Intervention effect and mechanism of Hippophae rhamnoides oil on glucocorticoid resistance in superantigen-induced atopic dermatitis mice / 中国药房

OBJECTIVE To study the intervention effect of Hippophae rhamnoides oil on glucocorticoid resistance in superantigen-induced atopic dermatitis （AD） mice，and to explore the mechanism of action. METHODS Fifty mice were randomly divided into 5 groups，i.e. normal control group （group A），model group （group B），dexamethasone intervention group （positive control，group C），H. rhamnoides oil intervention group （group D），dexamethasone+H. rhamnoides oil intervention group （group E），with 10 mice in each group. Except for group A，other groups were given 2，4-dinitrochlorobenzene+staphylococcal enterotoxin B to induce the AD mice model. Starting from the 7th day of the experiment，groups C，D and E were given dexamethasone （1.5 mg/kg） and/or H. rhamnoides oil （10 mL/kg） intragastrically，once a day，for 28 consecutive days. After the last medication，the pathomorphological changes of ear tissue were observed by 节作用。E-mail：57667478@qq.com HE staining； the serum levels of immunoglobulin E （IgE） and interleukin 4 （IL-4） were detected by enzyme-linked immunosorbent assay. Positive cell count of glucocorticoid receptor α （GRα） and GRβ in the ear tissue of mice was detected by tyramide signal amplification. The expressions of GRα protein，GRβ protein，and protein kinase B （AKT）/ribosomal protein S6 kinase 1，S6K1 （S6K1） signaling pathway-related proteins were determined by Western blot assay. RESULTS Compared with group B，the skin inflammation in the left ear of the mice was significantly reduced in groups C，D and E，the serum levels of IgE and IL-4 were decreased significantly in groups D and E （P＜ 0.05），while the number of GRα positive cells and GRα protein expression were increased significantly （P＜0.05）； the protein levels of G protein inhibitory subunit 1 （Gαi1），Gαi3，phosphorylated S6K1 （p-S6K1） and phosphorylated AKT （p-AKT） were decreased significantly （P＜0.05）； the number of GRβ positive cells and protein expression of GRβ was decreased significantly in group E（P＜0.05）. Compared with group C，the skin inflammation in the left ear of the mice was almost clear away in group E，the serum levels of IgE and IL-4 were decreased significantly （P＜0.05）； the number of GRα positive cells and GRα protein expression were increased significantly in groups D and E （P＜0.05）； the protein levels of GRβ，Gαi1，p-S6K1 and p-AKT were all decreased significantly in groups D and E（P＜0.05）； and protein level of Gαi3 was decreased significantly in group E （P＜0.05）. CONCLUSIONS H. rhamnoides oil has an intervention effect on superantigen-induced glucocorticoid resistance of AD mice，which may be exerted by inhibition of the Gαi1/3-induced AKT/S6K1 signaling pathway.

Huatanjiangqi capsule regulates Nrf2/HDAC2 and improves glucocorticoid resistance of 16HBE cells / 中国临床药理学与治疗学

AIM: To explore the effect of Huatanjiangqi capsule medicated serum (HTJQ) on the resistance of human bronchial epithelial cells (16HBE) to glucocorticoid (GC) stimulated by cigarette smoke extract (CSE). METHODS: After 16HBE cells were treated with HTJQ, the effects of different concentrations of HTJQ on the viability of 16HBE cells were determined by CCK-8 method. 16HBE cells were pretreated with HTJQ, and then cultured with dexamethasone (DEX) and lipopolysaccharide (LPS) for 24 hours, the effect of HTJQ on glucocorticoid (GC) resistance of 16HBE cells was determined by Enzyme-linked immunosorbent assay (ELISA). The effects of HTJQ, sulforaphane (SFN) and glutathione (GSH) on the expression of NF-E2-related factors 2 (Nrf2), Heme oxygenase-1 (HO-1) and histone deacetylase 2 (HDAC2) in 16HBE cells stimulated by CSE were measured by Western blot, and the effects of HTJQ, SFN and GSH on interleukin-8 (IL-8) in 16HBE cells were measured by ELISA. RESULTS: HTJQ promoted the proliferation of 16HBE cells at 1 h, 2 h and 4 h, the results of ELISA and Western blot showed that CSE induced GC resistance and decreased the expression of Nrf2, HO-1 and HDAC2 in 16HBE cells, HTJQ significantly decreased IL-8 and improved GC sensitivity of 16HBE cells (P<0.01), and up-regulated the expression of Nrf2, HO-1 and HDAC2 (P<0.01). In addition, HTJQ significantly up-regulated the level of GSH in 16HBE cells (P<0.01). Nrf2 agonists SFN and GSH significantly improved the glucocorticoid sensitivity of 16HBE cells (P<0.01), and up-regulated the expression of Nrf2, HO-1 and HDAC2 (P<0.01). CONCLUSION: HTJQ improves the GC resistance of 16HBE cells by up-regulating the expression of Nrf2/HDAC2 protein and the level of intracellular GSH.

Effects of dexamethasone on neutrophil airway inflammation and HMGB1 expression in asthmatic mice / 解放军医学杂志

Objective: To investigate the effect of dexamethasone intervention on neutrophil airway inflammation and high mobility group box 1 protein (HMGB1) expression in asthmatic mice. Methods: Forty healthy SPF grade female Balb/c mice were randomly divided into four groups (n=10): Control group, Asthma group, 1 mg/kg dexamethasone intervention group and 5 mg/kg dexamethasone intervention group. The asthmatic mice model was induced by egg-free ovalbumin. The airway hyper-responsiveness was measured by the invasive pulmonary function instrument; the number and classification of inflammatory cells in bronchoalveolar lavage fluid (BALF) were detected; lung pathological changes were observed by HE staining; HMGB1 expression was detected by immunohistochemistry and Western blotting. Results: Compared with Control group, the airway responsiveness of asthmatic mice was significantly enhanced (P0.05). Conclusions: The expression of HMGB1 in airway epithelium and lung tissue of asthmatic mice with neutrophilic airway inflammation was significantly increased. After dexamethasone intervention, asthmatic mice still showed higher neutrophilic airway inflammation and expression of HMGB1 in lung tissue, suggesting that HMGB1 may be associated with neutrophilic airway inflammation and glucocorticoid resistance in asthma.

The recognition of clinical application of glucocorticoids / 医学研究生学报

Because of the significant anti-inflammatory and immunosuppressive effects,glucocorticoids (GCs) have been widely used in clinic However,adverse reactions caused by long-term use of GCs and glucocorticoid resistance (GR) are always troublesome problems in clinical department.Therefore,it is the hot point to explore the ways to reduce adverse reactions of GCs and to improve sensitivity of GCs.In this article,we mainly discuss new strategies of reducing adverse reactions and improving sensitivity of GCs.

The relationship between mRNA level of glucocorticoid receptor α, heat shock protein 90, protein level of macrophage migration inhibitory factor and glucocorticoid resistance in systemic lupus erythematosus / 中华内科杂志

Objective To investigate the mRNA level of glucocorticoid receptor α (GRα) and heat shock protein 90 (HSP90) in peripheral blood mononuclear cells (PBMCs) and the plasma protein level of macrophage migration inhibitory factor (MIF) in patients with systemic lupus erythematosus (SLE) and to analyze their association with glucocorticoid (GC) resistance.Methods One hundred and six patients with SLE and thirty-eight healthy controls were enrolled in this study.Transcription levels of GRα and HSP90 were determined by real-time polymerase chain reaction.Enzyme-linked immunosorbent assay was used to detect the protein level of plasma MIF.The association between these parameters and GC resistance was analyzed by Spearman correlation analysis.The multivariate logistic regression model was used to analyze the risk factors for GC resistance.Results The mRNA level of GRα and HSP90 in GC resistance group was significantly lower than that in GC sensitive group [10.18(3.12,17.20) vs 16.83(12.01,24.18), P =0.001;18.46(14.77,26.45) vs 25.84 (17.97,35.90), P =0.005].MIF protein level in GC resistance group was significantly higher than that in GC sensitive group [(23.21 ±7.98) μg/L vs (18.34 ±6.29)μg/L;P =0.013].The mRNA level of HSP90 in the high MIF group was significantly lower than that in the low MIF group [23.67 (13.84,28.32) vs 26.64 (23.61,47.16);P =0.001], as well as HSP90/GRαratio(P =0.008).Additionally, the plasma protein level of MIF was negatively correlated with HSP90 (r =-0.275, P =0.004) and HSP90/GRα ratio(r =-0.341, P ＜ 0.001).SLE activity index score in GC resistance group was significantly higher than that in GC sensitive group [(12.23 ±2.86) μg./L vs (9.63 ± 3.48) μg/L;P =0.003].Logistic regression model indicated that disease activity was an independent risk factor for GC resistance (OR =17.481, 95％ CI 1.747-174.903, P =0.015).Conclusions Our preliminary findings suggest that low mRNA level of GRα and HSP90 and high protein level of MIF are associated with GC resistance.Elevated MIF level in SLE patients may play an important role in the development of GC resistance through down-regulating HSP90 and destabilizing the balance of HSP90/ Grα.Disease activity is the risk factor for GC resistance, which might be the viable evidence of therapy response.

Síndrome de resistencia a los glucocorticoides / Glucocorticoid resistance syndrome

Los glucocorticoides participan en importantes procesos biológicos del organismo. El síndrome de resistencia a los glucocorticoides, o síndrome de Chrousos, es una afección genética causada por mutaciones en el gen del receptor de los glucocorticoides humano. Se caracteriza por la disminución en la sensibilidad tisular al cortisol, con aumento compensatorio en la actividad del eje hipotálamo-hipófisis-adrenal, lo que provoca una elevación de los mineralocorticoides, el cortisol y los andrógenos suprarrenales. El cuadro clínico es variable: asintomático, leve, o con manifestaciones más graves, con hipertensión e hiperandrogenismo. Para el diagnóstico, deben estar ausentes las manifestaciones cushingoides, y demostrarse el hipercortisolismo bioquímico, y la resistencia del eje hipotálamo-hipófisis-adrenal a la supresión con dexametasona. El objetivo del tratamiento es frenar la secreción excesiva de la hormona adrenocorticotropa mediante glucocorticoides que no tengan actividad mineralocorticoide, como es el caso de la dexametasona. En el futuro se espera estén disponibles terapias que permitan corregir directamente los defectos genéticos en el gen del receptor de los glucocorticoides humano(AU)

Glucocorticoids are involved in important biological processes of the body. The glucocorticoid resistance syndrome or Chrousos's syndrome is a genetic disease caused by the human glucocorticoid receptor gene mutations. It is characterized by reduced tissue sensitivity to cortisol and compensatory increase of the hypothalamus-hypophysis-adrenal axis activity, which leads to a rise of minrealocorticoids, cortisol and adrenal androgens levels. The clinical picture is variable, going from asymptomatic, mild or severe manifestations to hypertension and hyperandrogenism. For a right diagnosis, there should be no Cushing-like manifestations and biochemical hypercortisolism as well as hypothalamus-hypophysis-adrenal axis resistance to dexamethasone suppression have to be proven. The objective of the treatment is to halt the excessive secretion of the adrenocorticotrope hormone through glucocorticoids that do not present mineralocorticoid action as it happens with dexamethasone. In the near future, corrective therapies are expected to be available in order to directly fix genetic defects in the human glucocorticoid receptor gen(AU)

The Expression of HDAC2 In PeripheraI BIood MononucIear CeIIs from Patients with Sudden SensorineuraI Hearing Loss / 听力学及言语疾病杂志

Objective To evaluate expression of HDAC2 in peripheral blood mononuclear cells(PBMCs)from glucocorticoid-resistant versus glucocorticoid-sensitive patients with sudden sensorineural hearing loss and identi-ty the relationship between the level of HDAC2 and glucocorticoid insensitivity.Methods PBMCs were collected from10 patients with deviation of nasal septum (control group)and 20 sudden sensorineural hearing loss patients be-fore and after intratympanic methylprednisolone for 10 days.We divided the SSNHL patients into 2 groups (GC sensitive group and GC insensitive group)according to their hearing recovery.Real time PCR and HDAC2 Assay Kit were used to detect the expression level of HDAC2 mRNA and HDAC2 activity in PBMCs.The data were analyzed with SPSS 17.0 software.ResuIts Before intratympanic methylprednisolone,the level of HDAC2 activity were sig-nificantly depressed in SSNHL patients,while the HDAC2 mRNA expressing much higher than the control group. The expression level of HDAC2 mRNA increased significantly after intratympanic methylprednisolone.The HDAC2 activity in GC sensitive group increased significantly.ConcIusion Knockdown of HDAC2 expression induces corti-costeroid in-sensitivity.Glucocorticoids can increase the expression of HDAC2 mRNA.HDAC2 activity can be down-regulated by post-translational modifications.

Rapamycin sensitizes glucocorticoid resistant acute lymphoblastic leukemia CEM-C1 cells to dexamethasone induced apoptosis through both mTOR suppression and up-regulation and activation of glucocorticoid receptor / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To explore the role of glucocorticoid (GC) receptor (GR) in rapamycin's reversion of GC resistance in human GC-resistant T-acute lymphoblastic leukemia (ALL) CEM-C1 cells.</p><p><b>METHODS</b>CEM-C1 cells were cultured in vitro and treated with rapamycin at different concentrations with or without 1 μmol/L dexamethasone (Dex). 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) test was performed to assess cell proliferation. The cell cycle and cell apoptosis were analyzed by flow cytometry. The expression of GRα mRNA was determined by real-time quantitative RT-PCR. The expression of GR, p-70S6K, Mcl-1, and Bim proteins was detected by Western blot.</p><p><b>RESULTS</b>When incubated with rapamycin at different concentrations, CEM-C1 cells showed significant growth inhibition in a time- and concentration-dependent manner. The growth inhibition was synergistically increased when CEM-C1 cells were treated with rapamycin plus 1 μmol/L Dex. CEM-C1 cells treated with rapamycin alone showed no apparent apoptosis, and were arrested at G0/G1 phase. After the treatment with Dex plus rapamycin, CEM-C1 cells demonstrated apparent apoptosis and increased the cell cycle arrested at G0/G1 phase. Rapamycin combined with Dex up-regulated GRα, phosphorylated GR(p-GR), and pro-apoptotic protein Bim-EL in CEM-C1 cells, but inhibited the expression of p-p70S6K, a downstream target protein of mTOR (mammalian target of rapamycin).</p><p><b>CONCLUSION</b>After the treatment with rapamycin plus Dex, Dex resistant CEM-C1 cells induce growth inhibition and apoptosis. The underlying mechanism may involve inhibition of the mTOR signaling pathway and also be associated with up-regulation of GR expression and activation of GC-GR signaling pathway.</p>

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.

Progress in the mechanisms of glucocorticoid resistance in ectopic ACTH syndrome / 中华内分泌代谢杂志

High level of eetopie serum ACTH can not be suppressed by endogenous or exogenous glucocorticoid, this is the cardinal characteristic of ectopic ACTH syndrome (EAS), that is to say there exists glucocorticoid resistance in EAS. However, the mechanism of glucocorticoid resistance remains unclear. Identifying the mechanism can help us to diagnose and treat the disease. This review focuses on the mechanism of glucocorticoid resistance from several aspects, including the pre-glucocorticoid receptor (GR), GR and post-GR.

Effect of Dexamethasone on Expression of Glucocorticoid Receptor in Human Monocyte Cell Line THP-1 / 华中科技大学学报（医学）（英德文版）

The effect of dexamethasone with differentconcentrations and different stimulating periods on the expression of glucocorticoid receptors (GRα, GRβ) protein was investigated in human monocyte cell line THP-1. The cultured human monocyte line THP-1 cells were stimulated by dexamethasone with different concentrations and different periods. The expression of GRα and GRβ protein was detected by Western blotting. The results showed that the expression of GRα and GRβ was detected in the THP-1 cells. The quantity of GRα expression was reduced by dexamethasone under the same concentration with the prolongation of the stimulating periods. The quantity of GRβ expression was increased by dexamethasone treatment in a time- and dose-dependent manner. It was concluded that dexamethasone stimulation time-dependently reduced the GRα expression in THP-1 cells. Dexamethasone stimulation time- and dose-dependently increased the GRβ expression in THP1 cells. The expression of GRα and GRβ was regulated by glucocorticoid.

Effects of dexamethasone on expression of glucocorticoid receptor in human monocyte cell line THP-1 / 中华急诊医学杂志

Objective To investigate the effects of dexamethasone on the expression of glucocorticoid receptor (GR ?, GR ?) in human monocyte cell line THP-1.Methods Cultured THP-1 cells were stimulated by dexamethasone with different concentrations and for different durations. The GR ? and GR ? protein expressions were examined by Western blotting. Results The expressions of GR ? and GR ? were observed in stimulated and unstimulated THP-1. The quantity of GR ? expression was reduced by dexamethasone treatment in a time-dependent manner. The quantity of GR ? expression was increased by dexamethasone treatment in time- and dose-dependent manner. Conclusion Dexamethas one stimulation time-dependent reduce GR ? expression in THP-1 cell. Dexamethasone stimulation time- dependent and dose-dependent increase GR ? expression in THP-I. The expressions of GR a and GR ? were regulated by glucocorticoid.

Changes of glucocorticoid receptor expression and activity in rat alveolar macrophages induced by lipopolysaccharide / 第三军医大学学报

Objective To investigate changes of glucocorticoid receptor (GR) expression and activity in rat alveolar macrophages (AMs) induced by lipopolysaccharide (LPS) within 24 h. Methods Primary cultured AMs were divided randomly into LPS treatment group and LPS+Dex treatment group. The expressions of GR mRNA and GR protein in AMs at different time points were detected by RT-PCR and Western blot. Electrophoretic mobility shift assay (EMSA) was used to measure the GR activity in AMs. Results The expression level of GR mRNA decreased after LPS treatment, but returned to the normal level at 24 h after LPS treatment. The expression level of GR also decreased and reached the lowest level at 4 h after LPS treatment. GR activity also decreased, reached the lowest level at 1 h after LPS treatment, but was still lower than that in the normal control group at 24 h after treatment. Dexamethasone treatment had no obvious effect on GR activity during the late period of treatment. Conclusion LPS treatment (100 ng/ml) down-regulates the protein expression of GR, which maybe associated with the decreased expression of mRNA and accelerate degradation of GR protein. The activity of GR is inhibited sharply, resulting in glucocorticoid resistance.