超抗原SEB对角质形成细胞糖皮质激素受体的作用研究

目的探讨超抗原金黄色葡萄球菌肠毒素B(SEB)对人永生化角质形成细胞(Ha Ca T细胞)糖皮质激素受体表达及核转移的影响。方法采用不同浓度SEB作用于体外培养的Ha Ca T细胞,RT-PCR、Western blot分别检测Ha Ca T细胞糖皮质激素受体α、β(GRα、GRβ)m RNA、蛋白的表达;随后用SEB预处理Ha Ca T细胞,地塞米松再作用Ha Ca T细胞8 h后,免疫荧光法检测Ha Ca T细胞GRα细胞内分布情况。结果 SEB作用Ha Ca T细胞后,其GRαm RNA、蛋白表达无明显变化,GRβm RNA、蛋白表达随SEB的浓度增高呈上升趋势,且在SEB质量浓度为100 ng/ml时达到最高值。10-6mol/L地塞米松作用8 h后能够诱导Ha Ca T细胞GRα由胞浆向胞核转移,该效应能够维持到24 h。与地塞米松组Ha Ca T细胞内GRα分布出现向核内转移现象不同,地塞米松+SEB组部分细胞GRα分布仍局限于胞质,并未出现核转移现象。结论 SEB可能通过诱导角质形成细胞GRβ表达上调及抑制地塞米松诱导的GRα由胞浆向胞核转移参与炎症性皮肤病外用糖皮质激素抵抗。     

糖皮质激素受体阻断对大鼠白细胞粘附的作用

目的明确ＧＲ阻断后对白细胞粘附的作用及可能的作用机制。方法１．在体实验。观察肠系膜微循环白细胞贴壁粘附数。 ２．高体实验。（１）ＰＭＮ与玻璃珠粘附;ＰＭＮ粘附率（％）粘附：ＰＭＮ粘附率（％）＝粘附前ＰＭＮ计数一洗脱液ＰＭＮ计数（３）ＰＭＮ粘附 粘附前ＰＭＮ计数分子ＣＤ１８：ＥＬＩＳＩＡ检测;（４）ＣＤ１８表达和ＰＭＮ与ＩＣＡＭ－１包被磁珠粘附的关系：ＰＭＮ与ＩＣＡＭ－１包被磁珠粘附,同时测定ＣＤ１８表达。结果１．在体实验。对照组仅有少量白细胞贴壁粘附（２．５０±２．１７）,阻断ＧＲ后白细胞贴壁粘附±Ｄｅｘ组的粘附率与ＴＮＦ组相比无显著差异（Ｐ＞０．０５）,Ｄｅｘ±ＴＮＦ组的粘附率与ＴＮＦ组相比有下降趋势．但差异不显著。ＴＮＦ＋Ｄｅｘ＋ＲＵ４８６组的粘附率与ＴＮＦ组和对照组相比均有差异（分别是 Ｐ＜０． ０５,Ｐ＜０． ０１）。 ２． ＰＭＮ与 ＥＣ粘附： ＴＮＦ组与ＴＮＦ＋Ｄｅｘ组结果同ＰＭＮ与玻璃珠粘附。Ｄｅｘ＋ＴＮＦ组的粘附率与ＴＮＦ组相比差异显著（Ｐ＜０．０５）。ＴＮＦ＋Ｄｅｘ＋ＲＵ４８６组的粘附率与对照组相差十分显著（Ｐ＜０．０１）,与ＴＮＦ组相比,两者无明显差异。３．ＰＭＮ与ＩＣＡＭ－１包被磁珠粘附：ＴＮＦ     

免疫反应对糖皮质激素受体的影响和意义

本文采用绵羊红细胞腹腔注入C_(57)BL小鼠产生抗绵羊红细胞的免疫反应。观察小鼠在免疫反应过程中,其脾脏淋巴细胞糖皮质激素受体(GCR)数的变化。发现在绵羊红细胞致敏后第五天小鼠脾淋巴细胞GCR数明显高于对照组(P<0.005),第七天达高峰,第十一天恢复至正常。用Dex抑制由植物血凝素(PHA)诱导的小鼠脾脏淋巴细胞的转化探讨致敏鼠脾淋巴细胞GCR变化的意义。结果提示Dex对淋转抑制程度可能与淋巴细胞GCR数有关。本文还用上述方法研究了妊娠小鼠,发现妊娠母体内脾淋巴细胞GCR数明显高于未孕小鼠(P<0.005),这在调节母胎免疫反应中有一定意义。     

NgR在糖皮质激素诱导视网膜神经节细胞凋亡中的作用

目的探讨糖皮质激素对视网膜神经节细胞(retinal ganglion cell,RGC)凋亡的影响及可能机制。方法分4组培养RGCs,即①对照组,②激素组(0.1μmol/L可的松),③激素-siNgR组(0.1μmol/L可的松+NgR反义核苷酸病毒),④激素-scRNA对照组(0.1μmol/L可的松+阴性核苷酸病毒)。3d后四甲基噻唑蓝(Thiazolyl blue tetrazolium bromide,MTT)检测细胞活力变化,倒置显微镜观察细胞形态学变化,Hoechst 33342染色检测细胞凋亡,Western blot检测Nogo受体(Nogo receptor,NgR)表达。结果RGCs细胞活力在激素组(76.3±6.8)%和激素-scRNA组(79.4±9.0)%明显低于对照组(100.0±0.0)%和激素-siNgR组(96.7±9.8)%。但是,NgR表达水平在激素组和激素-scRNA组明显高于对照组和激素-siNgR组(P<0.01)。Hoechst 33342染色显示,激素组及激素-scRNA组RGCs可见大量亮蓝色的凋亡细胞,但在对照组及激素-siNgR组未见凋亡细胞。结论糖皮质激素诱导RGC凋亡与上调NgR表达相关。     

兴奋性氨基酸、糖皮质激素及其受体与癫痫

近几年的研究证明,兴奋性氨基酸、抑制性氨基酸、钙内流、类固醇激素等在癫痫发病中扮演了重要角色.其中,兴奋性氨基酸(EAA)、糖皮质激素(GC)及其受体与癫痫的关系越来越受到重视.     

糖皮质激素对大鼠脾淋巴细胞表达IL—2受体的调节

采用荧光标记的抗ＣＤ２５单抗，观察了地塞米松对大鼠脾淋巴细胞表达低亲和力ＩＬ－２受体（ＣＤ２５抗原）的影响，结果显示，在ＣｏｎＡ激活的淋巴细胞培养体系中加入地塞米松后，低亲和力ＩＬ－２受体的表达明显受到抑制，表达ＣＤ２５抗原的阳性细胞率亦明显减少，采用＾１２５Ｉ－ｒＩＬ－２结合分析实验，进一步研究了地塞米松对高亲和力ＩＬ－２受体的影响，结果证实，１０ｎｍｏｌ／Ｌ地塞米松使高亲和力ＩＬ－２受体的数量     

兴奋性氨基酸、糖皮质激素及其受体与阗痫

近几年的研究证明,兴奋性氨基酸、抑制性氨基酸、钙内流、类固醇激素等在癫痫发病中扮演了重要角色.其中,兴奋性氨基酸(EAA)、糖皮质激素(GC)及其受体与癫痫的关系越来越受到重视.     

糖皮质激素受体对大鼠中性粒细胞粘附的影响

本文通过Percoll梯度离心法分离获得大鼠中性粒细胞(PMNS)后,采用PMNS与玻璃珠粘附的模型,通过给予Dex及糖皮质激素受体(GR)阻断剂Mifepristone(RU_(38486))研究大鼠PMNS粘附过程中GR的作用。结果显示,Dex可以明显抑制PMNS的粘附,其作用随着Dex浓度的增大而增强;单纯给予不同浓度的RU_(38486)未发现明显的PMNS粘附增强,说明RU_(38486)本身对离体的PMNS粘附没有明显的作用;若同时给予Dex和RU_(38486),则Dex抑制PMNS粘附的作用逐渐减小,直至完全逆转。该结果强烈提示:糖皮质激素(GC)具有抑制PMNS粘附的作用,其作用是通过GR介导的,当GR被阻断时,这一抑制作用减弱,甚至消失。     

多发性骨髓瘤糖皮质激素受体研究进展

糖皮质激素是多发性骨髓瘤联合化疗的主要药物，通过与糖皮质激素受体持异结合抑制骨髓瘤细胞增殖，对糖皮质激素耐药的骨髓瘤细胞不仅糖皮质激素受体数量减少，而且功能异常。     

Long-term lack of endogenous glucocorticoids down-regulates glucocorticoid receptor levels in the rat forebrain

To understand the effect of a chronic lack of endogenous glucocorticoids on glucocorticoid receptor levels, the changes of glucocorticoid receptor content in the rat forebrain five months after adrenalectomy were investigated. In the long-term adrenalectomized rats that showed a hormone deficiency and loss of glucocorticoid receptor immunoreactivity in the forebrain, an intraperitoneal injection of corticosterone was used to elevate the serum hormone levels and recover glucocorticoid receptor immunoreactivity in the forebrain. One hour later, when the blood corticosterone returned to the normal level, the recovery of glucocorticoid receptor immunoreactivity in the forebrain was examined by immunohistochemistry. Since the complete restoration of glucocorticoid receptor immunoreactivity was shown to depend on the presence of normal levels of both serum hormone and intracellular glucocorticoid receptors, the weak reappearance of glucocorticoid receptor immunoreactivity in any forebrain area of the long-term adrenalectomized rats that had normal serum corticosterone might reflect the low intracellular glucocorticoid receptor levels there. Our results revealed a weak reappearance of glucocorticoid receptor immunoreactivity in some forebrain areas of the long-term adrenalectomized rats after corticosterone treatment; the hippocampal granule cell layer and cerebral cortex in particular showed very weak recovery of glucocorticoid receptor immunoreactivity. Conversely, neurons in the CA1/CA2 subfields of the hippocampal pyramidal cell layer, immediately adjacent to the granule cell layer on the same brain section, exhibited a strong reappearance of glucocorticoid receptor immunoreactivity, to near normal levels.

These results suggest that, five months after adrenalectomy, the intracellular glucocorticoid receptor content decreased in the rat granule cell layer and cerebral cortex. Therefore, the long-term lack of endogenous glucocorticoids after adrenalectomy might down-regulate but not up-regulate the intracellular glucocorticoid receptor level, and the presence of glucocorticoids is important for the continued synthesis of glucocorticoid receptors.     

Differential expression of glucocorticoid receptor in carcinomas of the human digestive system

Aims:  To investigate the in situ expression profile of glucocorticoid receptor (GR) in normal and carcinomatous tissues of the human digestive system.
Methods and results:  Specimens from 306 carcinomas of the human digestive tract were assayed for the expression of GR by immunohistochemistry. GR expression was strong in oesophageal squamous epithelia, pancreatic islet cells and hepatocytes, but generally weak or negative in non-squamous epithelia. Consistently, GR expression was found in a high percentage of oesophageal squamous cell carcinomas (SCC) (98.1%) and hepatocellular carcinomas (HCC) (92.9%), but rarely in gastric adenocarcinomas (7.4%) and not at all in colorectal adenocarcinomas (0%). Dexamethasone (DEX) was found to confer chemoresistance in oesophageal SCC and HCC cells, suggesting that GR expression may be biologically important in some GR-expressing carcinomas.
Conclusions:  Distribution of GR expression is markedly diverse among tissues of the human digestive system. The general lack of GR in adenocarcinomas contrasts with the high percentage of SCCs and HCCs expressing GR, and, along with the generation of chemoresistance by DEX, warrants prospective study of the effects of steroids on these cancers.     

Effect of neonatal respiratory infection on adult BALB/c hippocampal glucocorticoid and mineralocorticoid receptors

The current study investigated the effects of neonatal infection with Chlamydia muridarum bacteria on glucocorticoid (GR) and mineralocorticoid (MR) receptors in the adult mouse hippocampus. In male adults infected at birth, circulating corticosterone was significantly increased when compared to same sex controls; while neonatal infection resulted in female adults with significantly increased GR mRNA compared to same sex controls. When comparing males and females after neonatal infection, males had significantly less GR protein than females. Interestingly, after control treatment, males had significantly more GR mRNA, MR mRNA, and GR protein with significantly lower corticosterone than females. Neonatal respiratory infection significantly impacts adult hippocampal GR and MR, and circulating corticosterone in a sex-specific manner potentially altering stress responsivity.     

Regulation of glucocorticoid receptor in nasal polyps by systemic and intranasal glucocorticoids

Background: Poor response of nasal polyps to glucocorticoids (GCs) may be because of abnormal expression of GC receptors (GR) α and β or to downregulation of GRα. We aimed to evaluate the in vivo regulation of GR isoforms in GC‐treated nasal polyps and to assess the relationship between clinical response to GCs and GR levels. Methods: Patients with nasal polyps were randomly (3:1) treated (n = 51) or not (n = 14) with oral prednisone and intranasal budesonide for 2 weeks, plus intranasal budesonide for 10 additional weeks. Nasal symptoms were evaluated. Biopsies were obtained before (w0) and after 2 (w2) and 12 (w12) weeks of treatment, and analysed for their inflammatory content and GR mRNA (10² cDNA copies/μg total RNA) and protein (% immunoreactive inflammatory cells) expression. Healthy nasal mucosa (n = 11) was also investigated. Data are presented as median and 25–75th percentile. Results: At w0, nasal polyps expressed less GRα mRNA (1343;683–2263; P < 0.05) and GR protein (41;29–54; P < 0.05) than nasal mucosa (2474;1346–2933; 60;51–72, respectively). GRβ immunoreactivity was higher in nasal polyps (11;4–19; P < 0.05) than in nasal mucosa (5;2–5). At w2, increased GRα mRNA (2010;1037–2732; P < 0.01) and GR protein (56;27–71; P = 0.056) were found compared with w0 (1177;759–2058; 37;29–55, respectively). At w12, GRα mRNA and GR protein were similar to w0. GRβ expression was unaltered by treatment. Neither GRα nor GRβ correlated with nasal symptoms. GR immunoreactivity negatively correlated with eosinophils (r = ?0.478; P < 0.001). Conclusions: GRα is downregulated in nasal polyps and upregulated by GC treatment. Neither GRα nor GRβ appear to determine the sensitivity to GCs in nasal polyposis.     

Expressions of hippocampal mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) in the single-prolonged stress-rats

Post-traumatic stress disorder (PTSD) is a stress-related mental disorder caused by traumatic experience. Single-prolonged stress (SPS) is one of the animal models proposed for PTSD. Rats exposed to SPS showed enhanced inhibition of the hypothalamo-pituitary-adrenal (HPA) axis, which has been reliably reproduced in patients with PTSD. Mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) in the hippocampus regulate HPA axis by glucocorticoid negative feedback. Abnormalities in negative feedback are found in PTSD, suggesting that GR and MR might be involved in the pathophysiology of these disorders.In the present study, we performed immunohistochemistry and western blotting to examine the changes in hippocampal MR- and GR-expression after SPS. Immunohistochemistry revealed decreased MR- and GR-immunoreactivity (ir) in the CA1 of hippocampus in SPS animals. Change in GR sub-distribution was also observed, where GR-ir was shifted from nucleus to cytoplasm in SPS rats. Western blotting showed that SPS induced significantly decreased MR- and GR-protein in the whole hippocampus, although the degree of decreased expression of both receptors was different. Meanwhile, we also found the MR/GR ratio decreased in SPS rats. In general, SPS induced down-regulation of MR- and GR-expression. These findings suggest that MR and GR play critical roles in affecting hippocampal function. Changes in MR/GR ratio may be relevant for behavioral syndrome in PTSD.     

Graves''甲亢患者外周血单个核细胞糖皮质激素受体表达类型的变化

目的：为检测Graves‘甲亢病人外周血单个核细胞hGRα/GRβ表达及影响因素，探讨糖皮质激素及其受体在该疾病中的作用。方法：本研究用半定量RT－PCR方法检测正常人及Graves‘甲亢病人外周血单个核细hGRα/GRβ，同时测定了晨8：00皮质醇、甲功水平，用多元回归分析法探讨了它们之间的关系。结果：该研究提示Graves甲亢组的hGRα/GRβmRNA比值与TT3、TT4相关（P＜0．05），相关系数分别为：0．61和 0．54。Graves‘甲亢组的血皮质醇明显高于正常组。TT3和TT4与皮质醇不相关。皮质醇与hGRα/GRβmRNA比值不相关。结论：Graves‘甲亢病人外周血单个核细胞hGRα/GRβ表达增高。     

连续单一应激后大鼠海马5-HT_(1A)受体活性与糖皮质激素受体表达的关系

目的:观察连续单一应激(SPS)大鼠海马糖皮质激素受体(GR)变化与5-HT1A受体的关系,探讨创伤后应激障碍的发病机制。方法:选用雄性成年Wistar大鼠45只,将大鼠随机分为对照组、模型组和阻断组,每组15只。模型组和阻断组给予SPS应激,其中阻断组大鼠在接受SPS前用55-HT1A受体阻断剂WAY100635预处理。采用免疫组织化学和免疫印迹技术测定海马GR水平,采用逆转录-聚合酶链式反应检测GRmRNA表达变化。结果:(1)免疫组织化学结果显示,模型组大鼠海马GR表达高于对照组(P0.01),阻断组则低于模型组(P0.05);(2)WesternBlot结果显示,模型组大鼠海马GR相对表达高于对照组(P0.01),阻断组低于模型组(P0.01);(3)RT-PCR结果表明,与对照组比较,模型组大鼠海马GRmRNA表达增强(P0.01);与模型组比较,阻断组表达量降低(P0.05)。结论:SPS海马GR表达变化与5-HT1A受体有关。     

糖皮质激素受体基因G1666T多态性与原发性高血压的相关性

目的探讨糖皮质激素受体基因第4内含子基因G1666T多态性与原发性高血压(essential hypertension,EH)的关系。方法用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)分析71例正常人及48例原发性高血压患者中GR基因第4内含子变异的多态性分布情况。结果从整体来讲,不分性别,GR基因第4内含子的变异在EH与对照组之间,其基因型频率、等位基因的频率无显著性差异。而在女性,与对照组(0.46)比较,EH(0.64)等位基因G的频率明显增高(P<0.05)。结论等位基因G的频率增高可能是原发性高血压的易感基因标志。