Increased Glucocorticoid Receptor Research Articles

Repetitive Administration of Low-Dose Lipopolysaccharide Improves Repeated Social Defeat Stress-Induced Behavioral Abnormalities and Aberrant Immune Response.

Repetitive exposure of innate immune cells to a subthreshold dosage of endotoxin components may modulate inflammatory responses. However, the regulatory mechanisms in the interactions between the central nervous system (CNS) and the immune system remain unclear. This study aimed to investigate the effects of lipopolysaccharide (LPS) preconditioning in repeated social defeat stress (RSDS)-induced abnormal immune responses and behavioral impairments. This study aimed to elucidate the mechanisms that underlie the protective effects of repeated administration of a subthreshold dose LPS on behavioral impairments using the RSDS paradigm. LPS preconditioning improved abnormal behaviors in RSDS-defeated mice, accompanied by decreased monoamine oxidases and increased glucocorticoid receptor expression in the hippocampus. In addition, pre-treated with LPS significantly decreased the recruited peripheral myeloid cells (CD11b+CD45hi), mainly circulating inflammatory monocytes (CD11b+CD45hiLy6ChiCCR2+) into the brain in response to RSDS challenge. Importantly, we found that LPS preconditioning exerts its protective properties by regulating lipocalin-2 (LCN2) expression in microglia, which subsequently induces expressions of chemokine CCL2 and pro-inflammatory cytokine. Subsequently, LPS-preconditioning lessened the resident microglia population (CD11b+CD45intCCL2+) in the brains of the RSDS-defeated mice. Moreover, RSDS-associated expressions of leukocytes (CD11b+CD45+CCR2+) and neutrophils (CD11b+CD45+Ly6G+) in the bone marrow, spleen, and blood were also attenuated by LPS-preconditioning. In particular, LPS preconditioning also promoted the expression of endogenous antioxidants and anti-inflammatory proteins in the hippocampus. Our results demonstrate that LPS preconditioning ameliorates lipocalin 2-associated microglial activation and aberrant immune response and promotes the expression of endogenous antioxidants and anti-inflammatory protein, thereby maintaining the homeostasis of pro-inflammation/anti-inflammation in both the brain and immune system, ultimately protecting the mice from RSDS-induced aberrant immune response and behavioral changes.

Prenatal Hypoxia Triggers a Glucocorticoid-Associated Depressive-like Phenotype in Adult Rats, Accompanied by Reduced Anxiety in Response to Stress.

Fetal hypoxia and maternal stress frequently culminate in neuropsychiatric afflictions in life. To replicate this condition, we employed a model of prenatal severe hypoxia (PSH) during days 14-16 of rat gestation. Subsequently, both control and PSH rats at 3 months old were subjected to episodes of inescapable stress to induce learned helplessness (LH). The results of the open field test revealed an inclination towards depressive-like behavior in PSH rats. Following LH episodes, control (but not PSH) rats displayed significant anxiety. LH induced an increase in glucocorticoid receptor (GR) levels in extrahypothalamic brain structures, with enhanced nuclear translocation in the hippocampus (HPC) observed both in control and PSH rats. However, only control rats showed an increase in GR nuclear translocation in the amygdala (AMG). The decreased GR levels in the HPC of PSH rats correlated with elevated levels of hypothalamic corticotropin-releasing hormone (CRH) compared with the controls. However, LH resulted in a reduction of the CRH levels in PSH rats, aligning them with those of control rats, without affecting the latter. This study presents evidence that PSH leads to depressive-like behavior in rats, associated with alterations in the glucocorticoid system. Notably, these impairments also contribute to increased resistance to severe stressors.

Effect of intermittent theta-burst stimulation on the thyroid and adrenal systems in resistant depressed patients

IntroductionDisturbances in the hypothalamic-pituitary-thyroid (HPT) and hypothalamic-pituitary-adrenal (HPA) axes have been frequently reported in treatment resistant depressed patients (TRDs). So far, the effects of intermittent theta-burst stimulation (iTBS) treatment—a form of repetitive transcranial magnetic stimulation (rTMS) technique—on the activity of the HPT and HPA axes are poorly understood.ObjectivesThe present study aimed to evaluate the effects of iTBS sessions, applied to the left dorsolateral prefrontal cortex, in TRDs with abnormal chronobiological HPT functioning at baseline (BL) possibly associated with hypercortisolemia.MethodsThe ∆∆TSH test (i.e., the difference between the thyrotropin response to protirelin tests [∆TSH] performed at 8 AM and 11 PM on the same day) and the dexamethasone suppression test (DST) were performed in 12 TRDs and 14 healthy hospitalized control subjects (HCs). To be enrolled in this study, patients had to show at BL reduced ∆∆TSH values (i.e., < 2.5 mU/L) and a score of 18 or greater on the 17-item Hamilton Rating Scale for Depression (HAMD-17). Post-DST cortisol maximum (CORmax) serum level in excess of 120 nmol/L defined DST non-suppression (i.e., hypercortisolemia)—6 TRDs were DST non-suppressors at BL. After 10 and 20 iTBS sessions the ∆∆TSH test and the DST were repeated in all inpatients. A positive clinical response was defined by a final HAMD-17 score ≤ 8.ResultsCompared to HCs, ∆∆TSH values were lower in TRDs at BL (p < 0.00001), and remained reduced after 10 and 20 iTBS sessions (p < 0.001 and p < 0.02 respectively). Post-DST CORmax levels were higher in TRDs than in HCs at BL (p < 0.01), but were comparable to those of HCs after 10 and 20 iTBS sessions. Responders (n = 5) were characterized by 1) a normalization of their ∆∆TSH values after 20 iTBS sessions (whereas after 10 iTBS sessions ∆∆TSH values were still reduced compared to HCs [p < 0.05]), and 2) a normality of post-DST CORmax levels at BL—while after 10 and 20 iTBS sessions post-DST CORmax levels were decreased compared to HCs (p < 0.006 and p < 0.03 respectively). Non-responders (n = 7) showed 1) no significant change in their ∆∆TSH values which remained lower than those of HCs at each assessment (all p < 0.001), 2) while increased post-DST CORmax levels found at BL (p < 0.0008 vs. HCs) normalized from the 10th iTBS session.ConclusionsThe present pilot study suggests that successful iTBS treatment can restore the chronobiological activity of the HPT axis. Although iTBS may increase glucocorticoid receptor signaling, baseline hypercortisolemia could negatively impact subsequent response to iTBS treatment.Disclosure of InterestNone Declared

Complement C5a Receptor Signaling Alters Stress Responsiveness and Modulates Microglia Following Chronic Stress Exposure

BackgroundAccumulating evidence underscores the pivotal role of heightened inflammation in the pathophysiology of stress-related diseases, but the underlying mechanisms remain elusive. The complement system, a key effector of the innate immune system, produces the C5–cleaved activation product C5a upon activation, initiating inflammatory responses through the canonical C5a receptor 1 (C5aR1). While C5aR1 is expressed in stress-responsive brain regions, its role in stress responsiveness remains unknown. MethodsTo investigate C5a-C5aR1 signaling in stress responses, mice underwent acute and chronic stress paradigms. Circulating C5a levels and messenger RNA expression of C5aR1 in the hippocampus and adrenal gland were measured. C5aR1-deficient mice were used to elucidate the effects of disrupted C5a-C5aR1 signaling across behavioral, hormonal, metabolic, and inflammation parameters. ResultsChronic restraint stress elevated circulating C5a levels while reducing C5aR1 messenger RNA expression in the hippocampus and adrenal gland. Notably, the absence of C5aR1 signaling enhanced adrenal sensitivity to adrenocorticotropic hormone, concurrently reducing pituitary adrenocorticotropic hormone production and enhancing the response to acute stress. C5aR1-deficient mice exhibited attenuated reductions in locomotor activity and body weight under chronic stress. Additionally, these mice displayed increased glucocorticoid receptor sensitivity and disrupted glucose and insulin homeostasis. Chronic stress induced an increase in C5aR1-expressing microglia in the hippocampus, a response mitigated in C5aR1-deficient mice. ConclusionsC5a-C5aR1 signaling emerges as a key metabolic regulator during stress, suggesting that complement activation and dysfunctional C5aR1 signaling may contribute to neuroinflammatory phenotypes in stress-related disorders. The results advocate for further exploration of complement C5aR1 as a potential therapeutic target for stress-related conditions.

Comparative analysis of antidepressant-like effects of five herbal essential oils on mice with reserpine-induced depression

The antidepressant-like effects of five herbal essential oils (EOs), Jasminum sambac (Linn.) Aiton essential oil (JSEOs), Magnolia denudata Desr. essential oil (MDEOs), Rosa rugosa Thunb. essential oil (RREOs), Aloysia citriodora Ortega ex Pers. essential oil (ACEOs) and Abies balsamea (L.) Mill. essential oil (ABEOs) were evaluated. By virtue of a reserpine-induced depression mouse model, the antidepression activities and mechanisms of these EOs were explored. The results indicated that the inhalation of EOs significantly ameliorated depression-like behaviors in reserpine-induced depression mice, including a decrease in anxiety and immobility time. JSEOs and ABEOs significantly attenuated reserpine-induced depression-like behaviors, particularly the decreased body weight and immobility time, as determined by tail suspension and forced swimming tests. Furthermore, RT-qPCR and western blotting analyses indicated that the EOs influenced brain-derived neurotrophic factor (BDNF), serotonin1A (5-HT1A), and inflammatory cytokine levels. ACEOs attenuated reserpine-induced hippocampal and neuronal damage, significantly increased glucocorticoid receptor (GR) and 5-HT1A levels, and suppressed the inflammatory response. These results provide new insights into the antidepressant effects of herbal EOs and suggest that the five EOs evaluated in this study are potential nutraceuticals for the treatment of depression.

The effect of taurochenodeoxycholic acid on the glucocorticoid receptormediated PLC-IP3 -calcium pathway in synoviocytes derived from a rat adjuvant arthritis model

Taurochenodeoxycholic acid is one of the main active components of the bile acid pool and has important anti-inflammatory and immunomodulatory properties. This study aimed to explore the therapeutic effects and mechanism of action of taurochenodeoxycholic acid in inflammatory arthritis using a rat adjuvant arthritis model. Fibroblast-like synoviocytes were derived from rats with adjuvant arthritis and cultured using the adherent tissue explant method. Western blotting, enzyme-linked immunosorbent assay, and fluorescent probe-based methods were used to detect the effects of taurochenodeoxycholic acid on glucocorticoid receptor expression, phospholipase C protein levels, and inositol trisphosphate and intracellular free Ca2+ concentrations in primary rat fibroblast-like synoviocytes. Taurochenodeoxycholic acid significantly induced the expression of glucocorticoid receptor (P<0.05) and phospholipase C (P<0.05) and enhanced phospholipase C phosphorylation. Moreover, taurochenodeoxycholic acid significantly increased the levels of inositol trisphosphate (P<0.05) and intracellular free Ca2+ concentrations. Our results suggest that taurochenodeoxycholic acid activates the phospholipase C-inositol trisphosphate-Ca2+ signaling pathway by increasing glucocorticoid receptor expression. These findings provide a theoretical foundation for future studies on the molecular mechanisms underlying taurochenodeoxycholic acid-based treatment of adjuvant arthritis. In conclusion, taurochenodeoxycholic acid exerted anti-inflammatory and immunomodulatory effects by enhancing glucocorticoid receptor expression via non-genomic signalling.

Glucocorticoid Receptor (GR) Activation Is Associated with Increased cAMP/PKA Signaling in Castration-Resistant Prostate Cancer.

In castration-resistant prostate cancer (CRPC), increased glucocorticoid receptor (GR) expression and ensuing transcriptional activity have been proposed as an oncogenic "bypass" mechanism in response to androgen receptor (AR) signaling inhibition (ARSi). Here, we report that GR transcriptional activity acquired following ARSi is associated with the upregulation of cyclic adenosine monophosphate (cAMP)-associated gene expression pathways in both model systems and metastatic prostate cancer patient samples. In the context of ARSi, the expression of GR-mediated genes encoding cAMP signaling pathway-associated proteins can be inhibited by treatment with selective GR modulators (SGRMs). For example, in the context of ARSi, we found that GR activation resulted in upregulation of protein kinase inhibitor beta (PKIB) mRNA and protein levels, leading to nuclear accumulation of the cAMP-dependent protein kinase A catalytic subunit (PKA-c). Increased PKA-c, in turn, is associated with increased cAMP response element-binding protein phosphorylation and activity. Furthermore, enzalutamide and SGRM combination therapy in mice bearing CRPC xenografts delayed CRPC progression compared with enzalutamide therapy alone, and reduced tumor PKIB mRNA expression. Supporting the clinical importance of GR/PKA signaling activation in CRPC, we found a significant enrichment of both cAMP pathway signaling-associated gene expression and high NR3C1 (GR) activity in patient-derived xenograft models and metastatic human CRPC samples. These findings suggest a novel mechanism linking CRPC-induced GR transcriptional activity with increased cAMP signaling in AR-antagonized CRPC. Furthermore, our findings suggest that GR-specific modulation in addition to AR antagonism may delay GR+ CRPC time to recurrence, at least in part, by inhibiting tumor cAMP/PKA pathways.

Cadmium exposure-induced rat testicular dysfunction and its mechanism of chronic stress

Cadmium is a common environmental pollutant in daily life, the toxic mechanisms of chronic cadmium exposure on the testes have not been fully elucidated. This study aimed to explore the effects of cadmium exposure on male reproductive health and its mechanism. The results showed that cadmium exposure led widened interstitial spaces, abnormal seminiferous tubule morphology, and decreased Leydig cell numbers. Moreover, sperm quality was significantly reduced, along with a decrease in fertility rate. And cadmium exposure could activate the hypothalamic-pituitary-adrenal (HPA) axis, elevate blood glucocorticoid levels, subsequently increase glucocorticoid receptor (GR) expression and activation in testicular Leydig cells.Then GR act on the glucocorticoid receptor element (GRE) in the DNA methyltransferase 3 A (DNMT3A) promoter region and upregulate DNMT3A expression. Consequently, this led to an increase in DNA methylation levels in the angiotensin II receptor 2 (AT2R) promoter region, resulting in reduced AT2R expression and inhibiting testicular steroidogenesis. This study systematically elucidated that cadmium exposure could lead to testicular steroidogenesis suppression and decreased fertility through the GR/DNMT3A/AT2R signaling pathway. This research further provides theoretical and experimental evidence for confirming the threat of cadmium exposure to human reproduction, and contributes to the guidance and protection of male reproductive health.

Astragalus polysaccharide liposome nanoparticles mediate fatty acid translocase (FAT)/CD36 to improve fatty acid metabolism and regulate glucocorticoid receptor levels in diabetic cardiomyopathy

Abnormal myocardial metabolism is the leading cause of diabetic cardiomyopathy (DCM). Astragalus polysaccharide (APS) combination with liposome nanoparticles (APS-nano) exhibits greater efficacy. Therefore, this study assessed regulatory effect of APS-nano on fatty acid translocase (FAT)/CD36. Fifty SD rats were assigned into control group, model group, APS group, APS-nano group, and FAT/CD36 inhibitor group (n =10, each group), followed by analysis of FAT/CD36 mRNA, protein levels, and glucocorticoid receptor expression. APS-nano group rats had highest level of insulin among all groups and lowest blood sugar. The content of Total cholesterol (TC), triglyceride (TG) and Free Fatty Acid (FFA) in APS-nano group was lower than APS and model groups (P = 0.000), with higher TC and FFA than control group (P <0.001), while insulin, blood sugar, TC, TG and FFA in the APS group were lower than model group (P = 0.000). FAT/CD36 mRNA in the model, APS, and APS-nano groups decreased to varying degrees (P <0.01). Administration of APS-nano greatly increased glucocorticoid receptor (P <0.01). APS-nano can regulate FAT/CD36 expression and improve fatty acid metabolism, thereby lowering myocardial tissue metabolism and inhibiting glucocorticoid receptor levels.

Acute restraint stress rapidly impacts reproductive neuroendocrinology and downstream gonad function in big brown bats (Eptesicus fuscus).

Animals face unpredictable challenges that require rapid, facultative physiological reactions to support survival but may compromise reproduction. Bats have a long-standing reputation for being highly sensitive to stressors, with sensitivity and resilience varying both within and among species, yet little is known about how stress affects the signaling that regulates reproductive physiology. Here, we provide the first description of the molecular response of the hypothalamic-pituitary-gonadal (HPG) axis of male big brown bats (Eptesicus fuscus) in response to short-term stress using a standardized restraint manipulation. This acute stressor was sufficient to upregulate plasma corticosterone and resulted in a rapid decrease in circulating testosterone. While we did not find differences in the mRNA expression of key steroidogenic enzymes (StAR, aromatase, 5-alpha reductase), seminiferous tubule diameter was reduced in stressed bats coupled with a 5-fold increase in glucocorticoid receptor (GR) mRNA expression in the testes. These changes, in part, may be mediated by RFamide-related peptide (RFRP) because fewer immunoreactive cell bodies were detected in the brains of stressed bats compared with controls - suggesting a possible increase in secretion - and increased RFRP expression locally in the gonads. The rapid sensitivity of the bat testes to stress may be connected to deleterious impacts on tissue health and function as supported by significant transcriptional upregulation of key pro-apoptotic signaling molecules (Bax, cytochrome c). Experiments like this broadly contribute to our understanding of the stronger ecological predictions regarding physiological responses of bats within the context of stress, which may impact decisions surrounding animal handling and conservation approaches.

Abstract 3082: Altered levels of corticosteroid-binding globulin: SerpinA6 and progression of prostate cancer

Abstract SerpinA6 is a main transport protein for cortisol binding, which helps in cortisol tissue delivery particularly at inflammatory sites. Cortisol plays a vital role in adaptation to stress, modulating fuel metabolism, and inflammation. SerpinA6 releases cortisol specifically at inflammatory sites upon cleavage by human neutrophil elastase between residues 344 and 345. Castration induce inflammation in the prostate increases glucocorticoids (GCs) level and elevates pro-inflammatory cytokine IL-6 levels. European and Asian populations represented association between single nucleotide polymorphisms (SNPs) in CYP17A1 and SERPINA6/A1 and circulating glucocorticoid concentrations. We propose increasing IL-6 levels after castration alters SerpinA6 levels in prostate may results in prostate cancer disease progression. Deficient SerpinA6 may not be sufficient to keep steroids inactive, due to the increasing GCs. Our data suggests IL-6 treatment of androgen independent prostate cancer (PC-3) cells decreases SerpinA6 level and conversely increases glucocorticoid receptor (GR) expression in a dose (1-10ng/ml) and time (30-180 minutes) dependent fashion. Moreover, IL-6 dose dependent treatment in PC-3 cells decreases FOXO3a expression, a major apoptotic protein dysregulated in prostate cancer. Next, we determine the role of SerpinA6 (30µg/ml) and IL-6 (5ng/ml) independently and in combination to PC-3 cells. We observed IL-6 and SerpinA6 co-treatment to PC-3 cells (charcoal stripped FBS media) for 6 hours reduced Neutrophil elastase levels significantly. Silencing IL-6 in PC-3 cells increased SerpinA6 expression. Moreover, silencing SerpinA6 in metastatic variant of PC-3 cells increased phospho-Akt-(ser-473), glucocorticoid receptor and increased apoptotic protein FOXO3a expressions. Using dexamethasone (15µM), which is known to suppress PC-3 cell migration, we found increased expression of SerpinA6. Conversely, Mifepristone (15µM), which inhibits PC-3 cell growth, deceases SerpinA6 expression after 24 hours of treatment. In humans the normal range of circulatory SerpinA6 level are 19-45µg/ml. We treated normal prostate epithelial cells (RWPE1) and prostate cancer (PC-3) cells with human recombinant protein 18 and 36µg/ml of doses for 24 hours; RWPE1 cells represented a SerpinA6 dose dependent increase in cellular viability, whereas PC-3 cells demonstrated no change in the viability after a dose response treatment with SerpinA6 for 24 hours. In-vivo data represented altered SerpinA6 levels in castrated TRansgenic Adenocarcinoma Mouse Prostate model after dexamethasone (GR agonist) and Mifepristone (GR antagonist) treatment. We suggest decreasing levels of SerpinA6 in prostate cancer patients may have potential role in disease progression. We need to have an effective agent, to prevent maintain SerpinA6 level to inhibit the progression of prostate cancer. Citation Format: Mohammed Al-Toubat, Jatinder Kumar, Shiva Gautam, Kethandapatti Balaji, Sanjeev Shukla. Altered levels of corticosteroid-binding globulin: SerpinA6 and progression of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3082.

Estrogen ameliorates sepsis-induced vascular hyporeactivity in thoracic aorta of female rats via permissive effect of GRα expression

ObjectiveEstrogen is correlated to the lower mortality and disease severity of female than that of male, which indicates the potential therapeutic role of estrogen supplement therapy in sepsis. The structure of Daidzein is similar to that of 17β estradiol (E2), an estrogen in human body, causing the exogenous Daidzein can interact with estrogen receptor as well as E2 in the body. We aim to explore the therapeutic role of estrogen in sepsis-induced vascular dysfunction. Also, we wonder if estrogen regulates blood pressure via glucocorticoid-mediated vascular reactivity. MethodsFemale SD rats received ovariectomy (OVX) to induce estrogen deficiency. After 12 weeks of administration, cecal ligation and puncture (CLP) was used to establish the in vivo model of sepsis. Lipopolysaccharide (LPS) was used to construct the in vitro model of sepsis in vascular smooth muscle cells (VSMCs). E2 and Daidzein were used for estrogen supplement therapy. ResultsE2 and Daidzein significantly inhibited inflammation infiltration and histopathological injury in thoracic aorta in the rat model with CLP. E2 and Daidzein improved carotid pressure and vascular hyporeactivity in sepsis rats with OVX. Importantly, E2 and Daidzein promoted glucocorticoid permissive action and increased glucocorticoid receptor α (GRα) expression in thoracic aorta smooth muscle cells. E2 and Daidzein upregulated GRα, and inhibits cytokine production, proliferative phenotype and cell migration in LPS-induced VSMCs. ConclusionEstrogen improved vascular hyporeactivity in thoracic aorta induced by sepsis via permissive effect of GRα expression.

Synergistic antidepressant-like effect of n-3 polyunsaturated fatty acids and probiotics through the brain-gut axis in rats exposed to chronic mild stress

N-3 polyunsaturated fatty acids (PUFA) and probiotics have antidepressant-like effects, but the underlying mechanisms are unclear. We hypothesized that n-3 PUFA combined with live and dead probiotics synergistically improves depression by modulating the hypothalamic-pituitary-adrenal (HPA) axis and serotonergic pathways through the brain-gut axis. Rats were randomly divided into seven groups (n = 8/group): nonchronic mild stress (CMS) with n-6 PUFA, CMS with n-3 PUFA, n-6 PUFA, live probiotics, dead probiotics, n-3 PUFA, and live probiotics, and n-3 PUFA and dead probiotics. Diets of n-6 and n-3 PUFA and oral supplementation of live and dead probiotics were provided for 12 weeks, and CMS was performed for the last 5 weeks. N-3 PUFA and probiotics improved depressive behaviors and modulated the brain and gut HPA axis by synergistically increasing glucocorticoid receptor expression and decreasing corticotropin-releasing factor expression and blood levels of adrenocorticotropic hormone and corticosterone. N-3 PUFA and probiotics upregulated the brain serotonergic pathway through serotonin levels and expression of brain-derived neurotrophic factor, phosphorylated cAMP response binding protein, and 5-hydroxytryptamine 1A receptor while downregulating the gut serotonergic pathway. Furthermore, n-3 PUFA and probiotics increased the abundance of Ruminococcaceae, brain and gut short chain fatty acid levels, and occludin expression while decreasing the expression of tumor necrosis factor-α, interleukin-1β, and prostaglandin E2 and blood lipopolysaccharides levels. There was no significant difference between the live and dead probiotics. In conclusion, n-3 PUFA and probiotics had synergistic antidepressant-like effects on the HPA axis and serotonergic pathways of the brain and gut through the brain-gut axis.

Chronic stress induced loudness hyperacusis, sound avoidance and auditory cortex hyperactivity

Hyperacusis, a debilitating loudness intolerance disorder, has been linked to chronic stress and adrenal insufficiency. To investigate the role of chronic stress, rats were chronically treated with corticosterone (CORT) stress hormone. Chronic CORT produced behavioral evidence of loudness hyperacusis, sound avoidance hyperacusis, and abnormal temporal integration of loudness. CORT treatment did not disrupt cochlear or brainstem function as reflected by normal distortion product otoacoustic emissions, compound action potentials, acoustic startle reflexex, and auditory brainstem responses. In contrast, the evoked response from the auditory cortex was enhanced up to three fold after CORT treatment. This hyperactivity was associated with a significant increase in glucocorticoid receptors in auditory cortex layers II/III and VI. Basal serum CORT levels remained normal after chronic CORT stress whereas reactive serum CORT levels evoked by acute restraint stress were blunted (reduced) after chronic CORT stress; similar changes were observed after chronic, intense noise stress. Taken together, our results show for the first time that chronic stress can induce hyperacusis and sound avoidance. A model is proposed in which chronic stress creates a subclinical state of adrenal insufficiency that establishes the necessary conditions for inducing hyperacusis.

Oncogenic deubiquitination controls tyrosine kinase signaling and therapy response in acute lymphoblastic leukemia.

Dysregulation of kinase signaling pathways favors tumor cell survival and therapy resistance in cancer. Here, we reveal a posttranslational regulation of kinase signaling and nuclear receptor activity via deubiquitination in T cell acute lymphoblastic leukemia (T-ALL). We observed that the ubiquitin-specific protease 11 (USP11) is highly expressed and associates with poor prognosis in T-ALL. USP11 ablation inhibits leukemia progression in vivo, sparing normal hematopoiesis. USP11 forms a complex with USP7 to deubiquitinate the oncogenic lymphocyte cell-specific protein-tyrosine kinase (LCK) and enhance its activity. Impairment of LCK activity leads to increased glucocorticoid receptor (GR) expression and glucocorticoids sensitivity. Genetic knockout of USP7 improved the antileukemic efficacy of glucocorticoids in vivo. The transcriptional activation of GR target genes is orchestrated by the deubiquitinase activity and mediated via an increase in enhancer-promoter interaction intensity. Our data unveil how dysregulated deubiquitination controls leukemia survival and drug resistance, suggesting previously unidentified therapeutic combinations toward targeting leukemia.

Frequently used antiemetic agent dexamethasone enhances the metastatic behaviour of select breast cancer cells.

Glucocorticoids, such as dexamethasone (Dex), are used to prevent common side effects induced by chemotherapy and are heavily prescribed for solid cancers such as breast cancer. There is substantial pre-clinical data to support that Dex activation of the glucocorticoid receptor overrides chemotherapy-induced apoptosis in breast cancer cell lines. These findings are compounded by a recent study demonstrating that increased glucocorticoid receptor activation by endogenous stress hormones increased breast cancer heterogeneity and metastasis. Our study is the first to use both in vitro and in vivo models to thoroughly compare the Dex response on the migration of multiple estrogen receptor negative (ER-) and ER+ cancer cell lines. ER+ and ER- breast cancer cell lines were studied to compare their endogenous glucocorticoid activity as well as their metastatic ability in response to Dex treatment. We show that in the ER- breast cancer lines, Dex increases cell numbers, invasiveness, and migration, while decreasing apoptotic ability. Furthermore, we show that following Dex treatment, ER- breast cancer lines migrate further in an in vivo zebrafish model in comparison to ER+ cell lines. The use of ROR1 antibody to block WNT signaling diminished the metastatic properties of ER- cells, however recombinant WNT5A alone was not sufficient to induce migration. Taken together, we demonstrate that Dex treatment exacerbates the metastatic potential of ER- but not ER+ cells. These findings add to the growing body of data stressing the potential adverse role of endogenous and synthetic glucocorticoids in breast cancer biology.

Social-single prolonged stress as an ether-free candidate animal model of post-traumatic stress disorder: Female and male outcomings

BackgroundSingle Prolonged Stress (SPS) is a valid animal model that reflects the core of post-traumatic stress disorder (PTSD) phenotypes. Although SPS has been a pivotal tool, it can bring ethics approval difficulties due to the use of ether as a stressor. The present study evaluated if changing a chemical (ether) with a social stressor resembles the PTSD hallmark symptoms. MethodsFemale and male young adult rats were distributed in Sham and Social-SPS groups. Rats in Social-SPS groups were subjected to stress, whereas those in Sham groups remained undisturbed. One set of animals performed the behavioral tests, elevated plus-maze (EPM) and Y-maze. Plasma corticosterone levels and cortical and hippocampal molecular protein contents were analyzed. Another set of animals performed the dexamethasone suppression test. ResultsA significant decrease in the percentage of time spent and the number of entries in open arms and an increase in anxiety index in the EPM were observed in rats of the social-SPS groups. In the Social-SPS groups, rats reduced the spontaneous alternations in Y-maze. The Social-SPS exposure enhanced the HPA-axis feedback and increased glucocorticoid receptor contents in the cerebral cortex and hippocampus of rats. A decrease in the content of synaptic integrity-related proteins, synaptophysin, and PSD-95, were found in the cortex and hippocampus of rats subjected to social-SPS. There were no statistical differences between males and females in any parameter analyzed. LimitationsThe absence of a task to recap criterion E ‘arousal’ and predictive validity experiments. ConclusionsThis study reveals that social-SPS recapitulated the main clusters required for a candidate animal model of PTSD.

Abstract 3983: Dysregulated SerpinA6 levels and progression of prostate cancer

Abstract SerpinA6 is a major cortisol binding transport protein, which helps in cortisol tissue delivery particularly at inflammatory sites. Moreover, SerpinA6 has been reported to participate in stress response by releasing cortisol specifically at inflammatory sites upon cleavage by human neutrophil elastase between residues 344 and 345. In castrate resistant prostate cancer (CRPC) patients, reports suggest castration induces inflammation in the prostate, which increases glucocorticoids (GCs) levels and elevates pro-inflammatory cytokine IL-6 levels. We propose declining SerpinA6 levels in the prostate may play a role in prostate cancer disease progression. This could be due to increasing IL-6 levels after castration, which may inhibit or degrade SerpinA6. Deficient SerpinA6 may not be sufficient to keep steroids inactive, due to the increasing GCs. Our data suggests IL-6 treatment of androgen independent prostate cancer (PC-3) cells decreases SerpinA6 level and conversely increases glucocorticoid receptor (GR) expression in a dose (1-10ng/ml) and time (30-180 minutes) dependent fashion. Moreover, IL-6 dose dependent treatment in PC-3 cells decreases FOXO3a expression, a major apoptotic protein dysregulated in prostate cancer. Next, we determine the role of SerpinA6 (30µg/ml) and IL-6(5ng/ml) independently and in combination to PC-3 cells. We observed IL-6 and SerpinA6 co-treatment to PC-3 cells (charcoal stripped FBS media) for 6 hours reduced Neutrophil elastase levels significantly. Additionally we observed increased FOXO3a and SerpinA6 expression, whereas decreased GR and HNF3α levels. However, silencing IL-6 in PC-3 cells increased SerpinA6 expression. To further support our findings, silencing SerpinA6 in metastatic variant of PC-3 cells increased phosphor-Akt-(ser-473), glucocorticoid receptor and increased apoptotic protein FOXO3a expressions. Using dexamethasone (15µM), which is known to suppress PC-3 cell migration, we found increased expression of SerpinA6. Conversely, Mifepristone (15µM), which inhibits PC-3 cell growth, deceases SerpinA6 expression after 24 hours of treatment. In humans the normal range of circulatory SerpinA6 level are 19-45ug/ml. We treated normal prostate epithelial cells (RWPE1) and prostate cancer (PC-3) cells with human recombinant protein 18 and 36ug/ml of doses for 24 hours; RWPE1 cells represented a SerpinA6 dose dependent increase in cellular viability, whereas PC-3 cells demonstrated no change in the viability after a dose response treatment with SerpinA6 for 24 hours. These findings suggest the SerpinA6 context dependent role. We suggest that decreasing levels of SerpinA6 and FOXO3a expressions in the prostate cancer patients may have potential role in disease progression. Moreover, we need to have an effective agent, which could prevent the decreasing levels of SerpinA6 and FOXO3a in prostate to inhibit the progression of prostate cancer. Citation Format: Carlos Riveros, Victor Chalfant, Jatinder Kumar, Sanjeev Shukla. Dysregulated SerpinA6 levels and progression of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3983.

Dysfunction of Inflammatory Pathways and Their Relationship With Psychological Factors in Adult Female Patients With Eating Disorders.

The attempts to clarify the origin of eating disorders (ED) have not been completely successful and their etiopathogenesis remains unknown. Current research shows an activation of the immune response in neuropsychiatric diseases, including ED. We aimed to investigate immune response parameters in patients with ED and to identify psychological factors influencing the inflammatory response. The relationship between inflammation markers and impulsivity and affective symptomatology was explored as well. Thirty-four adult female patients with current diagnosis of ED, none of them under psychopharmacological treatment (excluding benzodiazepines), were included in this study. Patients were compared with a healthy control group of fifteen adult females. The levels of inflammatory markers and indicators of oxidative/nitrosative stress were evaluated in plasma and/or in peripheral blood mononuclear cells (PBMCs). Subjects were assessed by means of different ED evaluation tools. Additionally, the Barratt Impulsiveness Scale, the Montgomery-Asberg Depression Rating Scale and the Hamilton Anxiety Rating Scale were also employed. Patients with ED shown increased plasma levels of the pro-inflammatory nuclear factor kappa B (NFκB) and the cytokine tumor necrosis factor-alpha (TNF-α), among other factors and an increment in the oxidative/nitrosative stress as well as increased glucocorticoid receptor (GR) expression levels in their PBMCs. Moreover, the inflammatory prostaglandin E2 (PGE2) correlated with impulsiveness and the anti-inflammatory prostaglandin J2 (15d-PGJ2) correlated with depressive symptomatology. Our results point towards a relationship between the immune response and impulsiveness and between the immune response and depressive symptomatology in female adult patients with ED.

SUMOylation inhibition enhances dexamethasone sensitivity in multiple myeloma

BackgroundMultiple myeloma (MM) is an incurable plasma cell malignancy. Although Dexamethasone (Dex) is the most widely used therapeutic drug in MM treatment, patients develop Dex resistance leading to progressive disease, demanding an urgent need to investigate the mechanisms driving Dex resistance and develop new reagents to address this problem. We propose SUMOylation as a potential mechanism regulating Dex resistance and SUMOylation inhibition can enhance Dex sensitivity in MM.MethodsUsing MM cell lines and primary MM samples from relapsing MM patients, we evaluated the effects of knockdown of SUMO E1 (SAE2) or using TAK-981, a novel and specific SUMO E1 inhibitor, on Dex sensitivity. Xenograft mouse models were generated to determine the in vivo anti-MM effects of TAK-981 as a single agent and in combination with Dex. miRNA-seq, RNA-seq and GSEA analysis were utilized for evaluating key factors mediating Dex resistance. Chromatin immunoprecipitation (ChIP) assay was performed to determine the binding occupancy of c-Myc on promoter region of miRs.ResultsWe observed a significant negative correlation between SUMO E1 (SAE2) expression and Dex sensitivity in primary MM samples. Knockdown of SAE2 or using TAK-981 significantly enhances myeloma sensitivity to Dex in MM cell lines. Moreover, the enhanced anti-MM activity by TAK-981 and Dex combination has been validated using primary relapsing MM patient samples and xenograft mouse models. SUMOylation inhibition increased glucocorticoid receptor (GR) expression via downregulation miR-130b. Using RNA and microRNA sequencing, we identified miR-551b and miR-25 as important miRs mediating Dex resistance in MM. Overexpression of miR-551b and miR-25 caused resistance to Dex, however, knockdown of miR-551b and miR-25 significantly enhanced Dex sensitivity in MM. SAE2 knockdown or TAK-981 treatment downregulated the expression of miR-551b and miR-25, leading to induction of miR targets ZFP36, ULK1 and p27, resulting in apoptosis and autophagy. We demonstrated c-Myc as a major transcriptional activator of miR-130b, miR-551b and miR-25 and SUMOylation inhibition downregulates these miRs level by decreasing c-Myc level.ConclusionOur study proves SUMOylation plays a crucial role in Dex resistance in MM and SUMOylation inhibition appears to be an attractive strategy to advance to the clinic for MM patients.