Glucocorticoid receptor modulators

Neuropsychiatric Adverse Effects of Synthetic Glucocorticoids: A Systematic Review and Meta-Analysis

CONTEXT

Synthetic glucocorticoids are widely used to treat patients with a broad range of diseases. While efficacious, glucocorticoids can be accompanied by neuropsychiatric adverse effects.

OBJECTIVE

This systematic review and meta-analysis assesses and quantifies the proportion of different neuropsychiatric adverse effects in patients using synthetic glucocorticoids.

METHODS

Six electronic databases were searched to identify potentially relevant studies. Randomized controlled trials, cohort studies, and cross-sectional studies assessing psychiatric side effects of glucocorticoids measured with validated questionnaires were eligible. Risk of bias was assessed with RoB 2, ROBINS-I, and AXIS appraisal tool. For proportions of neuropsychiatric outcomes, we pooled proportions, and when possible, differences in questionnaire scores between glucocorticoid users and nonusers were expressed as standardized mean differences (SMD). Data were pooled in a random-effects logistic regression model.

RESULTS

We included 49 studies with heterogeneity in study populations, type, dose, and duration of glucocorticoids. For glucocorticoid users, meta-analysis showed a proportion of 22% for depression (95% CI, 14%-33%), 11% for mania (2%-46%), 8% for anxiety (2%-25%), 16% for delirium (6%-36%), and 52% for behavioral changes (42%-61%). Questionnaire scores for depression (SMD of 0.80 [95% CI 0.35-1.26]), and mania (0.78 [0.14-1.42]) were higher than in controls, indicating more depressive and manic symptoms following glucocorticoid use.

CONCLUSION

The heterogeneity of glucocorticoid use is reflected in the available studies. Despite this heterogeneity, the proportion of neuropsychiatric adverse effects in glucocorticoid users is high. The most substantial associations with glucocorticoid use were found for depression and mania. Upon starting glucocorticoid treatment, awareness of possible psychiatric side effects is essential. More structured studies on incidence and potential pathways of neuropsychiatric side effects of prescribed glucocorticoids are clearly needed.

Glucocorticoid receptor-mediated oncogenic activity is dependent on breast cancer subtype

Breast cancer incidence has been steadily rising and is the leading cause of cancer death in women due to its high metastatic potential. Individual breast cancer subtypes are classified by both cell type of origin and receptor expression, namely estrogen, progesterone and human epidermal growth factor receptors (ER, PR and HER2). Recently, the importance and context-dependent role of glucocorticoid receptor (GR) expression in the natural history and prognosis of breast cancer subtypes have been uncovered. In ER-positive breast cancer, GR expression is associated with a better prognosis as a result of ER-GR crosstalk. GR appears to modulate ER-mediated gene expression resulting in decreased tumor cell proliferation and a more indolent cancer phenotype. In ER-negative breast cancer, including GR-positive triple-negative breast cancer (TNBC), GR expression enhances migration, chemotherapy resistance and cell survival. In invasive lobular carcinoma, GR function is relatively understudied, and more work is required to determine whether lobular subtypes behave similarly to their invasive ductal carcinoma counterparts. Importantly, understanding GR signaling in individual breast cancer subtypes has potential clinical implications because of the recent development of highly selective GR non-steroidal ligands, which represent a therapeutic approach for modulating GR activity systemically.

Bispecific antibody drug conjugates: Making 1+1>2

Bispecific antibody‒drug conjugates (BsADCs) represent an innovative therapeutic category amalgamating the merits of antibody‒drug conjugates (ADCs) and bispecific antibodies (BsAbs). Positioned as the next-generation ADC approach, BsADCs hold promise for ameliorating extant clinical challenges associated with ADCs, particularly pertaining to issues such as poor internalization, off-target toxicity, and drug resistance. Presently, ten BsADCs are undergoing clinical trials, and initial findings underscore the imperative for ongoing refinement. This review initially delves into specific design considerations for BsADCs, encompassing target selection, antibody formats, and the linker-payload complex. Subsequent sections delineate the extant progress and challenges encountered by BsADCs, illustrated through pertinent case studies. The amalgamation of BsAbs with ADCs offers a prospective solution to prevailing clinical limitations of ADCs. Nevertheless, the symbiotic interplay among BsAb, linker, and payload necessitates further optimizations and coordination beyond a simplistic "1 + 1" to effectively surmount the extant challenges facing the BsADC domain.

Novel agents to treat adrenal insufficiency: findings of preclinical and early clinical trials

INTRODUCTION

Adrenal insufficiency currently affects over 300/million population, with higher morbidity and mortality compared to the general population. Current glucocorticoid replacement therapy is limited by a lack of reliable biomarkers to guide dosing, inter-patient variation in metabolism and narrow therapeutic window. Increased morbidity and mortality may relate to unappreciated under- or over-exposure to glucocorticoids and impaired cortisol circadian rhythm. New agents are required to emulate physiological cortisol secretion and individualize glucocorticoid dosing.

AREAS COVERED

History of glucocorticoid therapy, current limitations, and novel chronotherapeutic glucocorticoid delivery mechanisms. Literature search incorporated searches of PubMed and Embase utilizing terms such as adrenal insufficiency, Chronocort, Plenadren, continuous subcutaneous hydrocortisone infusion (CHSI), and glucocorticoid receptor modulator.

EXPERT OPINION

Glucocorticoid chronotherapy is necessary to optimize glucocorticoid exposure and minimize complications. Current oral chronotherapeutics provide improved dosing functionality, but are modifiable only in specific increments and cannot accommodate ultradian cortisol variation. Current data show improvement in quality of life but not morbidity or mortality outcomes. CHSI has significant potential for individualized glucocorticoid dosing, but would require a suitable biomarker of glucocorticoid adequacy to be implementable. Avenues for future research include determining a glucocorticoid sufficiency biomarker, development of interstitial or systemic cortisol monitoring, or development of glucocorticoid receptor modulators.

Stress-induced Neuroinflammation of the Spinal Cord is Restrained by Cort113176 (Dazucorilant), A Specific Glucocorticoid Receptor Modulator

Glucocorticoids exert antiinflammatory, antiproliferative and immunosupressive effects. Paradoxically they may also enhance inflammation particularly in the nervous system, as shown in Cushing´ syndrome and neurodegenerative disorders of humans and models of human diseases. ."The Wobbler mouse model of amyotrophic lateral sclerosis shows hypercorticoidism and neuroinflammation which subsided by treatment with the glucocorticoid receptor (GR) modulator Dazucorilant (CORT113176). This effect suggests that GR mediates the chronic glucocorticoid unwanted effects. We now tested this hypothesis using a chronic stress model resembling the condition of the Wobbler mouse Male NFR/NFR mice remained as controls or were subjected to a restraining / rotation stress protocol for 3 weeks, with a group of stressed mice receiving CORT113176 also for 3 weeks. We determined the mRNAS or reactive protein for the proinflamatory factors HMGB1, TLR4, NFkB, TNFα, markers of astrogliosis (GFAP, SOX9 and acquaporin 4), of microgliosis (Iba, CD11b, P2RY12 purinergic receptor) as well as serum IL1β and corticosterone. We showed that chronic stress produced high levels of serum corticosterone and IL1β, decreased body and spleen weight, produced microgliosis and astrogliosis and increased proinflammatory mediators. In stressed mice, modulation of the GR with CORT113176 reduced Iba + microgliosis, CD11b and P2RY12 mRNAs, immunoreactive HMGB1 + cells, GFAP + astrogliosis, SOX9 and acquaporin expression and TLR4 and NFkB mRNAs vs. stress-only mice. The effects of CORT113176 indicate that glucocorticoids are probably involved in neuroinflammation. Thus, modulation of the GR would become useful to dampen the inflammatory component of neurodegenerative disorders.

Ginsenoside compound K exerts anti-inflammatory effects through transcriptional activation and transcriptional inhibition of glucocorticoid receptor in rheumatoid arthritis fibroblast-like synoviocytes

Ginsenoside compound K (GCK) has anti-inflammatory and immunoregulatory effects, and glucocorticoid receptor (GR) has been considered as its potential target. But the mechanism by which GCK exerts its anti-inflammatory effects after GR activation remains unclear. In this study, molecular docking, isothermal titration calorimetry, siRNA of GR and GRA458T mutation were used to confirm the anti-inflammatory mechanism of GCK targeting GR in fibroblast-like synoviocytes (FLS). The results showed that the key binding sites of GR and GCK were identified as ASN564, MET560 and ASN638, with binding levels at the μm level. In addition, the inhibitory effect of GCK on the proliferation of FLS and the secretion of inflammatory cytokines (IL-6, IL-8, and IL-1β) were mediated by transcriptional activation of GR, but on the migration, invasion, and TNF-α secretion of FLS were mediated by transcriptional inhibition of GR. These actions exert anti-inflammatory effects through indirect and direct inhibition of NF-κB transcriptional activity, respectively. In conclusion, this study elucidates that GCK can directly bind to and activate GR. Furthermore, after activation, GR mediates the anti-inflammatory effects of GCK through two mechanisms: transcriptional activation and transcriptional inhibition.

Molecular pharmacology of mineralocorticoid receptor antagonists: The role of co-regulators

Mineralocorticoid receptor (MR) antagonists have shown remarkable benefits in the treatment of cardiovascular disease. However, their underutilization in clinical practice may be attributed to concerns regarding the risk of hyperkalemia. An ideal selective MR modulator would inhibit the detrimental effects of MR in non-epithelial cells of the cardiovascular system while sparing its physiological function in kidney epithelial cells, thereby reducing the risk of adverse events. To address this issue, a new generation of non-steroidal MR antagonists, including esaxereneone, balcinrenone, ocedurenone, and finerenone, has been developed with distinct molecular structures and pharmacology. They share a mechanism of action that is different from the previously developed steroidal MR antagonists, leading to altered co-regulator interaction, potentially involving conformational changes of the receptor. Interfering with MR co-regulator interaction or the co-regulator itself may enable selective targeting of downstream signaling cascades and - in the long term - lead to more personalized medicine. In this review article, we summarize what is currently known about the mechanisms of action of the different MR antagonists with a focus on MR co-factor interaction and what may be inferred from this for future developments.

Glucocorticoid feedback paradox: a homage to Mary Dallman

As the end product of the hypothalamus-pituitary-adrenal (HPA) axis, the glucocorticoid hormones cortisol and corticosterone coordinate circadian activities, stress-coping, and adaptation to change. For this purpose, the hormone promotes energy metabolism and controls defense reactions in the body and brain. This life-sustaining action exerted by glucocorticoids occurs in concert with the autonomic nervous and immune systems, transmitters, growth factors/cytokines, and neuropeptides. The current contribution will focus on the glucocorticoid feedback paradox in the HPA-axis: the phenomenon that stress responsivity remains resilient if preceded by stress-induced secretion of glucocorticoid hormone, but not if this hormone is previously administered. Furthermore, in animal studies, the mixed progesterone/glucocorticoid antagonist RU486 or mifepristone switches to an apparent partial agonist upon repeated administration. To address these enigmas several interesting phenomena are highlighted. These include the conditional nature of the excitation/inhibition balance in feedback regulation, the role of glucose as a determinant of stress responsivity, and the potential of glucocorticoids in resetting the stress response system. The analysis of the feedback paradox provides also a golden opportunity to review the progress in understanding the role of glucocorticoid hormone in resilience and vulnerability during stress, the science that was burned deeply in Mary Dallman's emotions.

Withaferin A: A potential selective glucocorticoid receptor modulator with anti-inflammatory effect

Glucocorticoids have been widely applied to various clinical treatment, however some serious side effects may occur during the treatment. It is widely known that glucocorticoids produce a marked effect through binding to glucocorticoid receptor (GR). As withaferin A can provide multiple health benefits, this work aims to confirm withaferin A as a potential selective GR modulator with anti-inflammatory effect. Fluorescence polarization assay confirmed that withaferin A could steadily bind to GR with an IC50 value of 203.80 ± 0.36 μM. Meanwhile, glucocorticoid receptor translocation of withaferin A was measured by nuclear fractionation assay. Dual luciferase reporter assay showed that withaferin A did not activate GR transcription. Furthermore, withaferin A decreased the GR-related protein expression with less side effects. The result of molecular docking showed that hydrogen-bonding and hydrophobic interactions contributed to the binding of withaferin A with GR. In addition, the GR-withaferin A complex maintained a stable binding throughout the dynamics simulation process. Enzyme-linked immunosorbent assay showed that withaferin A inhibited the production of cytokines, confirming its anti-inflammatory effect. These findings indicate that withaferin A is a potential selective GR modulator and this work may provide a research basis for developing dietary supplements and nutraceuticals against inflammation.

From Ligands to Behavioral Outcomes: Understanding the Role of Mineralocorticoid Receptors in Brain Function

Stress is a normal response to situational pressures or demands. Exposure to stress activates the hypothalamic-pituitary-adrenal (HPA) axis and leads to the release of corticosteroids, which act in the brain via two distinct receptors: mineralocorticoid receptors (MR) and glucocorticoid receptors (GR). Persistent HPA axis overactivation or dysregulation can disrupt an individual's homeostasis, thereby contributing to an increased risk for mental illness. On the other hand, successful coping with stressful events involves adaptive and cognitive processes in the brain that render individuals more resilient to similar stressors in the future. Here we review the role of the MR in these processes, starting with an overview of the physiological structure, ligand binding, and expression of MR, and further summarizing its role in the brain, its relevance to psychiatric disorders, and related rodent studies. Given the central role of MR in cognitive and emotional functioning, and its importance as a target for promoting resilience, future research should investigate how MR modulation can be used to alleviate disturbances in emotion and behavior, as well as cognitive impairment, in patients with stress-related psychiatric disorders.

Glucocorticoid Receptor and Ovarian Cancer: From Biology to Therapeutic Intervention

Ovarian cancer (OC) is the leading cause of death from gynecological malignancies worldwide. Fortunately, recent advances in OC biology and the discovery of novel therapeutic targets have led to the development of novel therapeutic agents that may improve the outcome of OC patients. The glucocorticoid receptor (GR) is a ligand-dependent transcriptional factor known for its role in body stress reactions, energy homeostasis and immune regulation. Notably, evidence suggests that GR may play a relevant role in tumor progression and may affect treatment response. In cell culture models, administration of low levels of glucocorticoids (GCs) suppresses OC growth and metastasis. Conversely, high GR expression has been associated with poor prognostic features and long-term outcomes in patients with OC. Moreover, both preclinical and clinical data have shown that GR activation impairs the effectiveness of chemotherapy by inducing the apoptotic pathways and cell differentiation. In this narrative review, we summarize data related to the function and role of GR in OC. To this aim, we reorganized the controversial and fragmented data regarding GR activity in OC and herein describe its potential use as a prognostic and predictive biomarker. Moreover, we explored the interplay between GR and BRCA expression and reviewed the latest therapeutic strategies such as non-selective GR antagonists and selective GR modulators to enhance chemotherapy sensitivity, and to finally provide new treatment options in OC patients.

Update on the Role of Glucocorticoid Signaling in Osteoblasts and Bone Marrow Adipocytes During Aging

PURPOSE OF REVIEW

Bone marrow adipose tissue (BMAT) in the skeleton likely plays a variety of physiological and pathophysiological roles that are not yet fully understood. In elucidating the complex relationship between bone and BMAT, glucocorticoids (GCs) are positioned to play a key role, as they have been implicated in the differentiation of bone marrow mesenchymal stem cells (BMSCs) between osteogenic and adipogenic lineages. The purpose of this review is to illuminate aspects of both endogenous and exogenous GC signaling, including the influence of GC receptors, in mechanisms of bone aging including relationships to BMAT.

RECENT FINDINGS

Harmful effects of GCs on bone mass involve several cellular pathways and events that can include BMSC differentiation bias toward adipogenesis and the influence of mature BMAT on bone remodeling through crosstalk. Interestingly, BMAT involvement remains poorly explored in GC-induced osteoporosis and warrants further investigation. This review provides an update on the current understanding of the role of glucocorticoids in the biology of osteoblasts and bone marrow adipocytes (BMAds).

Structural basis of glucocorticoid receptor signaling bias

Dissociation between the healthy and toxic effects of cortisol, a major stress-responding hormone has been a widely used strategy to develop anti-inflammatory glucocorticoids with fewer side effects. Such strategy falls short when treating brain disorders as timing and activity state within large-scale neuronal networks determine the physiological and behavioral specificity of cortisol response. Advances in structural molecular dynamics posit the bases for engineering glucocorticoids with precision bias for select downstream signaling pathways. Design of allosteric and/or cooperative control for the glucocorticoid receptor could help promote the beneficial and reduce the deleterious effects of cortisol on brain and behavior in disease conditions.

Mechanic Insight into the Distinct and Common Roles of Ovariectomy Versus Adrenalectomy on Adipose Tissue Remodeling in Female Mice

Dysfunctions of the ovaries and adrenal glands are both evidenced to cause aberrant adipose tissue (AT) remodeling and resultant metabolic disorders, but their distinct and common roles are poorly understood. In this study, through biochemical, histological and RNA-seq analyses, we comprehensively explored the mechanisms underpinning subcutaneous (SAT) and visceral adipose tissue (VAT) remodeling, in response to ovariectomy (OVX) versus adrenalectomy (ADX) in female mice. OVX promoted adipocyte differentiation and fat accumulation in both SAT and VAT, by potentiating the Pparg signaling, while ADX universally prevented the cell proliferation and extracellular matrix organization in both SAT and VAT, likely by inactivating the Nr3c1 signaling, thus causing lipoatrophy in females. ADX, but not OVX, exerted great effects on the intrinsic difference between SAT and VAT. Specifically, ADX reversed a large cluster of genes differentially expressed between SAT and VAT, by activating 12 key transcription factors, and thereby caused senescent cell accumulation, massive B cell infiltration and the development of selective inflammatory response in SAT. Commonly, both OVX and ADX enhance circadian rhythmicity in VAT, and impair cell proliferation, neurogenesis, tissue morphogenesis, as well as extracellular matrix organization in SAT, thus causing dysfunction of adipose tissues and concomitant metabolic disorders.

Central serous chorioretinopathy: Treatment

Central serous chorioretinopathy (CSC) is a pachychoroid spectrum disease characterized by serous detachment of the neurosensory retina with subretinal fluid in young and middle-aged adults. The pathogenesis of CSC is not yet fully understood. However, it is considered a multifactorial disease that is strongly associated with choroidal dysfunction or vascular engorgement. Although there is no consensus on the treatment of CSC, photodynamic therapy has been effectively used to manage serous retinal detachment (SRD) in CSC. Moreover, micropulse diode laser photocoagulation and focal laser treatment have also been used. Recently, oral medications, including mineralocorticoid receptor antagonists, have been proposed for the management of CSC. Multimodal imaging plays a significant role in the diagnosis and treatment of CSC. Optical coherence tomography angiography (OCTA) has the advantage of detecting vascular flow in the retina and choroid layer, allowing for a better understanding of the pathology, severity, prognosis, and chronicity of CSC. In addition, early detection of choroidal neovascularization in CSC is possible using OCTA. This review article aims to provide a comprehensive and updated understanding of CSC, focusing on treatment.

Stereoisomers of an Aryl Pyrazole Glucocorticoid Receptor Agonist Scaffold Elicit Differing Anti-inflammatory Responses

Glucocorticoids (GCs) are heavily prescribed to control inflammation in various human diseases; however, side effects associated with GCs are well documented and lead to serious metabolic and immunological complications with long-term use. The paradigm for GC function includes two well described modes of activity: dimer formation of the glucocorticoid receptor (GR) promotes transactivation, while monomeric interaction with co-regulators promotes transrepression. Previously, a set of aryl pyrazole-derived glucocorticoid receptor agonists (APGRAs) with potency rivaling current commercially available glucocorticoids were described. In this study, a further series of existing and novel stereopure APGRAs were thoroughly examined for biological activity and evaluated for structure-activity relationships (SARs). The si isomers with an upward OH moiety were ∼70% more active on average than the re isomers. Additionally, AP13 was found to elicit 79% transrepression of dexamethasone while eliciting less than half the transactivation response in 832/13 cells, a rat insulinoma cell line.

Association between use of systemic and inhaled glucocorticoids and changes in brain volume and white matter microstructure: a cross-sectional study using data from the UK Biobank

OBJECTIVE

To test the hypothesis that systemic and inhaled glucocorticoid use is associated with changes in grey matter volume (GMV) and white matter microstructure.

DESIGN

Cross-sectional study.

SETTING

UK Biobank, a prospective population-based cohort study of adults recruited in the UK between 2006 and 2010.

PARTICIPANTS

After exclusion based on neurological, psychiatric or endocrinological history, and use of psychotropic medication, 222 systemic glucocorticoid users, 557 inhaled glucocorticoid users and 24 106 controls with available T1 and diffusion MRI data were included.

MAIN OUTCOME MEASURES

Primary outcomes were differences in 22 volumetric and 14 diffusion imaging parameters between glucocorticoid users and controls, determined using linear regression analyses adjusted for potential confounders. Secondary outcomes included cognitive functioning (six tests) and emotional symptoms (four questions).

RESULTS

Both systemic and inhaled glucocorticoid use were associated with reduced white matter integrity (lower fractional anisotropy (FA) and higher mean diffusivity (MD)) compared with controls, with larger effect sizes in systemic users (FA: adjusted mean difference (AMD)=-3.7e-3, 95% CI=-6.4e-3 to 1.0e-3; MD: AMD=7.2e-6, 95% CI=3.2e-6 to 1.1e-5) than inhaled users (FA: AMD=-2.3e-3, 95% CI=-4.0e-3 to -5.7e-4; MD: AMD=2.7e-6, 95% CI=1.7e-7 to 5.2e-6). Systemic use was also associated with larger caudate GMV (AMD=178.7 mm³, 95% CI=82.2 to 275.0), while inhaled users had smaller amygdala GMV (AMD=-23.9 mm³, 95% CI=-41.5 to -6.2) than controls. As for secondary outcomes, systemic users performed worse on the symbol digit substitution task (AMD=-0.17 SD, 95% CI=-0.34 to -0.01), and reported more depressive symptoms (OR=1.76, 95% CI=1.25 to 2.43), disinterest (OR=1.84, 95% CI=1.29 to 2.56), tenseness/restlessness (OR=1.78, 95% CI=1.29 to 2.41), and tiredness/lethargy (OR=1.90, 95% CI=1.45 to 2.50) compared with controls. Inhaled users only reported more tiredness/lethargy (OR=1.35, 95% CI=1.14 to 1.60).

CONCLUSIONS

Both systemic and inhaled glucocorticoid use are associated with decreased white matter integrity and limited changes in GMV. This association may contribute to the neuropsychiatric side effects of glucocorticoid medication, especially with chronic use.

Comparison of mechanisms of angiostasis caused by the anti-inflammatory steroid 5α-tetrahydrocorticosterone versus conventional glucocorticoids

5α-Tetrahydrocorticosterone (5αTHB) is an effective topical anti-inflammatory agent in mouse, with less propensity to cause skin thinning and impede new blood vessel growth compared with corticosterone. Its anti-inflammatory effects were not prevented by RU38486, a glucocorticoid receptor antagonist, suggesting alternative mechanisms. The hypothesis that 5αTHB directly inhibits angiogenesis to a lesser extent than hydrocortisone was tested, focussing on glucocorticoid receptor mediated actions. New vessel growth from aortae from C57BL/6 male mice was monitored in culture, in the presence of 5αTHB, hydrocortisone (mixed glucocorticoid/mineralocorticoid receptor agonist) or the selective glucocorticoid receptor agonist dexamethasone. Transcript profiles were studied, as was the role of the glucocorticoid receptor, using the antagonist, RU38486. Ex vivo, 5αTHB suppressed vessel growth from aortic rings, but was less potent than hydrocortisone (EC50 2512 nM 5αTHB, versus 762 nM hydrocortisone). In contrast to conventional glucocorticoids, 5αTHB did not alter expression of genes related to extracellular matrix integrity or inflammatory signalling, but caused a small increase in Per1 transcript, and decreased transcript abundance of Pecam1 gene. RU38486 did not antagonise the residual effects of 5αTHB to suppress vessel growth or regulate gene expression, but modified effects of dexamethasone. 5αTHB did not alter expression of glucocorticoid-regulated genes Fkbp51 and Hsd11b1, unlike hydrocortisone and dexamethasone. In conclusion, compared with hydrocortisone, 5αTHB exhibits limited suppression of angiogenesis, at least directly in blood vessels and probably independent of the glucocorticoid receptor. Discriminating the mechanisms employed by 5αTHB may provide the basis for the development of novel safer anti-inflammatory drugs for topical use.

The Role of Conformational Dynamics and Allostery in the Control of Distinct Efficacies of Agonists to the Glucocorticoid Receptor

Glucocorticoid receptor (GR) regulates various cellular functions. Given its broad influence on metabolic activities, it has been the target of drug discovery for decades. However, how drugs induce conformational changes in GR has remained elusive. Herein, we used five GR agonists (dex, AZ938, pred, cor, and dibC) with different efficacies to investigate which aspect of the ligand induced the differences in efficacy. We performed molecular dynamics simulations on the five systems (dex-, AZ938-, pred-, cor-, and dibC-bound systems) and observed a distinct discrepancy in the conformation of the cofactor TIF2. Moreover, we discovered ligand-induced differences regarding the level of conformational changes posed by the binding of cofactor TIF2 and identified a pair of essential residues D590 and T39. We further found a positive correlation between the efficacies of ligands and the interaction of the two binding pockets’ domains, where D590 and T739 were involved, implying their significance in the participation of allosteric communication. Using community network analysis, two essential communities containing D590 and T739 were identified with their connectivity correlating to the efficacy of ligands. The potential communication pathways between these two residues were revealed. These results revealed the underlying mechanism of allosteric communication between the ligand-binding and cofactor-binding pockets and identified a pair of important residues in the allosteric communication pathway, which can serve as a guide for future drug discovery.

Brain mineralocorticoid and glucocorticoid receptor balance in neuroendocrine regulation and stress-related psychiatric etiopathologies

Cortisol and corticosterone (CORT) coordinate circadian events and manage the stress response by differential activation of two complementary brain receptor systems, i.e., the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR), which mediate rapid non-genomic and slow genomic actions. Several recent discoveries are highlighted from molecular fine-tuning of the MR/GR balance by FKBP5 to CORTs role in neural network regulation underlying stress adaptation in emotional, cognitive, and social domains of behavior. The data suggest that MR mediates CORT action on risk assessment, social interaction, and response selection, while GR activation promotes memory consolidation and behavioral adaptation; there are also sex differences in CORT action. New evidence suggests that targeting the MR/GR balance resets a dysregulated stress response system and promotes resilience.

Meta-Analysis of the Effectiveness and Safety of Glucocorticoid for the Treatment of IgA Kidney Disease

Purpose

To explore the effect of glucocorticoid on immune globulin A (IgA) nephropathy by meta-analysis.

Method

Search the data and literature libraries of ScienceDirect, EBSCO, Wiley, PubMed, CBMdisc, and CNKI and collect the literature on the treatment of IgA nephropathy with glucocorticoids as randomized controlled trials published at home and abroad from 1995 to 2021. The standardized mean difference (SMD) and 95% confidence interval (CI) were calculated by fixed-effects model. RevMan 5.0 software was used for meta-analysis of the subgroups of overall curative effect, different degree of proteinuria, different course of treatment, different creatinine level, and combined ACEI.

Result

① The overall efficacy of glucocorticoid in the treatment of IgA nephropathy was better than that in the control group (P = 0.00001). ② The efficacy of glucocorticoid treatment in patients with IgA nephropathy with proteinuria greater than 1.50 g/d and less than 1.50 g/d was better than that in the control group (P < 0.01). ③ For IgA nephropathy patients with serum creatinine less than 1.50 mg/dl, the curative effect of glucocorticoid treatment was better than that of the control group (P < 0.01). ④ The effects of short-term treatment (<1 year) and long-term treatment (≥1 year) with glucocorticoid were better than those in the control group (P < 0.01). ⑤ The effect of hormone combined with ACEI drugs on IgA nephropathy was more significant (P < 0.01).

Conclusion

The overall efficacy of glucocorticoid in the treatment of IgA nephropathy is accurate. Hormone treatment is effective for different degrees of IgA nephropathy. Considering that there is no significant effect on the efficacy of different courses of treatment, it is suggested that the course of hormone treatment can be appropriately shortened. Hormone combined with angiotensin-converting enzyme inhibitors (ACEI) can reduce proteinuria more effectively than ACEI drugs alone.

Variation in glucocorticoid sensitivity and the relation with obesity

Increasing evidence points to a relation between increased glucocorticoid (GC) exposure and weight gain. In support, long-term cortisol measurements using hair analysis revealed that many individuals with obesity appear to have cortisol values in the high physiological range. The mechanisms behind this relationship need to be determined in order to develop targeted therapy to reach sustainable weight loss in these subgroups. The effect of GCs is not only determined by the plasma concentration of GCs but also by individual differences in GC sensitivity and the target tissue, which can be analyzed by functional GC assays. GC sensitivity is influenced by multiple genetic and acquired (e.g., disease-related) factors, including intracellular GC availability, hormone binding affinity, and expression levels of the GC receptors and their isoforms, as well as factors involved in the modulation of gene transcription. Interindividual differences in GC sensitivity also play a role in the response to exogenous GCs, with respect to both therapeutic and adverse effects. Accordingly, in this review, we summarize current knowledge on mechanisms that influence GC sensitivity and their relationships with obesity and discuss personalized treatment options targeting the GC receptor.

Seizure activity triggers tau hyperphosphorylation and amyloidogenic pathways

OBJECTIVE

Although epilepsies and neurodegenerative disorders show pathophysiological similarities, their direct functional associations are unclear. Here, we tested the hypothesis that experimental seizures can induce tau hyperphosphorylation and amyloidogenic modifications over time, with intersections with neuroinflammation.

METHODS

We used a model of mesial temporal lobe epilepsy (MTLE) where unilateral intrahippocampal injection of kainic acid (KA) in C57BL/6 mice elicits epileptogenesis and spontaneous focal seizures. We used a model of generalized status epilepticus (SE) obtained by intraperitoneal KA injection in C57BL/6 mice. We performed analyses and cross-comparisons according to a schedule of 72 h, 1 week, and 8 weeks after KA injection.

RESULTS

In experimental MTLE, we show AT100, PHF1, and CP13 tau hyperphosphorylation during epileptogenesis (72 h-1 week) and long-term (8 weeks) during spontaneous seizures in the ipsilateral hippocampi, the epileptogenic zone. These pathological modifications extended to the contralateral hippocampus, a seizure propagating zone with no histological lesion or sclerosis. Two kinases, Cdk5 and GSK3β, implicated in the pathological phosphorylation of tau, were activated. In this MTLE model, the induction of the amyloidogenic pathway (APP, C99, BACE1) was prominent and long-lasting in the epileptogenic zone. These Alzheimer's disease (AD)-relevant markers, established during seizure progression and recurrence, reciprocated an enduring glial (GFAP, Iba1) inflammation and the inadequate activation of the endogenous, anti-inflammatory, glucocorticoid receptor system. By contrast, a generalized SE episode provoked a predominantly transient induction of tau hyperphosphorylation and amyloidogenic markers in the hippocampus, along with resolving inflammation. Finally, we identified overlapping profiles of long-term hippocampal tau hyperphosphorylation by comparing MTLE to J20 mice, the latter a model relevant to AD.

SIGNIFICANCE

MTLE and a generalized SE prompt persistent and varying tau hyperphosphorylation or amyloidogenic modifications in the hippocampus. In MTLE, an AD-relevant molecular trajectory intertwines with neuroinflammation, spatiotemporally involving epileptogenic and nonlesional seizure propagating zones.

Post COVID-19 Complications, Adjunct Therapy Explored, And Steroidal After Effects

For survivors of the COVID-19 disease, defeating the virus is just the beginning of a long road to recovery. The virus’s inducibility and catastrophic effects are distributed in multiple organs. The induction of cytokine storms in COVID-19 patients is due to the interaction of the SARS-CoV-2 virus and the host receptor, leading to various immunopathological consequences that might eventually lead to death. So far, it has hit tons of people across the world, but there is still no effective treatment. Patients facing the complications of COVID-19 after recovering have shown extensive clinical symptoms similar to previously circulating coronaviruses. Previous knowledge, and literature have opened up ways to treat this disease and manage post-COVID-19 complications, which poses a severe challenge to health system globally and may exacerbate the fragmentation of diseases. The use of steroids, as a treatment, showed various health problems and side-effects in COVID-19 patients. This review substantially discusses various post-COVID-19 complications observed, adjunctive therapies used along with common COVID-19treatment and spotlighted their side effects and consequences. This review provides latest literature on COVID-19 which emphasizes the subsequent complications in various organs, side-effects of drug, and alternative regimes that were used to treat COVID-19.

Chronic Glucocorticoids Consumption Triggers and Worsens Experimental Alzheimer's Disease-Like Pathology by Detrimental Immune Modulations

INTRODUCTION

Among the risk factors identified in the sporadic forms of Alzheimer's disease (AD), environmental and lifestyle elements are of growing interest. Clinical observations suggest that stressful events can anticipate AD onset, while stress-related disorders can promote AD. Here, we tested the hypothesis that a chronic treatment with glucocorticoids is sufficient to trigger or exacerbate AD molecular hallmarks.

METHODS

We first validated a rat model of experimental chronic glucocorticoids (GC) consumption (corticosterone [CORT] in drinking water for 4 weeks). Then, to evaluate the consequences of chronic GC consumption on the onset of amyloid-β (Aβ) toxicity, animals chronically treated with GC were intracerebroventricularly injected with an oligomeric solution of Aβ25-35 (oAβ) (acute model of AD). We evaluated AD-related cognitive deficits and pathogenic mechanisms, with a special emphasis on neuroinflammatory markers.

RESULTS

Chronic CORT consumption caused the inhibition of the nonamyloidogenic pathways, the impairment of Aβ clearance processes and the induction of amyloidogenic pathways in the hippocampus. The principal enzymes involved in glucocorticoid receptor activation and Tau phosphorylation were upregulated. Importantly, the AD-like phenotype triggered by chronic CORT was analogous to the one caused by oAβ. These molecular commonalities across models were independent from inflammation, as chronic CORT was immunosuppressive while oAβ was pro-inflammatory. When chronic CORT consumption anticipated the induction of the oAβ pathology, we found a potentiation of neuroinflammatory processes associated with an exacerbation of synaptic and memory deficits but also an aggravation of AD-related hallmarks.

DISCUSSION/CONCLUSION

This study unravels new functional outcomes identifying chronic CORT consumption as a main risk factor for AD and suggests that glucocorticoid-based therapies should be prescribed with caution in populations with AD risk.

Acute and chronic effects of cortisol on milk yield, the expression of key receptors, and apoptosis of mammary epithelial cells in Saanen goats

Cortisol (CORT) induces mammary development in late gestation and is fundamental to the differentiation of mammary epithelial cells and lactogenesis. The objective of this study was to investigate the relationship between CORT, insulin, prolactin, growth hormone, and insulin-like growth factor-1 in milk as well as the effect of CORT on the expression of receptors of insulin (INSR), prolactin (PRLR), growth hormone (GHR); we also studied the insulin-like growth factor-1 (IGF1R), glucocorticoid (NR3C1), mineralocorticoid (NR3C2), B-cell lymphoma 2 (BCL2), BCL-2-like protein X (BAX) genes, and the apoptosis rate of mammary epithelial cells of lactating Saanen goats in vivo and in vitro. The following experiments were conducted: (1) comparing hormone release in milk and blood after ACTH or a placebo administration; (2) evaluating the effect of acute CORT increases in mammary gland expression and milk yield in vivo; and (3) evaluating the effect of a chronic increase in CORT concentration in epithelial mammary cell apoptosis in vitro. In vivo, ACTH administration significantly increased CORT release but did not affect insulin, prolactin, growth hormone, and insulin-like growth factor-1 release in plasma and milk versus placebo. The results show also that a low CORT release after ACTH administration increased the expression of GHR and PRLR genes in the mammary tissue. Indeed, CORT release significantly increased the milk yield from goats subjected to ACTH versus goats subjected to the placebo. However, a higher amount of CORT added in vitro upregulated the NR3C1, GHR, PRLR, and BAX genes and downregulated the IGF1R and INSR genes, which could negatively modulate the apoptosis of mammary epithelial cells. Finally, the effect of CORT in vivo after ACTH administration demonstrated the increased expression of the PRLR and GHR genes, which may improve epithelial cell responsiveness and be associated with the positive effect of CORT observed on milk yield at mid-end lactation.

CYP3A Activity in End-of-Life Cancer Patients Measured by 4β-Hydroxycholesterol/cholesterol Ratio, in Men and Women

Simple Summary

The elimination of drugs by enzymes in the liver may be impaired in cancer patients that are close to death (end-of-life). This could cause unwanted side effects or lack of effect of drugs and compromise the quality of life in patients. Blood samples collected in 137 deceased end-of-life cancer patients were analyzed for the marker 4β-hydroxycholesterol/cholesterol (4β-OHC/C), representing the activity of the most important drug eliminating enzyme, CYP3A. In addition, samples from young (n = 280) and elderly (n = 30) controls were analyzed for 4β-OHC/C. The average 4β-OHC/C was higher in male and female end-of-life cancer patients than in young and elderly controls without cancer. This finding may suggest that the ability to eliminate drugs by CYP3A is maintained until end of life and that drugs metabolized by CYP3 may not need dose adjustment or discontinuation in cancer patients close to death.

Abstract

More than 50% of all drugs are metabolized by the cytochrome P450 3A enzyme (CYP3A). The aim of this study was to investigate if the CYP3A activity, measured by the endogenous marker 4β-hydroxycholesterol/cholesterol ratio (4β-OHC/C), is changed during the last weeks and days of life in men and women. To this end, serum samples from 137 deceased patients (median age 70 years) collected at a single time point 1–60 days before death, were analyzed and compared to 280 young (median 27 years), and 30 elderly (median age 70 years) non-cancer controls. There were no significant differences in the 4β-OHC/C ratio between men and women in end-of-life patients (p < 0.25). The median 4β-OHC/C was significantly higher in end-of-life male patients compared to both young (p < 0.0001) and elderly (p < 0.05) male controls. In a similar manner, 4β-OHC/C in end-of-life female patients was significantly higher compared to young and elderly female controls, p < 0.0001 and p < 0.001, respectively. There was no significant correlation between 4β-OHC/C and survival time. The results from this study suggest maintained CYP3A activity to the very last days of life and even a capacity of induction of the enzyme in end-of-life cancer patients.

New Avenues for Treatment and Prevention of Drug-Induced Steatosis and Steatohepatitis: Much More Than Antioxidants

Drug-induced lipid accumulation in the liver may induce two clinically relevant conditions, drug-induced steatosis (DIS) and drug-induced steatohepatitis (DISH). The list of drugs that may cause DIS or DISH is long and heterogeneous and includes therapeutically relevant molecules that cannot be easily replaced by less hepatotoxic medicines, therefore making specific strategies necessary for DIS/DISH prevention or treatment. For years, the only available tools to achieve these goals have been antioxidant drugs and free radical scavengers, which counteract drug-induced mitochondrial dysfunction but, unfortunately, have only limited efficacy. In the present review we illustrate how in vitro preclinical research unraveled new key players in the pathogenesis of specific forms of DISH, and how, in a few cases, proof of concept of the beneficial effects of their pharmacological modulation has been obtained in vivo in animal models of this condition. The key issue emerging from these studies is that, in selected cases, liver toxicity depends on mechanisms unrelated to those responsible for the desired, primary pharmacological effects of the toxic drug and, therefore, specific strategies can be designed to overcome steatogenicity without making the drug ineffective. In particular, the hepatotoxic drug could be given in combination with a second molecule intended to selectively antagonize its liver toxicity whilst, ideally, potentiating its desired pharmacological activity. Although most of the evidence that we discuss is from in vitro or animal models and will need to be further explored and validated in humans, it highlights new avenues to be pursued in order to improve the safety of steatogenic drugs.

Eosinophil-associated microinflammation in the gastroduodenal tract contributes to gastric hypersensitivity in a rat model of early-life adversity

Gastric hypersensitivity is a major pathophysiological feature of functional dyspepsia (FD). Recent clinical studies have shown that a large number of patients with FD present with gastroduodenal microinflammation, which may be involved in the pathophysiology of FD. However, no animal model reflecting this clinical characteristic has been established. The underlying mechanism between microinflammation and FD remains unknown. In this study, using a maternal separation (MS)-induced FD model, we aimed to reproduce the gastroduodenal microinflammation and reveal the interaction between gastroduodenal microinflammation and gastric hypersensitivity. The MS model was established by separating newborn Sprague-Dawley rats for 2 h a day from postnatal day 1 to day 10. At 7-8 wk of age, electromyography was used to determine the visceromotor response to gastric distention (GD) and immunohistochemistry was performed to detect distension-associated neuronal activation as well as immunohistological changes. Our results demonstrated that MS-induced FD rats underwent gastric hypersensitivity with GD at 60 and 80 mmHg, which are related to increased p-ERK1/2 expression in the dorsal horn of T9-T10 spinal cords. Eosinophils, but not mast cells, were significantly increased in the gastroduodenal tract, and the coexpression rate of CD11b and major basic protein significantly increased in MS rats. Treatment with dexamethasone reversed gastric hypersensitivity in MS-induced FD rats by inhibiting eosinophil infiltration. These findings indicated that neonatal MS stress induces eosinophil-associated gastroduodenal microinflammation and gastric hypersensitivity in adulthood in rats. Microinflammation contributes to gastric hypersensitivity; therefore, anti-inflammatory therapy may be effective in treating patients with FD with gastroduodenal microinflammation.NEW & NOTEWORTHY We showed for the first time that neonatal MS stress-induced FD rats undergo gastroduodenal eosinophil-associated microinflammation in adulthood. Suppression of microinflammation attenuated gastric hypersensitivity in MS rats. These findings established a functional link between microinflammation and gastric hypersensitivity, which may provide a potential clue for the clinical treatment of FD.

Depression with Comorbid Diabetes: What Evidence Exists for Treatments Using Traditional Chinese Medicine and Natural Products?

Comorbidity between diabetes mellitus (DM) and depression, two chronic and devastating diseases spreading worldwide, has been confirmed by a large body of epidemiological and clinical studies. Due to the bidirectional relationship between DM and depression, this comorbidity leads to poorer outcomes in both conditions. Given the adverse effects and limited effectiveness of the existing therapies for depression associated with diabetes, the development of novel therapeutic drugs with more potency and fewer side effects is still the most important goal. Hence, many researchers have made great efforts to investigate the potential usefulness of traditional Chinese medicine (TCM) and natural products, including natural extracts and purified compounds, in the treatment of comorbid depression in diabetes. Here, we reviewed the related literature on TCM and natural products that can remedy the comorbidity of diabetes and depression and presented them on the basis of their mechanism of action, focusing on shared risk factors, including insulin resistance, oxidative stress and inflammation, and nervous disturbances. In short, this review suggests that TCM and natural products could expand the therapeutic alternatives to ameliorate the association between DM and depressive disorders.

The Molecular Mechanism of Chronic High-Dose Corticosterone-Induced Aggravation of Cognitive Impairment in APP/PS1 Transgenic Mice

Clinical studies have found that some Alzheimer’s disease (AD) patients suffer from Cushing’s syndrome (CS). CS is caused by the long-term release of excess glucocorticoids (GCs) from the adrenal gland, which in turn, impair brain function and induce dementia. Thus, we investigated the mechanism of the effect of corticosterone (CORT) on the development and progression of AD in a preclinical model. Specifically, the plasma CORT levels of 9-month-old APP/PS1 Tg mice were abnormally increased, suggesting an association between GCs and AD. Long-term administration of CORT accelerated cognitive dysfunction by increasing the production and deposition of β-amyloid (Aβ). The mechanism of action of CORT treatment involved stimulation of the expression of BACE-1 and presenilin (PS) 1 in in vitro and in vivo. This observation was confirmed in mice with adrenalectomy (ADX), which had lower levels of GCs. Moreover, the glucocorticoid receptor (GR) mediated the effects of CORT on the stimulation of the expression of BACE-1 and PS1 via the PKA and CREB pathways in neuroblastoma N2a cells. In addition to these mechanisms, CORT can induce a cognitive decline in APP/PS1 Tg mice by inducing apoptosis and decreasing the differentiation of neurons.

A Brief Overview of the Paradoxical Role of Glucocorticoids in Breast Cancer

Glucocorticoids (GCs) are stress hormones that play multiple roles in the regulation of cancer cell differentiation, apoptosis, and proliferation. Some types of cancers, such as hematological malignancies, can be effectively treated by GCs, whereas the responses of epithelial cancers to GC treatment vary, even within cancer subtypes. In particular, GCs are frequently used as supporting treatment of breast cancer (BC) to protect against chemotherapy side effects. In the therapy of nonaggressive luminal subtypes of BC, GCs can have auxiliary antitumor effects due to their cytotoxic actions on cancer cells. However, GCs can promote BC progression, colonization of distant metastatic sites, and metastasis. The effects of GCs on cell proliferation vary with BC subtype and its molecular profile and are realized via the activation of glucocorticoid receptor (GR), a well-known transcriptional factor involved in the regulation of the expression of multiple genes, cell-cell adhesion, and cell migration and polarity. This review focuses on the roles of GC signaling in the adhesion, migration, and metastasis of BC cells. We discuss the molecular mechanisms of GC actions that lead to BC metastasis and propose alternative pharmacological uses of GCs for BC treatment.

Current Pharmacological Treatment Options for Central Serous Chorioretinopathy: A Review

Central serous chorioretinopathy (CSC) is a common cause of visual impairment in patients generally aged 20 to 60 and it is characterized by acute or chronic neurosensory detachments of the retina. Although CSC resolves spontaneously in most cases, in some patients it may cause permanent visual impairment in the working population; for this reason, several approaches, including photodynamic therapy (PDT), subthreshold micropulse laser treatment and oral mineralocorticoid receptor antagonists, have been studied as first-line treatment options for CSC. To date, half-dose PDT has provided the most encouraging results in this regard, supported by large, multicenter, randomized clinical trials such as the “Prospective Randomized Controlled Treatment Trial for Chronic Central Serous Chorioretinopathy” (PLACE) trial; however, the role of novel possible non-invasive treatment options is attracting interest. This review article aims to discuss the current pharmacological treatment options investigated for the management of CSC, including aspirin, ketoconazole, beta blockers, rifampicin and many others. In particular, further evidence about oral mineralocorticoid receptor antagonists, firstly seen as promising non-invasive alternatives for treating CSC, will be provided and discussed in light of the recent “Eplerenone for chronic central serous chorioretinopathy in patients with active, previously untreated disease for more than 4 months” (VICI) trial results, which have largely resized their role as possible first-line oral treatment options for treating CSC.

Experimental Glucocorticoid Receptor Agonists for the Treatment of Asthma: A Systematic Review

Inhaled corticosteroids (ICSs) are considered the cornerstone of asthma treatment. Despite the solid evidence documenting the efficacy and safety of ICSs at the level of the airways, their use can be affected by pulmonary and systemic adverse events (AEs) when administered chronically and/or at high doses. Thus, there is a pharmacological and medical need for new glucocorticoid (GC) receptor (GR) ligands with a more favorable therapeutic index, in order to overcome the shortcomings of currently available ICSs. The therapeutic profile of GCs can be improved by enhancing genomic mechanisms mediated by transrepression, which is assumed to be responsible for several anti-inflammatory and immunomodulatory actions, rather than transactivation, which causes most of the GC-associated AEs. It was assumed that an independent modulation of the molecular mechanisms underlying transactivation and transrepression could translate into the dissociation of beneficial effects from AEs. Therefore, current research is looking for GCs that are able to elicit prevalently transrepression with negligible transactivating activity. These compounds are known as selective glucocorticoid receptor agonists (SEGRAs). In this review, experimental GR agonists currently in pre-clinical and clinical development for the treatment of asthma have been systematically assessed. Several compounds are currently under pre-clinical development, but only three novel experimental GR agonists (GW870086X, AZD5423, AZD7594) seem to have some potential therapeutic relevance and have entered clinical trials for the treatment of asthma. Since data from pre-clinical studies have not always been confirmed in clinical investigations, well-designed randomized controlled trials are needed in asthmatic patients to confirm the potentially positive benefit/risk ratio of each specific SEGRA and to optimize the development strategy of these agents in respiratory medicine.

COVID-19 Drug Treatment in China

Purpose of Review

An unprecedented outbreak of the novel coronavirus in China (COVID-19) occurred in December 2019, and then engulfed the entire world, presenting a significant and urgent threat to global health. Many research institutes have been involved in the development of drugs and vaccines against COVID-19.

Recent Findings

At present, the strategy of new use of old drugs is mainly used to screen candidate drugs against the novel coronavirus (later termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)) and inhibit excessive immune response. Related research has made great progress.

Summary

In this review, we summarize the drugs used for COVID-19 treatment in China based on the emerging basic and clinical data. It is hoped that this review will be useful to provide guidance for the prevention, treatment, and control of COVID-19.

The neuroprotective effect of Riparin IV on oxidative stress and neuroinflammation related to chronic stress-induced cognitive impairment

BACKGROUND

Cognitive impairment is identified as one of the diagnostic criteria for major depressive disorder and can extensively affect the quality of life of patients. Based on these findings, this study aimed to investigate the possible effects of Riparin IV (Rip IV) on cognitive impairment induced by chronic administration of corticosterone in mice.

METHODS

Female Swiss mice were divided into four groups: control (Control), corticosterone (Cort), Riparin IV (Cort + Rip IV), and Fluvoxamine (Cort + Flu). Three groups were administered corticosterone (20 mg/kg) subcutaneously during the 22-day study, while the control group received only vehicle. After the 14th day, the groups were administered medications: Riparin IV (Rip IV), fluvoxamine (Flu), or distilled water, by gavage, 1 h after the subcutaneous injections. After treatment, mice underwent behavioral testing, and brain areas were removed for oxidative stress and cytokine content assays.

RESULTS

The results revealed that Cort-treated mice developed a cognitive impairment and exhibited a neuroinflammatory profile with an oxidative load and Th1/Th2 cytokine imbalance. Rip IV treatment significantly ameliorated the cognitive deficit induced by Cort and displayed a neuroprotective effect.

CONCLUSION

The antidepressant-like ability of Rip IV treatment against chronic Cort-induced stress may be due to its potential to mitigate inflammatory damage and oxidative stress. The antioxidant and anti-inflammatory effect observed indicates Rip IV as a possible drug for antidepressant treatment of non-responsive patients with severe and cognitive symptoms.

Gene-Specific Actions of Transcriptional Coregulators Facilitate Physiological Plasticity: Evidence for a Physiological Coregulator Code

The actions of transcriptional coregulators are highly gene-specific, that is, each coregulator is required only for a subset of the genes regulated by a specific transcription factor. These coregulator-specific gene subsets often represent selected physiological responses among multiple pathways targeted by a transcription factor. Regulating the activity of a coregulator via post-translational modifications would thus affect only a subset of the transcription factor's physiological actions. Using the context of transcriptional regulation by steroid hormone receptors, this review focuses on gene-specific actions of coregulators and evidence linking individual coregulators with specific physiological pathways. Such evidence suggests that there is a 'physiological coregulator code', which represents a fertile area for future research with important clinical implications.

Glucocorticoid receptors signaling impairment potentiates amyloid-β oligomers-induced pathology in an acute model of Alzheimer's disease

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis occurs early in Alzheimer's disease (AD), associated with elevated circulating glucocorticoids (GC) and glucocorticoid receptors (GR) signaling impairment. However, the precise role of GR in the pathophysiology of AD remains unclear. Using an acute model of AD induced by the intracerebroventricular injection of amyloid-β oligomers (oAβ), we analyzed cellular and behavioral hallmarks of AD, GR signaling pathways, processing of amyloid precursor protein, and enzymes involved in Tau phosphorylation. We focused on the prefrontal cortex (PFC), particularly rich in GR, early altered in AD and involved in HPA axis control and cognitive functions. We found that oAβ impaired cognitive and emotional behaviors, increased plasma GC levels, synaptic deficits, apoptosis and neuroinflammatory processes. Moreover, oAβ potentiated the amyloidogenic pathway and enzymes involved both in Tau hyperphosphorylation and GR activation. Treatment with a selective GR modulator (sGRm) normalized plasma GC levels and all behavioral and biochemical parameters analyzed. GR seems to occupy a central position in the pathophysiology of AD. Deregulation of the HPA axis and a feed-forward effect on PFC GR sensitivity could participate in the etiology of AD, in perturbing Aβ and Tau homeostasis. These results also reinforce the therapeutic potential of sGRm in AD.

The New Genetic Landscape of Cushing's Disease: Deubiquitinases in the Spotlight

Cushing’s disease (CD) is a rare condition caused by adrenocorticotropic hormone (ACTH)-producing adenomas of the pituitary, which lead to hypercortisolism that is associated with high morbidity and mortality. Treatment options in case of persistent or recurrent disease are limited, but new insights into the pathogenesis of CD are raising hope for new therapeutic avenues. Here, we have performed a meta-analysis of the available sequencing data in CD to create a comprehensive picture of CD’s genetics. Our analyses clearly indicate that somatic mutations in the deubiquitinases are the key drivers in CD, namely USP8 (36.5%) and USP48 (13.3%). While in USP48 only Met415 is affected by mutations, in USP8 there are 26 different mutations described. However, these different mutations are clustering in the same hotspot region (affecting in 94.5% of cases Ser718 and Pro720). In contrast, pathogenic variants classically associated with tumorigenesis in genes like TP53 and BRAF are also present in CD but with low incidence (12.5% and 7%). Importantly, several of these mutations might have therapeutic potential as there are drugs already investigated in preclinical and clinical setting for other diseases. Furthermore, network and pathway analyses of all somatic mutations in CD suggest a rather unified picture hinting towards converging oncogenic pathways.

Is AD a Stress-Related Disorder? Focus on the HPA Axis and Its Promising Therapeutic Targets

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that has important health and economic impacts in the elderly. Despite a better understanding of the molecular mechanisms leading to the appearance of major pathological hallmarks (senile plaques and neurofibrillary tangles), effective treatments are still lacking. Sporadic AD forms (98% of all cases) are multifactorial, and a panoply of risk factors have been identified. While the major risk factor is aging, growing evidence suggests that chronic stress or stress-related disorders increase the probability to develop AD. An early dysregulation of the hypothalamic-pituitary-adrenal axis (HPA axis or stress axis) has been observed in patients. The direct consequence of such perturbation is an oversecretion of glucocorticoids (GC) associated with an impairment of its receptors (glucocorticoid receptors, GR). These steroids hormones easily penetrate the brain and act in synergy with excitatory amino acids. An overexposure could be highly toxic in limbic structures (prefrontal cortex and hippocampus) and contribute in the cognitive decline occurring in AD. GC and GR dysregulations seem to be involved in lots of functions disturbed in AD and a vicious cycle appears, where AD induces HPA axis dysregulation, which in turn potentiates the pathology. This review article presents some preclinical and clinical studies focusing on the HPA axis hormones and their receptors to fight AD. Due to its primordial role in the maintenance of homeostasis, the HPA axis appears as a key-actor in the etiology of AD and a prime target to tackle AD by offering multiple angles of action.

Glucocorticoid and Mineralocorticoid Receptors in the Brain: A Transcriptional Perspective

Adrenal glucocorticoid hormones are crucial for maintenance of homeostasis and adaptation to stress. They act via the mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs)—members of the family of nuclear receptors. MRs and GRs can mediate distinct, sometimes opposite, effects of glucocorticoids. Both receptor types can mediate nongenomic steroid effects, but they are best understood as ligand-activated transcription factors. MR and GR protein structure is similar; the receptors can form heterodimers on the DNA at glucocorticoid response elements (GREs), and they share a number of target genes. The transcriptional basis for opposite effects on cellular physiology remains largely unknown, in particular with respect to MR-selective gene transcription. In this review, we discuss proven and potential mechanisms of transcriptional specificity for MRs and GRs. These include unique GR binding to “negative GREs,” direct binding to other transcription factors, and binding to specific DNA sequences in conjunction with other transcription factors, as is the case for MRs and NeuroD proteins in the brain. MR- and GR-specific effects may also depend on specific interactions with transcriptional coregulators, downstream mediators of transcriptional receptor activity. Current data suggest that the relative importance of these mechanisms depends on the tissue and physiological context. Insight into these processes may not only allow a better understanding of homeostatic regulation but also the development of drugs that target specific aspects of disease.

Acute kidney injury induces dramatic p21 upregulation via a novel, glucocorticoid-activated, pathway

The cyclin kinase inhibitor p21 is acutely upregulated during acute kidney injury (AKI) and exerts cytoprotective effects. A proposed mechanism is oxidant stress-induced activation of p53, the dominant p21 transcription factor. Glycerol-induced rhabdomyolysis induces profound renal oxidant stress. Hence, we studied this AKI model to determine whether p53 activation corresponds with p21 gene induction and/or whether alternative mechanism(s) might be involved. CD-1 mice were subjected to glycerol-induced AKI. After 4 or 18 h, plasma, urinary, and renal cortical p21 protein and mRNA levels were assessed. Renal p53 activation was gauged by measurement of both total and activated (Ser15-phosphorylated) p53 and p53 mRNA levels. Glycerol evoked acute, progressive increases in renal cortical p21 mRNA and protein levels. Corresponding plasma (~25-fold) and urinary (~75-fold) p21 elevations were also observed. Renal cortical ratio of total to phosphorylated (Ser15) p53 rose three- to fourfold. However, the p53 inhibitor pifithrin-α failed to block glycerol-induced p21 gene induction, suggesting that an alternative p21 activator might also be at play. To this end, it was established that glycerol-induced AKI 1) dramatically increased plasma (~5-fold) and urinary (~75-fold) cortisol levels, 2) the glucocorticoid receptor antagonist mifepristone blocked glycerol-induced p21 mRNA and protein accumulation, and 3) dexamethasone or cortisol injections markedly increased p21 protein and mRNA in both normal and glycerol-treated mice, although no discernible p53 protein or mRNA increases were observed. We conclude that AKI-induced "systemic stress" markedly increases plasma and urinary cortisol, which can then activate renal p21 gene expression, at least in part, via a glucocorticoid receptor-dependent signaling pathway. Discernible renal cortical p53 increases are not required for this dexamethasone-mediated p21 response.

Top-down and bottom-up control of stress-coping

In this 30th anniversary issue review, we focus on the glucocorticoid modulation of limbic-prefrontocortical circuitry during stress-coping. This action of the stress hormone is mediated by mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs) that are co-expressed abundantly in these higher brain regions. Via both receptor types, the glucocorticoids demonstrate, in various contexts, rapid nongenomic and slower genomic actions that coordinate consecutive stages of information processing. MR-mediated action optimises stress-coping, whereas, in a complementary fashion, the memory storage of the selected coping strategy is promoted via GR. We highlight the involvement of adipose tissue in the allocation of energy resources to central regulation of stress reactions, point to still poorly understood neuronal ensembles in the prefrontal cortex that underlie cognitive flexibility critical for effective coping, and evaluate the role of cortisol as a pleiotropic regulator in vulnerability to, and treatment of, trauma-related psychiatric disorders.

Corticosteroid Action in the Brain: The Potential of Selective Receptor Modulation

Glucocorticoid hormones have important effects on brain function in the context of acute and chronic stress. Many of these are mediated by the glucocorticoid receptor (GR). GR has transcriptional activity which is highly context-specific and differs between tissues and even between cell types. The outcome of GR-mediated transcription depends on the interactome of associated coregulators. Selective GR modulators (SGRMs) are a class of GR ligands that can be used to activate only a subset of GR-coregulator interactions, thereby giving the possibility to induce a unique combination of agonistic and antagonistic GR properties. We describe SGRM action in animal models of brain function and pathology, and argue for their utility as molecular filters, to characterize context-specific GR interactome and transcriptional activity that are responsible for particular glucocorticoid-driven effects in cognitive processes such as memory consolidation. The ultimate objective of this approach is to identify molecular processes that are responsible for adaptive and maladaptive effects of glucocorticoids in the brain.

Central Role of Glucocorticoid Receptors in Alzheimer's Disease and Depression

Alzheimer’s disease (AD) is the principal neurodegenerative pathology in the world displaying negative impacts on both the health and social ability of patients and inducing considerable economic costs. In the case of sporadic forms of AD (more than 95% of patients), even if mechanisms are unknown, some risk factors were identified. The principal risk is aging, but there is growing evidence that lifetime events like chronic stress or stress-related disorders may increase the probability to develop AD. This mini-review reinforces the rationale to consider major depressive disorder (MDD) as an important risk factor to develop AD and points the central role played by the hypothalamic-pituitary-adrenal (HPA) axis, glucocorticoids (GC) and their receptors (GR) in the etiology of MDD and AD. Several strategies directly targeting GR were tested to neutralize the HPA axis dysregulation and GC overproduction. Given the ubiquitous expression of GR, antagonists have many undesired side effects, limiting their therapeutic potential. However, a new class of molecules was developed, highly selective and acting as modulators. They present the advantage to selectively abrogate pathogenic GR-dependent processes, while retaining beneficial aspects of GR signaling. In fact, these “selective GR modulators” induce a receptor conformation that allows activation of only a subset of downstream signaling pathways, explaining their capacity to combine agonistic and antagonistic properties. Thus, targeting GR with selective modulators, alone or in association with current strategies, becomes particularly attractive and relevant to develop novel preventive and/or therapeutic strategies to tackle disorders associated with a dysregulation of the HPA axis.

Resetting the Stress System with a Mifepristone Challenge

Psychotic depression is characterized by elevated circulating cortisol, and high daily doses of the glucocorticoid/progesterone antagonist mifepristone for 1 week are required for significant improvement. Using a rodent model, we find that such high doses of mifepristone are needed because the antagonist is rapidly degraded and poorly penetrates the blood–brain barrier, but seems to facilitate the entry of cortisol. We also report that in male C57BL/6J mice, after a 7-day treatment with a high dose of mifepristone, basal blood corticosterone levels were similar to that of vehicle controls. This is surprising because after the first mifepristone challenge, corticosterone remained elevated for about 16 h, and then decreased towards vehicle control levels at 24 h. At that time, stress-induced corticosterone levels of the 1xMIF were sevenfold higher than the 7xMIF group, the latter response being twofold lower than controls. The 1xMIF mice showed behavioral hyperactivity during exploration of the circular hole board, while the 7xMIF mice rather engaged in serial search patterns. To explain this rapid reset of corticosterone secretion upon recurrent mifepristone administration, we suggest the following: (i) A rebound glucocorticoid feedback after cessation of mifepristone treatment. (ii) Glucocorticoid agonism in transrepression and recruitment of cell-specific coregulator cocktails. (iii) A more prominent role of brain MR function in control of stress circuit activity. An overview table of neuroendocrine MIF effects is provided. The data are of interest for understanding the mechanistic underpinning of stress system reset as treatment strategy for stress-related diseases.