Skeletal muscle mitochondrial free-fatty-acid content and membrane potential sensitivity in different thyroid states: involvement of uncoupling protein-3 and adenine nucleotide translocase.
The effect of triiodothyronine (T3) on mitochondrial efficiency could be related to an increase in the concentrations of some proteins, such as uncoupling proteins (UCPs). Free fatty acids (FFA) seem to be a cofactor essential for the uncoupling activity of UCP3. In this paper, we report that the hypothyroidism-hyperthyroidism transition is accompanied by increases: (i) in the endogenous levels of mitochondrial FFA and (ii) in the sensitivity to FFA shown by the mitochondrial respiration rate and membrane potential, which correlated with the level of UCP3 protein. The level of the mRNA for adenine-nucleotide translocase-1 (ANT) was not affected by the thyroid state, while the ANT contribution to FFA-induced changes in mitochondrial uncoupling was low in the hypothyroid and euthyroid states but became more relevant in the hyperthyroid state at the highest concentration of FFA.
Lombardi
A
A
Dipartimento di Fisiologia Generale ed Ambientale, Università degli Studi di Napoli Federico II, Via Mezzocannone 8, 80134 Napoli, Italy.
Silvestri
E
E
Moreno
M
M
De Lange
P
P
Farina
P
P
Goglia
F
F
Lanni
A
A
D033741:Adenine Nucleotide Translocator 1 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D000818:Animals; D002352:Carrier Proteins / Q000032:analysis / Q000502:physiology*; D019069:Cell Respiration / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005230:Fatty Acids, Nonesterified / Q000032:analysis*; D006980:Hyperthyroidism / Q000378:metabolism / Q000503:physiopathology; D007037:Hypothyroidism / Q000378:metabolism / Q000503:physiopathology; D007473:Ion Channels; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D024101:Mitochondrial Proteins; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D019301:Oleic Acid / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D013959:Thyroid Diseases / Q000378:metabolism*; D013961:Thyroid Gland / Q000378:metabolism / Q000502:physiology; D000071247:Uncoupling Protein 3
D033741:Adenine Nucleotide Translocator 1; D002352:Carrier Proteins; D005230:Fatty Acids, Nonesterified; D007473:Ion Channels; D024101:Mitochondrial Proteins; D012333:RNA, Messenger; C000604394:Ucp3 protein, rat; D000071247:Uncoupling Protein 3; D019301:Oleic Acid