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

Objective To explore the role of glucocorticoid （GC） receptor （GR） in rapamycin＇s reversion of GC resistance in humanGC-resistant T-acute lymphoblastic leukemia （ALL） CEM-C1 cells. Methods 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. Results 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 ofmTOR （mammalian target of rapamycin）. Conclusion 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.

Glucocorticoid receptor expression in neonatal rat cortex following recurrent seizures The role in developing brain injury

BACKGROUND： Studies have explored changes in neonatal rat glucocorticoid receptor （GR） expression changes following mature brain injury. OBJECTIVE： To investigate the temporal and special changes of GR during brain development in rats with recurrent seizures. DESIGN, TIME AND SE＇n＇ING： A randomized, controlled animal experiment was performed at the Department of Pediatrics, Second Xiangya Hospital of Central South University, from February 2008 to March 2009. MATERIALS： Rabbit anti-rat GR monoclonal antibody was purchased from Santa Cruz Biotechnology, USA; goat anti-rabbit IgG was purchased from Zhongshan Goldenbridge Biotechnology, China. METHODS： A total of 48 Sprague-Dawley rats, 7 days old, were randomly assigned to control and seizure groups, with 24 animals in each group. Seizures were induced by inhalant flurothyl. MAIN OUTCOME MEASURES： Changes in GR protein expression in the rat cerebral cortex were detected by Western blotting analysis and immunohistochemistry. RESULTS： GR expression in the cerebral cortex of control rats significantly increased with aging （P 〈 0.05）, and varied in the frontal lobe, temporal lobe, and parietal lobe. GR was predominantly expressed in the cytoplasm early and rapidly increased in the nuclei. GR protein expression in the cerebral cortex after seizure was lower in the cytoplasm at 15 days and in nuclear protein at 19 days. CONCLUSION： GR expression displayed temporal and spatial changes in brain development. Recurrent seizures in neonatal rats cause abnormal GR expression and might play an important role in developing brain injury.

Effects of glucocorticoids on the growth and chemosensitivity of carcinoma cells are heterogeneous and require high concentration of functional glucocorticoid receptors

AIM： To determine how glucocorticoids （GCs） may affect the growth and chemosensitivity of common carcinoma cells. METHODS： The effect of dexamethasone （DEX） on growth and chemosensitivity was assessed in 14 carcinoma cell lines. The function of GC receptors （GR） was assessed by MMTV reporter assay. Overexpression of GR was done by in vitro transfection and expression of a GR-expressing vector. Immunohistochemical stain of tissues and ceils were done by PA1-511A, an anti-GR monodonal antibody. RESULTS： DEX inhibited cell growth of four （MCF-7, MCF- 7/MXR1, MCF-7/TPT300, and HeLa）, increased cisplatin cytoxicity of one （SiHa）, and decreased dsplatin cytotoxicity of two （H460 and Hep3B） cell lines. The GR content of the seven cell lines affected by DEX was significantly higher than those of the seven cell lines unaffected by DEX （5.2±2.5×10^4 sites/cell vs1.3±1.4×10^4 sites/cell, P= 0.005）. Only two DEX-unresponsive cell lines {NPC-TW01 and NPC- TW04） oontained high GR amounts in the range （1.9-8.1×10^4 sites/cell） of the seven DEX-responsive cell lines. The GR function of NPC-TW01 and NPC-TW04, however, was foundto be impaired. The importance of high cellular amount of GR in mediating DEX susceptibility of the cells was further exemplified by GR dose-dependent drug resistance to cisplatin of AGS, a cell line with low GR content and was unaffected by DEX before transfection of GR-expressing vector. Immunohistochemical studies of human cancer tissues showed that 5 of the 45 （11.1%） breast cancer and 43 of the 85 （50.6%） non-small cell lung cancer had high GR contents at the ranges of the GC-responsive carcinoma cell lines. CONCLUSION： The growth and chemosensitivity of human carcinomas with high GR contents may be affected by GC. However, in light of the heterogeneous and even contradictive effects of GC on these cells, routine examination of GR contents of human carcinoma tissues may not be clinically useful until other markers that help predict the ultimate effect of GC on individual patients are identified.

Glucocorticoid receptor gene haplotype structure and steroid therapy outcome in IBD patients

AIM: To study whether the glucocorticoid receptor (GR/ NR3C1) gene haplotypes influence the steroid therapy outcome in inflammatory bowel disease (IBD). METHODS: We sequenced all coding exons and flanking intronic sequences of the NR3C1 gene in 181 IBD patients, determined the single nucleotide polymorphisms, and predicted the NR3C1 haplotypes. Furthermore, we investigated whether certain NR3C1 haplotypes are significantly associated with steroid therapy outcomes. RESULTS: We detected 13 NR3C1 variants, which led to the formation of 17 different haplotypes with a certainty of > 95% in 173 individuals. The three most commonly occurring haplotypes were included in the association analysis of the influence of haplotype on steroid therapy outcome or IBD activity. None of the NR3C1 haplotypes showed statistically signifi cant association with glucocorticoid therapy success. CONCLUSION: NR3C1 haplotypes are not related to steroid therapy outcome.

Clinical relevance of the glucocorticoid receptor gene polymorphisms in glucocorticoid-induced ocular hypertension and primary open angle glaucoma

AIM: To avoid the side effects of ocular hypertension of glucocorticoid(GC) usage in eye, we must identify susceptible individuals, which exists in about one-third of all population. Further, the majority of all primary open angle glaucoma(POAG) patients show this phenotype.Glucocorticoid receptor(GR) regulates C responsiveness in trabecular meshwork(TM) cells. In this study, single nucleotide polymorphism(SNP) genotyping was used to determine whether there are differences in the Bcl I(rs41423247) and N363S(rs6195) polymorphisms of the GR gene in healthy and POAG patients, and glucocorticoid-induced ocular hypertension(GIOH)populations.METHODS: Three hundred and twenty-seven unrelated Chinese adults, including 111 normal controls, 117 GIOH subjects and 99 POAG patients, were recruited. DNA samples were prepared and the Bcl I and N363 S polymorphisms were screened using real-time polymerase chain reaction(RT-PCR)-restriction fragment length polymorphism(RFLP) analysis. Frequencies of the Bcl I and N363 S polymorphisms were determined and compared using Fisher’s exact test and the Chi-squared test.RESULTS: Only the Bcl I polymorphism was identified in the Chinese Han population. The frequency of the G allele was 21.6 % in normal controls, 18.3% in GIOH patients, and 13.64% in the POAG patients. There was no significant difference in polymorphism or allele frequency in the 3 groups. Furthermore, no N363 S polymorphism was found in the study subjects.CONCLUSION: The Bcl I polymorphisms in GR gene had no association with GIOH and POAG patients, and N363 S polymorphism might not exist in the Chinese Han population. Therefore, the Bcl I polymorphism might not be responsible for the development of GC-induced ocular hypertension or POAG.

Effect of Calpain inhibitor I on glucocorticoid receptor-dependent degradation and its transactivation ability

Objective: To investigate the effect of Calpain inhibitor I on glucocorticoid receptor-dependent proteasomal degradation and its transcriptional activity. Methods: After Raw-264.7 cells were treated with Calpain inhibitor I, dexamethasone, or both for about 12 h, the change of glucocorticoid receptor was detected by western blot analysis. COS-7 cells were transfected with PRsh-GRα expression vector and glucocorticoid-responsive receptor pMAMneo-CAT, then the effect of Calpain inhibitor I on glucocorticoid receptor transcriptional activation ability was determined by CAT activity. Results: The glucocorticoid receptor levels decreased after RAW-264.7 cells were treated with dexamethasone for 12 hours, which effect can be inhibited by Calpain inhibitor I to some extent. CAT activity assay showed that Calpain inhibitor I enhance glucocorticoid receptor transcriptional activity. Conclusion: Calpain inhibitor I can inhibit the down-regulation of dexamethasone on glucocorticoid receptor, and enhances glucocorticoid receptor transactivation ability.

A facile,branched DNA assay to quantitatively measure glucocorticoid receptor auto-regulation in T-cell acute lymphoblastic leukemia

Glucocorticoid(GC) steroid hormones are used to treat acute lymphoblastic leukemia(ALL) because of their pro-apoptotic effects in hematopoietic cells.However,not all leukemia cells are sensitive to GC,and no assay to stratify patients is available.In the GC-sensitive T-cell ALL cell line CEM-C7,auto-up-regulation of RNA transcripts for the glucocorticoid receptor(GR) correlates with increased apoptotic response.This study aimed to determine if a facile assay of GR transcript levels might be promising for stratifying ALL patients into hormone-sensitive and hormone-resistant populations.The GR transcript profiles of various lymphoid cell lines and 4 bone marrow samples from patients with T-cell ALL were analyzed using both an optimized branched DNA(bDNA) assay and a real-time quantitative reverse transcription-polymerase chain reaction assay.There were significant correlations between both assay platforms when measuring total GR(exon 5/6) transcripts in various cell lines and patient samples,but not for a probe set that detects a specific,low abundance GR transcript(exon 1A3).Our results suggest that the bDNA platform is reproducible and precise when measuring total GR transcripts and,with further development,may ultimately offer a simple clinical assay to aid in the prediction of GC-sensitivity in ALL patients.

Characterization of Glucocorticoid Receptor on Lymphocytes in Chinese Patients with Glucocorticoid-induced Glaucoma

Purpose : We studied the pathogenesis of glucocorticoid-induced glucoma (GIG) through characterization of glucocorticoid receptor (GR) on lymphocytes in Chinese patients with GIG.Methods:By radioligand receptor binding followed by Scatchard analysis, the specific binding sites were characterized and quantitated for glucocorticoid receptors on peripheral blood lymphocytes obtained from patients with GIG and the control group.Results:The binding sites we detected were as follows; 12.7 ± 1.47 × 103 receptors per cell with a KD of 3.02 ± 0.62nmol/L in patients with GIG, 7.26 ± 0.45 × 103 receptors per cell with a KD of 3.03 ± 0.56nmol/L in the control group. The statistical difference of receptors per cell is significant between two groups (p < 0.05), patients with GIG having more GR binding sites, while the difference of Kd is not significant ( p > 0.05 ) . Conclusion: The preliminary findings suggest that patients with GIG are more sensitive to glucocorticoid and the increase of binding sites of

Glucocorticoid receptor regulates expression of microRNA-22 and downstream signaling pathway in apoptosis of pancreatic acinar cells

AIM To elucidate the underlying mechanism that microRNA-22(miR-22) promotes the apoptosis of rat pancreatic acinar cells(AR42 J) and the elements that regulate the expression of miR-22.METHODS One hundred nanomoles per liter of caerulein(Cae)was administrated to induce the apoptosis of AR42 J cells and the apoptosis rate was detected by flow cytometry analysis. An amylase assay kit was used to measure the amylase expression level in the supernatant. Quantitative real-time PCR(qRT-PCR)was adopted to measure miR-22 expression. We used online tools to predict the potential transcription promoter of miR-22 and the binding sites, which was further identified by using luciferase reporter analysis,chromatin immunoprecipitation(ChIP) and ChIPqP CR assays. Then, a mimic of miR-22, Nr3 c1 plasmid encoding the glucocorticoid receptor(GR), and siNr3 c1 were used to transfect AR42 J cells, respectively.The mRNA expression of miR-22, Nr3 c1, and Erb-b2 receptor tyrosine kinase 3(ErbB3) was confirmed by qRT-PCR and the apoptosis rate of AR42 J cells was detected by flow cytometry analysis. Western blot was used to detect the expression of ErbB3, GR, PI3 k, PI3 kp85α, Akt, p-Akt, Bad, Bax, Bcl-xl, Bcl-2, and cleaved caspase3.RESULTS After inducing apoptosis of AR42 J cells in vitro, the expression of miR-22 was significantly increased by2.20 ± 0.26 and 4.19 ± 0.54 times, respectively, at3 h and 6 h in comparison with the control group.As revealed by qRT-PCR assay, the expression of miR-22 was 78.25 ± 6.61 times higher in the miR-22 mimic group relative to the miRNA control group,accompanied with an obviously increased acinar cell apoptosis rate(32.53 ± 1.15 vs 18.07 ± 0.89, P =0.0006). The upregulation of miR-22 could suppress its target gene, ErbB3, and the phosphorylation of PI3 k and Akt. Furthermore, we predicted the potential transcription promoter of miR-22 and the binding sites using online tools. Luciferase reporter analysis and sitedirected mutagenesis indicated that the binding site(GACAGCCATGTACA) of the GR, which is encoded by the Nr3 c1 gene. Downregulation of the expression of GR could upregulate the expression of miR-22, which further promoted the apoptosis of AR42 J cells.CONCLUSION GR transcriptionally represses the expression of miR-22,which further promotes the apoptosis of pancreatic acinar cells by downregulating the downstream signaling pathway.

Novel insights into the effect of Xiaoyao san on corticosterone-induced hepatic steatosis:inhibition of glucocorticoid receptor/perilipin-2 signaling pathway

Objective:Xiaoyao san(XYS)is a classic traditional Chinese medicinal formula.It has been clinically administered to regulate liver function.However,its mechanisms in glucocorticoid-induced hepatic steatosis are unknown.This study aimed to investigate whether XYS protects against corticosterone(CORT)-induced hepatic steatosis,and to explore its mechanism.Methods:High-fat diet mice induced with hepatic steatosis by 2mg/kg CORT were administered 2.56 g/kg or 5.12 g/kg XYS daily for 7 weeks.The effects of XYS on hepatic steatosis in mice were evaluated by H&E and Oil Red O staining and by measuring their plasma lipids(triglyceride,total cholesterol,and free fatty acids).The mechanism of XYS against hepatic steatosis was investigated by network pharmacology,immunohistochemistry,western blotting,and gain-of-function/loss-offunction experiments.Results:XYS alleviated CORT-induced steatosis,decreased plasma lipids,and inhibited glucocorticoid receptor(GR)activation in the liver.Network pharmacology data indicated that XYS may have mitigated hepatic steatosis via GR which mediated adipose differentiation-related protein(ADFP).Gain-of-function/loss-of-function experiments in vitro confirmed that GR positively regulated ADFP expression.Conclusions:XYS ameliorated CORT-induced hepatic steatosis by downregulating the GR/ADFP axis and inhibiting lipid metabolism.Our studies implicate that XYS is promising as a therapy for CORT-induced hepatic steatosis,and lay the foundation for designing novel prophylactic and therapeutic strategies on CORT-induced hepatic steatosis.

Effects of glucocorticoid and glucocorticoid receptors on stress-induced neurogenesis suppression

Studies have shown that cerebral ischemia activates neurogenesis and that stress inhibits neurogenesis.However,the role of stress hormone levels on neurogenesis following cerebral ischemia remains poorly understood.The present study explored the possible regulatory mechanisms of adult neurogenesis under pathological conditions by examining changes and regulation of glucocorticoid receptors in adult rats subjected to transient unilateral middle cerebral artery suture occlusion.Corticosterone levels gradually increased following middle cerebral artery occlusion,and the number of glucocorticoid receptor-positive cells decreased.The number of5-bromodeoxyuridine-and nestin-positive cells significantly increased at 1 and 2 weeks after ischemia.A large number of doublecortin-positive cells migrated from the hippocampus to the cortex.At 3 weeks post-surgery,the number of 5-bromodeoxyuridine-and nestin-positive cells significantly reduced in the subventricular zone.Increased corticosterone levels decreased vascular endothelial cell proliferation and neurogenesis,and the number of glucocorticoid receptor-positive cells decreased.In the sham surgery group,vascular endothelial cell proliferation related to post-ischemic cerebral rehabilitation was not detected.Corticosterone levels increased,but the number and distribution of glucocorticoid receptor-positive cells were not changed.However,normal neuregenesis and migration of neural stem cells existed in the adult rat brain in the sham surgery group.Results suggested that glucocorticoid receptors influenced neurogenesis and were negatively regulated by glucocorticoid levels following focal cerebral ischemia and reperfusion.

Studies on the homogeneity between high-and lowaffinity glucocorticoid receptor

The homogeneity between the high-and low-affinity glucocorticoid receptors(GR_H and GR_L)was testified by immunoaffinity chromatography using Mab N250(recognizing the immunogenic domain at the N terminal of GR_H)and Mab BuGR1(recognizing the DNA binding domain of GR_H).The specific binding peak of 0.98μmol/L[~3H]triamcinolone acetonide(TA)was higher than that of 52.50nmol/L[~3H]TA.The re-sult suggests that the antigenic determinants of GR_L are similar to those of GR_H.ThecDNA of rat liver GR_H was introduced into GR_H-and GR_L-negative mouse fibroblast cellline E82.A3 by calcium phosphate coprecipitation.A number of clones which expressGR_H were selected with G418(400μg/ml).The results of radioligand binding assay indicatethat GR_H gene is expressed successfully and GR_L also may be encoded by GR_H gene.

Escin enhances anti-rheumatoid arthritis effects of low dose glucocorticoids through up-regulation of glucocorticoid receptor

OBJECTIVE To investigate the anti-rheumatoid arthritis(RA)effect of Escin combined with low dose of GCs(dexameth⁃asone,Dex)and its underlying mechanism.METHODS Adjuvant-induced rheumatoid arthritis rats and LPS-injured RAW 264.7 were used to investigate the anti-RA effects of Escin combined with low dose Dex in vivo and in vitro.In vivo experiment:rats were randomly divided into model group(AIA),dexamethasone high dose(Dex,0.2 mg·kg^-1)group,dexamethasone low dose(Dex,0.05 mg·kg^-1)group,Escin 10 mg·kg^-1 group,Dex 0.05+Escin group,10 rats in each group,another 10 were used as normal control group.The vehicle and the corresponding drug were administered intragastrically(ig)daily for 14 d.In vitro experiment:LPS was used to stimulate RAW 264.7 macrophages for inflammatory models,which were divided into control group,LPS group,Dex with high dose(50 nmol·L^-1)group,and Dex with low dose(12.5 nmol·L^-1)group.In the Escin 10μmol·L^-1 group and the Dex+Escin(12.5 nmol·L^-1+10μmol·L^-1)group,the corresponding drugs were added to each well.After 2 h,LPS was added to induce inflammation.RESULTS Escin combined with low dose Dex significantly decreased arthritic index,serum IL-6 and TNF-α,improved paw swelling,and ameliorated the joint pathology immune organ pathology significantly.Gene chip results revealed that Nr3c1(GR)altered significantly.And that GR activation by Escin and low dose Dex was confirmed both in vivo and in vitro.Furthermore,Escin combined with low dose Dex also significant increase GR mRNA expression.However,when suppression of GR by its specific inhibitor,the anti-RA effect of Escin combined with low dose Dex was abolished.CONCLUSION Escin combined with Dex reduces the dose of Dex,and exerts significant anti-RA effects,which could also reduce the adverse effects of Dex.This combination might be attributed to GR activation.This study might provide a new combination drugs for the treatment of RA.

Effect of Dexamethasone on Expression of Glucocorticoid Receptor in Human Monocyte Cell Line THP-1

The effect of dexamethasone with different concentrations 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 hlotting. 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 expression was increased by dexamethasone treatment the stimulating periods. The quantity of GRβ 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 THP- 1 cells. The expression of GRα and GRβas regulated by glucocorticoid.

GLUCOCORTICOID RECEPTOR IN CHILDHOOD ACUTE LYMPHOBLASTIC LEUKEMIA

Objective: To investigate the relationship among glucocorticoid receptor (GCR) level, immunological classification and clinical efficacy of chemotherapy in acute lymphoblastic leukemia (ALL) children. Methods: The GCR level of venous blood lymphocytes was measured by receptor radioligand binding assay in 50 cases with childhood ALL and 41 normal children. The immunological classification of 32 children with ALL was analyzed by ABC immunoenzymatic method. Results: The GCR number in venous blood lymphocytes of normal children was 4651±1617 binding sites/cell. The normal range (95%) was 1482–7800 binding sites/cell. The GCR level of 50 cases with ALL (6695±5256 binding sites/cell) was significantly higher than that of the normal ones (t=2.50, P<0.05). The GCR level of the ALL children with good prognosis was significantly higher than that of bad prognosis (t=4.39, P<0.001). The relationship between immunological classification and GCR level of 32 cases with children ALL was as follows: GCR level of T-ALL and B-ALL were significantly lower than AUL, C-ALL and pre-B-ALL; the prognosis of T-ALL and B-ALL was also bad; the GCR level of the group with good prognosis was significantly higher than that with bad prognosis in all immunological types. Conclusion: The GCR level of the peripheral venous blood lymphocytes in children ALL may be an important biochemistry indicator and used to predict prognosis and guide combination chemotherapy. The relationship between GCR and immunological classification can be useful to the expectation of prognosis.

Blockage of glucocorticoid receptors during memory acquisition, retrieval and reconsolidation prevents the expression of morphine-induced conditioned place preferences in mice

Association between the reward caused by consuming drugs and the context in which they are consumed is essential in the formation of morphine-induced conditioned place preference (CPP). Glucocorticoid receptor (GRs) activation in different regions of the brain affects reward-based reinforcement and memory processing. A wide array of studies have demonstrated that blockage of GRs in some brain areas can have an effect on reward-related memory; however, to date there have been no systematic studies about the involvement of glucocorticoids (GCs) in morphine-related reward memory. Here, we used the GR antagonist RU38486 to investigate how GRs blockage affects the sensitization and CPP behavior during different phases of reward memory included acquisition, retrieval and reconsolidation. Interestingly, our results showed RU38486 has the ability to impair the acquisition, retrieval and reconsolidation of reward-based memory in CPP and sensitization behavior. But RU38486 by itself cannot induce CPP or conditioned place aversion (CPA) behavior. Our data provide a much more complete picture of the potential effects that glucocorticoids have on the reward memory of different phases and inhibit the sensitization behavior.

Blockage of glucocorticoid receptors during memory acquisition,retrieval and reconsolidation prevents the expression of morphine-induced conditioned place preferences in mice

Association between the reward caused by consuming drugs and the context in which they are consumed is essential in the formation of morphine-induced conditioned place preference(CPP).Glucocorticoid receptor(GRs)activation in different regions of the brain affects reward-based reinforcement and memory processing.A wide array of studies have demonstrated that blockage of GRs in some brain areas can have an effect on reward-related memory;however,to date there have been no systematic studies about the involvement of glucocorticoids(GCs)in morphine-related reward memory.Here,we used the GR antagonist RU38486 to investigate how GRs blockage affects the sensitization and CPP behavior during different phases of reward memory included acquisition,retrieval and reconsolidation.Interestingly,our results showed RU38486 has the ability to impair the acquisition,retrieval and reconsolidation of reward-based memory in CPP and sensitization behavior.But RU38486 by itself cannot induce CPP or conditioned place aversion(CPA)behavior.Our data provide a much more complete picture of the potential effects that glucocorticoids have on the reward memory of different phases and inhibit the sensitization behavior.

Study on glucocorticoid receptor of brain cytosol in rats with traumatic brain edema

The high-affinity glucocorticoid binding sites（HAGS）and the low-affinity glucocor-ticoid binding sites（LAGS）with steroid specificity were demonstrated in cerebral cytosol ofrats by using the radioligand binding assay.The equilibrium dissocation constant（Kd）of HAGSand LAGS were（2.78+0.71）×10-8mol/L and（2.12±1.06）×10-6mol/L respectively as esti-mated by Scatchard and Pseudoseatchard analysis.Glucocorticoid receptors（GR）in the trau-matized（left）hemisphere cytosol were decreased more significantly than those in both the con-trol（right）hemisphere cytosol at 6 h postinjury and normal brain tissue（P【0.05）,but Kd ofGR showed no significant changes.GR of liver cytosol at 6h postinjury were more markedly de-creased than normal hepatic cytosol,but Kd of GR underwent no significant changes.These da-ta demonstrate that high-dose glucocorticoid（GC）used in the treatment of traumatic brain ede-ma might maintain target-cell reactions by increasing the production of GC receptor complexesand is most likely to be mediated by LAGS.

Forskolin augments the effects of glucocorticoids on proliferation and differentiation of a human osteosarcoma cell line by up-regulation of glucocorticoid receptor

The effect of forskolin, an activator of adenylate cyclase, on glucocorticoid-induced modulation of proliferation and differentiation of a human osteosarcoma cell line(HOS-8603) was iniually studied. It was found that forskolin could significantly augment

Effect of Fufei Gushen Decoction on airway inflammation and glucocorticoid receptor of chronic obstructive pulmonary disease rat

Objective:To investigate the effect of Fufei Gushen Decoction on airway inflammation and glucocorticoid receptor in rats with chronic obstructive pulmonary disease.Methods:Fifty Wistar male rats were randomly divided into 5 groups:blank control group,COPD model group,Fufei Gushen Yin high,medium and low dose groups,10 rats in each group,except the blank control group,the remaining 4 groups were Smoked combined with lipopolysaccharide(LPS),cold air stimulation to create CODP rat model.After successful modeling,the blank control group and COPD model group were fed with distilled water 3ml/only,Fufei Gushen Yin high,medium and low dose groups were given 1.02,0.51,0.26g Chinese medicine granules/100g/day,respectively.2 times a day for 28 consecutive days.Samples were collected,hematoxylin-eosin(HE)staining was used to observe the pathological changes of lung tissue,and enzyme-linked immunosorbent assay(ELISA)was used to detect the tumor necrosis factor alpha(TNF-α)in the serum and right alveolar lavage fluid(BALF)of rats in each group.),the content of transforming growth factorβ1(TGF-β1),interleukin-17(IL-17A)and matrix metalloproteinase(MMP-9)and tissue inhibitor of metalloproteinase-1(TIMP-1)in the left lung tissue The expression level of real-time fluorescence quantitative polymerase chain reaction(Real-time PCR)rat left lung tissue GRmRNA,immunohistochemistry(IHC)to determine the expression level of left lung tissue glucocorticoid receptor(GR).Results:The content of TNF-α,TGF-β1 and IL-17A in the serum of COPD rats in Fufei Gushen Yin high,medium and low dose groups and BALF were significantly reduced compared with the COPD model group(P<0.05);The expressions of TIMP-1 and MMP-9 in tissues were lower than those in COPD model group(P<0.05);the expressions of GRmRNA and GR in lung tissues were higher than those in COPD model group(P<0.05),and were higher in Fufei Gushen Yin Among the middle-and low-dose groups,the middle-dose group has the most significant effect.Conclusion:Fufei Gushen Decoction can inhibit the release of inflammatory factors in lung tissue of COPD rats,improve airway inflammation and remodeling,and increase hormone sensitivity.