Para entender la acción de cortisol en inflamación aguda: una mirada desde la glándula suprarrenal hasta la célula blanco / Understanding cortisol action in acute inflammation: a view from the adrenal gland to the target cell

Glucocorticoids (cortisol in humans) are essential for numerous biological functions. Among critically ill patients, therapy with cortisol has gained strength in recent years, but clinical results have been mixed. A series of events, that may explain the diversity of clinical responses, occur from the synthesis of cortisol in the adrenal gland to the activation of the cortisol receptor by the hormone when it enters the nucleus of the target cell. Some of these events are revised; a proposition for identifying critically ill patients who may benefit with this therapy is suggested.

Changes in 11β-Hydroxysteroid Dehydrogenase and Glucocorticoid Receptor Expression in Kawasaki Disease

BACKGROUND AND OBJECTIVES: This study aims to investigate the significance of changes in the expression 11β-hydroxysteroid dehydrogenase (11β-HSD) and glucocorticoid receptor (GR) for the development of Kawasaki disease (KD). SUBJECTS AND METHODS: Real-time polymerase chain reaction was performed to determine the mRNA expression levels of GR and 11β-HSD in peripheral blood monocytes, both in the acute phase of the disease and after treatment. Western blotting was performed to determine the protein expression levels of GR and 11β-HSD. RESULTS: The expression levels of GRβ, GRβ, and 11β-HSD1 mRNA in the acute phase were significantly higher than levels at baseline (p<0.01) and after treatment (p<0.05). The 11β-HSD2 mRNA levels were lower in the acute phase than in the normal group (p<0.01), and they were significantly higher after treatment than before (p<0.01). Western blot results were consistent with the real-time PCR results. The coronary artery lesion group exhibited significantly different 11β-HSD2 expression levels from that of the group with normal coronary arteries (p<0.01). CONCLUSION: GR and 11β-HSD expression changes in the acute phase of KD are important factors for regulating inflammatory responses in KD.

Relationship between DNA methylation of glucocort icoid receptor gene promotor and glucocorticoid receptor gene mRNA expression in systemic lupus erythematosus patients / 中华风湿病学杂志

Objective To investigate the relatio nship between the DNA methylation status of gluco-corticoid receptor (GR) gene promoter and mRNA expression level of GRα gene of peripheral blood mononuclear cells (PBMCs) in patients with systemic lupus erythematosus (SLE). Methods Fifteen new onset SLE patients and fifteen healthy controls were enrolled in this study. The DNA methylation status of GR gene promoter 1 of PBMCs was detected through bisulfite sequencing polymerase chain reaction (PCR). The mRNA expression of GRα, DNA methyltransferases, growth arrest and DNA damage-induced 45α (GADD45α) of PBMCs was detected using the quantitative real-time polymerase chain reaction method. T-test and χ2-test were used to detect the differences between the two groups, Pearson's correlation coefficient was used to analyze the linear correlation between two variables. Results Compared with healthy controls, the mRNA expression of GRα was signi-ficantly declined in SLE patients (10±5, 17±7, t=2.69, P<0.05), and the mRNA expression of DNMT1 and GADD45α was significantly elevated in SLE patients (t=3.11, P<0.05 and t=2.98, P<0.05). The overall mean methylation status of the 142 CpG islands of the four promoters was significantly elevated in SLE patients [(16±8)%vs (11±6)%, t=2.75, P<0.05]. The global methylation status of PBMCs in SLE patients was obviously lower than healthy controls (t=4.39, P<0.05). Conclusion Hypermethylation of GRα promoter may result in GRαgene low expression in PBMCs of patients with SLE.

SEB superantigen induces steroid resistance in PBMCs / 中国病理生理杂志

AIM: To establish a model of staphylococcal enterotoxin B (SEB)-induced steroid resistance in human peripheral blood mononuclear cells (PBMCs), and to investigate the potential mechanism of SEB superantigen-induced steroid resistance in vitro. METHODS: PBMCs were isolated from normal children blood by Ficoll-Hypaque gradient centrifugation and stimulated with SEB at different concentrations. The proliferation rate of cells was measured by MTT assay. The subcellular localization of glucocorticoid receptor α (GRα) was examined by confocal microscopy. Protein phosphorylation was measured by means of Western blotting. RESULTS: SEB induced steroid resistance in a range of 10-500 μg/L and no significant difference among concentrations was observed. In SEB-stimulated PBMCs, the GRα did not translocate to the nuclear after dexamethasone treatment. ERK inhibitor U0126 significantly attenuated the inhibition of GRα nuclear translocation in SEB-stimulated PBMCs. SEB also induced more rapid and sustained phosphorylation of ERK1/2 in PBMCs. CONCLUSION: This study demonstrates that SEB may contribute to steroid resistance through ERK pathway and is associated with abrogation of GRα nuclear translocation.

Relationship between protein level and ? mRNA,? mRNA isoforms of glucocorticoid receptor and effect of intravenous injection of methylprednisolone effect in multiple sclerosis patients / 中华神经科杂志

Objective To investigate the expression of glucocorticoid receptor(GR), GR? mRNA and GR? mRNA in peripheral blood mononuclear cells(PBMC)of patients with multiple sclerosis(MS) and healthy controls and investigate the relationship between GR protein, GR? mRNA, GR? mRNA and intravenous injection methylprednisolone(IVMP)effect.Methods GR in PBMC was measured by radioligand assays in 20 patients with relapsing-remitting MS(RRMS), 6 with the second progressive MS (SPMS)and 26 healthy controls.Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR)was used to detect the expression of GR? mRNA and GR? mRNA in PBMC of patients with MS and healthy controls.The effect of IVMP was evaluated by the expanded disability status scale(EDSS). Results(1)Before IVMP, GR in PBMC of MS was significantly lower(RRMS:(3.8?0.2)?10~3 site/cell;SPMS:(1.6?0.2)?10~3 site/cell)than those of controls((4.2?0.8)?10~3 site/cell, P

Effects of Glucocorticoids on Proliferation and Differentiation of a Human Megakaryoblastic Leukemia Cell Line / 第二军医大学学报

The cellular effects of glucocorticoids on proliferation and differentiation of a human inegakaryoblastic leukemia cell line (HIMeg) were studied in comparison with sex steroid hormones. In both liquid and methylcellulose culture systems, glucocorticoids suppressed the proliferate of HIMeg cells in a dose-dependent manner. In contrast, sex steroid hormones except progesterone had little effects on the proliferation of HIMeg cells. In liquid culture systems, morphological changes were not evident, and the percentage of cells with multilobular nuclei increased slightly from 2% to 8% after glucocorticoid treatment. Similarly, only 2% of HIMeg cells expressed glycoprotein Ⅱb/Ⅲa (GP Ⅱb/Ⅲa) antigen without hormone, whereas 30% of the cells expressed GP Ⅱb/Ⅲa with the addition of glucocorticoids. These data indicated that glucocorticoids could induce differentiation of HIMeg cells. To clarify the molecular mechanisms, glucocorticoid receptor (GR) expression was examind by Scatchard analysis, and it was found that there was a saturable, high affinity GR in HIMeg cells. Furthermore, the cellular effects of glucocorticoids on HIMeg cells could be reversed by RU486, a potent glucocorticoid antagonist. These observations suggest that the cellular effects of glucocorticoids on HIMeg cells were mediated by GR.

Construction and screening of cDNA library of alveolar macrophages / 解放军医学杂志

Objective To construct cDNA library of alveolar macrophages after lipopolysaccharide (LPS) and dexamethasone (Dex) treatment for exploring the protein molecule interactive with glucocorticoid receptor (GR) in condition of inflammation. Methods After the cultured AMs were treated with LPS (10mg/ml) and Dex (10 -5 mol/L) for 4h, total RNA was extracted from AMs, then the cDNA was synthesized from total RNA of AMs and amplified using primers SMARTⅢ TM and CDSⅢoligo (dT) as the base of recombination. The purified PCR products as well as the linearized plasmid pGADT7-Rec were co-transformed into the competent yeast AH109. They were recombined by yeast homologous recombinase in the yeast cells and became the active cyclic plasmid. The transformed yeasts grew in the SD/-Leu plates. All the growing clones were harvested and then constituted the cDNA library. Furthermore, the bait pGBKT7-rGR transformed the yeast AH109 of library was constructed, and the protein molecule interactive with GR was screened. Results cDNA library of AMs was constructed with high multiplication and good capacity. 1.07?106 recombinants were obtained from the cDNA library. The amplified PCR fragments were between 0.3-1.5kb in size. One true positive clone, obtained by screening the cDNA library, was confirmed to be BAG-1 by sequencing and BLAST. Conclusion The yeast two-hybrid cDNA library of AMs was successfully constructed by Clontech SMART method; GR can interact with BAG-1 in yeast cells.

Changes in glucocorticoid receptor expression and activity in lung tissue of acute lung injury induced by lipopolysaccharide in rats / 解放军医学杂志

Objective To investigate changes in glucocorticoid receptor (GR) expression and activity in lung tissue of acute lung injury induced by lipopolysaccharide (LPS) within 24h in rat. Methods A total of 70 Wistar rats were divided randomly into LPS treatment group and LPS+ Dexamethasone (Dex) treatment group. The GR mRNA and GR protein expressions in the lung tissue of LPS challenged rats were assessed by RT-PCR and Western blot at different time points. Electrophoretic mobility shift assays (EMSA) were used to determine the GR activity in the lung tissue. Results The expression level of GR mRNA was depressed, but it returned to normal level at 24h after LPS challenge. The expression level of GR was also lowered, reaching the lowest level at 8h. GR activity was decreased, reaching the lowest level at 1h, and remaining lower than that of normal control at 24h. Dex treatment showed no obvious effect on GR activity during the late period of treatment. Conclusion The GR protein expression decreases in lung tissue of acute lung injury in rats, and it maybe associated with the decreased expression of mRNA and accelerated degradation of GR protein. The activity of GR is inhibited sharply, resulting in glucocorticoid resistance.