GR Gene Research Articles

Does repeated anticipation induce neuroendocrine modulation of the immune system in domestic pigs?

To improve animal welfare in pig husbandry it is necessary to expand our knowledge of affective states and their physiological effects. In our study, we used a controlled setup to induce affective states and neuroendocrine immune modulation. For each trial, six female piglets were being housed in individual pens in the same room. Three of these piglets were conditioned six times a day to a sound that was followed by a positive stimulus (food), a negative stimulus (air-puff) or a random choice of food or air-puff. This was supposed to induce positive, negative or conflicting anticipation, respectively. The other three piglets obtained positive, negative or no stimuli without conditioning and served as controls. Within four weeks, we expected changes in mood and consequently physiological effects. Preliminary analyses showed an increase in heart rate and heart rate variability in positively anticipating pigs during the sound reflecting an activation of the sympathetic nervous system. These animals also showed an increased serotonin turnover in the ventral tegmental area and a significant decrease in SEB-induced T-cell proliferation. The immunoglobulin production showed an age-dependent increase which was less pronounced for IgM of positively anticipating pigs. While plasma ACTH and salivary cortisol concentrations decreased during the experiment indicating adaptation, there were no treatment-induced effects and in line with this no differences in CRH and GR gene expression in the brain. Our data indicate that a supposedly positive anticipation may be accompanied by a frequent arousal of the pigs with a potentially negative influence on immunocompetence.

Glutathione Reductase from Oryza sativa Increases Acquired Tolerance to Abiotic Stresses in a Genetically Modified Saccharomyces cerevisiae Strain

Glutathione reductase (GR, E.C. 1.6.4.2) is an important enzyme that reduces glutathione disulfide (GSSG) to a sulfydryl form (GSH) in the presence of an NADPH-dependent system. This is a critical antioxidant mechanism. Owing to the significance of GR, this enzyme has been examined in a number of animals, plants, and microbes. We performed a study to evaluate the molecular properties of GR (OsGR) from rice (Oryza sativa). To determine whether heterologous expression of OsGR can reduce the deleterious effects of unfavorable abiotic conditions, we constructed a transgenic Saccharomyces cerevisiae strain expressing the GR gene cloned into the yeast expression vector p426GPD. OsGR expression was confirmed by a semiquantitative reverse transcriptase polymerase chain reaction (semiquantitative RT-PCR) assay, Western-blotting, and a test for enzyme activity. OsGR expression increased the ability of the yeast cells to adapt and recover from H2O2-induced oxidative stress and various stimuli including heat shock and exposure to menadione, heavy metals (iron, zinc, copper, and cadmium), sodium dodecyl sulfate (SDS), ethanol, and sulfuric acid. However, augmented OsGR expression did not affect the yeast fermentation capacity owing to reduction of OsGR by multiple factors produced during the fermentation process. These results suggest that ectopic OsGR expression conferred acquired tolerance by improving cellular homeostasis and resistance against different stresses in the genetically modified yeast strain, but did not affect fermentation ability.

Mifepristone Inhibits GRβ Coupled Prostate Cancer Cell Proliferation

The GR gene produces GRα and GRβ isoforms by alternative splicing of a C-terminal exon. GRα binds glucocorticoids, modulates transcription in a glucocorticoid dependent manner and has a growth inhibitory role in prostate cells. Due to this role glucocorticoids are often used to treat androgen independent prostate cancer. In contrast, GRβ has intrinsic transcriptional activity and binds mifepristone (RU486) but not glucocorticoids to control gene expression. To our knowledge the role of GRβ in prostate cell proliferation is unknown. We determined GRβ levels in various prostate cancer cell lines by reverse transcriptase-polymerase chain reaction and Western blot. The effect of GRβ on the kinetics of prostate cancer cell growth was determined by cell counting and flow cytometry upon mifepristone and dexamethasone treatment. Cell proliferation was also examined after siRNA mediated knockdown and over expression of GRβ. GRβ mRNA and protein were up-regulated in LNCaP cells that over expressed the androgen receptor co-factor ARA70β. Treatment of LNCaP-ARA70β with mifepristone or siRNA targeting GRβ inhibited proliferation compared to that of parental LNCaP cells. The immortal but nontumorigenic RC165 prostate cell line and the tumorigenic DU145 prostate cell line with endogenous GRβ also showed partial growth reduction upon GRβ depletion but to a lesser extent than LNCaP-ARA70β cells. The growth stimulatory effect of ARA70β on LNCaP cells was partly GRβ dependent, as was the proliferation of RC165 cells and to a lesser extent of DU145 cells. Results suggest that patients with a primary tumor that expresses GRβ and ARA70β may benefit from mifepristone.

Breed-Dependent Transcriptional Regulation of 5′-Untranslated GR (NR3C1) Exon 1 mRNA Variants in the Liver of Newborn Piglets

Glucocorticoids are vital for life and regulate an array of physiological functions by binding to the ubiquitously expressed glucocorticoid receptor (GR, also known as NR3C1). Previous studies demonstrate striking breed differences in plasma cortisol levels in pigs. However, investigation into the breed-dependent GR transcriptional regulation is hampered by lacking porcine GR promoter information. In this study, we sequenced 5.3 kb upstream of the translation start codon of the porcine GR gene, and identified seven alternative 5′-untranslated exons 1–4, 1–5, 1–6, 1–7, 1–8, 1–9,10 and 1–11. Among all these mRNA variants, exons 1–4 and 1–5, as well as the total GR were expressed significantly (P<0.05) higher in the liver of newborn piglets of Large White (LW) compared with Erhualian, a Chinese indigenous breed. Overall level of CpG methylation in the region flanking exons 1–4 and 1–5 did not show breed difference. However, nuclear content of Sp1, p-CREB and GR in the liver was significantly (P<0.05) higher in LW piglets, associated with enhanced binding of p-CREB, and higher level of histone H3 acetylation in 1–4 and 1–5 promoters. In contrast, GR binding to promoters of exons 1–4 and 1–5 was significantly diminished in LW piglets, implicating the presence of negative GREs. These results indicate that the difference in the hepatic expression of GR transcript variants between two breeds of pigs is determined, at least partly, by the disparity in the binding of transcription factors and the enrichment of histone H3 acetylation to the promoters.

Association between plasma lipid, glucose, cortisol and adrenocorticotropic hormone levels and GR and ACTHR gene polymorphisms

To explore the association between plasma fat and glucose, cortisol and adrenocorticotropic hormone (ACTH) levels and genotypes of GR and ACTHR genes in healthy Chinese Han subjects. Two hundred healthy subjects were analyzed for GR and ACTHR gene polymorphisms using PCR-restriction fragment length polymorphism method. Plasma lipid, glucose, cortisol, ACTH levels were determined and correlated with the genotypes. No significant difference was found between plasma lipid and glucose levels and various GR and ACTHR genotypes. Subjects with AG genotype of GR 5556A/G polymorphism had lower plasma cortisol levels than AA genotype. Compared with subjects with GG genotype of GR 4534-4536GAG/AAA [GAGAGG (GluArg)>GAAAAG(GluLys)] polymorphism, those with AG genotype had significantly lower plasma cortisol levels. Subjects with CC and CG genotypes of GR 6294C/G polymorphism also had significantly lower plasma cortisol levels compared with those with GG genotype. With regard to plasma ACTH levels, those with TT genotype of ACTHR 2T/C polymorphism were significantly lower than CC and CT genotypes, and those with AG genotype for GR 5556 A/G polymorphism were also significantly lower than AA genotype. There was no difference in plasma cortisol and glucose levels between subjects with GR and ACTHR gene variants. GR gene variants (5556A/G, 4534-4536GAG/AAA and 6294C/G polymorphisms) may influence plasma cortisol level, and ACTHR 2T/C, GR 5556A/G polymorphisms may decrease plasma ACTH level.

P-1096 - Integration of clinical, psychosocial, cognitive and genetic measures to predict antidepressant treatment outcome in mdd patients: a preliminary clinical study

The main aim of this study is to investigate the capacity of a number of variables from four dimensions (clinical, psychosocial, cognitive and genetic domains) to predict the antidepressant treatment outcome, and combined the predictors in one integrate regression model with the aim to investigate which predictor contributed most. In a semi-naturalistic prospective cohort study with a total of 241 fully assessed MDD patients, decrease in HAM-D scores from baseline to after 6 weeks of treatment was used to measure the antidepressant treatment outcome. The clinical and psychosocial model (R 2 = 0.451) showed that HAM-D scores at baseline and MMPI-2 scale paranoia was the best clinical and psychosocial predictor of treatment outcome respectively. The cognitive model (R 2 = 0.502) revealed that combination of better performance on TMT-B test and worse performance on TOH and WAIS-R Digit Backward testes could predict decline in HAM-D scores. The genetics analysis only found median of percent improvement in HAM-D scores in G-allele of GR gene BclI polymorphism carriers (72.2%) was significant lower than that in non-G allele carriers (80.1%). The integrate model showed that three predictors, combination of HAM-D scores at baseline, MMPI-2 scale paranoia and TMT-B test, explained 57.1% of the variance. Three markers, HAM-D scores at baseline, MMPI-2 scale paranoia and TMT-B test, might serve as predictor of antidepressant outcome in daily psychiatric practice.

Associations of GR and ACTHR gene polymorphisms with quantitative trait of strain

To explore association between GR and ACTHR gene polymorphisms and quantitative trait of stress in Chinese Han population. Four polymorphic markers (GRA5556G, A5556G, GAGG4534/4536AAAG, promoter T-2C) in GR gene and ACTHR gene were genotyped with PCR-RLFP in 200 healthy Hans. ISTA6.0 and life event stressor questionnaire was used to assess stressors. JSS, SCL-90 and GWB questionnaires were used to quantify the phenotypes of stress. Blood cortical and ACTH levels, and nervous behavior function were measured to assess Physiological strain. CWAI questionnaire was used to assess work ability. Then strain was assessed with Structural equation modeling (SEM). The subjects with GR A5556G genotype (G/A) showed significantly higher plasma cortisol levels, higher psychological stress scores, lower work ability scores and lower plasma ACTH levels compared with the subjects with wild-type (P < 0.01). Psychological stress scores and plasma cortisol levels in the subjects with GR GAGG4534/4536AAAG AG genotype were significantly higher than those in the subjects with wild-type, but the reaction and action sensitivity in the subjects with GR GAGG4534/4536AAAG AG genotype were significantly lower than those in ones with wild-type (P < 0.01). The ACTH level in the subjects with ACTHR promoter T-2C T/T genotype was significantly lower than that in ones with C/C and C/T genotype (P < 0.01). Interaction of GRA5556G and GG4534/4536AAAG with plasma cortisol was positively associated (βs = 0.543, P < 0.01), but with SCL-90 score was negatively associated (βs = -0.374, P < 0.01). Interaction of GRA5556G and GGC6294G with plasma cortisol was correlated (βs = 0.465, P < 0.05). While GR and ACTHR gene variants are the risk factors for psychological strain, physiological strain and decreased work ability (βs are 0.62, 0.43, -0.74, respectively (P < 0.01). While scarce social support, job stressors, negative life stressors and dangerous individual characters are the risk factors for occupational strain, psychological strain, physiological strain and decreased work ability (P < 0.01). GRA5556G, GRA5556G, GAGG4534/4536AAAG and ACTHR promoter T-2C variants might be associated with quantitative trait of strain, and GR and ACTHR gene variants with stressors increased the risk for developing strain.

Origin and functional activity of the membrane-bound glucocorticoid receptor

Glucocorticoids (GCs) exert their antiinflammatory and immunosuppressive effects in humans primarily via the cytosolic GC receptor (cGR) but also via rapid, nongenomic mechanisms. Most likely, membrane-bound GRs (mGR) are involved in nongenomic GC signaling. The aim of this study was to investigate the origin and functional activity of mGR. We analyzed the origin of mGR using mGR-expressing HEK 293T cells, by transient and stable RNA interference-mediated GR reduction. GR messenger RNA (mRNA) and cGR and mGR protein levels were analyzed by real-time quantitative polymerase chain reaction, immunoblotting, and high-sensitivity immunofluorescence staining. Furthermore, we analyzed the functional activity of mGR, using membrane-impermeable bovine serum albumin (BSA)-bound dexamethasone (DEX-BSA) in human monocytes. Membrane-bound GR-expressing monocytes were treated with DEX, DEX-BSA, or BSA. Cell lysates were analyzed using PepChip arrays in order to identify kinases triggered by DEX-BSA, with validation using Bio-Plex assays and immunoblotting. Our data showed that transient reduction of GR mRNA in HEK 293T cells decreased cGR protein levels but not mGR protein levels. However, stably transfected cells showed reduced cGR protein expression and significantly reduced mGR protein expression. Furthermore, 51 kinase substrates were identified for which phosphorylation was either reduced or increased. We observed p38 MAP kinase (MAPK) as one possible upstream kinase. Validation of these data by Bio-Plex phosphoprotein assay and immunoblotting showed increased phosphorylation of p38 MAPK after treatment with DEX-BSA. Our data demonstrate that the human GR gene encodes for both cGR and mGR. Membrane-bound GR retains functional activity, as indicated by induced phosphorylation of p38 MAPK due to DEX-BSA treatment. Membrane-bound GR-mediated cellular signaling needs to be investigated further in order to clarify its therapeutic potential.

Glucocorticoid receptor gene polymorphisms in Italian patients with eating disorders and obesity

Glucocorticoids (GCs) are involved in the control of eating behaviors, and it has been proposed that GCs and their receptors (GR) could play a significant role in the pathophysiology of eating disorders (EDs) and obesity. We studied whether genetic variants, such as N363S (rs56149945), exon 9-β (rs6198), ER22/23EK (rs6189-6190), and the intronic BclI restriction site (rs41423247) polymorphisms in the GR gene, could be considered as risk factors for the development of EDs and obesity in Italian patients. We investigated the distribution of these single nucleotide polymorphisms in 572 Italian patients: 118 patients with anorexia nervosa, 108 patients with bulimia nervosa, 62 patient with binge eating disorder, 177 obese non-binge eating disorder patients, and 107 unrelated, normal, age-matched controls. In addition, we analyzed their possible effects on body mass index and in relation to different psychopathological features. A significant association between the single nucleotide polymorphism rs56149945 (N363S) and a higher body mass index was identified, even after adjusting for age, sex, and diagnosis, independently of the eating psychopathology. Moreover, the rs6198 polymorphism was associated to binge eating symptoms, whereas no significant association between the different GR polymorphisms and the other ED diagnoses was observed. Our results suggest the possible role of the GC system in the genetics of eating psychopathology, weight control, and energy balance in ED and obese patients.

Glucocorticoid receptor signaling and prostate cancer

Glucocorticoids (GCs) are provided to hormone-refractory prostate cancer (HRPC) patients partly due to the inhibitory effects on adrenal androgen production acting as a pituitary suppressant. Nowadays, the combination of chemotherapy and dexamethasone is a standard treatment for HRPC patients while increasing evidence suggests that a lot of local tissue factors like growth factors, angiogenic/lymphogenic factors, apoptosis-related factors, cytokines related to the transition of prostate cancer from androgen dependence to hormone-refractory status, are among the targets of GR signaling. However, although glucocorticoids have been recognized to be one of a limited number of treatment options for HRPC, the molecular basis of GC-induced effects in prostate cancer remains poorly defined. In this review, we focus on how GCs induce effects via the GR-mediated transcriptional regulation of specific genes known to play key roles in cellular/tissue functions, including growth, apoptosis, inflammation, metastasis, differentiation, cell survival and angiogenesis. In our effort to unravel the molecular interplay of GR signaling with other signaling cascades prevalent in prostate cancer, we also include a detailed description of GR gene and protein structure/function and provide the knowledge gained recently into the mechanism(s) of the cross talk between GR and other signaling cascades via which GCs exert their multiple effects.

Intrauterine growth retardation affects expression and epigenetic characteristics of the rat hippocampal glucocorticoid receptor gene

Studies in humans and rats suggest that intrauterine growth retardation (IUGR) permanently resets the hypothalamic-pituitary-adrenal (HPA) axis. HPA axis reprogramming may involve persistently altered expression of the hippocampal glucocorticoid receptor (hpGR), an important regulator of HPA axis reactivity. Persistent alteration of gene expression, long after the inciting event, is thought to be mediated by epigenetic mechanisms that affect mRNA and mRNA variant expression. GR mRNA variants in both humans and rats include eleven 5'-end variants and GRalpha, the predominant 3'-end variant. The 3'-end variants associated with glucocorticoid resistance in humans (GRbeta, GRgamma, GRA, and GRP) have not been reported in rats. We hypothesized that in the rat hippocampus IUGR would decrease total GR mRNA, increase GRbeta, GRgamma, GRA, and GRP, and affect epigenetics of the GR gene at birth (D0) and at 21 days of life (D21). IUGR increased hpGR and exon 1.7 hpGR mRNA in males at D0 and D21, associated with increased trimethyl H3/K4 at exon 1.7 at both time points. IUGR also increased hpGRgamma in males at D0 and D21, associated with increased acetyl H3/K9 at exon 3 at both time points. hpGRA increased in female IUGR rats at D0 and D21. In addition, our data support the existence of hpGRbeta and hpGRP in the rat. IUGR has sex-specific, persistent effects on GR expression and its histone code. We speculate that postnatal changes in hippocampal GR variant and total mRNA expression may underlie IUGR-associated HPA axis reprogramming.

BTG1, a Gene Frequently Deleted in Pre-B ALL, Controls Glucocorticoid Receptor-Mediated Gene Expression.

Abstract 3458Poster Board III-346 BackgroundBy genome wide profiling we have found that about 10 % of pediatric pre-B ALL cases contain a (single copy) deletion of the B cell translocation gene 1 (BTG1) gene. BTG1 belongs to a family of potential tumor suppressor genes, which include BTG2, BTG3, TOB and TOB2. Proteins encoded by members of this gene family have been implicated in the induction of growth arrest or apoptosis in a variety of model systems. Moreover, BTG1 associates with and regulates the activity of the arginine methyl transferase PRMT1, a coactivator of nuclear receptor-mediated transcription. Hence we hypothesized that loss of BTG1 function, for instance due to deletion, may affect glucocorticoid induced therapy responses in ALL. ResultsUsing RNA interference, we find that loss of BTG1 expression decreases sensitivity of pre-B ALL cells to the apoptosis-inducing effects of synthetic GCs about 10,000 fold (Figure). This acquired GC resistance is accompanied by a greater than 10 fold reduction in GR protein expression as well as a (near complete) loss of GC-induced gene expression. Conversely, re-expression of BTG1 restores GC sensitivity by potentiating GC-induced GR expression. By chromatin immunoprecipitations using anti PRMT1 antibodies we show that PRMT1 is recruited to the GR gene promoter in a BTG1-dependent manner, consistent with a role for this arginine methyl transferase in the regulation of GR-mediated gene expression. ConclusionsTogether, our results demonstrate the importance of the BTG1/PRMT1 complex in regulating GR-mediated gene expression and reveal how deregulation of the this complex can give rise to GC resistance. Targeting of these coactivators as part of the GR regulatory circuitry could offer novel opportunities for improving the efficacy of GC based therapies in ALL as well as other hematological malignancies. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Brain glucocorticoid receptors are necessary for the rhythmic expression of the clock protein, PERIOD2, in the central extended amygdala in mice

The adrenal glucocorticoid, corticosterone, induces changes in gene expression in both neural and non-neural tissues. The rhythmic release of corticosterone has been shown in rats to be necessary for the rhythmic expression of the clock protein PERIOD2 (PER2) in select regions of the limbic forebrain. The mechanisms mediating the effects of glucocorticoids on changes in gene expression have been linked to the transcriptional activity of the low affinity glucocorticoid receptor, GR. We examined the patterns of PER2 expression in the brains of mice containing an inactivation of GR gene restricted to neural tissues (GR NesCre mice). We found that central deletion of the GR gene blunts the daily pattern of PER2 expression in the oval nucleus of the bed nucleus of the stria terminalis (BNSTov) and central nucleus of the amygdala (CEA) both of which make up the central extended amygdala, but not in the suprachiasmatic nucleus (SCN), basolateral amygdala (BLA) or dentate gyrus of the hippocampus (DG). These results implicate brain GR receptors in the regulation of PER2 expression in the BNSTov and CEA and are consistent with our previous findings that the rhythmic expression of PER2 in these areas is selectively sensitive to fluctuations in circulating corticosterone.

No association of glucocorticoid receptor polymorphisms with asthma and response to glucocorticoids

Glucocorticoids are the most effective anti-inflammatory drugs in asthma therapy. They act via receptors localized in target cells that after activation by glucocorticoids may affect expression of inflammatory genes thus reducing inflammation in asthma. However, 10-20% of patients, particularly with severe, difficult-to-treat asthma may not respond well to glucocorticoids and remain symptomatic even after being treated with high doses of inhaled or systemic glucocorticoids. Therefore, we investigated if polymorphisms known to affect expression or function of the glucocorticoid receptor may be responsible for lower efficacy of steroid therapy and the need to use high doses of inhaled drug. We analyzed 113 pediatric patients in age from 6 to 18 with diagnosed asthma, including 54 children with severe, difficult-to-treat asthma. The diagnosis was based on clinical manifestation, a lung function test, increased IgE level and positive skin prick tests. We also analyzed 123 healthy control subjects. The polymorphisms were genotyped with the use of PCR-RFLP method. Linkage disequilibrium analysis was performed using Haploview. We did not observe any significant differences between asthmatic and healthy children for any of the polymorphisms analyzed. Weak linkage between two of the four polymorphisms studied: rs41423247 and rs6195 (D'=1.0; LOD=2.91, r2=0.044) was found in linkage disequilibrium analysis. We did not find any association of GR polymorphisms with the dose of inhaled glucocorticoids needed to achieve asthma control in the group of patients. The results may suggest that studied polymorphisms of the GR gene are not associated with asthma susceptibility and do not influence response to inhaled glucocorticoids in our sample.

Molecular cloning of glutathione reductase cDNAs and analysis of GR gene expression in cowpea and common bean leaves during recovery from moderate drought stress

Two cDNAs of the enzyme glutathione reductase (GR; EC 1.6.4.2) encoding a dual-targeted isoform (dtGR) and a cytosolic isoform (cGR), were cloned from leaves of common bean (Phaseolus vulgaris L.). Moderate drought stress (Psi w=-1.5MPa) followed by re-watering was applied to common bean cultivars, one tolerant to drought (IPA), the other susceptible (Carioca) and to cowpea (Vigna unguiculata L. Walp) cultivars, one tolerant to drought (EPACE-1), and the other susceptible (1183). mRNA levels were much higher for PvcGR than for PvdtGR in all cases. Moderate drought stress induced an up-regulation of the expression of PvcGR in the susceptible cultivars. On the contrary, PvdtGR expression decreased. In the tolerant cowpea EPACE-1, GR gene expression remained stable under drought. During recovery from drought, an up-regulation of the two GR isoforms occurred, with a peak at 6-10h after re-hydration. This suggests that moderate drought stress may lead to a hardening process and acclimation tolerance. The role of GR isoforms in plant tolerance and capacity to recover from drought stress is discussed.

Urinary Free Cortisol Is Not a Biochemical Marker of Hypertension

Increasing evidence suggests that glucocorticoids might play a role in blood pressure (BP) control. These reports show that cortisol (F) can increase the BP acting on the mineralocorticoid receptor in kidney, brain, heart, and blood vessel. The aim of this study was to evaluate the effects of F in the renal salt and water reabsorption in essential hypertensive patients (EH). We studied 364 EH and 102 normotensive (NT) subjects. We obtained 24-h urine to measure urinary free cortisol (UFF) and creatinine (Cr). The upper limit of the UFF/Cr ratio was calculated from NT subjects. Patients with a high UFF/Cr ratio underwent dexamethasone suppression test (DST). Blood samples were used to determine plasma renin activity (PRA), aldosterone (SA), F, cortisone (E), urinary Na/K ratios, adrenocorticotrophic hormone levels, and also to purify lymphocytes for binding assays and genetic analysis. In EH subjects the UFF/Cr and F/E ratios were higher than in normotensives (48.3 microg/g [33.6 to 57.5 microg/g] v 32.6 microg/g [5.6 to 34.6 microg/g], P < .001 and 3.9 microg/g [3.3 to 4.8 microg/g] v 3.0 microg/g [2.4 to 3.6 microg/g], respectively), whereas the SA and PRA levels were similar. The upper limit value for UFF/Cr was set at 51.6 microg/g. The EH patients with high UFF/Cr (123/364, 34%) had lower PRA (1.5 ng/mL/h [0.9 to 2.5 ng/mL/h] v 2.0 ng/mL/h [1.1 to 3.0 ng/mL/h], P = .012, SA levels (7.1 ng/dL [4.1 to 10.5 ng/dL] v 7.9 ng/dL [5.2 to 11.0 ng/dL], P = .045) and Na/K ratios (3.6 [2.8 to 5.8] v 4.0 [3.1 to 6.6], P < or = .05) than those with normal UFF/Cr ratios. We found a slight negative relationship between UFF/Cr and PRA (r = -0.117, P = .031), SA (r = -0.096, P = .058) and Na/K ratios (r = 0.176, P = .059). We did not find significant differences in serum F/E ratios between EH patients with high or normal UFF/Cr (3.9 [3.3 to 5.1] v 3.8 [3.2 to 4.7], P = not significant [NS]) or a correlation between F/E ratio and UFF excretion (r = 0.032, P = NS). We did not find any association between UFF/Cr with systolic BP (P = .349) or diastolic BP (P = .895). Forty EH with the highest UFF/Cr values underwent the DST, which resulted in suppressed serum F in all of them. Binding assays in 4 of 13 EH with the highest UFF/Cr ratio showed a low affinity to dexamethasone (K(d) 13.7 to 33.0 nmol/L). The polymerase chain reaction (PCR) amplification of the GR gene (ligand-binding domain exons) did not show mutations or gross alterations. We found an EH subpopulation with abnormally high values of UFF but evidence of only a minor mineralocorticoid action, which was not directly related to the BP elevation, suggesting that another alternative mechanism could be triggering the F-induced hypertension. The origin of hypercortisoluria was not elucidated; however, a subtle glucocorticoid resistance was found in some cases.

Cortisol Resistance in Conditions such as Asthma and the Involvement of 11β-HSD-2: A Hypothesis

The two types of corticosteroid hormones, the mineralocorticoids and glucocorticoids, act in a complementary manner and are functionally closely linked. Aldosterone and glucocorticoids express their functions through the glucocorticoid receptors (GRs; GRalpha and GRbeta) and the mineralocorticoid receptors (MRs). Commercially available steroidal drugs used in conditions such as asthma may act on both GR and MR receptors; although glucocorticoid-receptor agonists play a fundamental role in the treatment of inflammatory conditions, prolonged exposure may have adverse effects such as the development of resistance. Glucocorticoid resistance in such conditions has been observed to be accompanied by a downregulation of GRalpha, a twofold decrease in GR protein half-life, downregulation of GRalpha mRNA expression, and enhanced expression of GRbeta. Other suggestions for glucocorticoid resistance include alternative splicing of the GR gene with subsequent expression of the GRbeta protein isoform, defective regulation of gene transcription of the GR gene or GR mutations, defective DNA binding and transactivating domains of the GR. In addition, we would like to suggest that dysregulation of the MR enzyme 11beta-HSD-2 may be one of the causes of resistance. When expressed in cells with MRs, this enzyme's major role is to prevent permanent occupancy of MR by glucocorticoid hormones, allowing concentration-dependent binding of aldosterone to MR. However, deficiency of the 11beta-HSD isoforms (particularly 11beta-HSD-2) leads to the activation of MRs by glucocorticoids rather than the glucocorticoids interacting with its "normal" receptors, the GRs. We will substantiate on support for our hypothesis in the dysregulation of this enzyme, which is typically associated with significantly higher levels of circulating plasma cortisol and elevated levels of cholesterol, little or no response to systemic glucocorticoids, and problems associated with homeostasis primarily in the distal nephron and distal colon. These are some of the symptoms typically noted in cortisol resistance.

Cancer is a functional repair tissue

When a wound occurs, growth and repair genes (GR genes, such as oncogenes, proto-oncogenes, etc.) in surrounding cells are activated and secretion of growth and repair factors (GR factors, such as growth, stem cell, and stimulating factors, etc.) is induced to heal the wound. However, if the wound is persistent due to chronic physical (radiation, electromagnetic field, trauma, particles, etc.), chemical (carcinogens, toxic chemicals, heavy metals etc.) or biological (aging, free radicals, inflammation, nutrient deficiency, bacteria and virus infections, stress, etc.) damage, amplification of GR gene activation in surrounding cells may lead to a clinical cancer. Based on the commonalities between cancer and wound healing, a new hypothesis of cancer is presented: malignancies are not passive mutated useless masses; rather, they are functional tissues produced by GR gene activation to secrete GR factors in an effort to heal persistent wounds in the body. Based on the hypothesis, current cancer treatments aimed at killing cancer cells only may be misguided. The logical extension of the hypothesis is that cancer treatment focused on wound healing by limiting causes of persistent wounds, providing repair cells, GR factors, and substrates required by repair cells may yield more fruitful results than treatments focused on killing cancer cells alone. Spontaneous regressions of cancer, although rare, may be successful examples of serendipitous spontaneous wound healing. Standard therapies aimed at killing cancer cells, should be limited to adjuvant status for limiting symptoms or buying time for completion of the wound healing process. Attempts to destroy cancer cells without healing underlying persistent wounds will allow for eventual recurrence.

GR gene haplotypes and hypothalamus-pituitary-adrenal (HPA) axis responses to stress

GR gene haplotypes and hypothalamus-pituitary-adrenal (HPA) axis responses to stress

GR gene haplotypes and hypothalamus-pituitary-adrenal (HPA) axis responses to stress

GR gene haplotypes and hypothalamus-pituitary-adrenal (HPA) axis responses to stress