| 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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Evidence for reversible, non-microtubule and non-microfilament-dependent nuclear translocation of hsp90 after heat shock in human fibroblasts
- 1992
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Ingår i: European Journal of Cell Biology. - 0171-9335 .- 1618-1298. ; 58:2, s. 356-364
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Tidskriftsartikel (refereegranskat)abstract
- A monoclonal antibody (29A) directed against rat liver heat shock protein M(r) 90,000 (hsp90) was produced. By Western immunoblotting of cytosols prepared from several different tissues and species, 29A was shown to specifically recognize only one band with M(r) approximately 90,000. Localization of hsp90 in human gingival fibroblasts was studied using the 29A antibody by indirect mono- and double-staining immunofluorescence and confocal laser scanning microscopy. The distribution was compared to that of the glucocorticoid receptor (GR) and various cytoskeletal structures. Cells were analyzed in interphase and mitosis under basal culture conditions, after heat shock and after microtubule and microfilament depolymerization, sometimes combined with heat shock. A major part of hsp90 immunoreactivity was diffusely distributed throughout the interphase cytoplasm, but a weak nuclear staining with non-stained nucleoli was also present, however, only detectable after methanol and not after formaldehyde/Triton X-100 fixation. Heat shock induced a time-dependent translocation of hsp90 from the cytoplasm to the cell nucleus reaching a plateau after 15 h. This compartment shift was reversible and also occurred in the absence of intact microtubules or intact microfilaments.
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| 3. |
- Akner, Gunnar, 1953-, et al.
(författare)
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Morphometric studies of the localization of the glucocorticoid receptor in mammalian cells and of glucocorticoid hormone-induced effects
- 1994
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Ingår i: Journal of Histochemistry and Cytochemistry. - : SAGE Publications. - 0022-1554 .- 1551-5044. ; 42:5, s. 645-657
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Tidskriftsartikel (refereegranskat)abstract
- We studied the subcellular distribution of the glucocorticoid receptor (GR) by light microscopy (LM) and confocal laser scanning microscopy (CLSM) in different mammalian cell types. The effect of added glucocorticoid hormones on GR distribution was investigated by photometric quantitation on optical sections obtained by CLSM followed by statistical analysis. In the control interphase cytoplasm, the distribution of GR was fibrillar in some and diffuse in other cell types. Fibrillar GR was distributed along cytoplasmic microtubules (MTs) with predilection for a subset of MTs. GR was also observed in the centrosomes. Nuclear GR was both diffuse and granular in distribution. During cell division, GR appeared in the mitotic apparatus at all stages of mitosis. These findings were not fixation-dependent. Glucocorticoid treatment increased both the nuclear and cytoplasmic GR signal. However, this was detectable only after precipitating but not cross-linking fixation. There was both intra- and intercellular GR heterogeneity in the absence and presence of hormone but no indication of a hormone-induced nuclear translocation of GR. We present a hypothetical model of two independent GR populations in the nucleus and cytoplasm, respectively, without any discernible ligand-induced nuclear translocation of GR. The extranuclear GR population may exert effect(s) on site in the cytoplasm without involving nuclear genomic transcription.
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| 4. |
- Akner, Gunnar, 1953-, et al.
(författare)
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Immunocytochemical localization of glucocorticoid receptor in human gingival fibroblasts and evidence for a colocalization of glucocorticoid receptor with cytoplasmic microtubules
- 1990
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Ingår i: European Journal of Cell Biology. - 0171-9335 .- 1618-1298. ; 53:2, s. 390-401
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Tidskriftsartikel (refereegranskat)abstract
- The cellular distribution of the glucocorticoid receptor (GR) in relation to various intracellular and plasma membrane structures in human fibroblasts was studied using indirect immunofluorescence techniques with monoclonal and polyclonal antibodies. During interphase, GR was located predominantly in the cytoplasm, showing a similar pattern as tubulin. In mitotic cells, GR and tubulin were localized in mitotic spindles and in telophase midbodies. Colchicine and vinblastine induced a similar redistribution of GR and tubulin to the cell periphery. This redistribution was reversible for colchicine but not for vinblastine. Vinblastine also induced paracrystals containing GR and tubulin. These results support the hypothesis that GR interacts in vivo with cytoplasmic microtubules.
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