NCBI Summary:
This gene encodes glucocorticoid receptor, which can function both as a transcription factor that binds to glucocorticoid response elements in the promoters of glucocorticoid responsive genes to activate their transcription, and as a regulator of other transcription factors. This receptor is typically found in the cytoplasm, but upon ligand binding, is transported into the nucleus. It is involved in inflammatory responses, cellular proliferation, and differentiation in target tissues. Mutations in this gene are associated with generalized glucocorticoid resistance. Alternative splicing of this gene results in transcript variants encoding either the same or different isoforms. Additional isoforms resulting from the use of alternate in-frame translation initiation sites have also been described, and shown to be functional, displaying diverse cytoplasm-to-nucleus trafficking patterns and distinct transcriptional activities (PMID:15866175). [provided by RefSeq, Feb 2011]
General function
Receptor, DNA binding, Transcription factor
Comment
Glucocorticoid exposure affects female fertility by exerting its effect on the uterus but not on the oocyte: lessons from a hypercortisolism mouse model. Li QN et al. (2018) What is the impact of glucocorticoid (GC) on female reproduction? Corticosterone (CORT) exposure causes little damage to oocyte quality or developmental competence but has an adverse effect on the uterus, which causes decreased implantation, embryo death and subsequent infertility. Chronic treatment with high GC doses is effective in controlling most allergic diseases but may lead to metabolic disorders such as obesity that are closely related with reproductive function. Hypercortisolism was induced in a female mouse model by supplementing the drinking water with 100 μg/ml of CORT. Controls received vehicle (1% v/v ethanol) only. After 4 weeks treatment mice were either mated or killed in estrus for hormone and organ measurements. In the first experiment, treatment with CORT or control continued during pregnancy but in the second CORT treatment was stopped after mating. To identify the effects of GC exposure on the uterus, blastocysts were generated by IVF of oocytes from CORT and control mice and replaced into recipients receiving the opposite treatment. The effects of hypercortisolism on female mice were first characterized by living body fat content, body weight, food intake, hormone and biochemical measurements, a glucose tolerance test and an insulin resistance test. Fertility was determined with or without CORT-treatment during pregnancy. Oocyte quality was assessed by oocyte maturation, mitochondrial distribution, reactive oxygen species production, mitochondrial DNA mutations and morphology of blastocysts produced in vivo or in vitro. Blastocyst cross-transfer was done to evaluate the causes of embryonic development failure. Fetus development and uterus morphology evaluation as well as culture of oocytes in vitro with gradient concentrations of CORT were also carried out. In the hypercortisolism female mouse model, body weight and food intake were much higher than in the control, and corticosterone, estradiol, cholesterol (CHO) and triglycerides (TG) in the plasma of CORT-treated mice was significantly increased. The hypercortisolism female mice were infertile when CORT-treatment was sustained during pregnancy but fertile if CORT-treatment was stopped after mating. The rate of successful implantation in hypercortisolism mice with sustained CORT-treatment during pregnancy was significantly lower than in the control, and the implanted embryos could not develop beyond 13.5 dpc. Blastocyst cross-transfer showed that blastocysts from CORT-treated mice could develop to term in the uterus of control mice, but blastocysts from control mice failed to develop to term when they were transferred into CORT-treated mice, providing evidence that the infertility was mainly caused by an altered uterine environment. CORT administration did not affect oocyte maturation, mitochondrial distribution, ROS production and blastocyst morphology, but increased mitochondrial DNA mutations. Culture of oocytes in vitro with gradient concentrations of CORT showed that only very high concentrations of CORT caused damage to oocyte developmental competence. NA. The mouse model has the advantages of a consistent genetic and physiological background and openness to experimental manipulation over clinical studies but may not represent the human situation. Our findings show that special care should be taken when administering CORT during pregnancy, and provide important information concerning female reproduction when treating patients by subjecting them to chronic GC exposure. This study was supported by the National Key R&D Program of China (Nos. 2016YFA0100400 and 2017YFC1000600) and the National Natural Science Foundation of China (31472055). The authors have no conflicts of interest.//////////////////
Cellular localization
Nuclear
Comment
Ovarian function
Follicle atresia
Comment
Glucocorticoid receptor isoforms and effects of glucocorticoids in ovulated mouse oocytes and preimplantation embryos. Cikoš Š et al. (2018) To investigate possible involvement of glucocorticoid receptor (GR) in mediating effects of maternal stress or therapeutically administered glucocorticoids on early embryo we analyzed the expression of GR subtypes in ovulated mouse oocytes and preimplantation embryos. RT-PCR analysis results showed that GRα and GRγ transcripts are relatively highly expressed in mouse oocytes, and both transcripts are present at lower amounts in preimplantation embryos. We also detected low expression of two other splice variants, GRβ and a transcript orthologous to the human GR-P subtype, mainly at the blastocyst stage. Using Western blot analysis, we detected several GR protein bands that differed in size between oocytes and preimplantation embryos. To compare the effects of corticosterone (a major endogenous glucocorticoid in rodents) and dexamethasone (a synthetic glucocorticoid) on early embryos, we cultured mouse preimplantation embryos in the presence of these glucocorticoids. Corticosterone showed a strong inhibitory effect on embryo development (starting from a 50 μM concentration), without a significant influence on apoptosis incidence. On the other hand, dexamethasone induced apoptosis in early embryo cells (starting from a 1.5 μM concentration), and its effect on embryo development was less detrimental than that found with the same dose of corticosterone. In summary, our results showed that different GR subtypes are expressed in ovulated mouse oocytes and preimplantation embryos and that the composition of GR subtypes changes during early embryo development. Moreover, we found significant differences in the effects of the two glucocorticoids on early embryo development, which might be associated with activation of different GR subtypes.//////////////////
Glucocorticoids impair oocyte developmental potential by triggering apoptosis of ovarian cells via activating the Fas system. Yuan HJ et al. (2016) Previous studies indicate that stress damages oocytes with increased secretion of glucorticoids. However, although injection of female mice with cortisol decreased oocyte competence, exposure of mouse oocytes directly to physiological or stress-induced concentrations of glucorticoids did not affect oocyte maturation and embryo development. This study has explored the mechanisms by which glucocorticoids impair oocyte competence. Female mice were injected with cortisol and the effects of cortisol-injection on oocyte competence, ovarian cell apoptosis and Fas/FasL activation were observed. The results showed that cortisol-injection decreased (a) oocyte developmental potential, (b) the E2/P4 ratio in serum and ovaries, and (c) expression of insulin-like growth factor 1, brain-derived neurotrophic factor and glucocorticoid receptor in mural granulosa cells (MGCs), while increasing levels of (a) cortisol in serum and ovaries, (b) apoptosis in MGCs and cumulus cells (CCs), (c) FasL secretion in ovaries and during oocyte maturation in vitro, and (d) Fas in MGCs, CCs and oocytes. The detrimental effects of cortisol-injection on oocyte competence and apoptosis of MGCs and CCs were significantly relieved when the gld (generalized lymphoproliferative disorder) mice harboring FasL mutations were observed. Together, the results suggested that glucocorticoids impair oocyte competence by triggering apoptosis of ovarian cells via activating the Fas system.//////////////////
Expression regulated by
Comment
Ovarian localization
Oocyte, Granulosa
Comment
Follicle stages
Comment
Phenotypes
PCO (polycystic ovarian syndrome)
Mutations
1 mutations
Species: human
Mutation name: type: naturally occurring fertility: subfertile Comment: Generalized glucocorticoid resistance: clinical aspects, molecular mechanisms, and implications of a rare genetic disorder. Charmandari E et al. (2008) Primary generalized glucocorticoid resistance is a rare genetic condition characterized by generalized, partial, target-tissue insensitivity to glucocorticoids. We review the clinical aspects, molecular mechanisms, and implications of this disorder. We conducted a systematic review of the published, peer-reviewed medical literature using MEDLINE (1975 through February 2008) to identify original articles and reviews on this topic. We have relied on the experience of a number of experts in the field, including our extensive personal experience. The clinical spectrum of primary generalized glucocorticoid resistance is broad, ranging from asymptomatic to severe cases of hyperandrogenism, fatigue, and/or mineralocorticoid excess. The molecular basis of the condition has been ascribed to mutations in the human glucocorticoid receptor (hGR) gene, which impair glucocorticoid signal transduction and reduce tissue sensitivity to glucocorticoids. A consequent increase in the activity of the hypothalamic-pituitary-adrenal axis compensates for the reduced sensitivity of peripheral tissues to glucocorticoids at the expense of ACTH hypersecretion-related pathology. The study of functional defects of natural hGR mutants enhances our understanding of the molecular mechanisms of hGR action and highlights the importance of integrated cellular and molecular signaling mechanisms for maintaining homeostasis and preserving normal physiology.//////////////////