Selective oestrogen receptor modulators differentially potentiate brain mitochondrial function.

TitleSelective oestrogen receptor modulators differentially potentiate brain mitochondrial function.
Publication TypeJournal Article
Year of Publication2012
AuthorsIrwin RW, Yao J, To J, Hamilton RT, Cadenas E, Brinton RD
JournalJ Neuroendocrinol
Volume24
Issue1
Pagination236-48
Date Published2012 Jan
ISSN1365-2826
KeywordsAnimals, Brain, Estradiol, Estrogen Receptor alpha, Estrogen Receptor beta, Female, Lipid Peroxidation, Mitochondria, Nitriles, Ovariectomy, Phenols, Propionates, Pyrazoles, Rats, Rats, Sprague-Dawley, Selective Estrogen Receptor Modulators
Abstract

The mitochondrial energy-transducing capacity of the brain is important for long-term neurological health and is influenced by endocrine hormone responsiveness. The present study aimed to determine the role of oestrogen receptor (ER) subtypes in regulating mitochondrial function using selective agonists for ERα (propylpyrazoletriol; PPT) and ERβ (diarylpropionitrile; DPN). Ovariectomised female rats were treated with 17β-oestradiol (E(2) ), PPT, DPN or vehicle control. Both ER selective agonists significantly increased the mitochondrial respiratory control ratio and cytochrome oxidase (COX) activity relative to vehicle. Western blots of purified whole brain mitochondria detected ERα and, to a greater extent, ERβ localisation. Pre-treatment with DPN, an ERβ agonist, significantly increased ERβ association with mitochondria. In the hippocampus, DPN activated mitochondrial DNA-encoded COX I expression, whereas PPT was ineffective, indicating that mechanistically ERβ, and not ERα, activated mitochondrial transcriptional machinery. Both selective ER agonists increased protein expression of nuclear DNA-encoded COX IV, suggesting that activation of ERβ or ERα is sufficient. Selective ER agonists up-regulated a panel of bioenergetic enzymes and antioxidant defence proteins. Up-regulated proteins included pyruvate dehydrogenase, ATP synthase, manganese superoxide dismutase and peroxiredoxin V. In vitro, whole cell metabolism was assessed in live primary cultured hippocampal neurones and mixed glia. The results of analyses conducted in vitro were consistent with data obtained in vivo. Furthermore, lipid peroxides, accumulated as a result of hormone deprivation, were significantly reduced by E(2) , PPT and DPN. These findings suggest that the activation of both ERα and ERβ is differentially required to potentiate mitochondrial function in brain. As active components in hormone therapy, synthetically designed oestrogens as well as natural phyto-oestrogen cocktails can be tailored to improve brain mitochondrial endpoints.

DOI10.1111/j.1365-2826.2011.02251.x
Alternate JournalJ. Neuroendocrinol.
PubMed ID22070562
PubMed Central IDPMC3264398
Grant List2R01AG032236 / AG / NIA NIH HHS / United States
R01 MH067159-05 / MH / NIMH NIH HHS / United States
R01 AG032236 / AG / NIA NIH HHS / United States
R01 AG032236-07 / AG / NIA NIH HHS / United States
R01 MH067159 / MH / NIMH NIH HHS / United States
R01 AG032236-06A2 / AG / NIA NIH HHS / United States
R01 AG032236-08 / AG / NIA NIH HHS / United States
Faculty Member Reference: 
Roberta Diaz Brinton, Ph.D