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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Estradiol modulates Kiss1 neuronal response to ghrelin

Full text
Author(s):
Frazao, Renata [1, 2] ; Lemko, Heather M. Dungan [2] ; da Silva, Regina P. [1] ; Ratra, Dhirender V. [3, 4] ; Lee, Charlotte E. [2] ; Williams, Kevin W. [2] ; Zigman, Jeffrey M. [2] ; Elias, Carol F. [3, 4, 2]
Total Authors: 8
Affiliation:
[1] Univ Sao Paulo, Inst Biomed Sci, Dept Anat, Sao Paulo - Brazil
[2] Univ Texas SW Med Ctr Dallas, Dept Internal Med, Div Hypothalam Res, Dallas, TX 75390 - USA
[3] Univ Michigan, Dept Mol & Integrat Physiol, Ann Arbor, MI 48109 - USA
[4] Univ Michigan, Dept Obstet & Gynecol, Ann Arbor, MI 48109 - USA
Total Affiliations: 4
Document type: Journal article
Source: AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM; v. 306, n. 6, p. E606-E614, MAR 2014.
Web of Science Citations: 34
Abstract

Ghrelin is a metabolic signal regulating energy homeostasis. Circulating ghrelin levels rise during starvation and fall after a meal, and therefore, ghrelin may function as a signal of negative energy balance. Ghrelin may also act as a modulator of reproductive physiology, as acute ghrelin administration suppresses gonadotropin secretion and inhibits the neuroendocrine reproductive axis. Interestingly, ghrelin's effect in female metabolism varies according to the estrogen milieu predicting an interaction between ghrelin and estrogens, likely at the hypothalamic level. Here, we show that ghrelin receptor (GHSR) and estrogen receptor-alpha (ER alpha) are coexpressed in several hypothalamic sites. Higher levels of circulating estradiol increased the expression of GHSR mRNA and the co-xpression of GHSR mRNA and ER alpha selectively in the arcuate nucleus (ARC). Subsets of preoptic and ARC Kiss1 neurons coexpressed GHSR. Increased colocalization was observed in ARC Kiss1 neurons of ovariectomized estradiol-treated (OVX + E-2; 80%) compared with ovariectomized oil-treated (OVX; 25%) mice. Acute actions of ghrelin on ARC Kiss1 neurons were also modulated by estradiol; 75 and 22% of Kiss1 neurons of OVX + E-2 and OVX mice, respectively, depolarized in response to ghrelin. Our findings indicate that ghrelin and estradiol may interact in several hypothalamic sites. In the ARC, high levels of E-2 increase GHSR mRNA expression, modifying the colocalization rate with ER alpha and Kiss1 and the proportion of Kiss1 neurons acutely responding to ghrelin. Our findings indicate that E-2 alters the responsiveness of kisspeptin neurons to metabolic signals, potentially acting as a critical player in the metabolic control of the reproductive physiology. (AU)

FAPESP's process: 12/12554-8 - 42nd Annual Meeting of the Society for Neuroscience - Neuroscience 2012
Grantee:Renata Frazão
Support Opportunities: Research Grants - Meeting - Abroad
FAPESP's process: 13/00801-3 - Involvement of Kiss1 neurons in the neural pathway through which the circadian system regulates the ovulatory cycle
Grantee:Regina Silva Paradela
Support Opportunities: Scholarships in Brazil - Master
FAPESP's process: 12/12202-4 - Kiss1 neurons biophysical properties modulation by circadian factors
Grantee:Renata Frazão
Support Opportunities: Regular Research Grants