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Genetic Variation in the Androgen Receptor Modifies the Association Between Testosterone and Vitality in Middle-Aged Men. J Sex Med 2020; 17:2351-2361. [PMID: 33011098 DOI: 10.1016/j.jsxm.2020.08.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/14/2020] [Accepted: 08/24/2020] [Indexed: 11/20/2022]
Abstract
BACKGROUND Low vitality is a common symptom of testosterone deficiency; however, clinical trial results remain inconclusive regarding the responsiveness of this symptom to hormone replacement. AIM The aim of the present study was to determine if the relationship between circulating testosterone levels and vitality would be moderated by the CAG repeat length in the androgen receptor (AR) gene, which influences the receptor's sensitivity to testosterone. METHODS We examined 676 men in the Vietnam Era Twin Study of Aging when they were, on average, 55.4 years old (SD = 2.5). Salivary testosterone levels were measured by using 3 samples collected at waking on 3 nonconsecutive days. The average testosterone level was classified as low, normal, or high based on 1-SD cutoffs. Analyses were conducted using multilevel, mixed linear models, which accounted for the nonindependence of the twin data, and adjusted for the effects of age, ethnicity, BMI, chronic health conditions, depressive symptoms, and sleep quality. OUTCOMES Vitality was measured using the 36-item Short Form (SF-36) vitality subscale. RESULTS We observed a significant interaction between salivary testosterone and the AR-CAG repeat length. When the repeat length was short, men with low testosterone had significantly lower vitality. As the AR-CAG repeat length increased, the magnitude of the testosterone effect decreased. CLINICAL TRANSLATION The observed interaction between testosterone and variation in the AR gene suggests that men with more sensitive ARs, as indicated by a shorter AR-CAG repeat, are more likely to experience symptoms of age-related testosterone deficiency. STRENGTHS & LIMITATIONS Strengths of the present study include our use of a large community-based sample, the use of multiple testosterone measurements, and the availability of a comprehensive set of covariates that may impact the association of interest. Limitations include the homogeneous nature of the sample with respect to ethnicity, the brevity of the 36-item Short Form vitality subscale, and our inability to establish change in testosterone levels because of the cross-sectional nature of data. CONCLUSIONS The association between testosterone and vitality appears to be clinically meaningful and is in part dependent on variation in the AR gene. Panizzon MS, Bree K, Hsieh T-C, et al. Genetic Variation in the Androgen Receptor Modifies the Association Between Testosterone and Vitality in Middle-Aged Men. J Sex Med 2020;17:2351-2361.
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Saranyutanon S, Srivastava SK, Pai S, Singh S, Singh AP. Therapies Targeted to Androgen Receptor Signaling Axis in Prostate Cancer: Progress, Challenges, and Hope. Cancers (Basel) 2019; 12:cancers12010051. [PMID: 31877956 PMCID: PMC7016833 DOI: 10.3390/cancers12010051] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/18/2019] [Accepted: 12/18/2019] [Indexed: 12/12/2022] Open
Abstract
Prostate cancer is the mostly commonly diagnosed non-cutaneous malignancy and the second leading cause of cancer-related death affecting men in the United States. Moreover, it disproportionately affects the men of African origin, who exhibit significantly greater incidence and mortality as compared to the men of European origin. Since androgens play an important role in the growth of normal prostate and prostate tumors, targeting of androgen signaling has remained a mainstay for the treatment of aggressive prostate cancer. Over the years, multiple approaches have been evaluated to effectively target the androgen signaling pathway that include direct targeting of the androgens, androgen receptor (AR), AR co-regulators or other alternate mechanisms that impact the outcome of androgen signaling. Several of these approaches are currently in clinical practice, while some are still pending further development and clinical evaluation. This remarkable progress has resulted from extensive laboratory, pre-clinical and clinical efforts, and mechanistic learnings from the therapeutic success and failures. In this review, we describe the importance of androgen signaling in prostate cancer biology and advances made over the years to effectively target this signaling pathway. We also discuss emerging data on the resistance pathways associated with the failure of various androgen signaling- targeted therapies and potential of this knowledge for translation into future therapies for prostate cancer.
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Affiliation(s)
- Sirin Saranyutanon
- Department of Pathology, College of Medicine, University of South Alabama, Mobile, AL 36617, USA; (S.S.)
- Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA
| | - Sanjeev Kumar Srivastava
- Department of Pathology, College of Medicine, University of South Alabama, Mobile, AL 36617, USA; (S.S.)
- Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA
- Correspondence: (S.K.S.); (A.P.S.); Tel.: +1-251-445-9874 (S.K.S.); +1-251-445-9843 (A.P.S.)
| | - Sachin Pai
- Department of Medical Oncology, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA;
| | - Seema Singh
- Department of Pathology, College of Medicine, University of South Alabama, Mobile, AL 36617, USA; (S.S.)
- Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Ajay Pratap Singh
- Department of Pathology, College of Medicine, University of South Alabama, Mobile, AL 36617, USA; (S.S.)
- Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
- Correspondence: (S.K.S.); (A.P.S.); Tel.: +1-251-445-9874 (S.K.S.); +1-251-445-9843 (A.P.S.)
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Paramanik V, Krishnan H, Kumar Thakur M. Estrogen Receptor α- and β-Interacting Proteins Contain Consensus Secondary Structures: An Insilico Study. Ann Neurosci 2018; 25:1-10. [PMID: 29887678 DOI: 10.1159/000481809] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Background Estrogen receptor (ER)α and ERβ are ligand-activated transcription factors that regulate gene expression by binding to estrogen-responsive elements and interacting with several coregulators through protein-protein interactions. Usually, these coregulators bind to the various conserved and functional domains of the receptor through a consensus LXXLL sequence, although variations can be found. The interaction of receptor domains and the consensus motif can be a possible target for nuclear receptor (NR) pharmacology, since modifications in these are responsible for possible pathogenesis of various diseases. Purpose The present study focuses on the secondary structure and conserved domains of the ERα and ERβ interacting proteins, using bioinformatics tools and their relation to the function of the coregulators. Methods Bioinformatics-based prediction tools like STRING, PSIPRED, PROTPARAM and Conserved Domain Database (CDD) were used. The prediction tools utilized in this study basically determines the characteristics of a possible coregulator by using an already existing protein as a template and determines the presence of any conserved consensus sequence. Coregulators have been enlisted with the help of NCBI, STRING and iHOP. The secondary structures were analyzed using PSIPRED and conserved domains were determined using CDD. Results The analysis of the structure has shown the presence of conserved domains and homology between the various coregulators. Each interacting protein contains conserved domains like the nuclear coactivators' domain, the helix-loop-helix domain and the SRC domain. Conclusion Such studies give the characteristic features of ERα and ERβ interacting proteins and maybe useful to determine their family and uses in NR pharmacology in health and diseases.
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Affiliation(s)
- Vijay Paramanik
- Department of Zoology, Cellular and Molecular Neurobiology and Drug Targeting Laboratory, Indira Gandhi National Tribal University, Amarkantak, India
| | - Harini Krishnan
- Department of Zoology, Biochemistry and Molecular Biology Laboratory, Banaras Hindu University, Varanasi, India
| | - Mahendra Kumar Thakur
- Department of Zoology, Biochemistry and Molecular Biology Laboratory, Banaras Hindu University, Varanasi, India
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Non-classical effects of estradiol on cAMP responsive element binding protein phosphorylation in gonadotropin-releasing hormone neurons: mechanisms and role. Front Neuroendocrinol 2014; 35:31-41. [PMID: 23978477 DOI: 10.1016/j.yfrne.2013.08.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 07/29/2013] [Accepted: 08/12/2013] [Indexed: 12/17/2022]
Abstract
Gonadotropin-releasing hormone (GnRH) is produced by a heterogenous neuronal population in the hypothalamus to control pituitary gonadotropin production and reproductive function in all mammalian species. Estradiol is a critical component for the communication between the gonads and the central nervous system. Resolving the mechanisms by which estradiol modulates GnRH neurons is critical for the understanding of how fertility is regulated. Extensive studies during the past decades have provided compelling evidence that estradiol has the potential to alter the intracellular signal transduction mechanisms. The common target of many signaling pathways is the phosphorylation of a key transcription factor, the cAMP response element binding protein (CREB). This review first addresses the aspects of estradiol action on CREB phosphorylation (pCREB) in GnRH neurons. Secondly, this review considers the receptors and signaling network that regulates estradiol's action on pCREB within GnRH neurons and finally it summarizes the physiological significance of CREB to estrogen feedback.
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Abstract
After five editions, the congress on "Steroids and Nervous System" held in Torino, Italy, represents an important international event for researchers involved in this field aimed to recapitulate mechanisms, physiological and pharmacological effects of neuroactive steroids. The present review introduces manuscripts collected in this supplement issue which are based on new interesting findings such as the influence of sex steroids on cannabinoid-regulated biology, the role of steroids in pain, the importance of co-regulators in steroidal mechanisms and the understanding of new non classical mechanism, the emerging role of vitamin D as a neuroactive steroid and the pathogenetic mechanisms mediated by glucocorticoid receptors. Finally, we have integrated these aspects with an update on some of the several and important observations recently published on this hot topic.
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Duncan KA, Jimenez P, Carruth LL. The selective estrogen receptor-alpha coactivator, RPL7, and sexual differentiation of the songbird brain. Psychoneuroendocrinology 2009; 34 Suppl 1:S30-8. [PMID: 19524373 DOI: 10.1016/j.psyneuen.2009.04.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 04/28/2009] [Accepted: 04/29/2009] [Indexed: 02/03/2023]
Abstract
The brain and behavior of the Australian zebra finch (Taeniopygia guttata) are sexually dimorphic. Only males sing courtship songs and the regions of the brain involved in the learning and production of song are significantly larger in males than females. Therefore the zebra finch serves as an excellent model for studying the mechanisms that influence brain sexual differentiation, and the majority of past research on this system has focused on the actions of steroid hormones in the development of these sex differences. Coregulators, such as coactivators and corepressors, are proteins and RNA activators that work by enhancing or depressing the transcriptional activity of the nuclear steroid receptor with which they associate, and thereby modulating the development of sex-specific brain morphologies and behaviors. The actions of these proteins may help elucidate the hormonal mechanisms that underlie song nuclei development. Research described in this review focus on the role of estrogen receptor coactivators in the avian brain; more specifically we will focus on the role of RPL7 (ribosomal protein L7; also known as L7/SPA) on sexual differentiation of the zebra finch song system. Collectively, these studies provide information about the role of steroid receptor coactivators on development of the zebra finch song system as well as on sexual differentiation of brain.
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Affiliation(s)
- Kelli A Duncan
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA
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Saldanha CJ, Duncan KA, Walters BJ. Neuroprotective actions of brain aromatase. Front Neuroendocrinol 2009; 30:106-18. [PMID: 19450619 PMCID: PMC2700852 DOI: 10.1016/j.yfrne.2009.04.016] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 04/02/2009] [Accepted: 04/14/2009] [Indexed: 12/16/2022]
Abstract
The steroidal regulation of vertebrate neuroanatomy and neurophysiology includes a seemingly unending list of brain areas, cellular structures and behaviors modulated by these hormones. Estrogens, in particular have emerged as potent neuromodulators, exerting a range of effects including neuroprotection and perhaps neural repair. In songbirds and mammals, the brain itself appears to be the site of injury-induced estrogen synthesis via the rapid transcription and translation of aromatase (estrogen synthase) in astroglia. This induction seems to occur regardless of the nature and location of primary brain damage. The induced expression of aromatase apparently elevates local estrogen levels enough to interfere with apoptotic pathways, thereby decreasing secondary degeneration and ultimately lessening the extent of damage. There is even evidence suggesting that aromatization may affect injury-induced cytogenesis. Thus, aromatization in the brain appears to confer neuroprotection by an array of mechanisms that involve the deceleration and acceleration of degeneration and repair, respectively. We are only beginning to understand the factors responsible for the injury-induced transcription of aromatase in astroglia. In contrast, much of the manner in which local and circulating estrogens may achieve their neuroprotective effects has been elucidated. However, gaps in our knowledge include issues about the cell-specific regulation of aromatase expression, steroidal influences of aromatization distinct from estrogen formation, and questions about the role of constitutive aromatase in neuroprotection. Here we describe the considerable consensus and some interesting differences in knowledge gained from studies conducted on diverse animal models, experimental paradigms and preparations towards understanding the neuroprotective actions of brain aromatase.
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Affiliation(s)
- Colin J Saldanha
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, United States.
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An overview of nuclear receptor coregulators involved in cerebellar development. THE CEREBELLUM 2009; 7:48-59. [PMID: 18418685 DOI: 10.1007/s12311-008-0018-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Nuclear receptors (NRs) precisely control the gene regulation throughout the development of the central nervous system, including the cerebellum. Functionally, the full activity of NRs requires their cognate coregulators to be recruited by NRs and modulate the activation or repression of target gene expression. Recent progress of in vitro studies of NR coregulators has revealed that NR coregulators form large complexes in a cyclic manner and subsequently exert genetic and epigenetic influence via various intrinsic enzyme activities. Moreover, NR coregulators physiologically provide a combinatorial code for time- and gene-specific responses depending on their expression levels, relative affinities for individual receptors, and posttranslational modification. Since expression of many cerebellar genes is known to be regulated by NRs critical in a specific period for cerebellar development, their partnership with cognate coregulators may be an important factor for normal cerebellar development. This review summarizes current findings regarding the molecular structures, molecular mechanisms, temporal and spatial expression patterns, and possible biological functions of NR coregulators related to cerebellar development.
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Duncan KA, Carruth LL. The sexually dimorphic expression of L7/SPA, an estrogen receptor coactivator, in zebra finch telencephalon. Dev Neurobiol 2008; 67:1852-66. [PMID: 17823931 DOI: 10.1002/dneu.20539] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Sex differences in the zebra finch (Taeniopygia guttata) brain are robust and include differences in morphology (song control nuclei in males are significantly larger) and behavior (only males sing courtship songs). In zebra finches, hormonal manipulations during development fail to reverse sex differences in song nuclei size and suggest that the classical model of sexual differentiation is incomplete for birds. Coactivators act to initiate transcriptional activity of steroid receptors, and may help explain why hormonal manipulations alone are not sufficient to demasculinize the male zebra finch brain. The present study investigated the expression and localization of L7/SPA (an estrogen receptor coactivator) mRNA and protein expression across the development of zebra finch song nuclei from males and females collected on P1 (song nuclei not yet formed), P10 (posthatch day 10, song nuclei formed), P30 (30 days posthatch, sexually immature but song nuclei formed and birds learning to sing), and adult birds (older than 65 days and sexually mature). Northern blot analysis showed a significant sex difference in P1 and adult L7/SPA mRNA expression while Western blot analysis also showed enhanced expression in the male brain at all age points. Both in situ hybridization and immunohistochemistry demonstrated that L7/SPA mRNA and protein were located in the song nuclei as well as expressed globally. Elevated coactivator expression may be a possible mechanism controlling the development of male song control nuclei, and coactivators such as L7/SPA may be important regulators of the masculinizing effects of estradiol on brain sexual differentiation.
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Affiliation(s)
- Kelli A Duncan
- Department of Biology, Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA 30303, USA
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Molenda-Figueira HA, Williams CA, Griffin AL, Rutledge EM, Blaustein JD, Tetel MJ. Nuclear receptor coactivators function in estrogen receptor- and progestin receptor-dependent aspects of sexual behavior in female rats. Horm Behav 2006; 50:383-92. [PMID: 16769066 PMCID: PMC2244585 DOI: 10.1016/j.yhbeh.2006.04.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Revised: 04/25/2006] [Accepted: 04/26/2006] [Indexed: 11/17/2022]
Abstract
The ovarian hormones, estradiol (E) and progesterone (P) facilitate the expression of sexual behavior in female rats. E and P mediate many of these behavioral effects by binding to their respective intracellular receptors in specific brain regions. Nuclear receptor coactivators, including Steroid Receptor Coactivator-1 (SRC-1) and CREB Binding Protein (CBP), dramatically enhance ligand-dependent steroid receptor transcriptional activity in vitro. Previously, our lab has shown that SRC-1 and CBP modulate estrogen receptor (ER)-mediated induction of progestin receptor (PR) gene expression in the ventromedial nucleus of the hypothalamus (VMN) and hormone-dependent sexual receptivity in female rats. Female sexual behaviors can be activated by high doses of E alone in ovariectomized rats, and thus are believed to be ER-dependent. However, the full repertoire of female sexual behavior, in particular, proceptive behaviors such as hopping, darting and ear wiggling, are considered to be PR-dependent. In the present experiments, the function of SRC-1 and CBP in distinct ER- (Exp. 1) and PR- (Exp. 2) dependent aspects of female sexual behavior was investigated. In Exp. 1, infusion of antisense oligodeoxynucleotides to SRC-1 and CBP mRNA into the VMN decreased lordosis intensity in rats treated with E alone, suggesting that these coactivators modulate ER-mediated female sexual behavior. In Exp. 2, antisense to SRC-1 and CBP mRNA around the time of P administration reduced PR-dependent ear wiggling and hopping and darting. Taken together, these data suggest that SRC-1 and CBP modulate ER and PR action in brain and influence distinct aspects of hormone-dependent sexual behaviors. These findings support our previous studies and provide further evidence that SRC-1 and CBP function together to regulate ovarian hormone action in behaviorally-relevant brain regions.
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Affiliation(s)
- Heather A. Molenda-Figueira
- Center for Neuroendocrine Studies, Neuroscience and Behavior Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Casey A. Williams
- Center for Neuroendocrine Studies, Neuroscience and Behavior Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Andreana L. Griffin
- Center for Neuroendocrine Studies, Neuroscience and Behavior Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Eric M. Rutledge
- Biology Department, Skidmore College, Saratoga Spring, NY 12866, USA
| | - Jeffrey D. Blaustein
- Center for Neuroendocrine Studies, Neuroscience and Behavior Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Marc J. Tetel
- Center for Neuroendocrine Studies, Neuroscience and Behavior Program, University of Massachusetts, Amherst, MA 01003, USA
- .Department of Biological Sciences and Neuroscience Program, Wellesley College, Wellesley, MA 02481, USA
- * Corresponding author. Department of Biological Sciences and Neuroscience Program, Wellesley College, Wellesley, MA 02481, USA. Fax: +1 781 283 3642. E-mail address: (M.J. Tetel)
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Barabás K, Szegõ EM, Kaszás A, Nagy GM, Juhász GD, Abrahám IM. Sex differences in oestrogen-induced p44/42 MAPK phosphorylation in the mouse brain in vivo. J Neuroendocrinol 2006; 18:621-8. [PMID: 16867183 DOI: 10.1111/j.1365-2826.2006.01447.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
In addition to the classical direct genomic mechanisms of action, oestrogen also exerts poorly understood, nonclassical effects on the signalling system in neurones. In the present study, we investigated whether sex differences exist in gonadectomy- and oestrogen-induced effects on p44/42 mitogen-activated protein kinase (MAPK) phosphorylation in specific brain regions of mice. We demonstrate that MAPK immunoreactivity was not altered by gonadectomy or oestrogen treatment in either sex. However, we show that the level of phosphorylated MAPK (pMAPK) within the anteroventral periventricular nucleus (AVPV) was consistently higher in males than females irrespective of gonadal steroid hormone status. In addition, gonadectomy was found to decrease pMAPK immunoreactivity within the piriform cortex of males. Oestrogen increased pMAPK immunoreactivity in the medial preoptic area and AVPV of females, but failed to have the same effect in male mice. Overall, these results demonstrate a marked sex difference in oestrogen-induced alteration of MAPK phosphorylation in the brain in vivo.
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Affiliation(s)
- K Barabás
- Neurobiology Research Group of Hungarian Academy of Sciences at Eötvös Loránd University, Budapest, Hungary
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12
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Yousefi B, Jingu H, Ohta M, Umezu M, Koibuchi N. Postnatal changes of steroid receptor coactivator-1 immunoreactivity in rat cerebellar cortex. Thyroid 2005; 15:314-9. [PMID: 15876152 DOI: 10.1089/thy.2005.15.314] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Steroid receptor coactivator-1 (SRC-1) interacts with nuclear hormone receptors (NRs) to mediate their action in a ligand-dependent manner. Among such ligands, thyroid hormone (TH) is particularly crucial for brain development. The expression of many TH target genes is regulated by TH only for a limited critical period, although TH receptor (TR) expression is not greatly altered after such period. To alter TH sensitivity, other factors may be involved. We thus examined the changes in SRC-1 expression during postnatal development in the rat cerebellum by immunohistochemistry and Western blotting. Strong SRC-1 immunoreactivity (IR) was constantly seen in Purkinje cell from postnatal days (P) 2 to P30. SRC-1 IR was also constantly observed in the internal granule cell layer. However, it was negative in the external granule cell layer at P2 and P7, whereas a weak IR was detected in the premigratory zone at P15. SRC-1 IR was detected in the molecular layer after P15. These results indicate that although TR is almost ubiquitously expressed in the developing cerebellum, the TH sensitivity could vary in each subset of cells. By Western blotting, SRC-1 protein level was greatest at P15, at which time TH action may be obvious. Taken together, the differential expression of SRC-1 may be crucial in mediating TH action during cerebellar development.
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Affiliation(s)
- Behnaz Yousefi
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
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Abstract
Aging is associated with a progressive decline in physical and cognitive functions. The impact of age-dependent endocrine changes regulated by the central nervous system on the dynamics of neuronal behavior, neurodegeneration, cognition, biological rhythms, sexual behavior, and metabolism are reviewed. We also briefly review how functional deficits associated with increases in glucocorticoids and cytokines and declining production of sex steroids, GH, and IGF are likely exacerbated by age-dependent molecular misreading and alterations in components of signal transduction pathways and transcription factors.
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Affiliation(s)
- Roy G Smith
- Huffington Center on Aging, Baylor College of Medicine, One Baylor Plaza, M320, Houston, TX 77030, USA.
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Tetel MJ, Ungar TC, Hassan B, Bittman EL. Photoperiodic regulation of androgen receptor and steroid receptor coactivator-1 in Siberian hamster brain. ACTA ACUST UNITED AC 2005; 131:79-87. [PMID: 15530655 PMCID: PMC2692347 DOI: 10.1016/j.molbrainres.2004.08.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2004] [Indexed: 12/01/2022]
Abstract
Seasonal changes in the neuroendocrine actions of gonadal steroid hormones are triggered by fluctuations in daylength. The mechanisms responsible for photoperiodic influences upon the feedback and behavioral effects of testosterone in Siberian hamsters are poorly understood. We hypothesized that daylength regulates the expression of androgen receptor (AR) and/or steroid receptor coactivator-1 (SRC-1) in specific forebrain regions. Hamsters were castrated and implanted with either oil-filled capsules or low doses of testosterone; half of the animals remained in 16L/8D and the rest were kept in 10L/14D for the ensuing 70 days. The number of AR-immunoreactive (AR-ir) cells was regulated by testosterone in medial amygdala and caudal arcuate, and by photoperiod in the medial preoptic nucleus and the posterodorsal medial amygdala. A significant interaction between photoperiod and androgen treatment was found in medial preoptic nucleus and posterodorsal medial amygdala. The molecular weight and distribution of SRC-1 were similar to reports in other rodent species, and short days reduced the number of SRC-1-ir cells in posteromedial bed nucleus of the stria terminalis (BNST) and posterodorsal medial amygdala. A significant interaction between androgen treatment and daylength in regulation of SRC-1-ir was found in anterior medial amygdala. The present results indicate that daylength-induced fluctuations in SRC-1 and AR expression may contribute to seasonally changing effects of testosterone.
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Affiliation(s)
| | | | | | - Eric L. Bittman
- Corresponding author. Tel.: +1 413 545 4344; fax: +1 413 545 3243. E-mail address: (E.L. Bittman)
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Blaustein JD. Progestin receptors: neuronal integrators of hormonal and environmental stimulation. Ann N Y Acad Sci 2004; 1007:238-50. [PMID: 14993057 DOI: 10.1196/annals.1286.023] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Although it originally was believed that neuronal steroid hormone receptors require binding to cognate ligand for activation, more recent evidence suggests that the receptors can be activated indirectly by other compounds, such as neurotransmitters and growth factors, acting through their own membrane receptors and specific intracellular signaling pathways. For example, as is the case with facilitation of sexual behavior by progesterone, facilitation of sexual behavior by D(1)/D(5) dopamine receptor agonists is blocked by disruption of progestin receptors. Therefore, some dopamine agonists facilitate sexual behavior at least in part by a progestin receptor-dependent mechanism, as does progesterone. This "ligand-independent activation" of neuronal progestin receptors is not limited to dopamine agonists; a variety of other compounds, as well as mating stimulation, facilitate sexual receptivity by a progestin receptor-dependent process. Steroid hormone receptors also can be regulated by afferent input in another way. Various neurotransmitters upregulate or downregulate steroid hormone receptors in some neurons. This, in turn, presumably confers greater or decreased sensitivity to the particular factors that can activate the particular steroid receptor in those particular neurons. Therefore, steroid hormones are but one class of factors that can regulate and activate steroid hormone receptors. Some additional factors that activate steroid hormone receptors have been identified, as have some factors that can regulate concentrations of receptors. Relatively little is known at this time about the range of neurotransmitters, humoral factors, and intracellular signaling pathways that are involved.
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Affiliation(s)
- Jeffrey D Blaustein
- Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003-9271, USA.
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Molenda HA, Kilts CP, Allen RL, Tetel MJ. Nuclear receptor coactivator function in reproductive physiology and behavior. Biol Reprod 2003; 69:1449-57. [PMID: 12855594 PMCID: PMC2683359 DOI: 10.1095/biolreprod.103.019364] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Gonadal steroid hormones act throughout the body to elicit changes in gene expression that result in profound effects on reproductive physiology and behavior. Steroid hormones exert many of these effects by binding to their respective intracellular receptors, which are members of a nuclear receptor superfamily of transcriptional activators. A variety of in vitro studies indicate that nuclear receptor coactivators are required for efficient transcriptional activity of steroid receptors. Many of these coactivators are found in a variety of steroid hormone-responsive reproductive tissues, including the reproductive tract, mammary gland, and brain. While many nuclear receptor coactivators have been investigated in vitro, we are only now beginning to understand their function in reproductive physiology and behavior. In this review, we discuss the general mechanisms of action of nuclear receptor coactivators in steroid-dependent gene transcription. We then review some recent and exciting findings on the function of nuclear receptor coactivators in steroid-dependent brain development and reproductive physiology and behavior.
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Affiliation(s)
- Heather A. Molenda
- Center for Neuroendocrine Studies, Neuroscience and Behavior Program, University of Massachusetts, Amherst, Massachusetts 01003
| | - Caitlin P. Kilts
- Department of Biology, Neuroscience Program, Skidmore College, Saratoga Springs, New York 12866
| | - Rachel L. Allen
- Department of Biology, Neuroscience Program, Skidmore College, Saratoga Springs, New York 12866
| | - Marc J. Tetel
- Center for Neuroendocrine Studies, Neuroscience and Behavior Program, University of Massachusetts, Amherst, Massachusetts 01003
- Department of Biology, Neuroscience Program, Skidmore College, Saratoga Springs, New York 12866
- Correspondence: Marc J. Tetel, Department of Biology and Neuroscience Program, Skidmore College, 815 North Broadway, Saratoga Springs, NY 12866. FAX: 518 580 5071; e-mail:
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Abstract
Recent advances in the field of steroid hormone action have significantly advanced our understanding of neuroendocrine regulation of sexual behavior in female rodents. The presumed classical steroid receptor-steroid hormone functional relationship has undergone significant modifications to integrate the wider context of cellular signaling mechanisms initiated by sensory and environmental stimuli and their transcriptional regulation of steroid hormone receptors in reproductive behavior. This effort has greatly been aided by recent studies identifying steroid hormone receptors as transcriptional mediators of a variety of ligands, whose functional flexibility is dependent upon their recruitment of coregulators, and the availability of gene knockout animal models. This review provides a framework for current concepts in the field of steroid hormone action in the context of their regulation of female sexual behavior.
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Affiliation(s)
- Shaila Mani
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
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18
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Abstract
Hormones and nuclear receptors (NRs) play important roles in brain development and function. The recently identified steroid receptor coactivator (SRC) family contains three homologous members that can enhance transcriptional activities of NRs and certain non-NR transcription factors. To study the role of SRC-1 in brain development and function, we examined the spatial and temporal expression patterns of SRC-1 and characterized the phenotypes of brain development and function in SRC-1 knock-out (SRC-1(-)/-) mice. In the adult mouse brain, SRC-1 is highly expressed in the olfactory bulb, hippocampus, piriform cortex, amygdala, hypothalamus, cerebellum, and brainstem. Multiple behavioral tests revealed that SRC-1(-)/- mice exhibit normal hippocampal function but moderate motor dysfunction. The behavior phenotypes correlate with the spatial distribution of the SRC family members. In most brain structures where SRC-1 is expressed, SRC-2 is expressed at lower levels; however, SRC-3 mRNA is detectable only in the hippocampus. In the adult cerebellum, Purkinje cells (PCs) preferentially express SRC-1 over SRC-2, but SRC-2 mRNA is slightly elevated in the SRC-1(-)/- PCs. During embryonic development, SRC-1 is expressed in the cerebellar primordium. SRC-2 is expressed in PCs after postnatal day (P) 10. Time course analysis revealed that the precursors of SRC-1(-)/- PCs were generated approximately 2 d later than wild-type precursor cells. A further delay in SRC-1(-)/- PC maturation was detected at the neonatal stage. The morphology and number of SRC-1(-)/- PCs were equivalent to wild type by P10; this timing correlated with the early expression of SRC-2 in the SRC-1(-)/- PCs. These results demonstrate that the relative levels of SRC expression are region specific, and the degree of overlapping expression may influence their functional redundancy. Disruption of SRC-1 specifically delays the PC development and maturation in early stages and results in moderate motor dysfunction in adulthood.
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Shao W, Halachmi S, Brown M. ERAP140, a conserved tissue-specific nuclear receptor coactivator. Mol Cell Biol 2002; 22:3358-72. [PMID: 11971969 PMCID: PMC133794 DOI: 10.1128/mcb.22.10.3358-3372.2002] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2001] [Revised: 01/10/2002] [Accepted: 02/07/2002] [Indexed: 11/20/2022] Open
Abstract
We report here the identification and characterization of a novel nuclear receptor coactivator, ERAP140. ERAP140 was isolated in a screen for ER alpha-interacting proteins using the ER alpha ligand binding domain as a probe. The ERAP140 protein shares no sequence and has little structural homology with other nuclear receptor cofactors. However, homologues of ERAP140 have been identified in mouse, Drosophila, and Caenorhabditis elegans. The expression of ERAP140 is cell and tissue type specific and is most abundant in the brain, where its expression is restricted to neurons. In addition to interacting with ER alpha, ERAP140 also binds ER beta, TR beta, PPAR gamma, and RAR alpha. ERAP140 interacts with ER alpha via a noncanonical interaction motif. The ER alpha-ERAP140 association can be competed by coactivator NR boxes, indicating ERAP140 binds ER alpha on a surface similar to that of other coactivators. ERAP140 can enhance the transcriptional activities of nuclear receptors with which it interacts. In vivo, ERAP140 is recruited by estrogen-bound ER alpha to the promoter region of endogenous ER alpha target genes. Furthermore, the E(2)-induced recruitment of ERAP140 to the promoter follows a cyclic pattern similar to that of other coactivators. Our results suggest that ERAP140 represents a distinct class of nuclear receptor coactivators that mediates receptor signaling in specific target tissues.
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Affiliation(s)
- Wenlin Shao
- Department of Adult Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA
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20
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Molenda HA, Griffin AL, Auger AP, McCarthy MM, Tetel MJ. Nuclear receptor coactivators modulate hormone-dependent gene expression in brain and female reproductive behavior in rats. Endocrinology 2002; 143:436-44. [PMID: 11796496 DOI: 10.1210/endo.143.2.8659] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Gonadal steroid hormones act in the brain to elicit changes in gene expression that result in profound effects on behavior and physiology. A variety of in vitro studies indicate that nuclear receptor coactivators are required for efficient transcriptional activity of steroid receptors. Two nuclear receptor coactivators, steroid receptor coactivator-1 (SRC-1) and cAMP response element binding protein-binding protein (CBP), have been shown to act in concert to enhance ER activity in vitro. In the present study, we investigated the function of these important nuclear receptor coactivators in estrogen action in rodent brain. Reduction of SRC-1 and CBP protein in brain disrupted ER-mediated activation of the behaviorally relevant progestin receptor gene. Furthermore, we found that SRC-1 and CBP function in brain to modulate the expression of hormone-dependent female sexual behavior. These findings indicate that these nuclear receptor coactivators function in brain to modulate ER transcriptional activity and the expression of hormone-dependent behavior.
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Affiliation(s)
- Heather A Molenda
- Center for Neuroendocrine Studies and Neuroscience and Behavior Program, University of Massachusetts, Amherst, Massachusetts 01003, USA
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21
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Kawata M. Subcellular steroid/nuclear receptor dynamics. ARCHIVES OF HISTOLOGY AND CYTOLOGY 2001; 64:353-68. [PMID: 11757905 DOI: 10.1679/aohc.64.353] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Steroid hormones, thyroid hormones, retinoic acids, and vitamin D bind to their receptors, which are now called steroid/nuclear receptors, and liganded receptors translocate either intracellularly or intranuclearly and form large protein complexes with cofactors to induce or repress gene transcription. Therefore, steroid/nuclear receptors are ligand-dependent transcription factors. With the advent of green fluorescent protein (GFP) and its color variants, the subcellular distribution of many steroid/nuclear receptors has been found to be much more dynamic than previously thought, with some of the receptors shuttling between the cytoplasm and nucleus. Steroid/nuclear receptors can be divided into three categories based on their unliganded distribution: those that are primarily in the nucleus, those in the cytoplasm, and those with mixed cytoplasmic and nuclear distributions. However, in all cases, the addition of a ligand leads to almost complete nuclear translocation of the receptors. Hormonal stimulation induces intranuclear receptor distribution from a homogeneous pattern to a heterogeneous dot-like image. Ligand binding to steroid/nuclear receptors leads to the recruitment of many proteins including cofactors to provoke the redistribution of receptor complexes in the nucleus. This focal organization could involve more complex events than simple DNA binding sites for transcription. Protein activities and interactions of steroid/nuclear receptors can be imaged and localized in a single cell.
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Affiliation(s)
- M Kawata
- Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Japan.
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22
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Abstract
Steroid hormones substantially influence brain development, reproduction sexual differentiation and emotion. These effects are mediated by steroid hormone receptors and cofactors, which directly regulate gene expression. Deciphering how and where these transcriptional activators occur in a cell provides the groundwork for elucidating the influence of these small hydrophobic signal molecules on various brain functions. This paper describes some of the recent investigations into the subcellular localization of steroid hormone receptors and cofactors using GFPs and other immunocytochemical methods.
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Affiliation(s)
- M Kawata
- Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
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