10 nmol/mg protein isotretinoin strongly diminished the active ANT content, decreased the Delta psi, inhibited the complex I and induced proton leak through the Fo fraction of complex V. The combination of OHTAM with isotretinoin only induced significant changes in the energy production systems at concentrations a parts per thousand yen5 nmol isotretinoin/mg protein. Therefore, our results suggest that isotretinoin-associated liver toxicity is possibly related with mitochondrial dysfunctions and that the combination with OHTAM may contribute to decrease its toxicity.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 14