Involvement of PGC-1, NRF-1, and NRF-2 in metabolic response by rat liver to hormonal and environmental signals

P. Venditti , A. Bari , L. Di Stefano , A. Cardone , F. Della Ragione , M. d'Esposito , S. Di Meo

We studied liver oxidative capacity and O consumption in hypothyroid rats treated for 10 days with T, or T, or treated for 10 days with T and exposed to cold for the last two days. The metabolic response of homogenates and mitochondria indicated that all treatments increased the synthesis of respiratory chain components, whereas only the cold induced mitochondrial proliferation. Determination of mRNA and protein expression of transcription factor activators, such as NRF-1 and NRF-2, and coactivators, such as PGC-1, showed that mRNA levels, except PGC-1 ones, were not related to aerobic capacities. Conversely, a strong correlation was found was between cytochrome oxidase activity and PGC-1 or NRF-2 protein levels. Such a correlation was not found for NRF-1. Our results strongly support the view that in rat liver PGC-1 and NRFs are responsible for the iodothyronine-induced increases in respiratory chain components, whereas their role in cold-induced mitochondrial proliferation needs to be further on clarified.

Mots clés: Cold-exposure; Thyroid hormone; Mitochondrial respiration; Mitochondrial proliferation; Transcription factor activators

P. Venditti, A. Bari, L. Di Stefano, A. Cardone, F. Della Ragione, et al.. Involvement of PGC-1, NRF-1, and NRF-2 in metabolic response by rat liver to hormonal and environmental signals. Molecular and Cellular Endocrinology, 2009, 305 (1-2), pp.22. ⟨10.1016/j.mce.2009.02.009⟩. ⟨hal-00499118⟩