Glucocorticoid Receptor Gene Expression Research Articles

Characterization of the glucocorticoid receptor of large yellow croaker (Larimichthys crocea) and its expression in response to salinity and immune stressors

Glucocorticoids are steroidal hormones critical to stress responses in vertebrates. To gain further insight into the role of the glucocorticoid receptor (GR) in acute stress responses in teleost fish, the relevant cDNA of large yellow croaker (Larimichthys crocea; LcGR) was cloned using the rapid amplification of cDNA ends (RACE) technique. Multiple alignment of the amino acids (aa) of LcGR and the GR of other teleosts indicated LcGR contained four commonly conserved domains and lacked the 9-aa insert seen in GR1. Phylogenetic analysis of the amino acid sequence revealed that LcGR grouped most closely with the GR2 of other teleosts and can therefore be considered a GR2 subtype. In healthy L. crocea, Lcgr mRNA was found to be expressed at high levels in the gill, brain, and muscle tissue, expressed at intermediate levels in heart and stomach tissue, and expressed at low levels in the kidney, intestine, head kidney, liver, and spleen tissue. The response of L. crocea to acute low-salinity stress was tested, with a significant increase in plasma cortisol concentration after 3 h, peaking after 6 h, and gradually returning to base levels. Regarding changes of Lcgr expression in different body tissues under the stress, there was up-regulation of the Lcgr transcript in the brain, liver, and gill tissues, but not in muscle tissue. Responses to pathogen mimics were also tested. Injection with lipopolysaccharide resulted in Lcgr expression, with an increase-decrease-increase trend in the head kidney. In contrast, a down-regulation of Lcgr expression in the head kidney was observed throughout the experimental period upon injection of polyinosinic:polycytidylic acid, revealing different roles of Lcgr for different types of pathogens. The results offer novel insights about the effects of different stressors on GR gene expression in L. crocea, and can facilitate further investigations into stress responses in other mariculture fish species.

Variability in Behavioral Phenotypes after Forced Swimming-Induced Stress in Rats Is Associated with Expression of the Glucocorticoid Receptor, Nurr1, and IL-1β in the Hippocampus.

Individual differences in coping with stress may determine either a vulnerable or resilient phenotype. Therefore, it is important to better understand the biology underlying the behavioral phenotype. We assessed whether individual behavioral phenotype to acute stress is related with the hippocampal expression of glucocorticoid receptor (GR), Nurr1, interleukin-1 beta (IL-1β) or brain-derived neurotrophic factor (BDNF). Wistar male rats were exposed to forced swimming for 15 min and sacrificed at different times. Behavioral response was analyzed, and it was compared with the gene and protein expression of GR, Nurr1, IL-1β and BDNF in the hippocampus for each time point. Behavioral phenotyping showed a group with high immobility (vulnerable) while another had low immobility (resilient). No significant differences were found in the Nurr1, IL-1β and BDNF mRNA levels between resilient and vulnerable rats at different recovery times except for Nr3c1 (gene for GR). However, exposure to stress caused significantly higher levels of GR, Nurr1 and IL-1β proteins of vulnerable compared to resilient rats. This variability of behavioral phenotypes is associated with a differential molecular response to stress that involves GR, Nurr1, and IL-1β as mediators in coping with stress. This contributes to identifying biomarkers of susceptibility to stress.

Individual-specific functional epigenomics reveals genetic determinants of adverse metabolic effects of glucocorticoids

Glucocorticoids (GCs) are widely used as anti-inflammatory drugs, but their long-term use has severe metabolic side effects. Here, by treating multiple individual adipose stem cell-derived adipocytes and induced pluripotent stem cell-derived hepatocytes with the potent GC dexamethasone (Dex), we uncovered cell-type-specific and individual-specific GC-dependent transcriptomes and glucocorticoid receptor (GR) cistromes. Individual-specific GR binding could be traced to single-nucleotide polymorphisms (SNPs) that altered the binding motifs of GR or its cooperating factors. We also discovered another set of genetic variants that modulated Dex response through affecting chromatin accessibility or chromatin architecture. Several SNPs that altered Dex-regulated GR binding and gene expression controlled Dex-driven metabolic perturbations. Remarkably, these genetic variations were highly associated with increases in serum glucose, lipids, and body mass in subjects on GC therapy. Knowledge of the genetic variants that predispose individuals to metabolic side effects allows for a precision medicine approach to the use of clinically relevant GCs.

Effects of acute low temperature stress on the hormones and gene expression of glucocorticoid receptor of large yellow croaker Larimichthys crocea.

The neuroendocrine system of fish responds to low temperature via regulating hormones. To explore the adaptability of Larimichthys crocea to low temperature, the levels of the plasma cortisol, thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), total cholesterol (TC), and glucose were determined after exposure to low temperature and during subsequent rewarming. Furthermore, the mRNA expression of the glucocorticoid receptor (GR) gene was analyzed under the stress. We found that the levels of the plasma cortisol, TSH, T3, glucose, and TC increased under the low temperature stress, suggesting that elevated hormones may be conducive to promoting the mobilization of the glucose and lipid in L. crocea exposed to low temperature. During the rewarming period, the plasma cortisol level decreased, whereas the T3 level was still significantly higher than that in the control group. Notably, the plasma T4 level was unaffected by the temperature changes. Furthermore, the sequence alignment and phylogenetic tree analysis revealed that the GR protein of L. crocea had high homology and a similar protein structure with those from other teleosts. Under the low temperature stress, the GR mRNA expression increased in the brain and head kidney, whereas it basically returned to the control level following rewarming. These findings revealed the changes of the hormones and the potential function of the GR gene in L. crocea following exposure to low temperature, providing some insights into breeding low temperature-resistant varieties of L. crocea.

Effect of dexamethasone on gene expression of cannabinoid receptor type 1 and adenosine monophosphate-activated protein kinase in the hypothalamus of broilers (Gallus domesticus)

Hypothalamic neural circuits play a critical role in integrating peripheral signals and conveying information about energy and nutrient status. We detected cannabinoid receptor type 1 (CB1) distribution in the hypothalamus, liver, duodenum, jejunum, and ileum among 7- and 35-day-old broilers. The effects of dexamethasone (DEX) on CB1 gene expression were evaluated by in vitro and in vivo experiments on glucocorticoid receptor (GR) and adenosine monophosphate-activated protein kinase (AMPK) in the hypothalamus of broilers. In vitro, hypothalamic cells from 17-day-old broiler embryos were incubated with either 0.1% dimethyl sulfoxide or DEX (100 nmol/mL) for 1 h. In the in vivo study, 28-day-old broilers were injected with DEX for 24 h or 72 h. Results showed that CB1 was mainly expressed in the hypothalamus, and 72 h DEX treatment increased the expression. One-day treatment of broilers with DEX did not change the hypothalamic CB1 gene expression. Moreover, DEX treatment for 24 h and 72 h increased the mRNA level of hypothalamic AMPKα2 and GR. However, no differences were observed on the gene expression of CB1, GR, and AMPKα2 in hypothalamic cells with DEX-treated for 1 h. In conclusion, CB1 is mainly expressed in the hypothalamus of broilers; 72-h DEX exposure can regulate the CB1 system and AMPK signaling pathway of the broiler hypothalamus.

Hippocampal glucocorticoid target genes associated with enhancement of memory consolidation.

Glucocorticoids enhance memory consolidation of emotionally arousing events via largely unknown molecular mechanisms. This glucocorticoid effect on the consolidation process also requires central noradrenergic neurotransmission. The intracellular pathways of these two stress mediators converge on two transcription factors: the glucocorticoid receptor (GR) and phosphorylated cAMP response element‐binding protein (pCREB). We therefore investigated, in male rats, whether glucocorticoid effects on memory are associated with genomic interactions between the GR and pCREB in the hippocampus. In a two‐by‐two design, object exploration training or no training was combined with post‐training administration of a memory‐enhancing dose of corticosterone or vehicle. Genomic effects were studied by chromatin immunoprecipitation followed by sequencing (ChIP‐seq) of GR and pCREB 45 min after training and transcriptome analysis after 3 hr. Corticosterone administration induced differential GR DNA‐binding and regulation of target genes within the hippocampus, largely independent of training. Training alone did not result in long‐term memory nor did it affect GR or pCREB DNA‐binding and gene expression. No strong evidence was found for an interaction between GR and pCREB. Combination of the GR DNA‐binding and transcriptome data identified a set of novel, likely direct, GR target genes that are candidate mediators of corticosterone effects on memory consolidation. Cell‐specific expression of the identified target genes using single‐cell expression data suggests that the effects of corticosterone reflect in part non‐neuronal cells. Together, our data identified new GR targets associated with memory consolidation that reflect effects in both neuronal and non‐neuronal cells.

Role and Mechanism of Chronic Restraint Stress in Regulating Energy Metabolism and Reproductive Function Through Hypothalamic Kisspeptin Neurons

Objectives: The purpose of this study was to investigate whether stress affected energy metabolism and reproductive function through the glucocorticoid receptor (GR) on Kisspeptin neurons in the hypothalamus. Methods: 1. The first part of this study focused on the effects of chronic restraint stress on energy metabolism and reproductive function in mice. 2. The second part of this study focused on the effects of chronic restraint stress on the expression of serum cortisol and prolactin and the expression of GR and Kiss1 genes in the hypothalamus.3. Based on the above research, we constructed Kisspeptin specific glucocorticoid receptor knock out (KGRKO) mice. The mice were subjected to restraint stress intervention, the body weight of the mice was monitored every day, and the vaginal smear was performed on the female mice to observe the estrous cycle. After 28 days of restraint stress, serum was collected to detect serum sex hormone levels, including LH, FSH and estrogen levels in female mice and testosterone level in male mice by ELISA. Results: 1.The body weight and energy intake of the restraint stress group were lower than those of the control. 2.After restraint stress, the female mice showed irregular estrous cycle. LH and FSH levels in the stress group were significantly decreased compared with the control group.3. After restraint stress, the levels of serum cortisol and prolactin in male and female mice were significantly higher than the control group, and the hypothalamus Kiss1 gene mRNA expression and Kisspeptin protein expression were significantly decreased.4. In female mice, compared with GRflox/flox/Kiss1Cre-control mice, the nadir serum cortisol increased significantly in the morning in GRflox/flox/Kiss1Cre+ KGRKO mice, however, there was no significant difference in the serum peak cortisol in the afternoon. Compared with the control group, the restraint stress group and the KGRKO + restraint stress group had a significant weight loss compared with the KGRKO group. Compared with the restraint stress group, the KGRKO+restraint stress group had a reduced weight loss, suggesting that restraint stress might partially affect the energy metabolism through GR on Kisspeptin neurons. Conclusions: Chronic restraint stress induced weight loss in mice and reversed body weight gain induced by high-fat diet. Chronic restraint stress played a negative role in regulating reproductive function. The effects of chronic restraint stress on energy metabolism and reproduction were partially mediated by GR on Kisspeptin neurons in the hypothalamus. This study provided a central mechanism for chronic restraint stress in affecting energy metabolism and reproductive function, and was of great significance in revealing the relationship between the HPA axis with energy metabolism and reproduction.

Xanthohumol ameliorates Diet-Induced Liver Dysfunction via Farnesoid X Receptor-Dependent and Independent Signaling.

The farnesoid X receptor (FXR) plays a critical role in the regulation of lipid and bile acid (BA) homeostasis. Hepatic FXR loss results in lipid and BA accumulation, and progression from hepatic steatosis to nonalcoholic steatohepatitis (NASH). This study aimed to evaluate the effects of xanthohumol (XN), a hop-derived compound mitigating metabolic syndrome, on liver damage induced by diet and FXR deficiency in mice. Wild-type (WT) and liver-specific FXR-null mice (FXRLiver−/−) were fed a high-fat diet (HFD) containing XN or the vehicle formation followed by histological characterization, lipid, BA and gene profiling. HFD supplemented with XN resulted in amelioration of hepatic steatosis and decreased BA concentrations in FXRLiver−/− mice, the effect being stronger in male mice. XN induced the constitutive androstane receptor (CAR), pregnane X receptor (PXR) and glucocorticoid receptor (GR) gene expression in the liver of FXRLiver−/− mice. These findings suggest that activation of BA detoxification pathways represents the predominant mechanism for controlling hydrophobic BA concentrations in FXRLiver−/− mice. Collectively, these data indicated sex-dependent relationship between FXR, lipids and BAs, and suggest that XN ameliorates HFD-induced liver dysfunction via FXR-dependent and independent signaling.

Muscle Cortisol Levels, Expression of Glucocorticoid Receptor and Oxidative Stress Markers in the Teleost Fish Argyrosomus regius Exposed to Transport Stress

Simple SummaryOver the years, increasing attention has been given to welfare of farmed animals, but with a focus on mammalian species. Nevertheless, even non-mammalian ones deserve to be considered and especially fish. Aquaculture, in fact, is a globally and rapidly growing industry, since a large variety of fish is consumed every day as an essential source of protein and healthy lipids for human nutrition. However, in common aquaculture practices, such as transportation, fish are exposed to a whole range of potentially adverse stimuli which may substantially influence the welfare of the fish. On this basis, the present study aimed to assess the welfare status of meagre juveniles subjected to a 48 h transport. For this purpose, stress response in terms of cortisol levels, glucocorticoid receptor and oxidative stress markers’ expression has been evaluated. Results revealed that fish were stressed during loading on the truck and within 16 h from departure and did not fully recover even at the end of the transport. This work highlights how the procedures prior to transport, in particular, loading, may represent a potential welfare concern rather than transport itself. However, it remains essential to follow live animal commercial transportation directions in order to protect animal health and welfare during transport.Fish commercial transport is an ordinary practice in the aquaculture industry. This study aimed to investigate the effect of a 48 h transport stress on stress response of meagre (Argyrosomus regius) juveniles. Radioimmunoassay (RIA) and Real-Time PCR were used to evaluate muscle cortisol levels and to assess glucocorticoid receptor (gr) gene expression in fish muscle and liver, respectively. Presence and localization of various oxidative stress markers were investigated in different tissues by immunohistochemistry. A significant increase in muscle cortisol levels was observed after loading but a significant decrease occurred after 16 h from departure even without returning to control levels. Molecular analysis on stress response revealed an increase in muscle gr expression after fish loading that started decreasing during the travel returning to the control level at the end of the transport. Instead, no differences in liver gr expression were observed along the different sampling points. Immunostaining for heat shock protein 70 (HSP70), 4-hydroxy-2-nonenal (HNE), nitrotyrosine (NT) and 8-hydroxy-2’-deoxyguanosine (8-OHdG) antibodies was detected in several organs. Notably, a higher NT immunostaining intensity was evident in skin and gills of the transported animals with respect to controls. Results demonstrated that cortisol and gr are useful indicators of stressful conditions in transported fish.

Spleen tissue changes after restraint stress: effects of aerobic exercise training

Inflammation has been described as a prominent mechanism involved in dysfunctions and diseases evoked by chronic stress. Notably, the spleen is an immune organ controlled by sympathetic and glucocorticoid mechanisms, but the impact of chronic stress in the spleen is not entirely understood. Besides, the impact of aerobic exercise training on the effects of chronic stress in the spleen has never been reported. Therefore, this study aimed to assess the changes caused in the spleen by repeated restraint stress and the effect of aerobic exercise training performed after a period of chronic restraint stress in rats. We identified that daily exposure to restraint stress (120 min per session, for 14 consecutive days) increased corticosterone and noradrenaline content, gene expression of glucocorticoid and β2-adrenergic receptors, TNF-α and IL-6 levels, and increased pro-oxidant substances in the spleen. Circulating levels of corticosterone were also increased in chronically stressed animals. Exercise training (1 h a day/5 days per week, for 60 days) increased glucocorticoid receptor gene expression, interleukin (IL)-10 and antioxidant mechanisms in the spleen. Exercise also decreased splenic noradrenaline, tumoral necrosis factor (TNF)-α, and IL-6 contents. Lastly, the effects of repeated restraint stress in the spleen were mitigated in animals subjected to aerobic training. Taken together, the results reported in the present study indicate that aerobic exercise training is a relevant non-pharmacological therapeutic approach to dysfunctions in the spleen caused by a period of stress.

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.

Early environmental enrichment rescues memory impairments provoked by mild neonatal hypoxia-ischemia in adolescent mice

Hypoxia-ischemia (HI) is a consequence of a lack of oxygen and glucose support to the developing brain, which causes several neurodevelopmental impairments. Environmental enrichment (EE) is considered an option to recover the alterations observed in rodents exposed to HI. The aim of this study was to investigate the impact of early EE on memory, hippocampal volume and brain-derived neurotrophic factor (Bbnf) and glucocorticoid receptor (Nr3c1) gene expression of mice exposed to HI. At P10, pups underwent right carotid artery permanent occlusion followed by 35 min of 8% O2 hypoxic environment. Starting at P11, animals were reared in EE or in standard cage (HI-SC or SHAM-SC) conditions until behavioral testing (P45). SHAM pups did not undergo carotid ligation and hypoxic exposure. Memory performance was assessed in the Y-maze, Novel object recognition, and Barnes maze. Animals were then sacrificed for analysis of hippocampal volume and Bdnf and Nr3c1 gene expression. We observed that animals exposed to HI performed worse in all three tests compared to SHAM animals. Furthermore, HI animals exposed to EE did not differ from SHAM animals in all tasks. Moreover, HI decreased hippocampal volume, while animals reared in early EE were not different compared to SHAM animals. Animals exposed to HI also showed upregulated hippocampal Bdnf expression compared to SHAM animals. We conclude that early EE from P11 to P45 proved to be effective in recovering memory impairments and hippocampal volume loss elicited by HI. Nevertheless, Bdnf expression was not associated with the improvements in memory performance observed in animals exposed to EE after a hypoxic-ischemic event.

Salinity, Temperature and Ammonia Acute Stress Response in Seabream (Sparus aurata) Juveniles: A Multidisciplinary Study.

Simple SummaryGilthead seabream (Sparus aurata) is a teleost fish of great relevance in marine aquaculture, especially in the Mediterranean area and one of the most important farmed food marine species in Europe. Nevertheless, in captivity fish are usually exposed to stressful conditions, with a consequent negative impact on animal welfare and growth. The principal goal of this study was to shed light on the acute stress response of gilthead seabream juveniles exposed to different stressors using a multidisciplinary approach. For this purpose, gilthead seabream have been exposed to three different stress tests (temperature, salinity, and ammonia changes) and several laboratory techniques have been used to evaluate their growth and stress response. Results revealed that all the tested stressors had an impact on fish growth and health, particularly thermic and chemical exposure, whereas salinity seems to have a minor effect since this species can efficiently face with extreme variations in environmental salinity. The present work aimed to obtain relevant information on acute stress response of gilthead seabream to be used for improving farming condition and ensuring fish welfare.The present study aimed to investigate the acute response of gilthead seabream (Sparus aurata) juveniles exposed to temperature, salinity and ammonia stress. Radioimmunoassay was used to evaluate cortisol levels, whereas insulin-like growth factors (igf1 and igf2), myostatin (mstn), heat-shock protein 70 (hsp70) and glucocorticoid receptor (gr) gene expression was assessed trough Real-Time PCR. The presence and localization of IGF-I and HSP70 were investigated by immunohistochemistry. In all the stress conditions, a significant increase in cortisol levels was observed reaching higher values in the thermic and chemical stress groups. Regarding fish growth markers, igf1 gene expression was significantly higher only in fish subjected to heat shock stress while, at 60 min, igf2 gene expression was significantly lower in all the stressed groups. Temperature and ammonia changes resulted in a higher mstn gene expression. Molecular analyses on stress response evidenced a time dependent increase in hsp70 gene expression, that was significantly higher at 60 min in fish exposed to heat shock and chemical stress. Furthermore, the same experimental groups were characterized by a significantly higher gr gene expression respect to the control one. Immunostaining for IGF-I and HSP70 antibodies was observed in skin, gills, liver, and digestive system of gilthead seabream juveniles.

The dysregulation of the hypothalamic\u2013pituitary\u2013adrenal axis in diet-induced prediabetic male Sprague Dawley rats

BackgroundAltered function of the hypothalamic–pituitary–adrenal (HPA) axis in type 2 diabetic patients, a condition preceded by pre-diabetes, has been shown to increase the risk of depression as well as cause downstream effects resulting in upregulation of gluconeogenesis and dyslipidemia. In addition, stress, either psychological from managing diabetes or lifestyle related, further activates the HPA axis causing an exaggerated stress response. This study investigated the activity of the HPA axis in selected markers of glucose handling, and the stress response relative to components of the HPA axis in a diet-induced pre-diabetic rat model.MethodsSprague Dawley Rats were randomly divided into non-pre-diabetic group (NPD) and pre-diabetic group (PD) (n = 6, per group) over a 20-week induction period and a further 12-week experimental period to get 32 weeks. At the end of the 20 and 32-week periods, glucose handling using the Homeostasis Model Assessment indices, adrenocorticotropic (ACTH) and corticosterone (CORT) concentrations were measured. Stress was induced and the forced swim test were performed in the 12-week experimental week. At the end of 32 weeks glucocorticoid and mineralocorticoid hippocampal receptors were also measured.ResultsImpaired glucose handling in the PD group as well as increase in corticosterone was observed at the end of both 20 and 32-week periods by comparison to NPD groups. No changes were observed in ACTH concentration at week 20 while, at week 32, a decrease in plasma ACTH concentration was observed in the PD group by comparison to the NPD group. The stressed-induced animals were stressed using the forced swim test: the behaviour observed showed an increase in immobility time in the PD stressed group by comparison to the NPD group. This was followed by the observation of a decrease in ACTH and CORT concentration in the PD stressed group by comparison to the NPD stressed group. Mineralocorticoid and glucocorticoid receptors gene expression were elevated in the stressed PD group relative to the stressed NPD group.ConclusionThese observations, together, suggest that diet-induced pre-diabetes is associated with impaired HPA axis activity and deteriorating response to stress.

Cortisol Metabolism in Carp Macrophages: A Role for Macrophage-Derived Cortisol in M1/M2 Polarization.

Macrophages are crucial not only for initiation of inflammation and pathogen eradication (classically polarized M1 macrophages), but also for inflammation inhibition and tissue regeneration (alternatively polarized M2 macrophages). Their polarization toward the M1 population occurs under the influence of interferon-γ + lipopolysaccharide (IFN-γ + LPS), while alternatively polarized M2 macrophages evolve upon, e.g., interlukin 4 (IL-4) or cortisol stimulation. This in vitro study focused on a possible role for macrophage-derived cortisol in M1/M2 polarization in common carp. We studied the expression of molecules involved in cortisol synthesis/conversion from and to cortisone like 11β-hydroxysteroid dehydrogenase type 2 and 3. (11β-HSD2 and 3) and 11β-hydroxylase (CYP11b), as well as the expression of glucocorticoid receptors (GRs) and proliferator-activated receptor gamma (PPARγ) in M1 and M2 macrophages. Lastly, we analyzed how inhibition of these molecules affect macrophage polarization. In M1 cells, upregulation of gene expression of GRs and 11β-HSD3 was found, while, in M2 macrophages, expression of 11β-hsd2 was upregulated. Moreover, blocking of cortisol synthesis/conversion and GRs or PPARγ induced changes in expression of anti-inflammatory interleukin 10 (IL-10). Consequently, our data show that carp monocytes/macrophages can convert cortisol. The results strongly suggest that cortisol, via intracrine interaction with GRs, is important for IL-10-dependent control of the activity of macrophages and for the regulation of M1/M2 polarization to finally determine the outcome of an infection.

Annual Research Review: Social relationships and the immune system during development.

A child's social relationships serve critical functions during development. The interface between a child's social world and their immune system, particularly innate immunity, which helped children survive in the face of infections, nutritional scarcity, and violence throughout human history, is the focus of this Annual Research Review. This article reviews the state of research on social relationships and innate immune inflammation during childhood. Warmth and rejection in childhood social relationships, as well as physical trauma and unpredictable social environments, were not consistently related to circulating inflammatory markers such as interleukin-6 and C-reactive protein during childhood. Instead, links between social environments and inflammation were observed in studies that focus on children with greater background risk factors, such as low family socioeconomic status, family history of mood disorders, or presence of chronic interpersonal stressors combined with acute episodic stressors. In addition, studies on worse childhood social environments and greater inflammation in adulthood were more consistent. Warmth and rejection in the social environment may be related to sensitivity of immune cells to the anti-inflammatory actions of glucocorticoids, though this is primarily observed in adolescent women at risk for depression. Additional mechanistic evidence suggests that greater warmth and less rejection are related to processes that regulate inflammation, including greater expression of the glucocorticoid receptor gene and lower expression of genes that are responsive to the pro-inflammatory transcription factor NF-kappa B. The article concludes by discussing implications of the interface between a child's social relationships and inflammation for mental health and other recent (on evolutionary timescales) health threats, as well as recommendations for future research, and recommendations for researchers interested in integrating inflammatory measures in developmental research.

Pyriproxyfen Exposure Impairs Cognitive Parameters and Alters Cortisol Levels in Zebrafish.

Pyriproxyfen is one of the most used larvicides and insecticides; it acts as an analog of juvenile insect hormone (a growth regulator). It is highly toxic during all stages of mosquito development, suppresses metamorphosis, and interferes in insect reproduction and proliferation. Pyriproxyfen and its main metabolite have been shown to affect brain development in rodents. This compound is employed mainly to eliminate outbreaks of the genus Aedes, even in potable water. Despite the increasing number of toxicological studies about larvicides and insecticides—with an indication of continuous use—there have been few studies about the effects of pyriproxyfen in non-target species such as fish. This study evaluated the effects of pyriproxyfen on behavioral, cognitive, and endocrine parameters in zebrafish. We exposed adult zebrafish to different pyriproxyfen (Pestanal®) concentrations (0.125, 0.675, and 1.75 mg/l) for 96 h. We analyzed behavioral parameters, memory, cortisol levels, and gene expression of glucocorticoid receptor (gr) and corticotrophin-releasing factor (crf) after pyriproxyfen exposure. This exposure did not alter locomotion (distance or mean speed), anxiety-like behavior (latency to enter to the top zone of the tank or time in the top zone of the tank), and social or aggressive behavior. However, there was impaired inhibitory avoidance memory at all tested pyriproxyfen concentrations. Cortisol levels were reduced in exposed groups when compared to control or vehicle. However, gr and crf gene expression in pyriproxyfen-treated animals were unaltered when compared to control or vehicle groups. Taken together, these findings indicate that pyriproxyfen may induce cognitive impairment and altered cortisol levels in zebrafish, a non-target species.

Glucocorticoid Receptor Expression Predicts Good Outcome in response to Taxane-Free, Anthracycline-Based Therapy in Triple Negative Breast Cancer.

Triple negative breast cancer (TNBC) is a poor outcome subset of breast cancers characterised by the lack of expression of ER α, PR, and HER2 amplification. It is a heterogeneous group of cancers which fail to derive benefit from modern, more targeted treatments such as Tamoxifen and Herceptin. Current standard of care (SoC) is cytotoxic chemotherapy, which is effective for some patients, with other patients deriving little/no benefit and lacking alternative treatments. This study has identified the glucocorticoid receptor (GR) as a potential predictive biomarker of response to anthracycline-based chemotherapy in triple negative breast cancer (TNBC). GR gene expression levels in patient samples were analysed through publicly available microarray datasets as well as protein expression through immunohistochemistry (IHC) and correlated with clinical/pathological outcomes, including survival. While the results confirmed previous observations that high GR expression is associated with poor outcome in response to taxane-based chemotherapy, this study shows for the first time that high GR expression is associated with improved outcomes in the context of anthracycline-based chemotherapy. GR therefore has the potential to be used as a predictive biomarker to guide treatment choices and ensure that patients derive the greatest benefit from first line treatment, avoiding unnecessary costs, side effects, and disease progression.

Glucocorticoid receptor modulates myeloid-derived suppressor cell function via mitochondria respiration and metabolism in immune thrombocytopenia

Abstract Methods We collected 27 immune thrombocytopenia (ITP) patients who had received high-dose dexamethasone treatment. The myeloid-derived suppressor cells (MDSCs) were induced in vitro and CHIP-qPCR assays were performed. Seahorse XF analyzer was used to analyze oxygen consumption rate and parameters of mitochondrial function of MDSCs. MDSCs were treated with CPT-1 inhibitor, etomoxir, to explore the effect of inhibiting fatty acid oxidation. Glucocorticoid receptor (GR) expression was blocked in murine MDSCs which were transplanted into ITP mice. Results The mRNA expression of GR and mtDNA-encoded genes (ATP8, COX1, CYTB, ND1, ND5), as well as the binding of GR to mtDNA in MDSCs were decreased in steroid-resistant ITP group compared to steroid-responsive ITP group and healthy controls. MDSCs in steroid-resistant patients had decreased levels of basal respiration, maximal respiration and ATP production, suggesting that the mitochondria of MDSCs in steroid-resistant group had lower activities of electron transport chains and oxidative phosphorylation. The function of MDSCs to inhibit T-cell proliferation was decreased in steroid-resistant group. Etomoxir reduced the ability of MDSCs to block T-cell proliferation in steroid-responsive group, but did not alter the suppressive function of MDSCs on T cells in steroid-resistant group. ITP mice transplanted with GR siRNA-treated MDSCs showed lower platelet counts than those with control siRNA-treated MDSCs, suggesting that the function of MDSCs to ameliorate ITP relied on GR. Conclusions This study demonstrated that GR-associated MDSCs impairments are involved in the pathogenesis of ITP. It might be related to the modulation of mitochondrial respiration and metabolism by GR.

Impact of Monosodium Glutamate and Corticosterone in the Hippocampus: Glucocorticoid Regulation and Caspase‐3 mediated Microvascular and Neuronal Apoptosis

Does monosodium glutamate (MSG) trigger stress circuitry axis and induce apoptosis in the hippocampus? If so, does it mimic the effect of corticosterone (CORT)? In order to test this hypothesis, we put forth a Glutamate model and CORT‐ induced model system in rats to study the modality of glucocorticoid response and apoptotic signaling cascade. Young adult (2‐month‐old) male Wistar rats weighing about 50–100 g body weight were divided into 4 groups. Group I control rats were injected with saline (NaCl 0.9%) and Group II rats with MSG at a dose of 4 mg/kg body weight. Group III control was ethanol‐saline injected and Group IV was CORT injected at 3 mg/kg body weight. Rats were injected subcutaneously with test materials or vehicles for 7 days and maintained for 8, 15 and 30 days and were sacrificed by decapitation. The MSG model showed an enhanced glucocorticoid receptor (GR) (Nr3c1) gene expression in the hippocampus on day 8, as an immediate response to stress, though not significant. This was followed by a down regulation on day 15 and day 30. Bax, a pro‐apoptotic factor gene showed an insignificant upregulated expression in the hippocampus on day 8, 15 and 30. This indicates the activation of Bax‐ dependent apoptotic pathways at the mRNA level. In the CORT model, GR (Nr3c1) gene expression in the hippocampus showed a very significant downregulation on day 8. Noticed an insignificant activation on day 15 and 30. Bax gene showed a very significant downregulation on day 8, an immediate time point. Day 15 and Day 30 displayed an insignificant up and down regulation. Immunohistochemical analysis revealed the Caspase‐3 mediated death program activation in the microvasculature and neurons of the hippocampus upon MSG and CORT exposure. In the hippocampus field CA1, CA2 and CA3 and dentate gyrus displayed prominent Caspase‐3 immunoreactivity in the microvessels, suggesting potential blood‐brain barrier (BBB) breach. A leaky BBB can transcend vasculotoxic and neurotoxic proteins to invade the brain. Probable events like this can pave way for the neurons and glial cells to be exposed to high levels of glutamate circulating in the blood, which can lead to receptor ‐ mediated neurotoxicity. Neuronal apoptosis is also activated in the hippocampus upon exposure to MSG and CORT. Our results suggest the potential disruption in the brain neural connectivity and neural synchronization upon exposure to MSG and CORT. Recent reports also state that BBB dysfunction and neuronal loss can be attributed and linked to neurodegenerative disorders like Alzheimer’s. Furthermore, MSG mimics the CORT in triggering‐Bax and Caspase dependent apoptotic signaling cascade, to suggest that MSG is a stressor and a neurotoxin. Our results raise concern over the use of MSG as a food additive which needs public awakening and awareness.Support or Funding InformationCUSAT Postdoctoral Fellowship‐Dr. Smita Mathew. U.O. No.Ac. B3/PDF/2016‐17(b) dt. 10.5.2017