Ontogeny of Cytochrome P450 Aromatase mRNA Expression in the Developing Sheep Brain

Roselli, Charles E.; Stormshak, F.

doi:10.1111/j.1365-2826.2011.02260.x

Cited by 16 publications

(11 citation statements)

References 69 publications

(96 reference statements)

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“…In addition, our anatomical study demonstrated that both ERa and AR are expressed within the central component of the foetal medial preoptic nucleus, which represents the nascent oSDN as defined by aromatase mRNA expression. These results complement our previous observation that aromatase mRNA expression has a similar pattern of distribution in the foetal mPOA, although this is not quantitatively different between the sexes (28). The simultaneous expression of aromatase, ERa and AR suggests that both androgens and oestrogens, either synthesised in the brain or derived from the circulation, are available to mediate the hormone dependent developmental processes that lead to functional and structural changes in brain areas important for male-typical differentiation.…”

Section: Discussionsupporting

confidence: 88%

Sex Differences in Expression of Oestrogen Receptor α but not Androgen Receptor mRNAs in the Foetal Lamb Brain

Reddy

Estill

Meaker

et al. 2014

J Neuroendocrinology

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Gonadal steroid hormones play important roles during critical periods of development to organize brain structures that control sexually dimorphic neuroendocrine responses and behaviors. Specific receptors for androgens and estrogens must be expressed at appropriate times during development in order to mediate these processes. The present study was performed to test for sex differences in the relative expression of estrogen receptor-α (ERα) and androgen receptor (AR) mRNA during the window of time in gestation that is critical for behavioral masculinization and differentiation of the ovine sexually dimorphic nucleus (oSDN) in the sheep. In addition, we examined whether ERα and AR mRNA expression is localized within the nascent oSDN and could be involved in its development. Using quantitative RT-PCR, we found that females expressed more ERα mRNA than males in medial preoptic area and medial basal hypothalamus during the mid-gestational critical period for brain sexual differentiation. No sex differences were found for AR mRNA in any tissue examined or for ERα in amygdala and frontal cortex. Using radioactive in situ hybridization, we found that the distributions of ERα and AR mRNA overlapped with aromatase mRNA, which delineates the boundaries of the developing oSDN and identifies this nucleus as a target for both androgens and estrogens These data demonstrate that the transcriptional machinery for synthesizing gonadal steroid receptors is functional in the fetal lamb brain during the critical period for sexual differentiation and suggest possible mechanisms for establishing dimorphisms controlled by gonadal steroids may exist at the level of steroid hormone receptor expression.

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Section: Discussionsupporting

confidence: 88%

Sex Differences in Expression of Oestrogen Receptor α but not Androgen Receptor mRNAs in the Foetal Lamb Brain

Reddy

Estill

Meaker

et al. 2014

J Neuroendocrinology

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“…In the cerebral cortex and amygdala aromatase activity was significantly greater in males than females, but similar sex differences were not observed in the preoptic area or hypothalamus ( Roselli and Resko, 1986 ). Conversely, analysis of fetal sheep brain (at gestational days 53, 65, 85, 100, 120, and 135) by Roselli and Stormshak (2012) revealed that Cyp19 expression levels in the amygdala was similar across days tested in males and females ( Roselli and Stormshak, 2012 ). This study also revealed that both sexes demonstrated a similar temporal pattern of Cyp19 expression in the preoptic area, suggesting that in both non-human primates and sheep aromatase expression in this brain region is not influenced by sexually dimorphic factors.…”

Section: Sex Differences In Aromatase During Critical Periods Of Devementioning

confidence: 97%

Sexually Dimorphic Effects of Aromatase on Neurobehavioral Responses

Shay

Vieira‐Potter

Rosenfeld

2018

Front. Mol. Neurosci.

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Aromatase is the enzyme responsible for converting testosterone to estradiol. In mammals, aromatase is expressed in the testes, ovaries, brain, and other tissues. While estrogen is traditionally associated with reproduction and sexual behavior in females, our current understanding broadens this perspective to include such biological functions as metabolism and cognition. It is now well-recognized that aromatase plays a vital lifetime role in brain development and neurobehavioral function in both sexes. Thus, ongoing investigations seek to highlight potentially vital sex differences in the role of aromatase, particularly regarding its centrally mediated effects. To characterize the role of aromatase in mediating such functions, effects of aromatase inhibitor (AI) treatments on humans and animal models have been determined. Aromatase knockout (ArKO) mice that systemically lack the enzyme have also been employed. Humans possessing mutations in the gene encoding aromatase, CYP19, have also provided critical insight into how aromatase affects brain function in a possible sex-dependent manner. A better understanding of how AIs, used to treat breast cancer and other clinical conditions, may detrimentally affect neurobehavioral responses will likely promote development of future therapies to combat these effects. Herein, we will provide a critical review of the current knowledge of sex differences in aromatase regulation of various neurobehavioral functions. Although many species have been used to better understand the functions of aromatase, this review focuses on rodent models and humans. Critical gaps in our present understanding of this area will be considered, and important future research directions will be discussed.

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“…The expression of P450Arom in the hypothalamus during ontogenesis has been reported in several long gestation species (see Table ) including sheep (Roselli & Stormshak, ), bovine (Peruffo, Cozzi, & Ballarin, ), monkey (Roselli & Resko, ), and man (Sasano et al, ).…”

Section: Discussionmentioning

confidence: 93%

Neurochemical characterization of the hypothalamus of the early fetal and newborn alpaca Vicugna pacos

Montelli

Graïc

Ruiz

et al. 2019

The Anatomical Record

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In this study we performed a neurochemical characterization of the hypothalamus in the developing alpaca (Vicugna pacos) with the aim of revealing the distributions of immunoreactive (-ir) cells containing parvalbumin (PV), calbindin (CB), calretinin (CR), the somatostatin (SOM), the enzyme aromatase P450 (P450Arom), the estrogen receptor α (ER-α), and estrogen receptor β (ER-β) in embryonal stages, early fetal age, and in the newborn. This analysis has been carried out on embryos at 20, 30, 45 days, fetuses at 90 days, and newborn alpaca. Our immunohistochemical results revealed no cells-ir throughout the embryonic hypothalami of 20, 30, and 45 days. On the fetal stage of 90 days, SOM-ir cells were observed in the lateral hypothalamus and the ventromedial nuclei of the tuberal region. We checked for the presence of P450Arom-ir cells in the periventricular area and dorsomedial hypothalamic nucleus of the tuberal region. In these fetal stages, no PV-ir, CB-ir, CR-ir or ERs-ir cells were identified. In the newborn, the PV-ir, CB-ir, CR-ir, and SOMir cells were detected in both the anterior and tuberal hypothalamic area. The P450Arom-ir cells the ER-α-ir and ER-β-ir cells were found in the anterior hypothalamus. Our results offer a contribution in the future purpose to obtain a time-expression pattern of the considered markers in alpaca during gestation and represents a foundation for future investigations on the alpaca brain to define the cross talk between PV, CB, CR, P450Arom, SOM, and ERs in the hypothalamus, the strategic region for the control of the reproductive behavior.

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Ontogeny of Cytochrome P450 Aromatase mRNA Expression in the Developing Sheep Brain

Cited by 16 publications

References 69 publications

Sex Differences in Expression of Oestrogen Receptor α but not Androgen Receptor mRNAs in the Foetal Lamb Brain

Sex Differences in Expression of Oestrogen Receptor α but not Androgen Receptor mRNAs in the Foetal Lamb Brain

Sexually Dimorphic Effects of Aromatase on Neurobehavioral Responses

Neurochemical characterization of the hypothalamus of the early fetal and newborn alpaca Vicugna pacos

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