Bovine Uterine,Cervical and Ovarian Cytosol Estrogen and Progesterone Receptor Concentrations in Cystic Ovarian Disease

Bovine cytosol estrogen (ERC) and progesterone receptor (PRC) concentrations were measured simultaneously in various regions of the uterus and in ovarian stromal tissue in cows with cystic ovarian disease (follicular cysts), arid the concentrations compared with those in animals with normal cycles. In cystic ovarian disease, ERC concentrations in endometrium (550 fmol/mg cytosol protein (c.p.)) and in myometrium (405) were significantly higher than in control animals. Very high PRC contents were measured in the endometrium (3115) and myometrium (2761) of cows with cystic ovarian disease. In control animals, PRC concentrations in the endometrium and myometrium were significantly lower than in diseased animals. No statistical differences were observed in ERC or PRC contents between the endometrium and the myometrium in cows with cystic ovarian disease. ERC and PRC concentrations in the uterine cervix and ovaries were low compared to those detected in the uterus. Bovine serum estradiol-17ß concentrations were higher (p<0.001) in cows with cystic ovarian disease than in control animals in postpartum anestrus or during the normal estrous cycle. Serum sex hormone-binding globulin (SHBG) concentrations were of the same magnitude as in control cows during their estrous cycles. These findings show that long standing low endogenous progesterone and elevated estradiol concentrations in serum are associated with elevated ERC and PRC concentrations in bovine uterus.     

硬骨鱼类雄激素受体研究进展

在脊椎动物中,雄激素的生理作用主要是通过核雄激素受体(nuclear androgen receptor,nAR)介导的,这种转录因子属于核受体超家族成员.从哺乳动物到硬骨鱼类,均存在nAR.与高等脊椎动物不同的是,由于基因倍增等原因,部分硬骨鱼类nAR存在2种亚型.它们在鱼类胚胎发育和性腺发育过程中表现为不同的组织分...     

Androgen Receptor CAG Repeats Length Polymorphism and the Risk of Polycystic Ovarian Syndrome (PCOS)

Objective

Polycystic ovarian syndrome (PCOS) refers to an inheritable androgen excess disorder characterized by multiple small follicles located at the ovarian periphery. Hyperandrogenism in PCOS, and inverse correlation between androgen receptor (AR) CAG numbers and AR function, led us to hypothesize that CAG length variations may affect PCOS risk.

Methods

CAG repeat region of 169 patients recruited following strictly defined Rotterdam (2003) inclusion criteria and that of 175 ethnically similar control samples, were analyzed. We also conducted a meta-analysis on the data taken from published studies, to generate a pooled estimate on 2194 cases and 2242 controls.

Results

CAG bi-allelic mean length was between 8.5 and 24.5 (mean = 17.43, SD = 2.43) repeats in the controls and between 11 and 24 (mean = 17.39, SD = 2.29) repeats in the cases, without any significant difference between the two groups. Further, comparison of bi-allelic mean and its frequency distribution in three categories (short, moderate and long alleles) did not show any significant difference between controls and various case subgroups. Frequency distribution of bi-allelic mean in two categories (extreme and moderate alleles) showed over-representation of extreme sized alleles in the cases with marginally significant value (50.3% vs. 61.5%, χ² = 4.41; P = 0.036), which turned insignificant upon applying Bonferroni correction for multiple comparisons. X-chromosome inactivation analysis showed no significant difference in the inactivation pattern of CAG alleles or in the comparison of weighed bi-allelic mean between cases and controls. Meta-analysis also showed no significant correlation between CAG length and PCOS risk, except a minor over-representation of short CAG alleles in the cases.

Conclusion

CAG bi-allelic mean length did not differ between controls and cases/case sub-groups nor did the allele distribution. Over-representation of short/extreme-sized alleles in the cases may be a chance finding without any true association with PCOS risk.     

雄激素受体的作用机制

主要概述了雄激素受体的作用机制,特别对影响雄激素受体特异性的因素进行探讨.雄激素受体（AR）属于甾体激素受体超家族,能通过配体依赖方式与特异的DNA序列结合,调控基因转录.     

The Androgen Hormone-Induced Increase in Androgen Receptor Protein Expression Is Caused by the Autoinduction of the Androgen Receptor Translational Activity

The androgen receptor (AR) plays a central role in prostate, muscle, bone and adipose tissue. Moreover, dysregulated AR activity is a driving force in prostate cancer (PCa) initiation and progression. Consequently, antagonizing AR signalling cascades via antiandrogenic therapy is a crucial treatment option in PCa management. Besides, very high androgen levels also inhibit PCa cells’ growth, so this effect could also be applied in PCa therapy. However, on the molecular and cellular level, these mechanisms have hardly been investigated so far. Therefore, the present study describes the effects of varying androgen concentrations on the viability of PCa cells as well as localization, transactivation, and protein stability of the AR. For this purpose, cell viability was determined via WST1 assay. Alterations in AR transactivity were detected by qPCR analysis of AR target genes. A fluorescent AR fusion protein was used to analyse AR localization microscopically. Changes in AR protein expression were detected by Western blot. Our results showed that high androgen concentrations reduce the cell viability in LNCaP and C4-2 cell lines. In addition, androgens have been reported to increase AR transactivity, AR localization, and AR protein expression levels. However, high androgen levels did not reduce these parameters. Furthermore, this study revealed an androgen-induced increase in AR protein synthesis. In conclusion, inhibitory effects on cell viability by high androgen levels are due to AR downstream signalling or non-genomic AR activity. Moreover, hormonal activation of the AR leads to a self-induced stabilization of the receptor, resulting in increased AR activity. Therefore, in clinical use, a therapeutic reduction in androgen levels represents a clinical target and would lead to a decrease in AR activity and, thus, AR-driven PCa progression.     

雄激素受体共调节因子与雄激素非依赖性前列腺癌

雄激素介导的雄激素受体（AR）信号途径对雄性胚胎的发育及雄激素依赖性靶组织的分化发育是必需的。异常的AR活性与前列腺癌由雄激素依赖转变为雄激素非依赖性密切相关。已证实AR共调节因子参与前列腺癌的发生和发展,并在雄激素非依赖性前列腺癌细胞的增殖中扮演着重要角色。它们的表达失衡,可导致AR转录活性的改变,促进晚期前列腺癌的进展。简要综述了AR共调节因子的类型和功能,及其与雄激素非依赖性前列腺癌的关系。     

雄激素受体的结构和功能

雄激素受体(AR)属于核受体超家族中的类固醇受体.AR一般由四个结构域组成:N端转录激活区(NTD)、DNA结合区(DBD)、铰链区和配体结合区(LBD).AR的配体,雄激素是主要的内源性性类固醇激素,而更多的研究却表明雄激素在鱼类性分化过程中不起作用,AR在此过程中的作用尚不清楚.本文讨论了雄激素受体的起源、进化,并着重阐述了雄激素受体各个结构域的功能.     

PTEN、HPVl6/18-E6蛋白和雌激素受体在宫颈腺癌中的表达及其临床意义

目的:探讨宫颈腺癌组织中抑癌蛋白PTEN、人乳头瘤病毒(HPV)16/18-E6蛋白和雌激素受体(ER)的表达及其临床意义.方法:采用免疫组织化学S-P法对65例宫颈腺癌组织进行PTEN、HPV16/18-E6蛋白和ER检测,对30例慢性宫颈炎组织中HPV16/18-E6蛋白和ER的表达进行检测.结果:宫颈腺癌组织细胞核中PTEN的表达显著低于癌旁宫颈腺上皮组织(P＜0.01),96%的宫颈腺癌细胞核呈低表达,而仅35%的癌旁宫颈腺上皮呈低表达(P＜0.01);HPV16/18-E6蛋白和ER在宫颈腺癌中的阳性表达率分别为32.1%与49.4%,均显著高于慢性宫颈炎组织(P＜0.01);HPVl6/18-E6蛋白和ER的表达与宫颈腺癌的病理学分级、临床分期无关,在宫颈腺癌中的表达呈正相关.结论:PTEN在宫颈腺癌的发生中起一定的作用,其抑癌作用环节可能在细胞核水平;部分宫颈腺癌的发病可能与HPV16/18-E6蛋白过度表达有关;部分宫颈腺癌可能属于激素依赖性,雌激素可能有协同人乳头瘤病毒致癌的作用.     

PTEN、HPV16/18-E6蛋白和雌激素受体在宫颈腺癌中的表达及其临床意义

目的：探讨宫颈腺癌组织中抑癌蛋白PTEN、人乳头瘤病毒（HPV）16/18-E6蛋白和雌激素受体（ER）的表达及其临床意义。方法：采用免疫组织化学S-P法对65例宫颈腺癌组织进行PTEN、HPV16/18-E6蛋白和ER检测,对30例慢性宫颈炎组织中HPV16/18-E6蛋白和ER的表达进行检测。结果：宫颈腺癌组织细胞核中PTEN的表达显著低于癌旁宫颈腺上皮组织（P〈0.01）,96%的宫颈腺癌细胞核呈低表达,而仅35%的癌旁宫颈腺上皮呈低表达（P〈0.01）;HPV16/18-E6蛋白和ER在宫颈腺癌中的阳性表达率分别为32.1%与49.4%,均显著高于慢性宫颈炎组织（P〈0.01）;HPV16/18-E6蛋白和ER的表达与宫颈腺癌的病理学分级、临床分期无关,在宫颈腺癌中的表达呈正相关。结论：PTEN在宫颈腺癌的发生中起一定的作用,其抑癌作用环节可能在细胞核水平;部分宫颈腺癌的发病可能与HPV16/18-E6蛋白过度表达有关;部分宫颈腺癌可能属于激素依赖性,雌激素可能有协同人乳头瘤病毒致癌的作用。     

Phosphorylation and Activation of Androgen Receptor by Aurora-A

Aurora-A kinase is frequently overexpressed/activated in various types of human malignancy, including prostate cancer. In this study, we demonstrate elevated levels of Aurora-A in androgen-refractory LNCaP-RF but not androgen-sensitive LNCaP cells, which prompted us to examine whether Aurora-A regulates the androgen receptor (AR) and whether elevated Aurora-A is involved in androgen-independent cell growth. We show that ectopic expression of Aurora-A induces AR transactivation activity in the presence and absence of androgen. Aurora-A interacts with AR and phosphorylates AR at Thr²⁸² and Ser²⁹³ in vitro and in vivo. Aurora-A induces AR transactivation activity in a phosphorylation-dependent manner. Ectopic expression of Aurora-A in LNCaP cells induces prostate-specific antigen expression and cell survival, whereas knockdown of Aurora-A sensitizes LNCaP-RF cells to apoptosis and cell growth arrest. These data indicate that AR is a substrate of Aurora-A and that elevated Aurora-A could contribute to androgen-independent cell growth by phosphorylation and activation of AR.     

Androgen Receptor Gene Polymorphism,Aggression, and Reproduction in Tanzanian Foragers and Pastoralists

The androgen receptor (AR) gene polymorphism in humans is linked to aggression and may also be linked to reproduction. Here we report associations between AR gene polymorphism and aggression and reproduction in two small-scale societies in northern Tanzania (Africa)—the Hadza (monogamous foragers) and the Datoga (polygynous pastoralists). We secured self-reports of aggression and assessed genetic polymorphism of the number of CAG repeats for the AR gene for 210 Hadza men and 229 Datoga men (aged 17–70 years). We conducted structural equation modeling to identify links between AR gene polymorphism, aggression, and number of children born, and included age and ethnicity as covariates. Fewer AR CAG repeats predicted greater aggression, and Datoga men reported more aggression than did Hadza men. In addition, aggression mediated the identified negative relationship between CAG repeats and number of children born.     

The Androgen Receptor Gene Mutations Database.

The current version of the androgen receptor (AR) gene mutations database is described. The total number of reported mutations has risen from 272 to 309 in the past year. We have expanded the database: (i) by giving each entry an accession number; (ii) by adding information on the length of polymorphic polyglutamine (polyGln) and polyglycine (polyGly) tracts in exon 1; (iii) by adding information on large gene deletions; (iv) by providing a direct link with a completely searchable database (courtesy EMBL-European Bioinformatics Institute). The addition of the exon 1 polymorphisms is discussed in light of their possible relevance as markers for predisposition to prostate or breast cancer. The database is also available on the internet (http://www.mcgill. ca/androgendb/ ), from EMBL-European Bioinformatics Institute (ftp. ebi.ac.uk/pub/databases/androgen ), or as a Macintosh FilemakerPro or Word file (MC33@musica.mcgill.ca).     

Regulation of Male Sexual Behavior by Progesterone Receptor, Sexual Experience, and Androgen

Recent studies have demonstrated that physiological doses of progesterone may facilitate the androgen-dependent display of male sexual behavior in laboratory rats and three species of lizard. We used mice with a targeted disruption of the progesterone receptor to investigate whether such interactions exist in male mice and whether they may be modified by sexual experience. We found that naive intact male progesterone receptor knockout (PRKO) mice exhibit reduced mount frequencies compared to wild-type (WT) mice. Also unlike WT mice, sexually experienced PRKO males show profound losses in many measures of sexual behavior following castration. In a second experiment, we tested whether male mice heterozygous for a null mutation at the progesterone receptor locus were responsive to testosterone and progesterone treatment. We found that heterozygous males showed a reduced response to testosterone. The data are consistent with experiments indicating that the progesterone receptor is able to facilitate male-typical sex behaviors in other species and suggest novel mechanisms underlying the interaction of androgens and experience.     

Androgen Receptor and Histone Lysine Demethylases in Ovine Placenta

Sex steroid hormones regulate developmental programming in many tissues, including programming gene expression during prenatal development. While estradiol is known to regulate placentation, little is known about the role of testosterone and androgen signaling in placental development despite the fact that testosterone rises in maternal circulation during pregnancy and in placenta-induced pregnancy disorders. We investigated the role of testosterone in placental gene expression, and focused on androgen receptor (AR). Prenatal androgenization decreased global DNA methylation in gestational day 90 placentomes, and increased placental expression of AR as well as genes involved in epigenetic regulation, angiogenesis, and growth. As AR complexes with histone lysine demethylases (KDMs) to regulate AR target genes in human cancers, we also investigated if the same mechanism is present in the ovine placenta. AR co-immunoprecipitated with KDM1A and KDM4D in sheep placentomes, and AR-KDM1A complexes were recruited to a half-site for androgen response element (ARE) in the promoter region of VEGFA. Androgenized ewes also had increased cotyledonary VEGFA. Finally, in human first trimester placental samples KDM1A and KDM4D immunolocalized to the syncytiotrophoblast, with nuclear KDM1A and KDM4D immunostaining also present in the villous stroma. In conclusion, placental androgen signaling, possibly through AR-KDM complex recruitment to AREs, regulates placental VEGFA expression. AR and KDMs are also present in first trimester human placenta. Androgens appear to be an important regulator of trophoblast differentiation and placental development, and aberrant androgen signaling may contribute to the development of placental disorders.     

Assay and Characterization of Ovarian Testosterone Receptor

Abstract

Ovarian cytosol from immature, hypophysectomized rats was used to characterize the biochemical properties of ovarian androgen receptor and to develop a reliable and convenient assay procedure for its measurement in small quantities of tissue. The results show that Sephadex G-25 columns provide a rapid and reliable method to separate bound from free testosterone for assay of androgen receptor in the ovarian tissue. The binding affinity (K_D=0.6 nM) and sedimentation value (ES) for the ovarian androgen receptor are similar to other steroid receptors and is saturable. It is inactivated by heat and protease digestion and the binding is specific for potent androgens. The ovary contains approximately equal quantities of androgen and estrogen receptor. A physiological role for the presence of androgen receptor in the ovarian tissue is proposed.     

Genetic Variations in the Androgen Receptor Are Associated with Steroid Concentrations and Anthropometrics but Not with Muscle Mass in Healthy Young Men

Objective

The relationship between serum testosterone (T) levels, muscle mass and muscle force in eugonadal men is incompletely understood. As polymorphisms in the androgen receptor (AR) gene cause differences in androgen sensitivity, no straightforward correlation can be observed between the interindividual variation in T levels and different phenotypes. Therefore, we aim to investigate the relationship between genetic variations in the AR, circulating androgens and muscle mass and function in young healthy male siblings.

Design

677 men (25–45 years) were recruited in a cross-sectional, population-based sibling pair study.

Methods

Relations between genetic variation in the AR gene (CAGn, GGNn, SNPs), sex steroid levels (by LC-MS/MS), body composition (by DXA), muscle cross-sectional area (CSA) (by pQCT), muscle force (isokinetic peak torque, grip strength) and anthropometrics were studied using linear mixed-effect modelling.

Results

Muscle mass and force were highly heritable and related to age, physical activity, body composition and anthropometrics. Total T (TT) and free T (FT) levels were positively related to muscle CSA, whereas estradiol (E₂) and free E₂ (FE₂) concentrations were negatively associated with muscle force. Subjects with longer CAG repeat length had higher circulating TT, FT, and higher E₂ and FE₂ concentrations. Weak associations with TT and FT were found for the rs5965433 and rs5919392 SNP in the AR, whereas no association between GGN repeat polymorphism and T concentrations were found. Arm span and 2D:4D finger length ratio were inversely associated, whereas muscle mass and force were not associated with the number of CAG repeats.

Conclusions

Age, physical activity, body composition, sex steroid levels and anthropometrics are determinants of muscle mass and function in young men. Although the number of CAG repeats of the AR are related to sex steroid levels and anthropometrics, we have no evidence that these variations in the AR gene also affect muscle mass or function.