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Martinez-Finley EJ, Goggin SL, Labrecque MT, Allan AM. Reduced expression of MAPK/ERK genes in perinatal arsenic-exposed offspring induced by glucocorticoid receptor deficits. Neurotoxicol Teratol 2011; 33:530-7. [PMID: 21784148 DOI: 10.1016/j.ntt.2011.07.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 07/08/2011] [Accepted: 07/08/2011] [Indexed: 11/17/2022]
Abstract
Changes within the glucocorticoid receptor (GR) cellular signaling pathway were evaluated in adolescent mice exposed to 50 ppb arsenic during gestation. Previously, we reported increased basal plasma corticosterone levels, decreased hippocampal GR levels and deficits in learning and memory performance in perinatal arsenic-exposed mice. The biosynthesis of members of the mitogen-activated protein kinase (MAPK) signaling pathway, known to be involved in learning and memory, is modulated by the binding of GR to glucocorticoid response elements (GREs) in the gene promoters. Two genes of the MAPK pathway, Ras and Raf, contain GREs which are activated upon binding of GRs. We evaluated the activity of GRs at Ras and Raf promoters using chromatin immunoprecipitation and real-time PCR and report decreased binding of the GR at these promoters. An ELISA-based GR binding assay was used to explore whether this decreased binding was restricted to in vivo promoters and revealed no differences in binding of native GR to synthetic GREs. The decreased in vivo GR binding coincides with significantly decreased mRNA levels and slight reductions of protein of both H-Ras and Raf-1 in perinatally arsenic-exposed mice. Nuclear activated extracellular-signal regulated kinase (ERK), a downstream target of Ras and Raf, whose transcriptional targets also play an important role in learning and memory, was decreased in the hippocampus of arsenic-exposed animals when compared to controls. GR-mediated transcriptional deficits in the MAPK/ERK pathway could be an underlying cause of previously reported learning deficits and provide the link to arsenic-induced deficiencies in cognitive development.
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Kawata M, Yuri K, Ozawa H, Nishi M, Ito T, Hu Z, Lu H, Yoshida M. Steroid hormones and their receptors in the brain. J Steroid Biochem Mol Biol 1998; 65:273-80. [PMID: 9699881 DOI: 10.1016/s0960-0760(98)00026-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Steroid hormones regulate several important functions of the brain by altering the expression of particular genes through their receptors. First in this paper the localization of glucocorticoid receptor immunoreactivity and mRNA in the brain was examined. Second biphasic effects of glucocorticoid on the hippocampus was described and particular emphasis was given on the apoptosis. Third the significance of estrogen receptor in the sexually dimorphic areas was discussed. These results suggest that steroids modulate the gene expression along with the alteration of cell structures in a different manner in a tissue-specific pattern.
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Affiliation(s)
- M Kawata
- Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Japan.
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Morimoto M, Morita N, Ozawa H, Yokoyama K, Kawata M. Distribution of glucocorticoid receptor immunoreactivity and mRNA in the rat brain: an immunohistochemical and in situ hybridization study. Neurosci Res 1996; 26:235-69. [PMID: 9121734 DOI: 10.1016/s0168-0102(96)01105-4] [Citation(s) in RCA: 365] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The localization of glucocorticoid receptor (GR) immunoreactivity and mRNA in the adult rat brain was examined by light microscopic and electron microscopic immunohistochemistries, and in situ hybridization. For the purpose of detailed investigation of the distribution and comparison of GR immunoreactivities and mRNAs, specific polyclonal antibodies against a part of the transcription modulation (TR) domain of rat GR were used in the immunohistochemistry, whereas fluorescein-labeled RNA probes, complementary to the TR domain in the GR cDNA were used in the in situ hybridization. In the rat brain, GR immunoreactivity was predominantly localized in the cell nucleus, and the expression of GR mRNA was detected in the cytoplasm. GR-immunoreactive and GR mRNA-containing cells were widely distributed from the olfactory bulb of the forebrain to the gracile-cuneate nuclei of the medulla oblongata. The highest densities of GR-immunoreactive and mRNA-containing cells were observed in the subfields of cerebral cortex, olfactory cortex, hippocampal formation, amygdala, septal region, dorsal thalamus, hypothalamus, trapezoid body, cerebellar cortex, locus coeruleus and dorsal nucleus raphe. The distributional pattern of GR immunoreactivity in many regions was well-correlated with that of GR mRNA, but in the CA3 and CA4 pyramidal layers of the hippocampus, different localization was noted. The present study provides the groundwork for elucidating the role of GRs in brain function.
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Affiliation(s)
- M Morimoto
- Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Japan
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4
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The glucocorticoid receptor functions at multiple steps during transcription initiation by RNA polymerase II. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)47296-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Abstract
The present knowledge of the human glucocorticoid receptor (hGCR) in primary malignancies is reviewed. It is concluded that hGCR is present in a large number of these tissues; in all tissue specimens of lymphoid malignancies and in varying fractions of the different solid tumors. The hGCR functions as a hormone dependent, specific enhancer interacting protein in mediating the considerable effects of glucocorticoids on growth regulation, both through stimulation and inhibition of expression of the target genes, including other transcription regulation systems. The processes of receptor activation and regulation, as well as the effects of glucocorticoids, are tissue-specific. Subjects for future research are proposed: Establishment of more cell lines and animal models to extend investigation beyond the present concentration on only a few cell lines, especially CEM-C7, application of 'dynamic' assays to cells obtained from patients, in an attempt to predict development of glucocorticoid resistance, and further investigation of the relationships among GCR and growth factors and oncogenes.
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Affiliation(s)
- P Nørgaard
- Department of Oncology, Rigshospitalet, Copenhagen, Denmark
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6
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Alnemri E, Maksymowych A, Robertson N, Litwack G. Overexpression and characterization of the human mineralocorticoid receptor. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)55238-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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7
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Barsony J, Pike JW, DeLuca HF, Marx SJ. Immunocytology with microwave-fixed fibroblasts shows 1 alpha,25-dihydroxyvitamin D3-dependent rapid and estrogen-dependent slow reorganization of vitamin D receptors. J Cell Biol 1990; 111:2385-95. [PMID: 2177476 PMCID: PMC2116405 DOI: 10.1083/jcb.111.6.2385] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Prior studies have given no evidence for regulation of vitamin D receptor (VDR) compartmentalization or subcellular organization. Microwave fixation (9-15 s) and an indirect immunodetection system of avidin-biotin enhancement and phycoerythrin fluorophore resulted in sufficient spatial and temporal resolution to allow analysis of these processes. We studied cultured fibroblasts from normals or from patients with four different types of hereditary defect compromising VDR function (mutant cells). Compartmentalization of VDRs in the absence of 1,25-dihydroxyvitamin D3 (calcitriol) was regulated by serum or estrogen. VDRs were mainly cytoplasmic in cells cultured without serum and phenol red, but VDRs were mainly intranuclear after addition of serum or an estrogen to cells for at least 18 h (slow regulation). Calcitriol initiated a rapid and multistep process (rapid regulation) of reorganization in a portion of VDRs: clumping within 15-45 s, alignment of clumps along fibrils within 30-45 s, perinuclear accumulation of clumps within 45-90 s, and intranuclear accumulation of clumps within 1-3 min. We found similar rapid effects of calcitriol on VDRs in various other types of cultured cells. These sequential VDR pattern changes showed calcitriol dose dependency and calcitriol analogue specificity characteristic for the VDR. In mutant fibroblasts VDR pattern changes after calcitriol were absent or severely disturbed at selected steps. Treatment of normal cells with wheat germ agglutinin, which blocks protein transport through nuclear pores, also blocked calcitriol-dependent translocation of VDRs. We conclude that immunocytology after microwave fixation provides evidence for regulation of VDR organization and localization.
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Affiliation(s)
- J Barsony
- Mineral Metabolism Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
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Veldscholte J, Voorhorst-Ogink MM, Bolt-de Vries J, van Rooij HC, Trapman J, Mulder E. Unusual specificity of the androgen receptor in the human prostate tumor cell line LNCaP: high affinity for progestagenic and estrogenic steroids. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1052:187-94. [PMID: 2322591 DOI: 10.1016/0167-4889(90)90075-o] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
UNLABELLED LNCaP tumor cells, derived from a metastatic lesion of a human prostatic carcinoma, are androgen-sensitive in cell culture. Although increase in growth rate is observed with low doses of progestagens or estradiol, these cells contain exclusively androgen receptors. In the present study the binding affinity of different ligands for both non-DNA- and DNA-binding (transformed) forms of the androgen receptor were analyzed. The cytosolic (non-transformed) form of the receptor displayed an abnormal high affinity for progestagens and estradiol when compared with the cytosolic androgen receptor from other sources. Subsequently the non-transformed forms of the androgen receptor obtained from LNCaP cell nuclei was studied. A high binding affinity was found not only for dihydrotestosterone, but also for progesterone and the synthetic progestagen R5020 (relative binding affinity 42% and 10% of dihydrotestosterone). The binding characteristics of the transformed androgen receptor were examined in intact cells at 37 degrees C. LNCaP cells were compared in this respect with COS cells containing the cloned human androgen receptor, normal human skin fibroblasts and PC3 (prostate) and NHIK (cervix) human tumor cell lines. The affinity of the transformed androgen receptors for the progestagen R5020 in LNCaP cells was significantly higher than in the other cell systems, although the differences were less pronounced than for the non-transformed receptor form. IN CONCLUSION the LNCaP tumor cells contain an androgen receptor with an abnormal binding site. This might be due to a mutation and/or a post-transcriptional effect.
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Affiliation(s)
- J Veldscholte
- Department of Biochemistry II, Erasmus University Rotterdam, The Netherlands
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Claire M, Machard B, Lombes M, Oblin ME, Bonvalet JP, Farman N. Aldosterone receptors in A6 cells: physicochemical characterization and autoradiographic study. THE AMERICAN JOURNAL OF PHYSIOLOGY 1989; 257:C665-77. [PMID: 2529773 DOI: 10.1152/ajpcell.1989.257.4.c665] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The A6 cell line is derived from the kidney of Xenopus laevis. Aldosterone increases sodium transport across A6 cell epithelia. In the present study, aldosterone binding characteristics were studied in A6 cell cytosol. Both type I (mineralocorticoid) and type II (glucocorticoid) receptors are present in the cytosolic fraction of these cells. Aldosterone and corticosterone had a high affinity for type I sites (Kd = 1.25 and 0.16 nM, respectively) and a lower affinity for type II sites (Kd = 39 and 10 nM, respectively). Testosterone and estradiol did not compete for aldosterone binding. RU 26988, a highly specific glucocorticoid agonist, competed with aldosterone for type II but not for type I sites. Hydrodynamic parameters of both type I and type II corticosterone receptor complexes were identical. Their Stokes radius was approximately 6 nm, as estimated by high-performance size-exclusion chromatography, and their sedimentation coefficient determined by ultracentrifugation on glycerol gradients was approximately 9s. The molecular mass calculated from these parameters was approximately 200 kDa, a value that is very close to the value estimated for nontransformed mineralocorticoid and glucocorticoid receptors of other species. The [3H]aldosterone labeling of intact A6 cells was examined by autohistoradiography. At every concentration tested (2, 20, and 50 nM), all cells were found to be specifically labeled in both cytoplasm and nucleus. At 20 nM, in the presence of an excess of RU 26988, labeling was also detected. At every concentration the labeling data was compatible with a Gaussian distribution, indicating that A6 cells correspond to a homogeneous population with regard to aldosterone binding and that probably both type I and type II sites are present in the same cells.
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Affiliation(s)
- M Claire
- Faculté de Pharmacie, Institut National de la Santé et de la Recherche Médicale U300, Montpellier, France
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Hutchens TW, Hawkins EF, Markland FS. Glucocorticoid receptor from lactating goat mammary tissue comparison of native and activated forms in a cell free system. JOURNAL OF STEROID BIOCHEMISTRY 1989; 32:651-68. [PMID: 2739406 DOI: 10.1016/0022-4731(89)90509-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Physicochemical properties of native and activated (DNA-binding) forms of the glucocorticoid receptor in cytosol prepared from lactating goat mammary tissue have been examined. Under hypotonic conditions the cytosolic receptor sediments at 8.4 S or 9.9 S in the absence or presence of 10 mM molybdate, respectively. The receptor in cytosol, either with or without molybdate elutes from DEAE-cellulose at approximately 200 mM potassium phosphate concentration. Isoelectric focusing reveals that this form of the receptor focuses at pH 5.5. Further, the cytosolic form of the receptor exhibits minimal binding affinity for polyanions such as DNA-cellulose. Its Stokes radius is 77 A and the mol. wt is approximately 331,000. Following exposure to in vitro activating conditions (including elevated ionic strength or temperature), the liganded receptor exhibits much lower affinity for DEAE-cellulose (elution at 35-55 mM potassium phosphate concentration). Other alterations in properties of the activated receptor, after partial purification, include sedimentation at 3.9 S in hypotonic sucrose gradients, binding to polyanions (DNA-cellulose), and an isoelectric point at pH 7.2. This receptor has a Stokes radius of 58 A and a mol wt of 98,000. A degraded form, with a mol. wt of approximately 57,000 and high affinity for polyanions, was the major form of the receptor obtained if appropriate precautions to prevent or remove proteolytic activity were not observed during purification and/or characterization of the activated receptor.
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Affiliation(s)
- T W Hutchens
- Department of Biochemistry, University of Southern California, School of Medicine, Los Angeles 90033
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Affiliation(s)
- F Auricchio
- II Cattedra di Patologia Generale, I Facolta' di Medicina e Chirurgia Universita' di Napoli, Italy
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12
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Cayanis E, Sarangarajan R, Lombes M, Nahon E, Edelman IS, Erlanger BF. Identification of an epitope shared by the DNA-binding domain of glucocorticoid receptor and the B chain of insulin. Proc Natl Acad Sci U S A 1989; 86:2138-42. [PMID: 2467302 PMCID: PMC286866 DOI: 10.1073/pnas.86.7.2138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
A monoclonal antibody (8G11-C6) generated by an auto-anti-idiotypic route and directed to a site near the ligand-binding site of the glucocorticoid receptor also binds to native insulin and the B chain of insulin but not to the A chain of insulin. The glucocorticoid receptor and the B chain of insulin, therefore, share a cross-reacting epitope. Examination of the primary sequences of the two proteins revealed a limited number of regions of identity or close homology. Several peptides representative of those regions were synthesized. A heptapeptide sequence of the B chain of insulin with homology to a sequence in the first "zinc finger" of the DNA-binding domain of the glucocorticoid receptor was identified as the cross-reactive epitope. This heptapeptide sequence is restricted to and highly conserved among insulins of various species. Homologous sequences are found in the DNA-binding domains of most steroid receptors and related DNA-binding proteins. Consistent with this is the finding that 8G11-C6 inhibits the binding of glucocorticoid receptor to DNA-cellulose.
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Affiliation(s)
- E Cayanis
- Department of Microbiology, Columbia University, New York, NY 10032
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