PubMed Health⌕ Search

Biomedical subjects

O Wrange

Publications and source records attributed to O Wrange.

At least 55 records · Page 3Linked to original sources
PubMed1983

Sequence-specific binding of glucocorticoid receptor to MTV DNA at sites within and upstream of the transcribed region.

Glucocorticoid receptor protein stimulates transcription initiation within murine mammary tumor virus (MTV) DNA sequences in vivo, and interacts selectively with MTV DNA in vitro. We mapped and compared five regions of MTV DNA that are bound specifically by purified receptor; one resides upstream of the transcription start site, and the others are distributed within transcribed sequences between 4 and 8 kb from the initiation site. Each region contains at least two strong binding sites for receptor, which itself appears to be a tetramer of 94,000 dalton hormone-binding subunits. Three of the five binding regions contain nine nuclease footprints that lack extensive homology, although a family of related octanucleotides can be discerned. Receptor interacts with the different regions with similar efficiencies, suggesting that receptor affinity for upstream and internal regions may differ by less than one order of magnitude. Moreover, each region appears to be bound independent of the others. A restriction fragment containing four footprint sequences from one of the regions has previously been shown to act in vivo as a receptor-dependent transcriptional enhancer element, implying that the binding sites detected in vitro may be biologically functional.

Animals↗
PubMed1983

Mineralcorticoid receptor in rat kidney and hippocampus: characterization and quantitation by isoelectric focusing.

The mineralcorticoid receptor in cytosol from the kidneys and hippocampi of adrenalectomized rats was characterized and quantified by use of isoelectric focusing in slabs of polyacrylamide gel. The mineralcorticoid receptor was labeled with [3H]aldosterone after selective blockade of the glucocorticoid receptor sites with a synthetic pure glucocorticoid RU 26988 [11 beta, 17 beta-dihydroxy-17 alpha-(1-propionyl)androsta-1,4,6-trien-3-one]. The apparent dissociation constant for aldosterone was 5.1 X 10(-9) M, and the ligand specificity studies revealed a mineralcorticoid pattern. The glucocorticoid and mineralocorticoid receptors were compared by limited trypsin digestion, followed by isoelectric focusing. Completely different fragmentation patterns were obtained for the two receptors in the same cytosol from either kidney or hippocampus. However, comparison of the mineralcorticoid receptor from the kidney with that from the hippocampus gave rise to identical fragmentation patterns. An antiglucocorticoid receptor antibody showed no crossreactivity with the mineralcorticoid receptor. Cytosol from kidney and hippocampus contained 28 +/- 24 and 155 +/- 115 fmol mineralcorticoid receptors/mg cytosol protein, respectively. Significant amounts of RU 26988-resistant [3H]aldosterone-binding sites were also present in cerebrum, cerebellum, spleen, and colon.

Aldosterone↗
PubMed1983

Absence in glucocorticoid-resistant mouse lymphoma P1798 of a glucocorticoid receptor domain responsible for biological effects.

Glucocorticoid-resistant (CR), in contrast to glucocorticoid-sensitive (CS), mouse lymphoma P1798 was shown to lack antiglucocorticoid receptor immunoactivity. Antibodies raised against the purified rat liver glucocorticoid receptor (GR) cross-reacted with the GR from CS, but not with the GR from CR, P1798 lymphoma. Using highly specific antisera against the GR in an indirect competitive enzyme-linked immunosorbent assay, it was demonstrated that alpha-chymotrypsin digestion of the GR from CS P1798 lymphoma caused a separation of a "resistant-like" nonimmunogenic steroid and DNA-binding domain (Stokes' radius, 3.3 nm) from an immunoactive domain (Stokes' radius, 2.6 nm). In contrast to CS P1798 lymphoma, neither before nor after alpha-chymotrypsin digestion, immunoactivity could be found in the cytosol from CR P1798 lymphoma. This was assayed after chromatography on DNA-cellulose or gel filtration on Agarose A (0.5 m). These results suggest that the domain of the CS GR containing the immunoactive determinant(s), normally removed by limited proteolysis by alpha-chymotrypsin, appears to be missing in CR P1798 lymphoma cytosol. It seems that this domain plays an important role in the mechanism of action of glucocorticoids. This might suggest that a mutation has occurred affecting the genome resulting in defective transcription of the receptor gene(s) in CR P1798 lymphoma.

Animals↗
PubMed1982

Multiple specific binding sites for purified glucocorticoid receptors on mammary tumor virus DNA.

Glucocorticoid hormones selectively stimulate the rate of transcription of integrated mammary tumor virus (MTV) sequences in infected rat hepatoma cells. Using two independent assays, we find that purified rat liver glucocorticoid receptor protein binds specifically to at least four widely separated regions on pure MTV proviral DNA. One of these specific binding domains, which itself contains at least two distinct receptor binding sites, resides within a fragment of viral DNA that maps 110-449 bp upstream of the promoter for MTV RNA synthesis. Three other binding domains lie downstream of the promoter and within the MTV primary transcription unit. Restriction fragments bearing separate binding domains have been introduced into cultured cells; transformants have been recovered in which the introduced fragments are expressed under glucocorticoid control. Thus, it appears that this assay will be useful for assessing the biological significance of the receptor binding sites detected in vitro.

Animals↗
PubMed1982

Estrogen and progestin receptors in intracranial meningiomas.

Tissue samples from 16 meningioma patients were analysed for the cytosolic estrogen receptor concentration using isoelectric focusing and 11 of the 16 cases were also analysed for the cytosolic progestin receptor concentration using sucrose gradient centrifugation. In this study, 15 of the 16 (94%) and 9 of the 11 (82%) meningiomas had detectable estrogen and progestin receptors, respectively. The mean estrogen receptor concentration in female subjects was 8.9 fmol/mg protein and in males 3.0 fmol/mg protein. This sexual difference in receptor content was statistically significant. When the progestin receptor concentrations were plotted against the estrogen receptor concentrations in the same tumors, a relatively good positive correlation was obtained in female patients (r = 0.87). These findings confirm and extend previous reports on the existence of sex steroid receptors in human brain tumors and might open up the possibility of selective endocrine therapy against meningiomas, especially in case of poor-risk patients.

Adult↗
PubMed1982

Immunochemical analysis of the glucocorticoid receptor: identification of a third domain separate from the steroid-binding and DNA-binding domains.

The glucocorticoid-receptor complex can be subdivided into three separate domains by limited proteolysis with trypsin or alpha-chymotrypsin. The following characteristics can be separated: steroid-binding activity (domain A), DNA-binding activity (domain B), and immunoactivity (domain C). We have previously reported the separation of the steroid-binding domain from the DNA-binding domain by limited proteolysis of the receptor with trypsin. In this paper, we report the detection by immunochemical analysis of a third domain of the glucocorticoid receptor, which does not bind hormone. Immunoactivity was detected by using specific antiglucocorticoid receptor antibodies raised in rabbits against purified rat liver glucocorticoid receptor and the assay used was an enzyme-linked immunosorbent assay. After digestion with alpha-chymotrypsin, the immunoactive region of the receptor (domain C) was separated from the other two domains (A and B). The immunoactive fragment was found to have a Stokes radius of 2.6 nm. Further digestion with alpha-chymotrypsin resulted in separation of the immunoactive fragment to give a fragment having a Stokes radius of 1.4 nm. The immunoactive domain could be separated from the half of the glucocorticoid receptor containing the steroid-binding and the DNA-binding domains (Stokes radius, 3.3 nm), by limited proteolysis of the receptor by alpha-chymotrypsin followed by gel filtration or chromatography on DNA-cellulose.

Animals↗
PubMed1982

Glucocorticoid-binding proteins in rat liver.

The distribution, metabolism and protein-binding of [3H] corticosterone in the rat liver was studied with respect to time and sex. The maximum recovery from the cell nuclei occurred 5 min after injection of the steroid. At this time, ten times more radioactivity was recovered from the liver cell nuclei of male animals compared to females. The recovered radioactivity in the cell nuclei was identified as mainly unmetabolised corticosterone and 5 alpha-dihydrocorticosterone. The radioactivity bound to the cytosolic glucocorticoid receptor protein also appeared to consist of unmetabolised corticosterone and 5 alpha-dihydrocorticosterone. However, 5 alpha-dihydrocorticosterone was found to have very little biological activity. The glucocorticoid receptor was found to exist in two forms with Stokes radii of 6.1 and 3.6 nm, respectively, following in vivo labelling with [3H] dexamethasone. The 6.1 nm form could be converted into the 3.6 nm form by incubation with trypsin, papain, alpha-chymotrypsin or an extract of purified rat liver lysosomes. Further incubation resulted in an even smaller form with a Stokes radius of 1.9 nm. With the help of biospecific adsorption chromatography based on the differential affinity of the activated and nonactivated complexes for DNA, the 6.1 nm form of the glucocorticoid-receptor complex was purified to near homogeneity by a rapid and simple technique. An immunoglobulin fraction from serum of a rabbit immunized with a highly purified preparation of glucocorticoid receptor contained specific antibodies to the receptor. The antibodies cross-reacted with the glucocorticoid receptor from human normal lymphocytes, chronic lymphatic leukemia cells and human hippocampus. Activated glucocorticoid receptor protein binds selectively in vitro to a cloned fragment of murine mammary tumor virus DNA. In contrast, the receptor fails to bind selectively to DNA restriction fragments from E coli plasmids pBR 322 and RSF 2124 or from bacteriophages alpha and T4.

Animals↗
PubMed1981

A qualitative comparison of the glucocorticoid receptor in cytosol from human brain and rat brain.

The glucocorticoid receptor in cytosol from human brain was studied using isoelectric focussing in slabs of polyacrylamide gel. [3H]Dexamethasone was used as tracer for receptor analysis. The glucocorticoid receptor from human brain was compared to the glucocorticoid receptor in rat brain. A similar peak of radioactivity with a pI of about 6.1 was obtained by isoelectric focussing of cytosol from both human brain and rat brain. The trypsin-induced fragmentation patterns of the glucocorticoid receptor from human brain and rat brain were very similar when analyzed by isoelectric focussing. The hormone specificity of the glucocorticoid receptor in human brain and in rat brain cytosol was compared by competition experiments using unlabelled dexamethasone, betamethasone, cortisol and corticosterone as competitors. No difference between human brain and rat brain cytosol was detected. It is concluded that the hormone specificity and the protein structure of the glucocorticoid receptors in human brain and in rat brain are similar.

Adrenalectomy↗
PubMed1981

Characterization of an antiserum against the glucocorticoid receptor.

An immunoglobulin (IgG) fraction from serum of a rabbit immunized with a highly purified preparation of glucocorticoid receptor from rat liver cytosol contained specific antibodies to glucocorticoid receptor. This was shown following incubation of the [3H]triamcinolone acetonide-glucocorticoid receptor (TA-GR) complex with the IgG fraction by (I) adsorption of the [3H]triamcinolone acetonide-glucocorticoid receptor (TA-GR) complex with the IgG fraction by (I) adsorption of the [3H]TA-GR-antibody complex to protein A linked to Sepharose, (II) an increased sedimentation rate of the [3H]TA-GR-antibody complex compared to that of the [3H]TA-GR complex, and (III) an increased molecular size of the [3H]TA-GR-antibody complex when compared to that of the [3H]TA-GR complex as judged from gel filtration. The antibody fraction was characterized with regard to titer, cross-reactivity and specificity. The antibodies cross-reacted with the glucocorticoid receptor from various rat tissues (liver, thymus and hippocampus), as well as with the glucocorticoid receptor from human normal lymphocytes, chronic lymphatic leukemia cells and human hippocampus. In the rat liver, the antibody bound to both the nuclear and the cytosolic glucocorticoid receptor (stokes radius 6.1 nm). It did not cross-react with the proteolytic fragments of the glucocorticoid receptors, the 3.6 nm complex or the 1.9 nm complex. Binding of the antibodies was not seen to the androgen, estrogen or progestin receptors in rat or to rat serum transcortin. With an indirect competitive ELISA (enzyme-linked immunosorbent assay) combined with various separation techniques, based on different physicochemical principles, it was shown that the glucocorticoid receptor was the only detectable antibody binding protein from rat liver cytosol using this assay system. These findings also indicate an immunochemical similarity between glucocorticoid receptors in different tissues as well as in different species, but not between glucocorticoid receptors and other steroid hormone receptor proteins. The cytosolic and nuclear glucocorticoid receptors in rat liver were shown to be immunochemically similar.

Animals↗
PubMed1981

Purified glucocorticoid receptors bind selectively in vitro to a cloned DNA fragment whose transcription is regulated by glucocorticoids in vivo.

Activated glucocorticoid receptor protein, purified to 40-60% homogeneity from rat liver extracts, binds selectively in vitro to a cloned fragment of murine mammary tumor virus (MTV) DNA. The DNA fragment tested contains about half of the sequences present in intact MTV DNA, and its rate of transcription, like that of the intact viral element, is strongly stimulated by glucocorticoids when it is introduced into the genome of a receptor-containing cell. In contrast, the receptor fails to bind selectively to DNA restriction fragments from E. coli plasmids pBR322 and RSF2124 or from bacteriophages lambda and T4. Preliminary experiments to localize regions within MTV DNA responsible for selective binding have revealed thus far one subfragment that fails to bind the receptor and one selectively bound subfragment that maps far downstream from the 5' terminus of the normal RNA transcript. These studies are consistent with the notion that steroid receptors may modulate rates of transcription by recognizing specific DNA sequences within or near the regulated genes.

Animals↗
PubMed1981

Multihormonal regulation of the estrogen receptor in rat liver.

Hepatic estrogen receptors were measured in ovariectomized female rats using isoelectric focusing in polyacrylamide gel. Hypophysectomy or adrenalectomy reduced the receptor level to approximately 10% and 42%, respectively, of the control value. Treatment of hypophysectomized (Hx) rats with dexamethasone alone was without effect. When Hx rats were given a pituitary transplant under the kidney capsule in order to induce liver estrogen receptors, dexamethasone treatment more than doubled the inductive effect of the pituitary transplant. The administration of human GH (hGH) in osmotic minipumps to Hx rats led to an induction of hepatic estrogen receptor levels to 48% of the control value. When hGH infusion was combined with dexamethasone treatment, a complete restoration of the receptor level to that in control rats was seen. When administered in minipumps, ovine PRL (oPRL) and bovine GH (bGH) as well as a combination of oPRL and bGH led to an induction of estrogen receptors in Hx rat livers when dexamethasone treatment was given simultaneously. However, oPRL, bGH, and oPRL plus bGH failed to give a complete restoration of hepatic estrogen receptor levels. It is concluded that the estrogen receptor in rat liver is under multihormonal control and that glucocorticoids in combination with a pituitary factor(s) with similar properties to hGH seem to be responsible for the maintenance of the normal level of the receptor in female rats. Possibly, both GH and PRL are involved in the control of the receptor.

Adrenalectomy↗
PubMed1981

A study of glucocorticoid receptors in intracranial tumors.

Tissue samples from 20 patients with various intracranial tumors and one case of cerebral contusion were analyzed for the cytosolic glucocorticoid-receptor concentration using isoelectric focusing in slabs of polyacrylamide gel. It is pointed out that the clinical response to dexamethasone in brain edema associated with various intracranial lesions is, to some extent, parallel to the glucocorticoid-receptor concentration in these tumors. The findings in this investigation suggest that the cytosolic glucocorticoid receptor might be responsible for the initiation of a series of biochemical effects of steroids affecting brain edema. It is possible that the first step in eliciting a beneficial clinical response to dexamethasone in patients with brain tumors is the formation of a steroid-receptor complex in the peripheral parts of the tumor.

Adolescent↗
PubMed1980

Estrogen receptor concentrations in 269 cases of histologically classified human breast cancer.

This report provides a histological review of 264 female primary breast cancers analyzed for estrogen receptor protein (ER). We also describe 5 cases of male breast cancer all of which bound estradiol specifically. Generally the ER concentrations were lower in the tumors of premenopausal women than in those of postmenopausal women. Three types of cancer with specific morphological features were shown to have ER concentrations that differed significantly from the other types of cancer. Medullary and comedo carcinoma had very low and papillary carcinoma very high levels of ER. No obvious trend in ER concentration was found in unspecified ductal carcinoma, colloid carcinoma, nor in lobular carcinoma. A positive correlation was demonstrated between ER content and degree of differentiation in ductal carcinoma. Cancer with lymphoid infiltration generally showed low ER levels.

Aged↗