Glucocorticoid Receptor Research Articles

Abstract PR004: Age-induced chronic accumulation of glucocorticoids drives therapy resistance in lung cancer

Abstract Non-small cell lung cancer (NSCLC), a highly aggressive cancer, is the leading cause of cancer- related deaths in the U.S. While chemotherapy and targeted therapy are the main treatment modalities in the clinic, many patients do not respond to these treatments. Strikingly, the median age for lung cancer diagnosis is 71. Yet, preclinical and clinical research have largely been skewed towards young mice and patients. Here, we address this gap in knowledge and evaluate if old age affects the response to standard of care NSCLC therapies in KRAS-driven NSCLC. Using human sera from young and old healthy subjects to treat NSCLC cell lines, we show that age-driven circulatory changes are sufficient to drive a state of profound resistance to both chemotherapies as well as KRASG12C targeted therapies. We confirmed the relevance of our findings in vivo, by transplanting cancer cells derived from the K-rasLSL-G12D/+; p53fl/fl genetically engineered mouse model of lung cancer into young and old C57BL/6 mice. Using this model we showed that unlike young lung tumor-bearing mice on chemotherapy, old tumor-bearing mice do not respond to treatment and have a poor prognosis. Mechanistically, we found that old age drives a transcriptional reprogramming that favors drug resistance and identified the glucocorticoid receptor as a major driver of these transcriptional changes. We traced this to an age-induced chronic accumulation of glucocorticoids in circulation and within the tumor interstitial fluid. Chronic treatment with age-relevant concentrations of cortisol alone was sufficient to drive glucocorticoid receptor activation and induce resistance to therapies mirroring the effects of old age. Further supporting a driving role for glucocorticoids in driving age- induced drug resistance, blocking the glucocorticoid receptor genetically or pharmacologically rescues the drug resistance state imposed by old age in NSCLC cells. Lastly, using TCGA patient data we show an inverse correlation between glucocorticoid receptor activation (GR score) and progression-free survival of lung cancer patients. Together, our work demonstrates a role for age-induced glucocorticoids in circulation in promoting therapy-resistance in NSCLC patients and supports the use of therapeutic agents that block the glucocorticoid receptor as a strategy to increase therapy efficacy in NSCLC patients. Citation Format: Devesh Raizada, Felicia Lazure, Stanislav Drapela, Nadir Sarigul, Joanne Tejero, Didem Ilter, Ana Da Silva Gomes. Age-induced chronic accumulation of glucocorticoids drives therapy resistance in lung cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr PR004.

Abstract C004: Glucocorticoids establish a metastatic-promoting tumor microenvironment in a PDAC mouse model

Abstract Disseminated cancer cells (DCCs) arriving to a new organ may either proliferate and form metastasis, get eliminated by immune cells, or enter a quiescent stage. The factors that determine the DCCs’ fate, including getting quiescent DCCs to re-initiate proliferation and successfully evade the immune system, remain poorly understood, in part due to the lack of robust mouse models. We established a pancreatic ductal adenocarcinoma (PDAC) mouse model of dormant DCCs in the liver. An “immunization protocol” was used to mimic PDAC resection in patients: KPC1199 PDAC cells were injected to establish primary tumors and allow an adaptive immune response to develop against the cancer cells; the tumors were surgically resected; and new KPC1199 cells were intrasplenically injected to establish experimental liver metastases. The overwhelming majority of the KPC1199 cells were eliminated. No metastases spontaneously formed during 20 months of observation, but about 3-8 sporadic, single DCCs were found per liver cross section, and 94% of these DCCs were negative for proliferation markers. Although the model is based on entraining an adaptive immune response, T cell depletion resulted in only 25-30% of mice developing just 1-3 metastases each. This suggests that T cell depletion results in metastasis from the small percentage of DCCs that were proliferating. The DCC-hosting mice therefore represents of model to identify factors that can trigger further DCC proliferation and metastatic recurrence. Patients with PDAC often experience significant stress, leading to excess of endogenous glucocorticoids (GCs). Additionally, synthetic GCs are used during e.g., chemotherapy to manage side effects. To mimic elevated GC levels in patients, we treated DCC-hosting mice with synthetic GCs resulting in an increased percentage of proliferating DCCs (increasing from <6% of the examined cells in control mice to about 36%). Yet, no metastases formed. GC treatment also decreased T cell and increased neutrophil liver infiltration. Neutrophils can form protease-containing neutrophil extracellular traps (NETs), which we previously showed trigger DCC proliferation by proteolytic remodeling of the extracellular matrix protein laminin. We found that neutrophils from GC-treated mice spontaneously formed more NETs, and additionally, NET-generated laminin remodeling was observed in the liver metastasis. Together, the data suggest, that GC treatment drive quiescent DCCs to proliferate via neutrophils but alone this is insufficient to cause metastases. Consistent with this interpretation, T cell depletion combined with GC treatment resulted in multiple metastases in all mice examined. Of note, deleting the GC receptor in the DCCs did not reduce metastases, supporting that GCs act on the host and not the cancer cells. In conclusion, our data suggest that for quiescent DCCs to form metastases, they need signals that trigger proliferation and simultaneously, they must overcome immune surveillance. Elevated GC levels or GC treatment in immune suppressed individuals represents such a scenario. Citation Format: Xiao Han, Xueyan He, Yuan Gao, Sicheng Pan, Mikala Egeblad. Glucocorticoids establish a metastatic-promoting tumor microenvironment in a PDAC mouse model [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C004.

The impact of long-term isolation on anxiety, depressive-like and social behavior in aging Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) male rats.

Aging is a complex process associated with multimorbidity. Hypertension, one of widespread states, is among main causes of age-related alterations in behavior, emotionality and sociability. We studied the effects of long-term isolated housing on anxiety, depressive-like and social behavior as well as changes in the adrenocortical and sympathetic systems in the aging normotensive Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR). Ten-month-old male rats of both strains were subjected to 90-day isolated or group housing. Surprisingly, social isolation induced only mild effect on anxiety without influencing other affective-related behaviors. No effects of isolated housing on sociability or social novelty preferences were revealed. Despite the adrenal gland hypertrophy in the SHRs, corticosterone levels remained stable within the period of isolation but the expression of nuclear glucocorticoid receptor (Nr3c1) mRNA in the adrenals was lower in the SHR as compared to WKY rats. Pre-existing hypertension, associated with SHR genotype, did not significantly contribute to the effects of social isolation. The data suggest that the aged WKY and SHR rats are relatively resilient to chronic social stress associated with isolated housing.

Regulatory mechanisms of steroid hormone receptors on gene transcription through chromatin interaction and enhancer reprogramming.

Regulation of steroid hormone receptors (SHRs) on transcriptional reprogramming is crucial for breast cancer progression. SHRs, including estrogen receptor (ER), androgen receptor (AR), progesterone receptor (PR), and glucocorticoid receptor (GR) play key roles in remodeling the transcriptome of breast cancer cells. However, the molecular mechanisms by which SHRs regulate chromatin landscape in enhancer regions and transcription factor interactions remain largely unknown. In this review, we summarized the regulatory effects of 3 types of SHRs (AR, PR, and GR) on gene transcription through chromatin interactions and enhancer reprogramming. Specifically, AR and PR exhibit bi-directional regulatory effects (both inhibitory and promoting) on ER-mediated gene transcription, while GR modulates the transcription of pro-proliferation genes in ER-positive breast cancer cells. In addition, we have presented four enhancer reprogramming mechanisms (transcription factor cooperation, pioneer factor binding, dynamic assisted loading, and tethering) and the multiple enhancer-promoter contact models. Based on these mechanisms and models, this review proposes that the combination of multiple therapy strategies such as agonists/antagonists of SHRs plus endocrine therapy and the adoption of the latest sequencing technologies are expected to improve the efficacy of ER positive breast cancer treatment.

The glucocorticoid receptor potentiates aldosterone-induced transcription by the mineralocorticoid receptor

The glucocorticoid and mineralocorticoid receptors (GR and MR, respectively) have distinct, yet overlapping physiological and pathophysiological functions. There are indications that both receptors interact functionally and physically, but the precise role of this interdependence is poorly understood. Here, we analyzed the impact of GR coexpression on MR genome-wide transcriptional responses and chromatin binding upon activation by aldosterone and glucocorticoids, both physiological ligands of this receptor. Transcriptional responses of MR in the absence of GR result in fewer regulated genes. In contrast, coexpression of GR potentiates MR-mediated transcription, particularly in response to aldosterone, both in cell lines and in the more physiologically relevant model of mouse colon organoids. MR chromatin binding is altered by GR coexpression in a locus- and ligand-specific way. Single-molecule tracking of MR suggests that the presence of GR contributes to productive binding of MR/aldosterone complexes to chromatin. Together, our data indicate that coexpression of GR potentiates aldosterone-mediated MR transcriptional activity, even in the absence of glucocorticoids.

Adipocyte associated glucocorticoid signaling regulates normal fibroblast function which is lost in inflammatory arthritis.

Fibroblasts play critical roles in tissue homeostasis, but in pathologic states they can drive fibrosis, inflammation, and tissue destruction. Little is known about what regulates the homeostatic functions of fibroblasts. Here, we perform RNA sequencing and identify a gene expression program in healthy synovial fibroblasts characterized by enhanced fatty acid metabolism and lipid transport. We identify cortisol as the key driver of the healthy fibroblast phenotype and that depletion of adipocytes, which express high levels of Hsd11b1, results in loss of the healthy fibroblast phenotype in mouse synovium. Additionally, fibroblast-specific glucocorticoid receptor Nr3c1 deletion in vivo leads to worsened arthritis. Cortisol signaling in fibroblasts mitigates matrix remodeling induced by TNF and TGF-β1 in vitro, while stimulation with these cytokines represses cortisol signaling and adipogenesis. Together, these findings demonstrate the importance of adipocytes and cortisol signaling in driving the healthy synovial fibroblast state that is lost in disease.

Stress disrupts engram ensembles in lateral amygdala to generalize threat memory in mice.

Stress induces aversive memory overgeneralization, a hallmark of many psychiatric disorders. Memories are encoded by a sparse ensemble of neurons active during an event (an engram ensemble). We examined the molecular and circuit processes mediating stress-induced threat memory overgeneralization in mice. Stress, acting via corticosterone, increased the density of engram ensembles supporting a threat memory in lateral amygdala, and this engram ensemble was reactivated by both specific and non-specific retrieval cues (generalized threat memory). Furthermore, we identified a critical role for endocannabinoids, acting retrogradely on parvalbumin-positive (PV+) lateral amygdala interneurons in the formation of a less-sparse engram and memory generalization induced by stress. Glucocorticoid receptor antagonists, endocannabinoid synthesis inhibitors, increasing PV+ neuronal activity, and knocking down cannabinoid receptors in lateral amygdala PV+ neurons restored threat memory specificity and a sparse engram in stressed mice. These findings offer insights into stress-induced memory alterations, providing potential therapeutic avenues for stress-related disorders.

Discovery and MD simulation of a Triterpenoid Zj7 as GR Modulator Targeting Non‐Classical GRE with Potent Anti‐Obesity Activity

Despite the potential of non‐classical glucocorticoid response element (GRE)‐selective glucocorticoid receptor (GR) modulators in biomedical sciences, progress has not yet been made. In this study, we discovered a first‐in‐class chemical modulator that selectively suppresses the transcriptional activity of the GR in a gene with a non‐classical GRE, but not with classical GREs. The orexigenic agouti‐related peptide (Agrp)‐gene with a non‐classical GRE was chosen for this study. Similarity‐implemented virtual screening and rational modification of the structure of the initial hit compounds led to the identification of a pentacyclic natural triterpenoid, Zj7 (2‐O‐trans‐p‐coumaroylalphitolic acid). With this compound, we recently reported the verification of the orexigenic function and mechanism of action of GR in AgRP neurons. Herein, we describe the detailed discovery process leading to the identification of Zj7 and propose its molecular mode of action using molecular dynamics simulation.

TMIC-44. ANDROGEN LOSS WEAKENS ANTI-TUMOR IMMUNITY AND ACCELERATES BRAIN TUMOR GROWTH

Abstract Many cancers, including glioblastoma (GBM), exhibit a male-biased incidence and outcome disparity. The underlying reasons for this sex bias are unclear but likely involve differences in tumor cell state and immune response. This effect is further influenced by sex hormones, including androgens, which have been shown to inhibit anti-tumor T cell immunity in other solid tumors. Using a series of pre-clinical models, we observed that androgens drive anti-tumor immunity in brain tumors, contrasting with their effect in other tumor types. Upon castration, tumor growth was accelerated in GBM and brain tumor models, while the opposite effect was observed when tumors were located outside the brain. This castration effect could be reversed by testosterone administration. Flow cytometry revealed decreased T cell function, indicated by reduced anti-tumor cytokines (IFNγ and TNFα), and increased T cell exhaustion in both tumors and peripheral tissues in castrated mice, suggesting systemic immunosuppression. Indeed, the survival difference was completely abrogated in T cell deficient mice (RAG1 knockout). Mechanistically, increased hypothalamus-pituitary-adrenal (HPA) axis activity in castrated mice was responsible for the observed systemic immunosuppression, particularly in those with brain tumors. Blocking glucocorticoid receptors reversed the accelerated tumor growth in castrated mice, indicating that elevated glucocorticoid signaling mediated the castration effect. This mechanism was brain-specific rather than GBM-specific, as hyperactivation of the HPA axis was also observed with intracranial implantation of non-GBM tumors. Neuroinflammation caused by brain tumors was stronger in castrated mice, and proinflammatory cytokines like IL-1 and TNF induced HPA axis hyperactivation. Together, these findings highlight that brain tumors drive distinct endocrine-mediated mechanisms in the androgen-deprived setting and highlight the importance of organ-specific effects on anti-tumor immunity.

Post-traumatic stress disorder and metabolic syndrome: the role of some antioxidants in treatment

The basis for the pathogenesis of cardiovascular, cancer, metabolic diseases, low-grade chronic inflammation (LGCI) and many other disorders is an imbalance between prooxidants and the antioxidant defense system. It is believed that the link between post-traumatic stress disorder (PTSD) and metabolic syndrome (MetS) is based on oxidative stress (OS), increased autonomic nervous system activity, glucocorticoid synthesis activation, or immunological dysregulation. Moreover, pathophysiological changes in the systemic LGCI pathways that result from modifications in glucocorticoid receptor reactivity (secondary to emotional and physiological arousal) may be the basis for inappropriate social behavior consistent with PTSD and MetS manifestations. Recently, evidence has emerged suggesting that a combination of high levels of systemic OS and activation of LGCI plays an important role in the pathogenesis of PTSD. On the other hand, PTSD is a type of recurrent and long-term trauma that exacerbates OS and accele­rates cellular aging. LGCI is accompanied by the release of reactive oxygen and nitrogen species, proinflammatory cytokines, and other biologically active substances that cause OS. The purpose of this review was to discuss the role of individual antioxidants, in particular polyphenols, flavonoids, carotenoids, N-acetylcysteine, melatonin, L-arginine, C and E vitamins, zinc, copper, and selenium, in the prevention/treatment of comorbid pathology of PTSD and MetS, as well as to analyze new trends and directions for future research. The search was conducted in Scopus, Science Direct (from Else­vier) and PubMed, including MEDLINE databases. The keywords used were “post-traumatic stress disorder,” “metabolic syndrome,” and “antioxidants.” To identify research results that could not be found during the online search, a manual search of the bibliography of publications was used.

Inhibition of sympathetic tone via hypothalamic descending pathway propagates glucocorticoid-induced endothelial impairment and osteonecrosis of the femoral head

Osteonecrosis of the femoral head (ONFH) is a common complication of glucocorticoid (GC) therapy. Recent advances demonstrate that sympathetic nerves regulate bone homeostasis, and GCs lower the sympathetic tone. Here, we show that the dramatically decreased sympathetic tone is closely associated with the pathogenesis of GC-induced ONFH. GCs activate the glucocorticoid receptor (GR) but hinder the activation of the mineralocorticoid receptor (MR) on neurons in the hypothalamic paraventricular nucleus (PVN). This disrupts the balance of corticosteroid receptors (GR/MR) and subsequently reduces the sympathetic outflow in the PVN. Vascular endothelial cells rapidly react to inhibition of sympathetic tone by provoking endothelial apoptosis in adult male mice treated with methylprednisolone (MPS) daily for 3 days, and we find substantially reduced H-type vessels in the femoral heads of MPS-treated ONFH mice. Importantly, treatment with a GR inhibitor (RU486) in the PVN promotes the activation of MR and rebalances the ratio of GR and MR, thus effectively boosting sympathetic outflow, as shown by an increase in tyrosine hydroxylase expression in both the PVN and the sympathetic postganglionic neurons and an increase in norepinephrine levels in both the serum and bone marrow of the femoral head of MPS-treated mice. Rebalancing the corticosteroid receptors mitigates GC-induced endothelial impairment and ONFH and promotes angiogenesis coupled with osteogenesis in the femoral head, while these effects are abolished by chemical sympathectomy with 6-OHDA or adrenergic receptor-β2 (Adrb2) knockout. Furthermore, activating Adrb2 signaling in vivo is sufficient to rescue the GC-induced ONFH phenotype. Mechanistically, norepinephrine increases the expression of the key glycolytic gene 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) via Adrb2-cyclic AMP response element-binding protein (CREB) signaling. Endothelial-specific overexpression of PFKFB3 attenuates endothelial impairment and prevents severe osteonecrosis in MPS-treated Adrb2 knockout mice. Thus, GC inhibits sympathetic tone via the hypothalamic descending pathway, which, in turn, acts as a mediator of GC-induced ONFH.

PU.1 eviction at lymphocyte-specific chromatin domains mediates glucocorticoid response in acute lymphoblastic leukemia

The epigenetic landscape plays a critical role in cancer progression, yet its therapeutic potential remains underexplored. Glucocorticoids are essential components of treatments for lymphoid cancers, but resistance, driven in part by epigenetic changes at glucocorticoid-response elements, poses a major challenge to effective therapies. Here we show that glucocorticoid treatment induces distinct patterns of chromosomal organization in glucocorticoid-sensitive and resistant acute lymphoblastic leukemia xenograft models. These glucocorticoid-response elements are primed by the pioneer transcription factor PU.1, which interacts with the glucocorticoid receptor. Eviction of PU.1 promotes receptor binding, increasing the expression of genes involved in apoptosis and facilitating a stronger therapeutic response. Treatment with a PU.1 inhibitor enhances glucocorticoid sensitivity, demonstrating the clinical potential of targeting this pathway. This study uncovers a mechanism involving PU.1 and the glucocorticoid receptor, linking transcription factor activity with drug response, and suggesting potential therapeutic strategies for overcoming resistance.

Decreased Brain pH Underlies Behavioral and Brain Abnormalities Induced by Chronic Exposure to Glucocorticoids in Mice.

Depressed patients may exhibit glucocorticoid hypersecretion, suggesting that elevated levels of glucocorticoids may play an important role in the pathophysiology of depression. Some postmortem brain studies have shown decreased pH and increased lactate levels in psychiatric patients, implying involvement of these factors in the pathogenesis. To investigate the effects of glucocorticoids on brain pH and lactate levels, and their roles in depressive symptoms, brain pH and lactate were examined in mice treated with corticosterone (CORT), the major bioactive glucocorticoid in rodents. A single administration of CORT decreased hippocampal pH after 24 h. Three weeks of CORT treatment decreased pH in the prefrontal cortex (PFC), striatum, and hippocampus (HC), whereas intake of pH 9.0 drinking water increased pH in these brain regions. pH and lactate levels were correlated in the PFC and HC of mice treated with CORT for 3 weeks. The suppression of body weight gain and decrease in adrenal weight observed after 3 weeks of CORT treatment were not alleviated by pH 9.0 water. However, an increase in immobility time in the forced swim test and a decrease in neurogenesis in the hippocampus were alleviated. The decrease in brain pH and increase in immobility time in the forced swim test and a decrease in neurogenesis in the hippocampus induced by CORT treatment were abolished by co-treatment with the glucocorticoid receptor (GR) antagonist mifepristone. These findings indicate that decreased brain pH via GRs may be related to glucocorticoid-induced depression-like behavior and decreased hippocampal neurogenesis.

Autonomous cortisol secretion promotes vascular calcification in vivo and in vitro under hyperaldosteronism.

Autonomous cortisol secretion (ACS) is not uncommon in patients with primary aldosteronism (PA). However, the cardiovascular burden of ACS due to its dysregulated cortisol secretion remains poorly understood. Thus, we examined the effects of ACS on vascular calcification in a hyperaldosteronism environment in vitro and in vivo. A total of 339 patients with PA with adrenal incidentaloma and low-dose dexamethasone suppression test data (cutoff level: cortisol > 1.8 μg/dL) from a prospectively maintained database were enrolled; abdominal aortic calcification (AAC) scores were quantitatively estimated. Human aortic smooth muscle cells (HAOSMCs) were used as in vitro model of vascular calcification. In this study, 65 of the 339 patients with PA had ACS; 274 did not. Patients with PA/ACS had a higher AAC score (1171.0 ± 2434.0 vs. 489.5 ± 1085.3, P = 0.012) than patients without ACS. ACS was independently associated with AAC score (β = 0.139, P = 0.004) in multivariate analysis, and post-suppression cortisol level was significantly correlated with the AAC score (P = 0.004). In the HAOSMC model, co-treatment with cortisol synergistically stimulated alkaline phosphatase activity and calcium deposition in a hyperaldosteronism environment. The stimulatory effect of cortisol was abolished by the mineralocorticoid receptor (MR) antagonist eplerenone, but not glucocorticoid receptor antagonist mifepristone, indicating a MR-dependent mechanism. In conclusion, the presence of ACS is associated with heavier vascular calcification in patients with PA. Aldosterone and cortisol synergistically activate HAOSMC calcification via MR signaling, via a process that can be attenuated by eplerenone.

SUBLIMATION-BASED CUTTING-EDGE TECHNOLOGY (SUSTAINABLE DEVELOPMENT GOALS 9 and 15) TO DEVELOP CURCUMIN NANOPARTICLES BY SOLVENT-FREE GREEN CHEMISTRY METHOD FOR THEIR ANTIOXIDANT AND ANTICANCER ACTIVITY

Objective: This research aimed to develop a new, cost-effective, solvent/surfactant/supercritical carbon dioxide-free, sublimation-based method to prepare curcumin nanoparticles. The research objective was to meet Sustainable Development Goals (SDG-3,9 and 15). The problem of poor absorption of curcumin is sorted out by micro or nanonization, solid dispersion, solid solution, β-cyclodextrin complexation, micelle formation, and solution-enhanced dispersion by supercritical carbon dioxide. Methods: The curcumin, mixed with menthol, was allowed to melt at 29 °C and placed under vacuum for 6 H (h). The menthol sublimates and leaves the curcumin particles as residue. The residual curcumin particles were characterised, and stability studies were also performed. Results: The curcumin nanoparticles were stable, in the nano-size range (10-300 nm); Fourier Transform Infrared Spectroscopy (FTIR) showed the presence of CH3 and CH2 bending, aromatic C=C and C=O stretching, aromatic CC and OH stretching, aliphatic C-H bending, aromatic-OH bending with both pure curcumin and curcumin nanoparticles, that no change in bonds and groups, and differential scanning calorimetry (DSC) showed the temperature (T) =162.03, 185.64 and peak maximum is 177.986 for pure curcumin while T=164.43, 185.68 and peak maximum is 177.784 for curcumin nanoparticles that indicated compatibility between curcumin and menthol. The curcumin nanoparticles showed improved solubility, dissolution, and antioxidant activity by calculating Inhibitory Concentration50 (IC50) value 114.51 and in vitro cytotoxicity (IC50=165.6±0.084 µg/ml) of curcumin nanoparticles against MCF-7, a human breast cancer cell line with estrogen, progesterone, and glucocorticoid receptors. Conclusion: It concluded that the sublimation technique can used to prepare the nanoparticles of drugs or might be for thermo-labile drugs.

Methotrexate inhibits glucocorticoids-induced osteoclastogenesis via activating IFN-γR/STAT1 pathway in the treatment of rheumatoid arthritis

ObjectivesRheumatoid arthritis (RA) is a chronic autoimmune disease characterised by the synovitis and bone erosion. The combination therapy of glucocorticoids (GCs) and methotrexate (MTX) is recommended in early RA management,...

Single Intranasal Administration of Ucn3 Affects the Development of PTSD Symptoms in an Animal Model

Post-traumatic stress disorder (PTSD) is a multifactorial psychological disorder that affects different neurotransmitter systems, including the central CRH system. CRH acts via the CRHR1 and CRHR2 receptors, which exert opposite effects, i.e., anxiogenic or anxiolytic. The aim of this work was to investigate how intranasal administration of the CRHR2-specific agonist urocortin 2 (Ucn2) or urocortin 3 (Ucn3) affects manifestations of PTSD in a single prolonged stress (SPS) animal model of PTSD. Elevated plus maze (EPM) and open field (OF) tests were used to assess anxiety-like behavior. Changes in the gene expressions of CRH, CRHR1, CRHR2, glucocorticoid receptor (GR), and FKBP5 were measured in brain regions (BNST, amygdala, and PVN) responsible for modulating the stress response. The SPS animals spent less time in the OF central zone and were less mobile than the controls; however, the Ucn3 treatment reversed this effect. SPS decreased the GR and FKPB5 mRNA levels in the PVN. Ucn3 suppressed the effect of SPS on FKBP5 mRNA expression in the PVN and increased FKBP5 mRNA in the BNST and PVN compared to the stressed animals. We demonstrate that Ucn3 has the potential to ameliorate anxiety-like behavior in SPS animals and also to affect the neuroendocrine system in the BNST and PVN. In addition, we confirm the important role of CRHR2 signaling in mediating the stress response.

Research status of anti-obesogenic functional foods: mechanism of endocrine-disrupting chemicals and glucocorticoid receptor pathway

Research status of anti-obesogenic functional foods: mechanism of endocrine-disrupting chemicals and glucocorticoid receptor pathway

Dexamethasone is a regulator of clock genes in testicular peritubular cells.

We recently found that peritubular cells of the human testis are a dominant site of expression of the glucocorticoid receptor (GR; encoded by NR3C1). Activation of GR by dexamethasone (Dex) strongly influences the phenotype of cultured human testicular peritubular cells (HTPCs), causing massive changes of their proteome and secretome. As glucocorticoids (GC) are also known to set the internal clock of peripheral organs by regulating clock genes, we tested such an influence of Dex in HTPCs. We performed cellular studies with HTPCs and immortalized nonhuman primate (Callithrix jacchus; Cj)-derived peritubular cells, organotypic incubations of testicular fragments of Cj, qPCR and proteomic, as well as immunohistochemical studies. Basal clock gene expression levels, when monitored by qPCR under standard culture conditions, showed alterations over 24 h, suggesting an endogenous circadian rhythm, especially for BMAL1. Dex (1 µM) when added to cells, caused a strong and significant increase of PER1, followed by elevations of BMAL1, and other clock genes. This action was observed as early as 4 h after the addition of Dex. Immunohistochemistry and data mining revealed GR in testicular peritubular cells and other somatic cells of Cj, in situ. We therefore performed organotypic incubations of testicular fragments of Cj (n = 3) and found that upon addition of Dex (1 µM), mRNA levels of BMAL1 and PER1 also increased in samples of two out of three animals after 6 h. Mass spectrometry did, however, not reveal significant alterations of the testicular proteome, possibly due to the short time point and/or the fact that the somatic GR-expressing cells represent only a small portion of the testis. In support for this assumption, Dex (1 µM; 6 h) significantly increased mRNA levels of BMAL1 and PER1 in Cj-derived immortalized testicular peritubular cells. The results indicate that an internal clock system likely exists in peritubular cells of the testis and that Dex, via testicular GR expressed by peritubular cells and other somatic cells, is a strong regulator of this system. In a physiological situation, GC thus may be important regulators of the testicular clock, while in a situation of prolonged stress or GC-medication, derangements in clock gene expression may result.

Dietary bile acids alleviate corticosterone-induced fatty liver and hepatic glucocorticoid receptor suppression in broiler chickens.

The aim of this study was to investigate the alleviating effects and mechanisms of bile acids (BA) on corticosterone-induced fatty liver in broiler chickens. Male Arbor Acres chickens were randomly divided into three groups: control group (CON), stress model group (CORT), and BA-treated group (CORT-BA). The CORT-BA group received a diet with 250mg/kg BA from 21 days of age. From day 36 to 43, both the CORT and CORT-BA groups received subcutaneous injections of corticosterone to simulate chronic stress. The results indicated that BA significantly mitigated the body weight loss, liver enlargement, and hepatic lipid deposition caused by corticosterone (P < 0.05). Liver RNA-seq analysis showed that BA alleviated corticosterone-induced fatty liver by inhibiting lipid metabolism pathways, including fatty acid biosynthesis, triglyceride biosynthesis, and fatty acid transport. Additionally, BA improved corticosterone-induced downregulation of glucocorticoid receptor (GR) expression (P < 0.05). Molecular docking and cellular thermal shift assays revealed that hyodeoxycholic acid (HDCA), a major component of compound bile acids, could bind to GR and enhance its stability. In conclusion, BA alleviated corticosterone-induced fatty liver in broilers by inhibiting lipid synthesis pathways and mitigating the suppression of hepatic GR expression.