The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Je-yong Choi - One of the best experts on this subject based on the ideXlab platform.
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Interrelationship of Runx2 and Estrogen pathway in skeletal tissues.
Journal of Biochemistry and Molecular Biology, 2011Co-Authors: Jae-hwan Jeong, Je-yong ChoiAbstract:Two key molecules in skeletal tissues are bone formation master transcription factor Runx2 and the steroid hormone Estrogen. It is well known that these two molecules play pivotal roles in bone homeostasis; however, the functional interaction between Runx2 and Estrogen Synthesis in skeletal tissues is largely unknown. Recent studies have indicated that there is a positive relationship between Runx2 and the Estrogen bioSynthesis pathway. In this review, a possible functional link between Runx2 and Estrogen Synthesis pathway in skeletal tissues will be discusses as well as the biological significance of this interaction. [BMB reports 2011; 44(10): 613-618]
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Interrelationship of Runx2 and Estrogen pathway in skeletal tissues.
BMB reports, 2011Co-Authors: Jae-hwan Jeong, Je-yong ChoiAbstract:Two key molecules in skeletal tissues are bone formation master transcription factor Runx2 and the steroid hormone Estrogen. It is well known that these two molecules play pivotal roles in bone homeostasis; however, the functional interaction between Runx2 and Estrogen Synthesis in skeletal tissues is largely unknown. Recent studies have indicated that there is a positive relationship between Runx2 and the Estrogen bioSynthesis pathway. In this review, a possible functional link between Runx2 and Estrogen Synthesis pathway in skeletal tissues will be discusses as well as the biological significance of this interaction.
Yann Guiguen - One of the best experts on this subject based on the ideXlab platform.
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rainbow trout gonadal masculinization induced by inhibition of Estrogen Synthesis is more physiological than masculinization induced by androgen supplementation
Biology of Reproduction, 2008Co-Authors: Denise Vizziano, Daniel Baron, Sophie Mahe, Chantal Cauty, Gwénaëlle Randuineau, Yann GuiguenAbstract:The present study was designed to obtain new insights into fish gonadal sex differentiation by comparing the effects of two different masculinizing treatments on some candidate gene expression profiles. Masculinization was induced in rainbow trout, Oncorhynchus mykiss, genetic all-female populations using either an active fish androgen (11betaAnd, 11betahydroxyandrostenedione) or an aromatase inhibitor (ATD, 1,4,6-androstatriene-3,17-dione). The expression profiles of 100 candidate genes were obtained by real-time RT-PCR, and 46 profiles displayed a significant differential expression between control populations (males and females) and ATD/ 11betaAnd-treated populations. These expression profiles were grouped in four temporally correlated expression clusters. Among the common responses shared by the two masculinizing treatments, the inhibition of some early female differentiating genes (cyp19a1, foxl2a, fst, and fshb) appears to be crucial for effective masculinization, suggesting that these genes act together via a short regulation loop to maintain high sex-specific ovarian expression of cyp19a1. This simultaneous down-regulation of female-specific genes could be triggered by some testicular genes, such as dmrt1, nr0b1 (also known as dax1), and pdgfra, which are quickly up-regulated by the two masculinizing treatments. In contrast to 11betaAnd, ATD quickly restored the expression levels of steroidogenesis related genes (cyp11b2.1, cyp11b2.2, hsd3b1, cyp17a, star, and nr5a1) and some Sertoli cell markers (sox9a2 and amh )t o the expression levels observed during control testicular differentiation. This demonstrates that these genes are probably not needed for active masculinization and that the inhibition of endogenous Estrogen Synthesis produces a much more complete and specific testicular pattern of gene expression than that observed following androgen-induced masculinization.
Juli Wade - One of the best experts on this subject based on the ideXlab platform.
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The Effects of Testicular Tissue and Prehatching Inhibition of Estrogen Synthesis on the Development of Courtship and Copulatory Behavior in Zebra Finches
Hormones and behavior, 1997Co-Authors: Mae Lee Springer, Juli WadeAbstract:As in many mammalian and avian species, testicular androgens or their metabolites activate courtship and copulatory behaviors in adult male zebra finches. However, studies of sexual differentiation of these behaviors and related anatomical structures provide conflicting results. For example, posthatching estradiol can both masculinize courtship and the neural structures involved in song in females and inhibit the development of masculine copulation in males. These and other results have led to the hypotheses that (1) testicular androgens are converted to estradiol in the brain of developing males, and estradiol serves to masculinize the song system, whereas (2) estradiol secretion by the female ovary allows feminine rather than masculine copulatory behavior to develop. Treating embryonic zebra finches with the Estrogen Synthesis inhibitor fadrozole causes functional testicular tissue to develop in genetic females. The present study investigated the effects of such treatment on the development of singing and copulatory behavior as well as song system anatomy in males and females. While exogenous testosterone facilitated the display of sexual behaviors in adult males, the testicular tissue in females had no masculinizing effect on the production of audible courtship song or copulation. Their song control nuclei were also not masculinized, even in individuals lacking ovarian tissue. In contrast, embryonic inhibition of Estrogen Synthesis in males significantly stimulated song production. These results suggest that while manipulations of steroid hormone exposure can influence the display of sexual behaviors, gonadal secretions may not be required for normal sexual differentiation of the song system in zebra finches.
Barney A. Schlinger - One of the best experts on this subject based on the ideXlab platform.
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Brain aromatase: new lessons from non-mammalian model systems.
Frontiers in neuroendocrinology, 2006Co-Authors: Paul M. Forlano, Barney A. Schlinger, Andrew H. BassAbstract:This review highlights recent studies of the anatomical and functional implications of brain aromatase (Estrogen synthase) expression in two vertebrate lineages, teleost fishes and songbirds, that show remarkably high levels of adult brain aromatase activity, protein and gene expression compared to other vertebrate groups. Teleosts and birds have proven to be important neuroethological models for investigating how local Estrogen Synthesis leads to changes in neural phenotypes that translate into behavior. Region-specific patterns of aromatase expression, and thus Estrogen Synthesis, include the vocal and auditory circuits that figure prominently into the life history adaptations of vocalizing teleosts and songbirds. Thus, by targeting, for example, vocal motor circuits without inappropriate steroid exposure to other steroid-dependent circuits, such as those involved in either copulatory or spawning behaviors, the neuroendocrine system can achieve temporal and spatial specificity in its modulation of neural circuits that lead to the performance of any one behavior.
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Estrogen Synthesis and secretion in the brown headed cowbird molothrus ater
General and Comparative Endocrinology, 1997Co-Authors: Colin J Saldanha, Barney A. SchlingerAbstract:Estrogens exert profound effects on vertebrate physiology and behavior. In most vertebrates, including birds, Estrogens derived from ovarian tissue circulate at high levels during discrete periods of reproductive activity, and Estrogen levels in males are low. In some songbirds (Passeriformes) plasma Estrogens are high in both males and females. In the zebra finch, aromatase (Estrogen-synthetase) is expressed abundantly in several regions of the male and female telencephalon and contributes to peripheral Estrogen titers. To determine if this pattern of neural aromatase and Estrogen Synthesis is found in other songbirds, we have examined the patterns of Estrogen Synthesis in various tissues of another songbird, the common North American cowbird (Molothrus ater). Radiolabeled aromatizable androgenic substrate was injectedin vivoor providedin vitroto telencephalic and gonadal tissue from adult male and female cowbirds. Estrogenic products were assayed in blood from the carotid artery and jugular vein, and in the telencephalon, ovary, and testes. Additionally, the presence of aromatase mRNA was studied in the brain usingin situhybridization. Radiolabeled androgenic substrate, injectedin vivo,was readily converted to Estrogens with higher amounts in the jugular compared to carotid blood, suggesting that the brain contains relatively high levels of aromatase. Further, radiolabeled androgens, providedin vitroto telencephalic, ovarian, and testicular tissue, resulted in the formation of radiolabeled Estrogens. Aromatase mRNA is distributed widely in several areas of the cowbird telencephalon including the hippocampus, caudomedial neostriatum (including Field L), and nucleus taeniae. This pattern of neural aromatase expression resembles what we have found previously in the zebra finch. Telencephalic aromatase may be characteristic of passerine songbirds and may function to provide local Estrogenic cues to Estrogen-sensitive neural loci, and/or contribute to peripheral Estrogen titers in male and female songbirds.
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Estrogen Synthesis in vivo in the adult zebra finch: additional evidence that circulating Estrogens can originate in brain
Endocrinology, 1993Co-Authors: Barney A. Schlinger, Arthur P. ArnoldAbstract:Aromatase activity is abundant in limbic and nonlimbic neural structures in zebra finches, especially in the telencephalon near neural circuits that control singing behavior. Also, male songbirds can have high Estrogen levels in blood. Because it is difficult to detect aromatase activity in other male tissues, we have postulated that the brain itself is the source of the Estrogen present in the blood of males. Previously, we developed methods to measure Estrogen Synthesis in vivo by injecting [3H]androgen into the systemic circulation or directly into tissues and then determining the quantity of [3H]Estrogen entering or leaving the brain. Our results support our hypothesis that the brain is the primary site of Estrogen Synthesis in males of this species. Here, we confirm that [3H]Estrogen emanates from the brain after systemic [3H]androgen injection by showing that the presumptive Estrogen in jugular plasma is significantly reduced by treatment with an aromatase inhibitor. In females, but not males, estro...
Jae-hwan Jeong - One of the best experts on this subject based on the ideXlab platform.
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Interrelationship of Runx2 and Estrogen pathway in skeletal tissues.
Journal of Biochemistry and Molecular Biology, 2011Co-Authors: Jae-hwan Jeong, Je-yong ChoiAbstract:Two key molecules in skeletal tissues are bone formation master transcription factor Runx2 and the steroid hormone Estrogen. It is well known that these two molecules play pivotal roles in bone homeostasis; however, the functional interaction between Runx2 and Estrogen Synthesis in skeletal tissues is largely unknown. Recent studies have indicated that there is a positive relationship between Runx2 and the Estrogen bioSynthesis pathway. In this review, a possible functional link between Runx2 and Estrogen Synthesis pathway in skeletal tissues will be discusses as well as the biological significance of this interaction. [BMB reports 2011; 44(10): 613-618]
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Interrelationship of Runx2 and Estrogen pathway in skeletal tissues.
BMB reports, 2011Co-Authors: Jae-hwan Jeong, Je-yong ChoiAbstract:Two key molecules in skeletal tissues are bone formation master transcription factor Runx2 and the steroid hormone Estrogen. It is well known that these two molecules play pivotal roles in bone homeostasis; however, the functional interaction between Runx2 and Estrogen Synthesis in skeletal tissues is largely unknown. Recent studies have indicated that there is a positive relationship between Runx2 and the Estrogen bioSynthesis pathway. In this review, a possible functional link between Runx2 and Estrogen Synthesis pathway in skeletal tissues will be discusses as well as the biological significance of this interaction.