| 1. |
- Akner, Gunnar, 1953-, et al.
(författare)
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Evidence for colocalization of glucocorticoid receptor with cytoplasmic microtubules in human gingival fibroblasts, using two different monoclonal anti-GR antibodies, confocal laser scanning microscopy and image analysis
- 1991
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Ingår i: Journal of Steroid Biochemistry and Molecular Biology. - : Elsevier BV. - 0960-0760 .- 1879-1220. ; 39:4A, s. 419-432
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Tidskriftsartikel (refereegranskat)abstract
- The cellular distribution of the glucocorticoid receptor (GR) in relation to the microtubule protein tubulin was studied in human gingival fibroblasts, using two different anti-GR antibodies of different Ig-classes, by indirect immunofluorescence immunocytology. Further studies were performed by confocal laser scanning microscopy and digital image analysis. The study focused on fluorochrome separation, optical sectioning, digital subtraction techniques and reconstruction of projections obtained using stacks of recorded transversal sections. The data presented further strengthens the notion of a structural colocalization between GR and cytoplasmic microtubules in human fibroblasts.
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| 2. |
- Akner, Gunnar, 1953-, et al.
(författare)
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Subcellular distribution of the glucocorticoid receptor and evidence for its association with microtubules
- 1995
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Ingår i: Journal of Steroid Biochemistry and Molecular Biology. - : Elsevier BV. - 0960-0760 .- 1879-1220. ; 52:1, s. 1-16
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Forskningsöversikt (refereegranskat)abstract
- The cellular distribution of the glucocorticoid receptor (GR) has not yet been firmly established. The extensive literature indicates that GR is present both in the cytoplasm and the cell nucleus, however, some studies have failed to detect cytoplasmic GR. It is still controversial as to whether GR is randomly diffusing in the cytoplasm and nucleus, or if the GR-distribution is organized or controlled in some way, which may be of importance for the transduction of glucocorticoid effects to cells. There is evidence that both non-activated and activated GR is associated with the plasma membrane, a number of cytoplasmic organelles and the nucleus. Both morphological and biochemical evidence show that GR is associated with microtubules during different stages of the cell cycle, i.e. GR co-localizes, co-purifies and co-polymerizes with tubulin. This indicates that GR is structurally linked to the intracellular MT-network which may be of importance in the mechanism of action of glucocorticoid hormones. The literature in this field is reviewed including the reported data on subcellular GR-localization.
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| 3. |
- Loinder, Kristina, 1963-, et al.
(författare)
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The nuclear receptor corepressor (N-CoR) modulates basal and activated transcription of genes controlled by retinoic acid
- 2003
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Ingår i: Journal of Steroid Biochemistry and Molecular Biology. - 0960-0760 .- 1879-1220. ; 84:1, s. 15-21
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Tidskriftsartikel (refereegranskat)abstract
- Variation in cell morphology and function is caused by differentiation. In myeloid differentiation, retinoid signaling, acting through heterodimers consisting of retinoic acid receptor and retinoid X receptor (RAR/RXR) plays a crucial part. The RAR/RXR heterodimers bind to naturally occurring response elements in the promoter regions of target genes, deciding whether the gene is to be transcribed or not. In the absence of the RAR-specific ligand all trans retinoic acid, RAR/RXR heterodimers are associated with the nuclear receptor corepressor N-CoR or the related SMRT.Here we show, using Western, far-Western and Northern blot techniques, that when the human monocytic cell line THP-1 is allowed to differentiate into macrophage-like cells the expression of N-CoR is down-regulated both at the protein and at the mRNA level. To investigate how this affects the transcriptional activity of retinoic acid response element (RARE)-controlled genes, we performed transient transfection experiments in THP-1 and CV-1 cells. The results indicate that N-CoR functions not merely as a repressor of basal transcription, but rather as a modulator of both basal and ligand-activated transcription of genes controlled by RAR/RXR heterodimers in a dose-dependent manner.
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| 4. |
- Wu, Xuxia, et al.
(författare)
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Expression of Bcl-2, Bcl-x, Mcl-1, Bax and Bak in human uterine leiomyomas and myometrium during the menstrual cycle and after menopause
- 2002
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Ingår i: Journal of Steroid Biochemistry and Molecular Biology. - 0960-0760 .- 1879-1220. ; 80:1, s. 77-83
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Tidskriftsartikel (refereegranskat)abstract
- To investigate the expression of Bcl-2, Bcl-x, Mcl-1, Bax and Bak proteins in human uterine leiomyomas and homologous myometrium during the menstrual cycle and after menopause.The expression of Bcl-2, Bcl-x, Mcl-1, Bax and Bak in leiomyomas (n=24) and myometrial samples (n=22) from women with leiomyomas was measured by immunohistochemistry and Western blot. Measured by immunohistochemistry, a significant difference between leiomyomas and myometrium was observed only for the Bax protein, in tissues obtained from women in the secretory phase of the menstrual cycle. The Bcl-2 staining was more abundant in leiomyomas than in myometrium only in tissues obtained in the proliferative phase of the cycle. Bcl-2 was more abundant in leiomyomas from women of fertile age than in leiomyomas from menopausal women. No significant differences were observed for the Bcl-x or Bak proteins, whereas the Mcl-1 protein was significantly less abundant in secretory phase leiomyomas than in leiomyomas from menopausal women. Western blot analysis based on pools of tissue extracts from the different groups essentially confirmed the data obtained by immunohistochemistry. Bcl-2 family proteins are expressed in leiomyomas and myometrium in different phases related to and influenced by gonadal steroids. These proteins are suggested to interact with each other in the regulation of programmed cell death, apoptosis, but their specific role in growth control of uterine leiomyomas remains to be investigated.
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| 5. |
- Abdel-Khalik, Jonas, et al.
(författare)
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Bile acid biosynthesis in Smith-Lemli-Opitz syndrome bypassing cholesterol: Potential importance of pathway intermediates.
- 2021
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Ingår i: The Journal of steroid biochemistry and molecular biology. - : Elsevier BV. - 1879-1220 .- 0960-0760. ; 206
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Tidskriftsartikel (refereegranskat)abstract
- Bile acids are the end products of cholesterol metabolism secreted into bile. They are essential for the absorption of lipids and lipid soluble compounds from the intestine. Here we have identified a series of unusual Δ5-unsaturated bile acids in plasma and urine of patients with Smith-Lemli-Opitz syndrome (SLOS), a defect in cholesterol biosynthesis resulting in elevated levels of 7-dehydrocholesterol (7-DHC), an immediate precursor of cholesterol. Using liquid chromatography - mass spectrometry (LC-MS) we have uncovered a pathway of bile acid biosynthesis in SLOS avoiding cholesterol starting with 7-DHC and proceeding through 7-oxo and 7β-hydroxy intermediates. This pathway also occurs to a minor extent in healthy humans, but elevated levels of pathway intermediates could be responsible for some of the features SLOS. The pathway is also active in SLOS affected pregnancies as revealed by analysis of amniotic fluid. Importantly, intermediates in the pathway, 25-hydroxy-7-oxocholesterol, (25R)26-hydroxy-7-oxocholesterol, 3β-hydroxy-7-oxocholest-5-en-(25R)26-oic acid and the analogous 7β-hydroxysterols are modulators of the activity of Smoothened (Smo), an oncoprotein that mediates Hedgehog (Hh) signalling across membranes during embryogenesis and in the regeneration of postembryonic tissue. Computational docking of the 7-oxo and 7β-hydroxy compounds to the extracellular cysteine rich domain of Smo reveals that they bind in the same groove as both 20S-hydroxycholesterol and cholesterol, known activators of the Hh pathway.
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| 6. |
- Alexanderson, Camilla, 1978, et al.
(författare)
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A single early postnatal estradiol injection affects morphology and gene expression of the ovary and parametrial adipose tissue in adult female rats.
- 2010
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Ingår i: The Journal of steroid biochemistry and molecular biology. - : Elsevier BV. - 1879-1220 .- 0960-0760. ; 122:1-3, s. 82-90
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Tidskriftsartikel (refereegranskat)abstract
- Events during early life can affect reproductive and metabolic functions in adulthood. We evaluated the programming effects of a single early postnatal estradiol injection (within 3h after birth) in female rats. We assessed ovarian and parametrial adipose tissue morphology, evaluated gene expression related to follicular development and adipose tissue metabolism, and developed a non-invasive volumetric estimation of parametrial adipose tissue by magnetic resonance imaging. Estradiol reduced ovarian weight, increased antral follicle size and number of atretic antral follicles, and decreased theca interna thickness in atretic antral follicles. Adult estradiol-injected rats also had malformed vaginal openings and lacked corpora lutea, confirming anovulation. Estradiol markedly reduced parametrial adipose tissue mass. Adipocyte size was unchanged, suggesting reduced adipocyte number. Parametrial adipose tissue lipoprotein lipase activity was increased. In ovaries, estradiol increased mRNA expression of adiponectin, complement component 3, estrogen receptor alpha, and glucose transporter 3 and 4; in parametrial adipose tissue, expression of complement component 3 was increased, expression of estrogen receptor alpha was decreased, and expression of leptin, lipoprotein lipase, and hormone-sensitive lipase was unaffected. These findings suggest that early postnatal estradiol exposure of female rats result in long-lasting effects on the ovary and parametrial adipose tissue at adult age.
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| 7. |
- Almokhtar, Mokhtar, et al.
(författare)
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Motor neuron-like NSC-34 cells as a new model for the study of vitamin D metabolism in the brain.
- 2016
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Ingår i: Journal of Steroid Biochemistry and Molecular Biology. - : Elsevier BV. - 0960-0760 .- 1879-1220. ; 158, s. 178-188
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Tidskriftsartikel (refereegranskat)abstract
- Vitamin D-3 is a pro-hormone, which is sequentially activated by 25- and 1 alpha-hydroxylation to form 25-hydroxyvitamin D-3 [25(OH)D-3] and 1 alpha,25-dihydroxyvitamin D-3 [1 alpha,25(OH)2D(3)], respectively. Subsequent inactivation is performed by 24-hydroxylation. These reactions are carried out by a series of CYP450 enzymes. The 25-hydroxylation involves mainly CYP2R1 and CYP27A1, whereas 1 alpha-hydroxylation and 24-hydroxylation are catalyzed by CYP27B1 and CYP24A1, respectively, and are tightly regulated to maintain adequate levels of the active vitamin D hormone, 1 alpha,25(OH)(2)D-3. Altered circulating vitamin D levels, in particular 25(OH)D-3, have been linked to several disorders of the nervous system, e.g., schizophrenia and Parkinson disease. However, little is known about the mechanisms of vitamin D actions in the neurons. In this study, we examined vitamin D metabolism and its regulation in a murine motor neuron-like hybrid cell line, NSC-34. We found that these cells express mRNAs for the four major CYP450 enzymes involved in vitamin D activation and inactivation, and vitamin D receptor (VDR) that mediates vitamin D actions. We also found high levels of CYP24A1-dependent 24,25-dihydroxyvitamin D-3 [24,25(OH)(2)D-3] production, that was inhibited by the well-known CYP enzyme inhibitor ketoconazole and by several inhibitors that are more specific for CYP24A1. Furthermore, CYP24A1 mRNA levels in NSC-34 cells were up-regulated by 1 alpha,25(OH)(2)D-3 and its synthetic analogs, EB1089 and tacalcitol. Our results suggest that NSC-34 cells could be a novel model for the studies of neuronal vitamin D metabolism and its mechanism of actions.
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| 8. |
- Amzaleg, Y., et al.
(författare)
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Estrogens and selective estrogen receptor modulators differentially antagonize Runx2 in ST2 mesenchymal progenitor cells
- 2018
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Ingår i: Journal of Steroid Biochemistry and Molecular Biology. - : Elsevier BV. - 0960-0760 .- 1879-1220. ; 183, s. 10-17
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Tidskriftsartikel (refereegranskat)abstract
- Estrogens attenuate bone turnover by inhibiting both osteoclasts and osteoblasts, in part through antagonizing Runx2. Apparently conflicting, stimulatory effects in osteoblast lineage cells, however, sway the balance between bone resorption and bone formation in favor of the latter. Consistent with this dualism, 17 beta-estradiol (E2) both stimulates and inhibits Runx2 in a locus-specific manner, and here we provide evidence for such locus specific regulation of Runx2 by E2 in vivo. We also demonstrate dual, negative and positive, regulation of Runx2-driven alkaline phosphatase (ALP) activity by increasing E2 concentrations in ST2 osteoblast progenitor cells. We further compared the effects of E2 to those of the Selective Estrogen Receptor Modulators (SERMs) raloxifene (ral) and lasofoxifene (las) and the phytoestrogen puerarin. We found that E2 at the physiological concentrations of 0.1-1 nM, as well as ral and las, but not puerarin, antagonize Runx2-driven ALP activity. At >= 10 nM, E2 and puerarin, but not ral or las, stimulate ALP relative to the activity measured at 0.1-1 nM. Contrasting the difference between E2 and SERMs in ST2 cells, they all shared a similar dose-response profile when inhibiting preosteoclast proliferation. That ral and las poorly mimic the locus-and concentration-dependent effects of E2 in mesenchymal progenitor cells may help explain their limited clinical efficacy.
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| 9. |
- Ankarberg-Lindgren, Carina, 1963, et al.
(författare)
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High-sensitivity quantification of serum androstenedione, testosterone, dihydrotestosterone, estrone and estradiol by gas chromatography-tandem mass spectrometry with sex- and puberty-specific reference intervals.
- 2018
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Ingår i: The Journal of steroid biochemistry and molecular biology. - : Elsevier BV. - 1879-1220 .- 0960-0760. ; 183, s. 116-124
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Tidskriftsartikel (refereegranskat)abstract
- Androgen and estrogen determinations serve as important diagnostic markers in a variety of clinical conditions. However, one challenge is to enhance assay sensitivity for determination in the lowest range, such as in prepubertal children. We here present a recently developed gas chromatography-tandem mass spectrometry (GC-MS/MS) method for determination of androstenedione (A4), dihydrotestosterone (DHT), testosterone (T), estrone (E1), and estradiol (E2) in children, which we have compared with the sensitive radioimmunoassays; E2 extraction-RIA and T-RIA.Steroids were extracted in ethyl acetate n-hexane solution from serum spiked with isotopically labeled internal standard and derivatized sequentially with pentafluorobenzyl bromide, pentafluorobenzyl hydroxylamine and pentafluoropropionic acid anhydride and analyzed by GC-MS/MS using a triple quadrupole mass spectrometer operated in negative chemical ionization mode. Leftover routine samples (n=414) were used to evaluate the concordance between GC-MS/MS and RIAs and the validity of GC-MS/MS for pediatrics; of these samples, 101 were from seemingly healthy children. Pubertal stage was recorded for reference interval evaluation.Lower limit of detection for A4, T, DHT, E1, and E2 were 0.1nmol/L, 0.1nmol/L, 27pmol/L, 9pmol/L, and 2pmol/L, respectively. Good agreement was found between GC-MS/MS and T-RIA (r=0.98) as well as between GC-MS/MS and E2 extraction-RIA (r=0.98, for E2 concentrations above 14pmol/L). In boys, T and DHT increased significantly from prepuberty throughout pubertal development, and in girls the same increase was observed for E1 and E2. The greatest increase in A4 for both genders, as well as E1 and E2 in boys and T and DHT in girls, occurred in mid to late puberty.We report the development of a GC-MS/MS method sensitive enough to accurately determine serum levels of androgens and estrogens in children.
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| 10. |
- Asnake, Solomon, 1985-, et al.
(författare)
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Species differences in ligand interaction and activation of estrogen receptors in fish and human
- 2019
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Ingår i: Journal of Steroid Biochemistry and Molecular Biology. - : Pergamon Press. - 0960-0760 .- 1879-1220. ; 195
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Tidskriftsartikel (refereegranskat)abstract
- Estrogen receptor (ER) sequences vary between species and this suggests that there are differences in the ligand-specificity, leading to species-specific effects. This would indicate that it is not possible to generalize effects across species. In this study, we investigated the differences in activation potencies and binding affinities of ER´s alpha (α) and beta (β) in human, zebrafish and sea bream to elucidate species differences in response to estradiol, estrone, estriol and methyltestosterone. In vitro analysis showed that estradiol had the highest activity for all the ER´s except for human ERβ and seabream ERβ2. Alignment of the ligand binding domain and ligand binding pocket (LBP) residues of the three species showed that different residues were involved in the LBPs which led to differences in pocket volume, affected binding affinity and orientation of the ligands. By combining in silico and in vitro results, it was possible to identify the ligand specificities of ER´s. The results demonstrated that the human ER´s show lower resolution in ligand-dependent activation, suggesting higher promiscuity, than the zebrafish and seabream ER´s. These results show species-specificity of ER´s and suggest that species-specific differences must be taken into consideration when studying different exposure scenarios.
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