Bed nuclei of the stria terminalis modulate memory consolidation via glucocorticoid-dependent and -independent circuits.

There is extensive evidence that glucocorticoid hormones enhance memory consolidation, helping to ensure that emotionally significant events are well remembered. Prior findings suggest that the anteroventral region of bed nuclei of the stria terminalis (avBST) regulates glucocorticoid release, suggesting the potential for avBST activity to influence memory consolidation following an emotionally arousing learning event. To investigate this issue, male Sprague-Dawley rats underwent inhibitory avoidance training and repeated measurement of stress hormones, immediately followed by optogenetic manipulations of either the avBST or its projections to downstream regions, and 48 h later were tested for retention. The results indicate that avBST inhibition augmented posttraining pituitary-adrenal output and enhanced the memory for inhibitory avoidance training. Pretreatment with a glucocorticoid synthesis inhibitor blocked the memory enhancement as well as the potentiated corticosterone response, indicating the dependence of the memory enhancement on glucocorticoid release during the immediate posttraining period. In contrast, posttraining avBST stimulation decreased retention yet had no effect on stress hormonal output. Subsequent experiments revealed that inhibition of avBST input to the paraventricular hypothalamus enhanced stress hormonal output and subsequent retention, whereas stimulation did not affect either. Conversely, stimulation-but not inhibition-of avBST input to the ventrolateral periaqueductal gray impaired consolidation, whereas neither manipulation affected glucocorticoid secretion. These findings indicate that divergent pathways from the avBST are responsible for the mnemonic effects of avBST inhibition versus stimulation and do so via glucocorticoid-dependent and -independent mechanisms, respectively.

Glucocorticoids attenuate interleukin-6-induced c-Fos and Egr1 expression and impair neuritogenesis in PC12 cells.

Interleukin-6 (IL-6) is a cytokine primarily known for immune regulation. There is also growing evidence that IL-6 triggers neurogenesis and impacts neural development, both life-long occurring processes that can be impaired by early-life and adult stress. Stress induces the release of glucocorticoids by activation of the hypothalamic-pituitary-adrenal (HPA) axis. On the cellular level, glucocorticoids act via the ubiquitously expressed glucocorticoid receptor. Thus, we aimed to elucidate whether glucocorticoids affect IL-6-induced neural development. Here, we show that IL-6 signalling induces neurite outgrowth in adrenal pheochromocytoma PC12 cells in a mitogen-activated protein kinase (MAPK) pathway-dependent manner, since neurite outgrowth was diminished upon Mek-inhibitor treatment. Using quantitative biochemical approaches, such as qRT-PCR analysis of Hyper-IL-6 treated PC12 cells, we show that neurite outgrowth induced by IL-6 signalling is accompanied by early and transient MAPK-dependent mRNA expression of immediate early genes coding for proteins such as early growth response protein 1 (Egr1) and c-Fos. This correlates with reduced proliferation and prolonged G0/G1 cell cycle arrest as determined by monitoring the cellular DNA content using flow cytometry. These results indicate for IL-6 signalling-induced neural differentiation. Interestingly, the glucocorticoid Dexamethasone impairs early IL-6 signalling-induced mRNA expression of c-Fos and Egr1 and restrains neurite outgrowth. Impaired Egr1 and c-Fos expression in neural development is implicated in the aetiology of neuropathologies. Thus, it appears likely that stress-induced release of glucocorticoids, as well as therapeutically administered glucocorticoids, contribute to the development of neuropathologies by reducing the expression of Egr1 and c-Fos, and by restraining IL-6-dependent neural differentiation.

Identification of dicyclohexyl phthalate as a glucocorticoid receptor antagonist by molecular docking and multiple in vitro methods.

The potential activities of phthalate esters (PAEs) that interfere with the endocrine system have been focused recently. However, information on modulating the glucocorticoid receptor (GR) of PAEs is scarce. Our aim was to evaluate the agonistic / antagonistic properties of PAEs on human GR. Luciferase reporter gene assay revealed that the tested chemicals displayed no agonistic effects but dicyclohexyl phthalate (DCHP) exerted antagonistic activity in a dose-responsive manner for GR in HeLa cells. The effects of DCHP on dexamethasone (DEX)-induced GR nuclear translocation and gene expression of glucocorticoid-responsive gene expression (G6Pase, PEPCK, FAS, GILZ and MKP-1), as well as protein expression of G6Pase and PEPCK were further examined by RT-qPCR and western blot analysis. DCHP antagonized DEX-induced GR nuclear translocation and suppressed gene expression in both mRNA and protein levels. Furthermore, the results of molecular docking and molecular dynamics simulation showed that DCHP could bind to GR and exhibited potential regulation on this target protein. Collectively, we demonstrate that DCHP may act as a GR antagonist in vitro and is considered to exert endocrine effects via human GR.

Lung epithelial tip progenitors integrate glucocorticoid- and STAT3-mediated signals to control progeny fate.

Insufficient alveolar gas exchange capacity is a major contributor to lung disease. During lung development, a population of distal epithelial progenitors first produce bronchiolar-fated and subsequently alveolar-fated progeny. The mechanisms controlling this bronchiolar-to-alveolar developmental transition remain largely unknown. We developed a novel grafting assay to test if lung epithelial progenitors are intrinsically programmed or if alveolar cell identity is determined by environmental factors. These experiments revealed that embryonic lung epithelial identity is extrinsically determined. We show that both glucocorticoid and STAT3 signalling can control the timing of alveolar initiation, but that neither pathway is absolutely required for alveolar fate specification; rather, glucocorticoid receptor and STAT3 work in parallel to promote alveolar differentiation. Thus, developmental acquisition of lung alveolar fate is a robust process controlled by at least two independent extrinsic signalling inputs. Further elucidation of these pathways might provide therapeutic opportunities for restoring alveolar capacity.

The glucocorticoid antagonist mifepristone attenuates sound-induced long-term deficits in auditory nerve response and central auditory processing in female rats.

Systemic corticosteroids have been the mainstay of treatment for various hearing disorders for more than 30 yr. Accordingly, numerous studies have described glucocorticoids (GCs) and stressors to be protective in the auditory organ against damage associated with a variety of health conditions, including noise exposure. Conversely, stressors are also predictive risk factors for hearing disorders. How both of these contrasting stress actions are linked has remained elusive. Here, we demonstrate that higher corticosterone levels during acoustic trauma in female rats is highly correlated with a decline of auditory fiber responses in high-frequency cochlear regions, and that hearing thresholds and the outer hair cell functions (distortion products of otoacoustic emissions) are left unaffected. Moreover, when GC receptor (GR) or mineralocorticoid receptor (MR) activation was antagonized by mifepristone or spironolactone, respectively, GR, but not MR, inhibition significantly and permanently attenuated trauma-induced effects on auditory fiber responses, including inner hair cell ribbon loss and related reductions of early and late auditory brainstem responses. These findings strongly imply that higher corticosterone stress levels profoundly impair auditory nerve processing, which may influence central auditory acuity. These changes are likely GR mediated as they are prevented by mifepristone.-Singer, W., Kasini, K., Manthey, M., Eckert, P., Armbruster, P., Vogt, M. A., Jaumann, M., Dotta, M., Yamahara, K., Harasztosi, C., Zimmermann, U., Knipper, M., Rüttiger, L. The glucocorticoid antagonist mifepristone attenuates sound-induced long-term deficits in auditory nerve response and central auditory processing in female rats.

Effects of fluvoxamine on nerve growth factor-induced neurite outgrowth inhibition by dexamethasone in PC12 cells.

In the present study, we examined the effects of fluvoxamine on nerve growth factor (NGF)-induced neurite outgrowth inhibition by dexamethasone (DEX) in PC12 cells. Fluvoxamine increased NGF-induced neurite outgrowth. Compared with co-treatment with NGF and fluvoxamine, p-Akt levels were higher than the values without fluvoxamine. The phosphorylated extracellular regulated kinase 1/2 levels were slightly increased by co-treatment with NGF and fluvoxamine. Fluvoxamine concentration-dependently improved NGF-induced neurite outgrowth inhibition by DEX. Fluvoxamine also improved the decrease in the NGF-induced p-Akt level caused by DEX. Interestingly, the sigma-1 receptor antagonist NE-100 blocked the improvement effects of fluvoxamine on NGF-induced neurite outgrowth inhibition by DEX. The selective sigma-1 receptor agonist PRE-084 also improved NGF-induced neurite outgrowth inhibition by DEX, which is blocked by NE-100. These results indicate that the improvement effects of fluvoxamine on NGF-induced neurite outgrowth inhibition by DEX may be attributable to the phosphorylation of Akt and the sigma-1 receptor.

Suppression of Dendritic Cell-Derived IL-12 by Endogenous Glucocorticoids Is Protective in LPS-Induced Sepsis.

Sepsis, an exaggerated systemic inflammatory response, remains a major medical challenge. Both hyperinflammation and immunosuppression are implicated as causes of morbidity and mortality. Dendritic cell (DC) loss has been observed in septic patients and in experimental sepsis models, but the role of DCs in sepsis, and the mechanisms and significance of DC loss, are poorly understood. Here, we report that mice with selective deletion of the glucocorticoid receptor (GR) in DCs (GR(CD11c-cre)) were highly susceptible to LPS-induced septic shock, evidenced by elevated inflammatory cytokine production, hypothermia, and mortality. Neutralizing anti-IL-12 antibodies prevented hypothermia and death, demonstrating that endogenous GC-mediated suppression of IL-12 is protective. In LPS-challenged GR(CD11c-cre) mice, CD8(+) DCs were identified as the major source of prolonged IL-12 production, which correlated with elevations of NK cell-derived IFN-γ. In addition, the loss of GR in CD11c(+) cells rescued LPS-induced loss of CD8(+) DCs but not other DC subsets. Unlike wild-type animals, exposure of GR(CD11c-cre) mice to low-dose LPS did not induce CD8(+) DC loss or tolerance to subsequent challenge with high dose, but neutralization of IL-12 restored the ability of low-dose LPS to tolerize. Therefore, endogenous glucocorticoids blunt LPS-induced inflammation and promote tolerance by suppressing DC IL-12 production.

AN INDIVIDUALIZED APPROACH TO THE EVALUATION OF CUSHING SYNDROME.

Cushing syndrome (CS) is caused by chronic exposure to excess glucocorticoids. Early recognition and treatment of hypercortisolemia can lead to decreased morbidity and mortality. The diagnosis of CS and thereafter, establishing the cause can often be difficult, especially in patients with mild and cyclic hypercortisolism. Surgical excision of the cause of excess glucocorticoids is the optimal treatment for CS. Medical therapy (steroidogenesis inhibitors, medications that decrease adrenocorticotropic hormone [ACTH] levels or glucocorticoid antagonists) and pituitary radiotherapy may be needed as adjunctive treatment modalities in patients with residual, recurrent or metastatic disease, in preparation for surgery, or when surgery is contraindicated. A multidisciplinary team approach, individualized treatment plan and long-term follow-up are important for optimal management of hypercortisolemia and the comorbidities associated with CS. ABBREVIATIONS: ACTH = adrenocorticotropic hormone; BIPSS = bilateral inferior petrosal sinus sampling; CBG = corticosteroid-binding globulin; CD = Cushing disease; CRH = corticotropin-releasing hormone; CS = Cushing syndrome; Dex = dexamethasone; DST = dexamethasone suppression test; EAS = ectopic ACTH syndrome; FDA = U.S. Food & Drug Administration; HDDST = high-dose DST; IPS/P = inferior petrosal sinus to peripheral; MRI = magnetic resonance imaging; NET = neuroendocrine tumor; PET = positron emission tomography; UFC = urinary free cortisol.

Beta-Ecdysone Protects Mouse Osteoblasts from Glucocorticoid-Induced Apoptosis In Vitro.

Glucocorticoid-induced osteoporosis is a common form of secondary osteoporosis. Glucocorticoids affect both bone formation and resorption, and prolonged glucocorticoid exposure can suppress osteoblast activities. beta-Ecdysone, found in many plants, is involved in protein synthesis, carbohydrate and lipid metabolism, and immunologic modulation. Here, we evaluated the effects of beta-ecdysone on osteoblast viability by assessing apoptosis following treatment with excess glucocorticoids. Mouse bone marrow stromal cells were induced to differentiate and grow into osteoblasts, and then treated with 10 µM glucocorticoid and 10, 1, or 0.1 µM beta-ecdysone. The expression levels of osteoblast growth and differentiation factors (runt-related transcription factor 2, osteogenic protein-1, and alkaline phosphatase), apoptosis-related genes (transformation-related protein 53, ataxia telangiectasia mutated protein, caspase-3, and caspase-8), and Akt1 and phospho-Akt (Thr308) were then assessed via alkaline phosphatase staining, acridine orange-propidium iodide staining, annexin V/PI apoptosis assay, real-time RT-PCR, and Western blot analyses. Notably, treatment with 10 µM glucocorticoid resulted in reduced osteoblast viability and the specific activity of alkaline phosphatase as well as reduced runt-related transcription factor 2, osteogenic protein-1, and alkaline phosphatase mRNA expression in vitro, indicating that glucocorticoid inhibited osteogenic differentiation. Moreover, glucocorticoid treatment yielded increased transformation-related protein 53, ataxia telangiectasia mutated protein, caspase-3, and caspase-8 expression and decreased Akt1 and phospho-Akt levels, indicating glucocorticoid-induced apoptosis. Meanwhile, beta-ecdysone inhibited glucocorticoid function, preserving the expression of Akt1 and phospho-Akt and reducing the expression of transformation-related protein 53, ataxia telangiectasia mutated protein, caspase-3, and caspase-8. Thus, beta-ecdysone prevented glucocorticoid-induced osteoblast apoptosis in vitro. These data highlight the potential for beta-ecdysone as a treatment for preventing the effects of glucocorticoid on bone growth.

Activating AMP-activated protein kinase by an α1 selective activator compound 13 attenuates dexamethasone-induced osteoblast cell death.

Excessive glucocorticoid (GC) usage may lead to non-traumatic femoral head osteonecrosis. Dexamethasone (Dex) exerts cytotoxic effect to cultured osteoblasts. Here, we investigated the potential activity of Compound 13 (C13), a novel α1 selective AMP-activated protein kinase (AMPK) activator, against the process. Our data revealed that C13 pretreatment significantly attenuated Dex-induced apoptosis and necrosis in both osteoblastic-like MC3T3-E1 cells and primary murine osteoblasts. AMPK activation mediated C13' cytoprotective effect in osteoblasts. The AMPK inhibitor Compound C, shRNA-mediated knockdown of AMPKα1, or dominant negative mutation of AMPKα1 (T172A) almost abolished C13-induced AMPK activation and its pro-survival effect in osteoblasts. On the other hand, forced AMPK activation by adding AMPK activator A-769662 or exogenous expression a constitutively-active (ca) AMPKα1 (T172D) mimicked C13's actions and inhibited Dex-induced osteoblast cell death. Meanwhile, A-769662 or ca-AMPKα1 almost nullified C13's activity in osteoblast. Further studies showed that C13 activated AMPK-dependent nicotinamide adenine dinucleotide phosphate (NADPH) pathway to inhibit Dex-induced reactive oxygen species (ROS) production in MC3T3-E1 cells and primary murine osteoblasts. Such effects by C13 were almost reversed by Compound C or AMPKα1 depletion/mutation. Together, these results suggest that C13 alleviates Dex-induced osteoblast cell death via activating AMPK signaling pathway.

Stress impairs the efficacy of immune stimulation by CpG-C: Potential neuroendocrine mediating mechanisms and significance to tumor metastasis and the perioperative period.

We recently reported that immune stimulation can be compromised if animals are simultaneously subjected to stressful conditions. To test the generalizability of these findings, and to elucidate neuroendocrine mediating mechanisms, we herein employed CpG-C, a novel TLR-9 immune-stimulating agent. Animals were subjected to ongoing stress (20-h of wet cage exposure) during CpG-C treatment, and antagonists to glucocorticoids, ß-adrenoceptor, COX2, or opioids were employed (RU486, nadolol, etodolac, naltrexone). In F344 rats, marginating-pulmonary NK cell numbers and cytotoxicity were studied, and the NK-sensitive MADB106 experimental metastasis model was used. In Balb/C mice, experimental hepatic metastases of the CT-26 colon tumor were studied; and in C57BL/6J mice, survival rates following excision of B16 melanoma was assessed - both mouse tumor models involved surgical stress. The findings indicated that simultaneous blockade of glucocorticoid and ß-adrenergic receptors improved CpG-C efficacy against MADB106 metastasis. In mice bearing B16 melanoma, long-term survival rate was improved by CpG-C only when employed simultaneously with blockers of glucocorticoids, catecholamines, and prostaglandins. Prolonged stress impaired CpG-C efficacy in potentiating NK activity, and in resisting MADB106 metastasis in both sexes, as also supported by in vitro studies. This latter effect was not blocked by any of the antagonists or by adrenalectomy. In the CT26 model, prolonged stress only partially reduced the efficacy of CpG-C. Overall, our findings indicate that ongoing behavioral stress and surgery can jeopardize immune-stimulatory interventions and abolish their beneficial metastasis-reducing impacts. These findings have implications for the clinical setting, which often involve psychological and physiological stress responses during immune-stimulation.

Antiglucocorticoid and related treatments for psychosis.

BACKGROUND: Hypothalamic-pituitary-adrenal (HPA) axis dysregulation has been implicated in the development and relapse of psychotic disorders. Elevated cortisol secretion has been positively linked with symptom severity in people with psychosis. Antiglucocorticoid and related drugs that target the HPA axis may be useful for the treatment of individuals with psychosis. OBJECTIVES: 1. To determine the effects of antiglucocorticoid and related drugs for the treatment of psychosis, when used alone or in combination with antipsychotic medication.2. To determine whether the effects of these medications differs between those in a prodromal phase or first episode of psychosis, and those with more established illness. SEARCH METHODS: We searched the Cochrane Schizophrenia Group's Trials Register (August 2009 and April 2014). SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing antiglucocorticoid and related drugs compared to placebo (either as a sole treatment or as an adjunct to atypical antipsychotics, typical antipsychotics, antidepressants or other combination treatment) for people with a primary diagnosis of a psychotic disorder, or for individuals at high risk of developing a psychotic disorder. DATA COLLECTION AND ANALYSIS: Review authors independently selected trials, assessed methodological quality and extracted data. We used a fixed-effect meta-analysis. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for dichotomous outcomes, and mean differences (MDs) and standardised mean differences (SMDs) with 95% CIs for continuous measures. We assessed risk of bias for included studies and used GRADE (Grading of Recommendations Assessment, Development and Evaluation) to create a 'Summary of findings' table. MAIN RESULTS: We included 11 studies that randomly assigned 509 people with schizophrenia, schizoaffective disorder or psychotic depression. No trials were conducted in patients at their first episode of psychotic illness and none included populations at high risk for developing psychosis. Our pre-stated outcomes of interest were mental state, global state, general functioning, adverse effects and quality of life.Two trials compared antiglucocorticoid drugs (mifepristone) versus placebo as sole treatment. Limited data from one trial showed no difference in the proportion responding to mifepristone when mental state was assessed immediately post intervention using the Brief Psychiatric Rating Scale (BPRS) (n = 5, 1 RCT, MD -5.20, 95% CI -17.91 to 7.51; very low-quality evidence); depressive symptoms (Hamilton Rating Scale for Depression (HAMD) total) were also similar between groups (n = 5, 1 RCT, MD 1.67, 95% CI -16.44 to 19.78; very low-quality evidence). However, a significant difference favoured treatment at short-term follow-up for global state (30% reduction in total BPRS, n = 221, 1 RCT, RR 0.58, 95% CI 0.38 to 0.89; low-grade quality evidence). This effect was also seen for short-term positive psychotic symptoms (50% reduction in BPRS positive symptom subscale, n = 221, 1 RCT, RR 0.60, 95% CI 0.43 to 0.84; low-grade quality evidence). Participants receiving mifepristone experienced a similar overall number of adverse effects as those receiving placebo (n = 226, 2 RCTs, RR 0.92, 95% CI 0.77 to 1.09; moderate-quality evidence). No data on general functioning or quality of life were available.One trial compared an antiglucocorticoid, dehydroepiandrosterone (DHEA), as an adjunct to atypical antipsychotic treatment to adjunctive placebo. Data for main outcomes of interest were of low quality, and analysis of useable data showed no significant effects of treatment on mental state or adverse effects. Data on global state, general functioning and quality of life were not available.Data from six trials comparing antiglucocorticoid drugs as an adjunct to combination treatment versus adjunctive placebo showed no significant differences between groups in mean endpoint scores for overall psychotic symptoms (n = 171, 6 RCTs, SMD 0.01, 95% CI - 0.29 to 0.32) or positive psychotic symptoms (n = 151, 5 RCTs, SMD -0.07, 95% CI - 0.40 to 0.25). Data from three trials showed no differences between groups in mean endpoint scores for negative symptoms (n = 94, 3 RCTs, MD 2.21, 95% CI -0.14 to 4.55). One study found improvements in global state that were similar between groups (n = 30, 1 RCT, RR 0.58, 95% CI 0.32 to 1.06; very low-quality evidence). In this comparison, pooled results showed that antiglucorticoids caused a greater overall number of adverse events (n = 199, 7 RCTs, RR 2.66, 95% CI 1.33 to 5.32; moderate quality evidence), but no quality of life data were available. AUTHORS' CONCLUSIONS: Good evidence is insufficient to conclude whether antiglucocorticoid drugs provide effective treatment for psychosis. Some global state findings suggest a favourable effect for mifepristone, and a few overall adverse effect findings favour placebo. Additional large randomised controlled trials are needed to justify findings.

Short-Term Curcumin Gavage Sensitizes Insulin Signaling in Dexamethasone-Treated C57BL/6 Mice.

BACKGROUND: Long-term dietary curcumin (>12 wk) improves metabolic homeostasis in obese mice by sensitizing insulin signaling and reducing hepatic gluconeogenesis. Whether these occur only secondary to its chronic anti-inflammatory and antioxidative functions is unknown. OBJECTIVE: In this study, we assessed the insulin sensitization effect of short-term curcumin gavage in a rapid dexamethasone-induced insulin resistance mouse model, in which the chronic anti-inflammatory function is eliminated. METHODS: Six-week-old male C57BL/6 mice received an intraperitoneal injection of dexamethasone (100 mg/kg body weight) or phosphate-buffered saline every day for 5 d, with or without simultaneous curcumin gavage (500 mg/kg body weight). On day 7, insulin tolerance tests were performed. After a booster dexamethasone injection and curcumin gavage on day 8, blood glucose and insulin concentrations were measured. Liver tissues were collected on day 10 for quantitative polymerase chain reaction and Western blotting to assess gluconeogenic gene expression, insulin signaling, and the expression of fibroblast growth factor 21 (FGF21). Primary hepatocytes from separate, untreated C57BL/6 mice were used for testing the in vitro effect of curcumin treatment. RESULTS: Dexamethasone injection impaired insulin tolerance (P < 0.05) and elevated ambient plasma insulin concentrations by ~2.7-fold (P < 0.01). Concomitant curcumin administration improved insulin sensitivity and reduced hepatic gluconeogenic gene expression. The insulin sensitization effect of curcumin was demonstrated by increased stimulation of S473 phosphorylation of protein kinase B (P < 0.01) in the dexamethasone-treated mouse liver, as well as the repression of glucose production in primary hepatocytes (P < 0.001). Finally, curcumin gavage increased FGF21 expression by 2.1-fold in the mouse liver (P < 0.05) and curcumin treatment increased FGF21 expression in primary hepatocytes. CONCLUSION: These observations suggest that the early beneficial effect of curcumin intervention in dexamethasone-treated mice is the sensitization of insulin signaling, involving the stimulation of FGF21 production, a known insulin sensitizer.

Maternal stress during pregnancy increases neonatal allergy susceptibility: role of glucocorticoids.

We sought to test experimentally whether maternal stress can promote susceptibility to development of asthma-like allergic airways disease in offspring. Normal pregnant mice (day 15) were subjected to a single restraint stress exposure. We subsequently tested their offspring for the development of airway hyperreactivity (AHR) and allergic airway inflammation (AI), after an intentionally suboptimal sensitization protocol. The offspring of stressed mothers showed levels of AI and enhanced airway responses to methacholine comparable to those seen in fully sensitized and challenged positive control animals; in contrast, minimal effects were seen in control offspring. Restraint stress caused a rapid and large increase in plasma corticosterone levels. Maternal treatment with dexamethasone on day 15 of pregnancy mimicked the stress effect and reproduced the AI and AHR outcomes, whereas blockade of the stress-induced corticosterone surge with metyrapone pretreatment of pregnant mice abrogated the effect. We conclude that stress-triggered glucocorticoids during pregnancy can increase susceptibility to allergy in offspring. Because inflammation typically includes a stress hormone response, the results also suggest a common pathway by which various injurious exposures during pregnancy might increase offspring susceptibility to asthma.

Glucocorticoid induced leucine zipper inhibits apoptosis of cardiomyocytes by doxorubicin.

Doxorubicin (Dox) is an indispensable chemotherapeutic agent for the treatment of various forms of neoplasia such as lung, breast, ovarian, and bladder cancers. Cardiotoxicity is a major concern for patients receiving Dox therapy. Previous work from our laboratory indicated that glucocorticoids (GCs) alleviate Dox-induced apoptosis in cardiomyocytes. Here we have found glucocorticoid-induced leucine zipper (GILZ) to be a mediator of GC-induced cytoprotection. GILZ was found to be induced in cardiomyocytes by GC treatment. Knocking down of GILZ using siRNA resulted in cancelation of GC-induced cytoprotection against apoptosis by Dox treatment. Overexpressing GILZ by transfection was able to protect cells from apoptosis induced by Dox as measured by caspase activation, Annexin V binding and morphologic changes. Western blot analyses indicate that GILZ overexpression prevented cytochrome c release from mitochondria and cleavage of caspase-3. When bcl-2 family proteins were examined, we found that GILZ overexpression causes induction of the pro-survival protein Bcl-xL. Since siRNA against Bcl-xL reverses GC induced cytoprotection, Bcl-xL induction represents an important event in GILZ-induced cytoprotection. Our data suggest that GILZ functions as a cytoprotective gene in cardiomyocytes.

Bronchial epithelial cells are rendered insensitive to glucocorticoid transactivation by transforming growth factor-ß1.

BACKGROUND: We have previously shown that transforming growth factor-beta (TGF-beta) impairs glucocorticoid (GC) function in pulmonary epithelial cell-lines. However, the signalling cascade leading to this impairment is unknown. In the present study, we provide the first evidence that TGF-beta impairs GC action in differentiated primary air-liquid interface (ALI) human bronchial epithelial cells (HBECs). Using the BEAS-2B bronchial epithelial cell line, we also present a systematic examination of the known pathways activated by TGF-beta, in order to ascertain the molecular mechanism through which TGF-beta impairs epithelial GC action. METHODS: GC transactivation was measured using a Glucocorticoid Response Element (GRE)-Secreted embryonic alkaline phosphatase (SEAP) reporter and measuring GC-inducible gene expression by qRT-PCR. GC transrepression was measured by examining GC regulation of pro-inflammatory mediators. TGF-beta signalling pathways were investigated using siRNA and small molecule kinase inhibitors. GRα level, phosphorylation and sub-cellular localisation were determined by western blotting, immunocytochemistry and localisation of GRα-Yellow Fluorescent Protein (YFP). Data are presented as the mean ± SEM for n independent experiments in cell lines, or for experiments on primary HBEC cells from n individual donors. All data were statistically analysed using GraphPad Prism 5.0 (Graphpad, San Diego, CA). In most cases, two-way analyses of variance (ANOVA) with Bonferroni post-hoc tests were used to analyse the data. In all cases, P <0.05 was considered to be statistically significant. RESULTS: TGF-beta impaired Glucocorticoid Response Element (GRE) activation and the GC induction of several anti-inflammatory genes, but did not broadly impair the regulation of pro-inflammatory gene expression in A549 and BEAS-2B cell lines. TGF-beta-impairment of GC transactivation was also observed in differentiated primary HBECs. The TGF-beta receptor (ALK5) inhibitor SB431541 fully prevented the GC transactivation impairment in the BEAS-2B cell line. However, neither inhibitors of the known downstream non-canonical signalling pathways, nor knocking down Smad4 by siRNA prevented the TGF-beta impairment of GC activity. CONCLUSIONS: Our results indicate that TGF-beta profoundly impairs GC transactivation in bronchial epithelial cells through activating ALK5, but not through known non-canonical pathways, nor through Smad4-dependent signalling, suggesting that TGF-beta may impair GC action through a novel non-canonical signalling mechanism.

Topical hesperidin prevents glucocorticoid-induced abnormalities in epidermal barrier function in murine skin.

Systemic and topical glucocorticoids (GC) can cause significant adverse effects not only on the dermis, but also on epidermal structure and function. In epidermis, a striking GC-induced alteration in permeability barrier function occurs that can be attributed to an inhibition of epidermal mitogenesis, differentiation and lipid production. As prior studies in normal hairless mice demonstrated that topical applications of a flavonoid ingredient found in citrus, hesperidin, improve epidermal barrier function by stimulating epidermal proliferation and differentiation, we assessed here whether its topical applications could prevent GC-induced changes in epidermal function in murine skin and the basis for such effects. When hairless mice were co-treated topically with GC and 2% hesperidin twice-daily for 9 days, hesperidin co-applications prevented the expected GC-induced impairments of epidermal permeability barrier homoeostasis and stratum corneum (SC) acidification. These preventive effects could be attributed to a significant increase in filaggrin expression, enhanced epidermal ß-glucocerebrosidase activity and accelerated lamellar bilayer maturation, the last two likely attributable to a hesperidin-induced reduction in stratum corneum pH. Furthermore, co-applications of hesperidin with GC largely prevented the expected GC-induced inhibition of epidermal proliferation. Finally, topical hesperidin increased epidermal glutathione reductase mRNA expression, which could counteract multiple functional negative effects of GC on epidermis. Together, these results show that topical hesperidin prevents GC-induced epidermal side effects by divergent mechanisms.

Pharmacotherapy in the aftermath of trauma; opportunities in the 'golden hours'.

Several lines of research have demonstrated that memories for fearful events become transiently labile upon re-exposure. Activation of molecular mechanisms is required in order to maintain retrieved information. This process is called reconsolidation. Targeting reconsolidation - as in exposure-based psychotherapy - offers therefore a potentially interesting tool to manipulate fear memories, and subsequently to treat disorders such as post-traumatic stress disorder (PTSD). In this paper we discuss the evidence for reconsolidation in rodents and humans and highlight recent studies in which clinical research on normal and abnormal fear extinction reduction of the expression of fear was obtained by targeting the process of reconsolidation. We conclude that reconsolidation presents an interesting opportunity to modify or alter fear and fear-related memories. More clinical research on normal and abnormal fear extinction is required.

Dehydroepiandrosterone exerts antiglucocorticoid action on human preadipocyte proliferation, differentiation, and glucose uptake.

Glucocorticoids increase adipocyte proliferation and differentiation, a process underpinned by the local reactivation of inactive cortisone to active cortisol within adipocytes catalyzed by 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1). The adrenal sex steroid precursor dehydroepiandrosterone (DHEA) has been shown to inhibit 11ß-HSD1 in murine adipocytes; however, rodent adrenals do not produce DHEA physiologically. Here, we aimed to determine the effects and underlying mechanisms of the potential antiglucocorticoid action of DHEA and its sulfate ester DHEAS in human preadipocytes. Utilizing a human subcutaneous preadipocyte cell line, Chub-S7, we examined the metabolism and effects of DHEA in human adipocytes, including adipocyte proliferation, differentiation, 11ß-HSD1 expression, and activity and glucose uptake. DHEA, but not DHEAS, significantly inhibited preadipocyte proliferation via cell cycle arrest in the G1 phase independent of sex steroid and glucocorticoid receptor activation. 11ß-HSD1 oxoreductase activity in differentiated adipocytes was inhibited by DHEA. DHEA coincubated with cortisone significantly inhibited preadipocyte differentiation, which was assessed by the expression of markers of early (LPL) and terminal (G3PDH) adipocyte differentiation. Coincubation with cortisol, negating the requirement for 11ß-HSD1 oxoreductase activity, diminished the inhibitory effect of DHEA. Further consistent with glucocorticoid-opposing effects of DHEA, insulin-independent glucose uptake was significantly enhanced by DHEA treatment. DHEA increases basal glucose uptake and inhibits human preadipocyte proliferation and differentiation, thereby exerting an antiglucocorticoid action. DHEA inhibition of the amplification of glucocorticoid action mediated by 11ß-HSD1 contributes to the inhibitory effect of DHEA on human preadipocyte differentiation.

Corticosteroid and calcineurin inhibitor sparing regimens in kidney transplantation.

Chronic kidney disease is a major public health problem that is associated with increased risks of kidney disease progression, cardiovascular disease and death. Kidney transplantation remains the renal replacement therapy of choice for patients with end-stage kidney disease. Despite impressive strides in short-term allograft survival, there has been little improvement in long-term kidney graft survival, and rates of death with a functioning allograft remain high. Long-term safety profiles of existing immunosuppressive regimens point to a need for continued search for alternative agents. This overview discusses emerging evidence on a few promising therapeutic approaches, juxtaposes conflicting findings and highlights remaining knowledge gaps.