Glucocorticoid resistance as a major drive in sepsis pathology

Glucocorticoid therapy for sepsis in the AI era: a survey on current and future approaches

Sepsis, a life-threatening medical condition, manifests as new or worsening organ failures due to a dysregulated host response to infection. Many patients with sepsis have manifested a hyperinflammatory phenotype leading to the identification of inflammatory modulation by corticosteroids as a key treatment modality. However, the optimal use of corticosteroids in sepsis treatment remains a contentious subject, necessitating a deeper understanding of their physiological and pharmacological effects. Our study conducts a comprehensive review of randomized controlled trials (RCTs) focusing on traditional corticosteroid treatment in sepsis, alongside an analysis of evolving clinical guidelines. Additionally, we explore the emerging role of artificial intelligence (AI) in medicine, particularly in diagnosing, prognosticating, and treating sepsis. AI's advanced data processing capabilities reveal new avenues for enhancing corticosteroid therapeutic strategies in sepsis. The integration of AI in sepsis treatment has the potential to address existing gaps in knowledge, especially in the application of corticosteroids. Our findings suggest that combining corticosteroid therapy with AI-driven insights could lead to more personalized and effective sepsis treatments. This approach holds promise for improving clinical outcomes and presents a significant advancement in the management of this complex and often fatal condition.

A BERT-based approach for identifying anti-inflammatory peptides using sequence information

The use of anti-inflammatory peptides (AIPs) as an alternative therapeutic approach for inflammatory diseases holds great research significance. Due to the high cost and difficulty in identifying AIPs with experimental methods, the discovery and design of peptides by computational methods before the experimental stage have become promising technology. In this study, we present BertAIP, a bidirectional encoder representation from transformers (BERT)-based method for predicting AIPs directly from their amino acid sequence without using any other information. BertAIP implements a BERT model to extract features of a protein, and uses a fully connected feed-forward network for AIP classification. It was constructed and evaluated using the AIP datasets that were reconstructed from the latest Immune Epitope Database. The experimental results showed that BertAIP achieved an accuracy of 0.751 and a Matthews correlation coefficient of 0.451, which were higher than other commonly used methods. The results of the independent test suggested that BertAIP outperformed the existing AIP predictors. In addition, to enhance the interpretability of BertAIP, we explored and visualized the amino acids that the model considered important for AIP prediction. We believe that the BertAIP proposed herein will be a useful tool for large-scale screening and identifying novel AIPs for drug development and therapeutic research related to inflammatory diseases.

Gut-brain axis in the pathogenesis of sepsis-associated encephalopathy

The gut-brain axis is a bidirectional communication network linking the gut and the brain, overseeing digestive functions, emotional responses, body immunity, brain development, and overall health. Substantial research highlights a connection between disruptions of the gut-brain axis and various psychiatric and neurological conditions, including depression and Alzheimer's disease. Given the impact of the gut-brain axis on behavior, cognition, and brain diseases, some studies have started to pay attention to the role of the axis in sepsis-associated encephalopathy (SAE), where cognitive impairment is the primary manifestation. SAE emerges as the primary and earliest form of organ dysfunction following sepsis, potentially leading to acute cognitive impairment and long-term cognitive decline in patients. Notably, the neuronal damage in SAE does not stem directly from the central nervous system (CNS) infection but rather from an infection occurring outside the brain. The gut-brain axis is posited as a pivotal factor in this process. This review will delve into the gut-brain axis, exploring four crucial pathways through which inflammatory signals are transmitted and elevate the incidence of SAE. These pathways encompass the vagus nerve pathway, the neuroendocrine pathway involving the hypothalamic-pituitary-adrenal (HPA) axis and serotonin (5-HT) regulation, the neuroimmune pathway, and the microbial regulation. These pathways can operate independently or collaboratively on the CNS to modulate brain activity. Understanding how the gut affects and regulates the CNS could offer the potential to identify novel targets for preventing and treating this condition, ultimately enhancing the prognosis for individuals with SAE.

Inflammatory liver diseases and susceptibility to sepsis

Patients with inflammatory liver diseases, particularly alcohol-associated liver disease and metabolic dysfunction-associated fatty liver disease (MAFLD), have higher incidence of infections and mortality rate due to sepsis. The current focus in the development of drugs for MAFLD is the resolution of non-alcoholic steatohepatitis and prevention of progression to cirrhosis. In patients with cirrhosis or alcoholic hepatitis, sepsis is a major cause of death. As the metabolic center and a key immune tissue, liver is the guardian, modifier, and target of sepsis. Septic patients with liver dysfunction have the highest mortality rate compared with other organ dysfunctions. In addition to maintaining metabolic homeostasis, the liver produces and secretes hepatokines and acute phase proteins (APPs) essential in tissue protection, immunomodulation, and coagulation. Inflammatory liver diseases cause profound metabolic disorder and impairment of energy metabolism, liver regeneration, and production/secretion of APPs and hepatokines. Herein, the author reviews the roles of (1) disorders in the metabolism of glucose, fatty acids, ketone bodies, and amino acids as well as the clearance of ammonia and lactate in the pathogenesis of inflammatory liver diseases and sepsis; (2) cytokines/chemokines in inflammatory liver diseases and sepsis; (3) APPs and hepatokines in the protection against tissue injury and infections; and (4) major nuclear receptors/signaling pathways underlying the metabolic disorders and tissue injuries as well as the major drug targets for inflammatory liver diseases and sepsis. Approaches that focus on the liver dysfunction and regeneration will not only treat inflammatory liver diseases but also prevent the development of severe infections and sepsis.

Acetylation-induced proteasomal degradation of the activated glucocorticoid receptor limits hormonal signaling

Glucocorticoid (GC) signaling is essential for mounting a stress response, however, chronic stress or prolonged GC therapy downregulates the GC receptor (GR), leading to GC resistance. Regulatory mechanisms that refine this equilibrium are not well understood. Here, we identify seven lysine acetylation sites in the amino terminal domain of GR, with lysine 154 (Lys154) in the AF-1 region being the dominant acetyl-acceptor. GR-Lys154 acetylation is mediated by p300/CBP in the nucleus in an agonist-dependent manner and correlates with transcriptional activity. Deacetylation by NAD+-dependent SIRT1 facilitates dynamic regulation of this mark. Notably, agonist-binding to both wild-type GR and an acetylation-deficient mutant elicits similar short-term target gene expression. In contrast, upon extended treatment, the polyubiquitination of the acetylation-deficient GR mutant is impaired resulting in higher protein stability, increased chromatin association and prolonged transactivation. Taken together, reversible acetylation fine-tunes duration of the GC response by regulating proteasomal degradation of activated GR.

Glucocorticoid dysfunction in children with severe malaria

Introduction

Malaria remains a widespread health problem with a huge burden. Severe or complicated malaria is highly lethal and encompasses a variety of pathological processes, including immune activation, inflammation, and dysmetabolism. Previously, we showed that adrenal hormones, in particular glucocorticoids (GCs), play critical roles to maintain disease tolerance during Plasmodium infection in mice. Here, GC responses were studied in Cameroon in children with uncomplicated malaria (UM), severe malaria (SM) and asymptomatic controls (AC).

Methods

To determine the sensitivity of leukocytes to GC signaling on a transcriptional level, we measured the ex vivo induction of glucocorticoid induced leucine zipper (GILZ) and FK506-binding protein 5 (FKBP5) by GCs in human and murine leukocytes. Targeted tracer metabolomics on peripheral blood mononuclear cells (PBMCs) was performed to detect metabolic changes induced by GCs.

Results

Total cortisol levels increased in patients with clinical malaria compared to AC and were higher in the SM versus UM group, while cortisol binding globulin levels were unchanged and adrenocorticotropic hormone (ACTH) levels were heterogeneous. Induction of both GILZ and FKBP5 by GCs was significantly reduced in patients with clinical malaria compared to AC and in malaria-infected mice compared to uninfected controls. Increased activity in the pentose phosphate pathway was found in the patients, but this was not affected by ex vivo stimulation with physiological levels of hydrocortisone. Interestingly, hydrocortisone induced increased levels of cAMP in AC, but not in clinical malaria patients.

Discussion

Altogether, this study shows that patients with SM have increased cortisol levels, but also a decreased sensitivity to GCs, which may clearly contribute to the severity of disease.

Corticosteroids in ARDS

Acute respiratory distress syndrome (ARDS) is frequently associated with sepsis. ARDS and sepsis exhibit a common pathobiology, namely excessive inflammation. Corticosteroids are powerful anti-inflammatory agents that are routinely used in septic shock and in oxygen-dependent SARS-CoV-2 related acute respiratory failure. Recently, corticosteroids were found to reduce mortality in severe community-acquired pneumonia. Corticosteroids may therefore also have a role to play in the treatment of ARDS. This narrative review was undertaken following a PubMed search for English language reports published before January 2023 using the terms acute respiratory distress syndrome, sepsis and steroids. Additional reports were identified by examining the reference lists of selected articles and based on personnel knowledge of the authors of the field. High-quality research is needed to fully understand the role of corticosteroids in the treatment of ARDS and to determine the optimal timing, dosing and duration of treatment.

Development of a nomogram for predicting 90-day mortality in patients with sepsis-associated liver injury

The high mortality rate in sepsis patients is related to sepsis-associated liver injury (SALI). We sought to develop an accurate forecasting nomogram to estimate individual 90-day mortality in SALI patients. Data from 34,329 patients were extracted from the public Medical Information Mart for Intensive Care (MIMIC-IV) database. SALI was defined by total bilirubin (TBIL) > 2 mg/dL and the occurrence of an international normalized ratio (INR) > 1.5 in the presence of sepsis. Logistic regression analysis was performed to establish a prediction model called the nomogram based on the training set (n = 727), which was subsequently subjected to internal validation. Multivariate logistic regression analysis showed that SALI was an independent risk factor for mortality in patients with sepsis. The Kaplan‒Meier curves for 90-day survival were different between the SALI and non-SALI groups after propensity score matching (PSM) (log rank: P < 0.001 versus P = 0.038), regardless of PSM balance. The nomogram demonstrated better discrimination than the sequential organ failure assessment (SOFA) score, logistic organ dysfunction system (LODS) score, simplified acute physiology II (SAPS II) score, and Albumin-Bilirubin (ALBI) score in the training and validation sets, with areas under the receiver operating characteristic curve (AUROC) of 0.778 (95% CI 0.730-0.799, P < 0.001) and 0.804 (95% CI 0.713-0.820, P < 0.001), respectively. The calibration plot showed that the nomogram was sufficiently successful to predict the probability of 90-day mortality in both groups. The DCA of the nomogram demonstrated a higher net benefit regarding clinical usefulness than SOFA, LODS, SAPSII, and ALBI scores in the two groups. The nomogram performs exceptionally well in predicting the 90-day mortality rate in SALI patients, which can be used to assess the prognosis of patients with SALI and may assist in guiding clinical practice to enhance patient outcomes.

Hepatoprotective functions of jujuboside B

Jujuboside B (JB) found in the seeds of Zizyphi Spinosi Semen possesses pharmacological functions, such as anti-inflammatory, antiplatelet aggregation, and antianxiety potentials. This study evaluated the effect of JB on liver failure in cecal ligation and puncture (CLP)-induced sepsis. First, we observed histopathological changes in the liver by optical microscopy and the activity of enzymes in serum such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST). We further measured the levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, nitric oxide (NO), and antioxidative parameters in liver homogenate. The expression of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), and glucocorticoid receptor (GR) in the liver was observed by Western blotting. CLP enhanced the migration of inflammatory cells, ALT and AST concentrations, and necrosis, which were reduced by JB. In addition, JB reduced 11β-HSD2 expression and levels of inflammatory mediators (TNF-α, IL-1β, and NO) in the liver, increased GR expression, enhanced endogenous antioxidative capacity. These results further suggest that JB may protect the liver against CLP-induced damage by regulating anti-inflammatory responses, downregulating 11β-HSD2 expression and antioxidation, and up-regulating GR expression.

Roles of ginsenosides in sepsis

The herbal medication Panax ginseng Meyer has widespread use in China, Korea, and other parts of the world. The main constituents of ginseng are ginsenosides, which include over 30 different triterpene saponins. It has been found that ginsenosides and their metabolites including Rg1, compound K, Rb1, Re, Rg3, and Rg5 exert anti-inflammatory activities by binding to the glucocorticoid receptor, modulating inflammation-related signaling, including NF-κB and MAPK signaling, and reducing levels of pro-inflammatory cytokines. Here, we review the recent literature on the molecular actions of ginsenosides in sepsis, suggesting ways in which they may be used to prevent and treat the disease.

Glucocorticoid receptor hypersensitivity enhances inflammatory signaling and inhibits cell cycle progression in porcine PBMCs

The consequences of glucocorticoid receptor (GR) hypersensitivity during infection have so far received little attention. We previously discovered that a natural gain-of-function Ala610Val substitution in the porcine GR aggravates response of pigs to lipopolysaccharide (LPS)-induced endotoxemia, which can be alleviated by dexamethasone (DEX) pretreatment. In this work, we investigated the relevant molecular basis of these phenotypes by transcriptomic profiling of porcine peripheral blood mononuclear cells (PBMCs) carrying different GR genotypes, in unstimulated conditions or in response to DEX and/or LPS in vitro. The Val allele differentially regulated abunda+nt genes in an additive-genetic manner. A subset of more than 200 genes was consistently affected by the substitution across treatments. This was associated with upregulation of genes related i.a. to endo-lysosomal system, lipid and protein catabolism, and immune terms including platelet activation, and antigen presentation, while downregulated genes were mainly involved in cell cycle regulation. Most importantly, the set of genes constitutively upregulated by Val includes members of the TLR4/LPS signaling pathway, such as LY96. Consequently, when exposing PBMCs to LPS treatment, the Val variant upregulated a panel of additional genes related to TLR4 and several other pattern recognition receptors, as well as cell death and lymphocyte signaling, ultimately amplifying the inflammatory responses. In contrast, when stimulated by DEX treatment, the Val allele orchestrated several genes involved in anti-inflammatory responses during infection. This study provides novel insights into the impact of GR hypersensitivity on the fate and function of immune cells, which may be useful for endotoxemia therapy.

Renaissance of glucocorticoids in critical care in the era of COVID-19: ten urging questions

The 40-year-old experience with glucocorticosteroids (GCs) in the context of severe infections is complex and troublesome. Recently, however, a clear indication for GCs in severe COVID-19 has been established. This may constitute a harbinger of a wider use of GCs in critical illnesses. A fundamental prerequisite of such an action is a better understanding of the heterogeneity of critical illness and GCs operationalization within the precision medicine approach. In this perspective, we formulate ten major questions regarding the use of GCs in critical illness. Answering them will likely facilitate a new era of effective and personalized GCs use in modern critical care.

Prediction of anti-inflammatory peptides by a sequence-based stacking ensemble model named AIPStack

Accurate and efficient identification of anti-inflammatory peptides (AIPs) is crucial for the treatment of inflammation. Here, we proposed a two-layer stacking ensemble model, AIPStack, to effectively predict AIPs. At first, we constructed a new dataset for model building and validation. Then, peptide sequences were represented by hybrid features, which were fused by two amino acid composition descriptors. Next, the stacking ensemble model was constructed by random forest and extremely randomized tree as the base-classifiers and logistic regression as the meta-classifier to receive the outputs from the base-classifiers. AIPStack achieved an AUC of 0.819, accuracy of 0.755, and MCC of 0.510 on the independent set 3, which were higher than other AIP predictors. Furthermore, the essential sequence features were highlighted by the Shapley Additive exPlanation (SHAP) method. It is anticipated that AIPStack could be used for AIP prediction in a high-throughput manner and facilitate the hypothesis-driven experimental design.

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AIPStack model was developed for the prediction of anti-inflammatory peptides

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The hybrid features were used to describe the peptide sequences

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The proposed model AIPStack outperformed existing ones

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SHAP was used to highlight the essential features required for AIP prediction

To protect or to kill: A persisting Darwinian immune dilemma

The immune system, which evolved as a protective system, can paradoxically mediate lethal effects when it is over-activated. These effects can be traced back to infected insects and are mainly mediated by phylogenetically old cytokines that have been found already in starfishes and sponges. We hypothesize that these anti-homeostatic effects are important for restricting the cumulative risk of transmission of highly mutating environmental pathogens that may endanger species, particularly when they start to originate and expand. Considering the Darwinian view that evolution is a permanent process, this anti-homeostatic program is preserved and expressed even when there is no risk for the species. Here, we review these aspects and discuss how evolutionary-imposed anti-homeostatic immune programs are expressed during acute and chronic human diseases, which can be further aggravated in the absence of medical interventions. The relevance of early identification of ancestral biomarkers that predict a shift from protective to deleterious immune outcomes is emphasized.

Glucocorticoid Treatment Strategies in Liver Failure

Liver failure is characterized by serious liver decompensation and high mortality. The activation of systemic immune responses and systemic inflammation are widely accepted as the core pathogenesis of liver failure. Glucocorticoids (GCs) are most regularly utilized to suppress excessive inflammatory reactions and immunological responses. GCs have been used in the clinical treatment of liver failure for nearly 60 years. While there has been no unanimity on the feasibility and application of GC treatment in liver failure until recently. The most recent trials have produced conflicting results when it comes to the dose and time for GC therapy of different etiology of liver failure. Our review outlines the issues and options in managing GC treatment in liver failure based on an investigation of the molecular mechanism that GC may give in the treatment.

Restrained expression of canine glucocorticoid receptor splice variants α and P prognosticates fatal disease outcome in SIRS

Glucocorticoids play a central role in the inflammatory response and alleviate the symptoms in critically ill patients. The glucocorticoid action relies on the glucocorticoid receptor (GR) which translocates into the nucleus upon ligand-binding and regulates transcription of a battery of genes. Although the GR is encoded by a single gene, dozens of its splice variants have been described in diverse species. The GRα isoform encodes the full, functionally active protein that is composed of a transactivation, a DNA-binding, and a C-terminal ligand-binding domain. The second most highly expressed receptor variant, the GR-P, is formed by an intron retention that introduces an early stop codon and results in a probably dysfunctional protein with truncated ligand-binding domain. We described the canine ortholog of GR-P and showed that this splice variant is highly abundant in the peripheral blood of dogs. The level of cGRα and cGR-P transcripts are elevated in patients of SIRS and the survival rate is increased with elevated cGRα and cGR-P expression. The ratio of cGRα and cGR-P mRNA did not differ between the survivor and non-survivor patients; thus, the total GR expression is more pertinent than the relative expression of GR isoforms in assessment of the disease outcome.

Circadian Rhythms in Bacterial Sepsis Pathology: What We Know and What We Should Know

Sepsis is a syndrome caused by a deregulated host response to infection, representing the primary cause of death from infection. In animal models, the mortality rate is strongly dependent on the time of sepsis induction, suggesting a main role of the circadian system. In patients undergoing sepsis, deregulated circadian rhythms have also been reported. Here we review data related to the timing of sepsis induction to further understand the different outcomes observed both in patients and in animal models. The magnitude of immune activation as well as the hypothermic response correlated with the time of the worst prognosis. The different outcomes seem to be dependent on the expression of the clock gene Bmal1 in the liver and in myeloid immune cells. The understanding of the role of the circadian system in sepsis pathology could be an important tool to improve patient therapies.

Glucocorticoid Resistance: Interference between the Glucocorticoid Receptor and the MAPK Signalling Pathways

Endogenous glucocorticoids (GCs) are steroid hormones that signal in virtually all cell types to modulate tissue homeostasis throughout life. Also, synthetic GC derivatives (pharmacological GCs) constitute the first-line treatment in many chronic inflammatory conditions with unquestionable therapeutic benefits despite the associated adverse effects. GC actions are principally mediated through the GC receptor (GR), a ligand-dependent transcription factor. Despite the ubiquitous expression of GR, imbalances in GC signalling affect tissues differently, and with variable degrees of severity through mechanisms that are not completely deciphered. Congenital or acquired GC hypersensitivity or resistance syndromes can impact responsiveness to endogenous or pharmacological GCs, causing disease or inadequate therapeutic outcomes, respectively. Acquired GC resistance is defined as loss of efficacy or desensitization over time, and arises as a consequence of chronic inflammation, affecting around 30% of GC-treated patients. It represents an important limitation in the management of chronic inflammatory diseases and cancer, and can be due to impairment of multiple mechanisms along the GC signalling pathway. Among them, activation of the mitogen-activated protein kinases (MAPKs) and/or alterations in expression of their regulators, the dual-specific phosphatases (DUSPs), have been identified as common mechanisms of GC resistance. While many of the anti-inflammatory actions of GCs rely on GR-mediated inhibition of MAPKs and/or induction of DUSPs, the GC anti-inflammatory capacity is decreased or lost in conditions of excessive MAPK activation, contributing to disease susceptibility in tissue- and disease- specific manners. Here, we discuss potential strategies to modulate GC responsiveness, with the dual goal of overcoming GC resistance and minimizing the onset and severity of unwanted adverse effects while maintaining therapeutic potential.

Metabolic Alterations in Sepsis

Sepsis is defined as “life-threatening organ dysfunction caused by a dysregulated host response to infection”. Contrary to the older definitions, the current one not only focuses on inflammation, but points to systemic disturbances in homeostasis, including metabolism. Sepsis leads to sepsis-induced dysfunction and mitochondrial damage, which is suggested as a major cause of cell metabolism disorders in these patients. The changes affect the metabolism of all macronutrients. The metabolism of all macronutrients is altered. A characteristic change in carbohydrate metabolism is the intensification of glycolysis, which in combination with the failure of entering pyruvate to the tricarboxylic acid cycle increases the formation of lactate. Sepsis also affects lipid metabolism—lipolysis in adipose tissue is upregulated, which leads to an increase in the level of fatty acids and triglycerides in the blood. At the same time, their use is disturbed, which may result in the accumulation of lipids and their toxic metabolites. Changes in the metabolism of ketone bodies and amino acids have also been described. Metabolic disorders in sepsis are an important area of research, both for their potential role as a target for future therapies (metabolic resuscitation) and for optimizing the current treatment, such as clinical nutrition.

Sepsis as a Pan-Endocrine Illness-Endocrine Disorders in Septic Patients

Sepsis is defined as "life-threatening organ dysfunction caused by a dysregulated host response to infection". One of the elements of dysregulated host response is an endocrine system disorder. Changes in its functioning in the course of sepsis affect almost all hormonal axes. In sepsis, a function disturbance of the hypothalamic-pituitary-adrenal axis has been described, in the range of which the most important seems to be hypercortisolemia in the acute phase. Imbalance in the hypothalamic-pituitary-thyroid axis is also described. The most typical manifestation is a triiodothyronine concentration decrease and reverse triiodothyronine concentration increase. In the somatotropic axis, a change in the secretion pattern of growth hormone and peripheral resistance to this hormone has been described. In the hypothalamic-pituitary-gonadal axis, the reduction in testosterone concentration in men and the stress-induced "hypothalamic amenorrhea" in women have been described. Catecholamine and β-adrenergic stimulation disorders have also been reported. Disorders in the endocrine system are part of the "dysregulated host response to infection". They may also affect other components of this dysregulated response, such as metabolism. Hormonal changes occurring in the course of sepsis require further research, not only in order to explore their potential significance in therapy, but also due to their promising prognostic value.

MicroRNA-124a contributes to glucocorticoid resistance in acute-on-chronic liver failure by negatively regulating glucocorticoid receptor alpha

INTRODUCTION AND OBJECTIVES

Glucocorticoid resistance frequently associating with inflammation, may severely compromise the therapeutic effect of glucocorticoids. In this study, we aimed to investigate the regulation of glucocorticoid resistance by microRNA-124a (miR-124a) in patients with acute-on-chronic liver failure (ACLF).

MATERIALS AND METHODS

The miR-124a levels and glucocorticoid receptor alpha (GRα) expressions in peripheral blood monocytes and liver tissues were measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), flow cytometry, and western blot analyses in the following four groups: healthy controls (HC), moderate chronic hepatitis B (CHB) patients, hepatitis B virus-related ACLF (HBV-ACLF) patients, and alcohol-induced ACLF (A-ACLF) patients. In addition, the serum miR-124a levels and multiple biochemical indices were determined. The effects of miR-124a transfection on GRα expression were assayed by qRT-PCR and western blotting in U937 and HepG2 cells stimulated with lipopolysaccharide (LPS).

RESULTS

Compared with the CHB patients and HC, the miR-124a levels in HBV-ACLF and A-ACLF patients increased, while GRα expressions decreased. No significant differences in miR-124a levels and GRα expressions were observed between the HBV-ACLF and A-ACLF patients. For the ACLF patients, miR-124a level was negatively related to GRα expression in monocytes and positively correlated with the inflammatory factors such as interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α). In U937 and HepG2 cells, LPS stimulated miR-124a levels but inhibited GRα expressions; meanwhile, increasing miR-124a levels reduced GRα expressions, and inhibiting miR-124a levels increased GRα expressions.

CONCLUSIONS

This study provides evidence that GRα expression was negatively regulated by miR-124a, which primarily determines the extent of acquired glucocorticoid resistance in ACLF.

Pharmacological principles guiding prolonged glucocorticoid treatment in ARDS

Current literature addressing the pharmacological principles guiding glucocorticoid (GC) administration in ARDS is scant. This paucity of information may have led to the heterogeneity of treatment protocols and misinterpretation of available findings. GCs are agonist compounds that bind to the GC receptor (GR) producing a pharmacological response. Clinical efficacy depends on the magnitude and duration of exposure to GR. We updated the meta-analysis of randomized trials investigating GC treatment in ARDS, focusing on treatment protocols and response. We synthesized the current literature on the role of the GR in GC therapy including genomic and non-genomic effects, and integrated current clinical pharmacology knowledge of various GCs, including hydrocortisone, methylprednisolone and dexamethasone. This review addresses the role dosage, timing of initiation, mode of administration, duration, and tapering play in achieving optimal response to GC therapy in ARDS. Based on RCTs’ findings, GC plasma concentration–time profiles, and pharmacodynamic studies, optimal results are most likely achievable with early intervention, an initial bolus dose to achieve close to maximal GRα saturation, followed by a continuous infusion to maintain high levels of response throughout the treatment period. In addition, patients receiving similar GC doses may experience substantial between-patient variability in plasma concentrations affecting clinical response. GC should be dose-adjusted and administered for a duration targeting clinical and laboratory improvement, followed by dose-tapering to achieve gradual recovery of the suppressed hypothalamic–pituitary–adrenal (HPA) axis. These findings have practical clinical relevance. Future RCTs should consider these pharmacological principles in the study design and interpretation of findings.

Nesfatin-1 and neuronostatin neurons are co-expressed with glucocorticoid receptors in the hypothalamus

Nesfatin-1 and neuronostatin in the central nervous system participate in regulating stress responses. Glucocorticoid hormones affect the brain through glucocorticoid receptors (GR). We investigated in the rat the possibility of co-localizing nesfatin-1 and neuronostatin neurons in hypothalamic areas with GR. using immunohistochemistry. We counted nesfatin-1 and neuronostatin stained neurons. We counted GR positive nesfatin-1 neurons in the arcuate nucleus (ARC) and paraventricular nucleus (PVN) and GR positive neuronostatin neurons in the periventricular nucleus (PeN). The percentage of nesfatin-1 neurons that expressed GR was 38.4% in female rats and 21.9% in male rats in the ARC, and 33.3% in female rats and 29.2% in male rats in the PVN. The percentage of neuronostatin neurons that expressed GR was 39.1% in female rats and 39.9% in male rats in the PeN. We found that a substantial portion of nesfatin-1 and neuronostatin neurons were stained for GR. We speculate that the pattern of GR might permit secretion of neuropeptides to be stimulated by peripheral glucocorticoid signals. Stress can suppress food intake, in part, through the GR in neurons that express nesfatin-1, which is a satiety molecule, and in neurons that express neuronostatin, which is an anorexigenic peptide.

Tetracycline Antibiotics Induce Host-Dependent Disease Tolerance to Infection

Several classes of antibiotics have long been known to have beneficial effects that cannot be explained strictly on the basis of their capacity to control the infectious agent. Here, we report that tetracycline antibiotics, which target the mitoribosome, protected against sepsis without affecting the pathogen load. Mechanistically, we found that mitochondrial inhibition of protein synthesis perturbed the electron transport chain (ETC) decreasing tissue damage in the lung and increasing fatty acid oxidation and glucocorticoid sensitivity in the liver. Using a liver-specific partial and acute deletion of Crif1, a critical mitoribosomal component for protein synthesis, we found that mice were protected against sepsis, an observation that was phenocopied by the transient inhibition of complex I of the ETC by phenformin. Together, we demonstrate that mitoribosome-targeting antibiotics are beneficial beyond their antibacterial activity and that mitochondrial protein synthesis inhibition leading to ETC perturbation is a mechanism for the induction of disease tolerance.

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Doxycycline protects from sepsis beyond its direct antibacterial activity

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Doxycycline protection from infection is microbiome-independent

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Inhibition of mitochondrial protein synthesis induces disease tolerance

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Mild and transient perturbations of the mitochondrial ETC induce disease tolerance

Latest perspectives on glucocorticoid-induced apoptosis and resistance in lymphoid malignancies

Glucocorticoids are essential drugs in the treatment protocols of lymphoid malignancies. These steroidal hormones trigger apoptosis of the malignant cells by binding to the glucocorticoid receptor (GR), which is a member of the nuclear receptor superfamily. Long term glucocorticoid treatment is limited by two major problems: the development of glucocorticoid-related side effects, which hampers patient quality of life, and the emergence of glucocorticoid resistance, which is a gradual process that is inevitable in many patients. This emphasizes the need to reevaluate and optimize the widespread use of glucocorticoids in lymphoid malignancies. To achieve this goal, a deep understanding of the mechanisms governing glucocorticoid responsiveness is required, yet, a recent comprehensive overview is currently lacking. In this review, we examine how glucocorticoids mediate apoptosis by detailing GR's genomic and non-genomic action mechanisms in lymphoid malignancies. We continue with a discussion of the glucocorticoid-related problems and how these are intertwined with one another. We further zoom in on glucocorticoid resistance by critically analyzing the plethora of proposed mechanisms and highlighting therapeutic opportunities that emerge from these studies. In conclusion, early detection of glucocorticoid resistance in patients remains an important challenge as this would result in a timelier treatment reorientation and reduced glucocorticoid-instigated side effects.

New insights into the cell- and tissue-specificity of glucocorticoid actions

Glucocorticoids (GCs) are endogenous hormones that are crucial for the homeostasis of the organism and adaptation to the external environment. Because of their anti-inflammatory effects, synthetic GCs are also extensively used in clinical practice. However, almost all cells in the body are sensitive to GC regulation. As a result, these mediators have pleiotropic effects, which may be undesirable or detrimental to human health. Here, we summarize the recent findings that contribute to deciphering the molecular mechanisms downstream of glucocorticoid receptor activation. We also discuss the complex role of GCs in infectious diseases such as sepsis and COVID-19, in which the balance between pathogen elimination and protection against excessive inflammation and immunopathology needs to be tightly regulated. An understanding of the cell type- and context-specific actions of GCs from the molecular to the organismal level would help to optimize their therapeutic use.

Overexpression of Gilz Protects Mice Against Lethal Septic Peritonitis

Sepsis in humans and experimental animals is characterized by an acute inflammatory response. glucocorticoids (GCs) are widely used for the treatment of many inflammatory disorders, yet their effectiveness in sepsis is debatable. One of the major anti-inflammatory proteins induced by GCs is glucocorticoid-induced leucine zipper (GILZ, coded by the TSC22D3 gene). We found that TSC22D3 mRNA expression is downregulated in white blood cells of human sepsis patients. Interestingly, transgenic GILZ-overexpressing mice (GILZ-tg) showed better survival rates in the cecal ligation and puncture (CLP) model of mouse sepsis. To our surprise, GILZ had only mild anti-inflammatory effects in this model, as the systemic proinflammatory response was not significantly reduced in GILZ-tg mice compared with control mice. During CLP, we observed reduced bacterial counts in blood of GILZ-tg mice compared with control mice. We found increased expression of Tsc22d3 mRNA specifically in peritoneal exudate cells in the CLP model, as well as increased capacity for bacterial phagocytosis of CD45 GILZ-tg cells compared with CD45 GILZ-wt cells. Hence, we believe that the protective effects of GILZ in the CLP model can be linked to a more efficient phagocytosis.

Evolution of severe acute respiratory syndrome coronavirus 2 RNA test results in a patient with fatal coronavirus disease 2019: a case report

A 65-year-old man was hospitalized owing to fever (38.6 °C) and dry cough since 4 days. He visited Wuhan 8 days ago. At admission, nasopharyngeal swab samples were taken, and polymerase chain reaction analysis confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA positivity. On day 9, after admission, the chest computed tomography scan showed diffuse ground-glass shadows in the patient's bilateral lungs. On day 11, his respiratory symptoms worsened. Subsequently, type I respiratory failure was diagnosed, coinciding with kidney injury, and subsequently, type II respiratory failure occurred, coupled with multiorgan failure including the heart and liver. However, the patient's constitution worsened although SARS-CoV-2 tests were negative since day 13. He died on day 21. Lung biopsy showed areas of diffuse alveolar damage, characterized by extensive acute alveolitis with numerous intra-alveolar neutrophil, lymphocyte, and macrophage infiltrations. Microthrombi were seen in the dilated pulmonary capillaries. Immunohistochemistry staining for SARS-CoV-2 N protein was negative. Taken together, the patient died of multiorgan failure although the SARS-CoV-2 infection was cleared already, implicating that for disease worsening, no active SARS-CoV-2 infection is required.

Towards a psychobiotic therapy for depression: Bifidobacterium breve CCFM1025 reverses chronic stress-induced depressive symptoms and gut microbial abnormalities in mice

BACKGROUND

Accumulating evidence points to an association between gut microbial abnormalities and depression disorder. The microbiota-gut-brain axis is an emerging target for treating depression using nutritional strategies, considering the numerous limitations of current pharmacological approaches. Here we studied the effect and probable mechanisms of psychobiotic treatment on depression.

METHODS

Chronically stressed C57BL/6J male mice were administered viable Bifidobacterium breve CCFM1025 for 5 weeks prior to behavioral testing. Brain neurological alterations, serum corticosterone, cytokines levels, fecal microbial composition, and short-chain fatty acid (SCFA) content were measured. In addition, the effect of SCFA on 5-hydroxytryptophan (5-HTP) biosynthesis was investigated in an in vitro model of enterochromaffin cells (RIN14B).

RESULTS

CCFM1025 treatment significantly reduced depression- and anxiety-like behaviors. The hyperactive hypothalamic-pituitary-adrenal response, as well as inflammation, were also alleviated, possibly via regulating the expression of glucocorticoid receptors (Nr3c1). Moreover, CCFM1025 also down-regulated the pCREB-c-Fos pathway but increased the expression of brain-derived neurotrophic factor (BDNF). Meanwhile, chronic stress-induced gut microbial abnormalities were restored, accompanied by increased SCFA and 5-HTP levels. The intestinal 5-HTP biosynthesis positively correlated with fecal SCFA and Bifidobacterium breve levels.

CONCLUSIONS

In summary, Bifidobacterium breve CCFM1025 showed considerable antidepressant-like and microbiota-regulating effects, which opens avenues for novel therapeutic strategies towards treating depression.

General Adaptation in Critical Illness: Glucocorticoid Receptor-alpha Master Regulator of Homeostatic Corrections

In critical illness, homeostatic corrections representing the culmination of hundreds of millions of years of evolution, are modulated by the activated glucocorticoid receptor alpha (GRα) and are associated with an enormous bioenergetic and metabolic cost. Appreciation of how homeostatic corrections work and how they evolved provides a conceptual framework to understand the complex pathobiology of critical illness. Emerging literature place the activated GRα at the center of all phases of disease development and resolution, including activation and re-enforcement of innate immunity, downregulation of pro-inflammatory transcription factors, and restoration of anatomy and function. By the time critically ill patients necessitate vital organ support for survival, they have reached near exhaustion or exhaustion of neuroendocrine homeostatic compensation, cell bio-energetic and adaptation functions, and reserves of vital micronutrients. We review how critical illness-related corticosteroid insufficiency, mitochondrial dysfunction/damage, and hypovitaminosis collectively interact to accelerate an anti-homeostatic active process of natural selection. Importantly, the allostatic overload imposed by these homeostatic corrections impacts negatively on both acute and long-term morbidity and mortality. Since the bioenergetic and metabolic reserves to support homeostatic corrections are time-limited, early interventions should be directed at increasing GRα and mitochondria number and function. Present understanding of the activated GC-GRα's role in immunomodulation and disease resolution should be taken into account when re-evaluating how to administer glucocorticoid treatment and co-interventions to improve cellular responsiveness. The activated GRα interdependence with functional mitochondria and three vitamin reserves (B1, C, and D) provides a rationale for co-interventions that include prolonged glucocorticoid treatment in association with rapid correction of hypovitaminosis.

GILZ in sepsis: "Poor is the pupil who does not surpass his master"

With the legendary saying of Leonardo da Vinci in the title, we suggest that Glucocorticoid Induced Leucine Zipper (GILZ) may have more promising effects against polymicrobial sepsis, than glucocorticoids (GC). Indeed, the use of GCs in sepsis remains a matter of debate. The rationale for their use in sepsis is to modulate the exaggerated inflammatory response while maintaining innate immunity. However, GC resistance and side-effects limit their therapeutic value in sepsis. Hence, there is a growing interest in understanding the mechanisms by which GCs modulate immune responses upon infection. In this issue of the European Journal of Immunology, Ellouze et al. provide data demonstrating that deregulated expression of GILZ, a GC-induced protein, in monocytes/macrophages (M/M) recovered from septic shock patients may contribute to the pathogenesis. Furthermore, the authors demonstrate that GILZ overexpression in M/M improves outcome in septic animals by limiting systemic inflammation while increasing bacterial clearance. Overall, these data provide evidence that GCs may modulate immune responses via GILZ and that GILZ is a valuable alternative for GC therapy in sepsis.

Effect of low high-density lipoprotein levels on mortality of septic patients: A systematic review and meta-analysis of cohort studies

BACKGROUND

An increase in high-density lipoprotein (HDL) is well associated with a decreased cardiovascular risk, especially atherosclerosis. Recent studies suggest that lower levels of HDL may also be associated with an increased risk of sepsis and an increased rate of mortality in septic patients. However, this conclusion remains controversial.

METHODS

MEDLINE, EMBASE, and CENTRAL databases were searched from inception to September 30, 2019. All studies were conducted to evaluate the correlation of lipoprotein levels and the risk and outcomes of sepsis in adult patients. The primary outcomes were the risk and mortality of sepsis.

RESULTS

Seven studies comprising 791 patients were included. Lower levels of HDL had no marked relevance with the risk of sepsis (odds radio [OR] for each 1 mg/dL increase, 0.94; 95% CI 0.86-1.02; P=0.078), whereas lower HDL levels were related to an increased mortality rate in septic patients (OR for below about median HDL levels, 2.00; 95% CI 1.23-3.24; P=0.005).

CONCLUSION

This meta-analysis did not reveal a significant association between lower HDL levels and an increase in the risk of sepsis, whereas it showed that lower HDL levels are associated with a higher mortality rate in septic adult patients. These findings suggest that HDL may be considered as a promising factor for the prevention and treatment of sepsis in the future.

The Management of Glucocorticoid Therapy in Liver Failure

Liver failure is characterized by rapid progression and high mortality. Excessive systemic inflammation is considered as the trigger of liver failure. Glucocorticoids (GCs) can rapidly suppress excessive inflammatory reactions and immune response. GCs have been applied in the treatment of liver failure since the 1970s. However, until now, the use of GCs in the treatment of liver failure has been somewhat unclear and controversial. New research regarding the molecular mechanisms of GCs may explain the controversial actions of GCs in liver failure. More results should be confirmed in a larger randomized clinical trial; this can aid the discovery of better definitions in terms of treatment schedules according to different clinical settings. Meanwhile, the timing and dosing of GCs in the treatment of liver failure should also be explored.

Is Inappropriate Response to Cosyntropin Stimulation Test an Indication of Corticosteroid Resistance in Septic Shock?

We recently published a comparison of two hydrocortisone dosage regimens in patients with septic shock. We compare the results conferred by the two regimens as a function of the response to cosyntropin stimulation test (CST). Patients with septic shock were treated by one of two hydrocortisone regimens: either a 50-mg intravenous bolus every 6 h during 7 days (200 mg group; n = 49), or a 100-mg initial bolus followed by a continuous infusion of 300 mg daily for 5 days (300 mg group; n = 50). Nonresponders was defined as a CST response of 9 μg/dL or less. Nonresponders had more severe septic shock, greater fluid resuscitation needs, and greater vasopressor dependence than responders. When analyzed only as a function of CST results, there was no difference in survival between responders and nonresponders. However, analyses crossing CST results and the treatment regimens showed that patients who were responders and in the 300 mg group had significantly less intensive care unit mortality compared with responders in the 200 mg group (respective mortality of 24% vs. 55% [relative risk 0.43, 95% confidence interval, 0.20 to 0.94, P = 0.018]). Multivariate analysis identified baseline blood cortisol as an independent prognostic factor for 28-day mortality in all groups (hazard ratio 1.002, 95% confidence interval, 1.001 to 1.002, P ≤ 0.0001). The results suggest that in patients who respond to CST, hydrocortisone can provide a dose-dependent benefit. In contrast, nonresponse may indicate corticosteroid resistance. This heterogeneity of response to hydrocortisone may explain the difficulties encountered when trying to demonstrate its benefit in septic shock.

TNF-α inhibits glucocorticoid receptor-induced gene expression by reshaping the GR nuclear cofactor profile

Glucocorticoid resistance (GCR) is defined as an unresponsiveness to the therapeutic effects, including the antiinflammatory ones of glucocorticoids (GCs) and their receptor, the glucocorticoid receptor (GR). It is a problem in the management of inflammatory diseases and can be congenital as well as acquired. The strong proinflammatory cytokine TNF-alpha (TNF) induces an acute form of GCR, not only in mice, but also in several cell lines: e.g., in the hepatoma cell line BWTG3, as evidenced by impaired Dexamethasone (Dex)-stimulated direct GR-dependent gene up- and down-regulation. We report that TNF has a significant and broad impact on this transcriptional performance of GR, but no impact on nuclear translocation, dimerization, or DNA binding capacity of GR. Proteome-wide proximity-mapping (BioID), however, revealed that the GR interactome was strongly modulated by TNF. One GR cofactor that interacted significantly less with the receptor under GCR conditions is p300. NFκB activation and p300 knockdown both reduced direct transcriptional output of GR whereas p300 overexpression and NFκB inhibition reverted TNF-induced GCR, which is in support of a cofactor reshuffle model. This hypothesis was supported by FRET studies. This mechanism of GCR opens avenues for therapeutic interventions in GCR diseases.

The hollow adrenal gland sign: a newly described enhancing pattern of the adrenal gland on dual-phase contrast-enhanced CT for predicting the prognosis of patients with septic shock

OBJECTIVE

To investigate the incidence, CT appearance, and implication for prognosis of the hollow adrenal gland sign (HAGS).

METHODS

A total of 194 patients with septic shock and 24 patients with hemorrhagic shock (as control group) were retrospectively included in this study and the patients with septic shock were further divided into four subgroups (digestive tract diseases, DTD, n = 49; biliary and pancreatic diseases, BPD, n = 41; postsurgical infection, PI, n = 64; and other diseases, OD, n = 40). All patients underwent a dual-phase contrast-enhanced CT within 1 week after diagnosis. CT findings and clinical records were reviewed. If in the arterial phase the central zone of adrenal gland showed temporally much lower attenuation than the peripheral zone, it was defined as HAGS positive. The incidence of the HAGS in patients with septic shock and hemorrhagic shock, the demographic features, and mortality between HAGS-positive and HAGS-negative patients in each group were respectively compared.

RESULTS

The incidence of the HAGS in the septic shock group was nearly 30%, while it was 0 in the hemorrhagic shock group. There was no significant difference in age or gender between HAGS-positive and HAGS-negative patients in all groups, while the mortality of HAGS-positive patients was significantly higher than that of HAGS-negative patients in each group (p < 0.05). The concordance correlation coefficient value showed excellent reproducibility of the two observers (κ = 0.977).

CONCLUSION

The HAGS is specific and common on dual-phase contrast-enhanced CT in patients with septic shock and predicts a poor prognosis.

KEY POINTS

• The hollow adrenal gland sign (HAGS) newly described in this study is a special enhancing pattern of adrenal gland on dual-phase contrast-enhanced CT in patients with septic shock. • The HAGS is characterized by the much lower-attenuated central zone of the adrenal gland in arterial phase and it showed excellent reproducibility between different observers. • The HAGS is specific and common on dual-phase contrast-enhanced CT in patients with septic shock and predicts a poor prognosis.

Kinetics of Physiological and Behavioural Responses in Endotoxemic Pigs with or without Dexamethasone Treatment

Although dexamethasone (DEX) is a widely used immunoregulatory agent, knowledge about its pharmacological properties in farm animals, especially pigs, is insufficient. Previous studies suggest that compared to other species, pigs are less sensitive to the immunosuppression conferred by DEX and more sensitive to the threat of bacterial endotoxins. However, there is a paucity of studies examining DEX immunomodulation in endotoxemia in this species. In this study, a porcine endotoxemia model was established by lipopolysaccharide (LPS) and the effect of DEX-pretreatment on the magnitude and kinetics of neuroendocrine, metabolic, hematologic, inflammatory, and behavioural responses were examined. DEX decreased cortisol, adrenocorticotropic hormone (ACTH), red blood cell, hemoglobin, hematocrit, and lymphocyte whereas glucose concentration was increased under both normal and endotoxemic conditions. By contrast, DEX decreased triglyceride, lactate, and IL-6 concentrations and increased platelet count only under an endotoxemic condition. DEX also reduced the frequency of sickness behaviour following LPS challenge. PCA showed that glucose and triglyceride metabolism together with red blood cell count mainly contributed to the separation of clusters during DEX treatment. Our study demonstrates that DEX protects pigs from inflammation and morbidity in endotoxemia, in spite of their less sensitivity to DEX. Moreover, its considerable role in the regulation of the metabolic and hematologic responses in endotoxemic pigs is revealed for the first time.

Characterization of Pathogenic Sepsis Etiologies and Patient Profiles: A Novel Approach to Triage and Treatment

Pathogenic sepsis is not a monolithic condition. Three major types of sepsis exist within this category: bacterial, viral, and fungal, each with its own mechanism of action. While similar in symptoms, the etiologies and immune mechanisms of these types differ enough that a discrete patient base can be recognized for each one. Non-specific treatment, such as broad-spectrum antibiotics, without determination of sepsis origins may worsen sepsis symptoms and leads to increased morbidity and mortality in patients. However, recognition of current and historical patterns in likely patients for each sepsis type may aid in differentiation between pathogens prior to definitive blood testing. Clinicians may ultimately be able to diagnose and treat bacterial, viral, and fungal sepsis using analysis of previous patient patterns and circumstances in addition to standard care. This method is likely to decrease incidence of multidrug-resistant organisms, organ failure due to ineffective treatment, and turnaround time to the correct treatment for each sepsis patient. Ultimately, we aim to provide classification information on these patient populations and to suggest epidemiology-based screening methods that can be integrated into critical care medicine, specifically triage and treatment of sepsis.

Disease- and treatment-associated acquired glucocorticoid resistance

The development of resistance to glucocorticoids (GCs) in therapeutic regimens poses a major threat. Generally, GC resistance is congenital or acquired over time as a result of disease progression, prolonged GC treatment or, in some cases, both. Essentially, disruptions in the function and/or pool of the glucocorticoid receptor α (GRα) underlie this resistance. Many studies have detailed how alterations in GRα function lead to diminished GC sensitivity; however, the current review highlights the wealth of data concerning reductions in the GRα pool, mediated by disease-associated and treatment-associated effects, which contribute to a significant decrease in GC sensitivity. Additionally, the current understanding of the molecular mechanisms involved in driving reductions in the GRα pool is discussed. After highlighting the importance of maintaining the level of the GRα pool to combat GC resistance, we present current strategies and argue that future strategies to prevent GC resistance should involve biased ligands with a predisposition for reduced GR dimerization, a strategy originally proposed as the SEMOGRAM-SEDIGRAM concept to reduce the side-effect profile of GCs.

Sex-specific deficits in biochemical but not behavioral responses to delay fear conditioning in prenatal alcohol exposure mice

BACKGROUND

Studies in clinical populations and preclinical models have shown that prenatal alcohol exposure (PAE) is associated with impairments in the acquisition, consolidation and recall of information, with deficits in hippocampal formation-dependent learning and memory being a common finding. The glucocorticoid receptor (GR), mineralocorticoid receptor (MR), and extracellular signal-regulated kinase 2 (ERK2) are key regulators of hippocampal formation development, structure and functioning and, thus, are potential mediators of PAE's effects on this brain region. In the present studies, we employed a well-characterized mouse model of PAE to identify biochemical mechanisms that may underlie activity-dependent learning and memory deficits associated with PAE.

METHODS

Mouse dams consumed either 10% (w/v) ethanol in 0.066% (w/v) saccharin (SAC) or 0.066% (w/v) SAC alone using a limited (4-h) access, drinking-in-the-dark paradigm. Male and female offspring (∼180-days of age) were trained using a delay conditioning procedure and contextual fear responses (freezing behavior) were measured 24 h later. Hippocampal formation tissue and blood were collected from three behavioral groups of animals: 20 min following conditioning (conditioning only group), 20 min following the re-exposure to the context (conditioning plus re-exposure group), and behaviorally naïve (naïve group) mice. Plasma corticosterone levels were measured by enzyme immunoassay. Immunoblotting techniques were used to measure protein levels of the GR, MR, ERK1 and ERK2 in nuclear and membrane fractions prepared from the hippocampal formation.

RESULTS

Adult SAC control male and female mice displayed similar levels of contextual fear. However, significant sex differences were observed in freezing exhibited during the conditioning session. Compared to same-sex SAC controls, male and female PAE mice demonstrated context fear deficits While plasma corticosterone concentrations were elevated in PAE males and females relative to their respective SAC naïve controls, plasma corticosterone concentrations in the conditioning only and conditioning plus re-exposure groups were similar in SAC and PAE animals. Relative to the respective naïve group, nuclear GR protein levels were increased in SAC, but not PAE, male hippocampal formation in the conditioning only group. In contrast, no difference was observed between nuclear GR levels in the naïve and conditioning plus re-exposure groups. In females, nuclear GR levels were significantly reduced by PAE but there was no effect of behavioral group or interaction between prenatal treatment and behavioral group. In males, nuclear MR levels were significantly elevated in the SAC conditioning plus re-exposure group compared to SAC naïve mice. In PAE females, nuclear MR levels were elevated in both the conditioning only and conditioning plus re-exposure groups relative to the naïve group. Levels of activated ERK2 (phospho-ERK2 expressed relative to total ERK2) protein were elevated in SAC, but not PAE, males following context re-exposure, and a significant interaction between prenatal exposure group and behavioral group was found. No main effects or interactions of behavioral group and prenatal treatment on nuclear ERK2 were found in female mice. These findings suggest a sex difference in which molecular pathways are activated during fear conditioning in mice.

CONCLUSIONS

In PAE males, the deficits in contextual fear were associated with the loss of responsiveness of hippocampal formation nuclear GR, MR and ERK2 to signals generated by fear conditioning and context re-exposure. In contrast, the contextual fear deficit in PAE female mice does not appear to be associated with activity-dependent changes in GR and MR levels or ERK2 activation during training or memory recall, although an overall reduction in nuclear GR levels may play a role. These studies add to a growing body of literature demonstrating that, at least partially, different mechanisms underlie learning, memory formation and memory recall in males and females and that these pathways are differentially affected by PAE.

A screening assay for Selective Dimerizing Glucocorticoid Receptor Agonists and Modulators (SEDIGRAM) that are effective against acute inflammation

It has been suggested that glucocorticoid receptor (GR) agonists that promote GR homodimerization more than standard glucocorticoids such as Dexamethasone could be more effective anti-inflammatory molecules against acute and life-threatening inflammatory conditions. To test this hypothesis, we set up a screening pipeline aimed at discovering such Selective Dimerizing GR Agonists and Modulators (SEDIGRAM). The pipeline consists of a reporter gene assay based on a palindromic glucocorticoid responsive element (GRE). This assay represents GR dimerization in human A549 lung epithelial cells. In the pipeline, this is followed by analysis of endogenous GRE-driven gene expression, a FRET assay confirming dimerization, and monitoring of in vitro and in vivo anti-inflammatory activity. In a proof of principle experiment, starting from seven candidate compounds, we identified two potentially interesting compounds (Cortivazol and AZD2906) that confer strong protection in a mouse model of aggressive TNF-induced lethal inflammation. A screening pipeline for SEDIGRAM may assist the search for compounds that promote GR dimerization and limit overwhelming acute inflammatory responses.

Reprogramming of basic metabolic pathways in microbial sepsis: therapeutic targets at last?

Sepsis is a highly lethal and urgent unmet medical need. It is the result of a complex interplay of several pathways, including inflammation, immune activation, hypoxia, and metabolic reprogramming. Specifically, the regulation and the impact of the latter have become better understood in which the highly catabolic status during sepsis and its similarity with starvation responses appear to be essential in the poor prognosis in sepsis. It seems logical that new interventions based on the recognition of new therapeutic targets in the key metabolic pathways should be developed and may have a good chance to penetrate to the bedside. In this review, we concentrate on the pathological changes in metabolism, observed during sepsis, and the presumed underlying mechanisms, with a focus on the level of the organism and the interplay between different organ systems.

Glucocorticoid Receptor Binding Induces Rapid and Prolonged Large-Scale Chromatin Decompaction at Multiple Target Loci

Glucocorticoids act by binding to the glucocorticoid receptor (GR), which binds to specific motifs within enhancers of target genes to activate transcription. Previous studies have suggested that GRs can promote interactions between gene promoters and distal elements within target loci. In contrast, we demonstrate here that glucocorticoid addition to mouse bone-marrow-derived macrophages produces very rapid chromatin unfolding detectable by fluorescence in situ hybridization (FISH) at loci associated with GR binding. Rapid chromatin decompaction was generally not dependent on transcription at those loci that are known to be inducible in both mouse and human macrophages and was sustained for up to 5 days following ligand removal. Chromatin decompaction was not dependent upon persistent GR binding, which decayed fully after 24 hr. We suggest that sustained large-scale chromatin reorganization forms an important part of the response to glucocorticoid and might contribute to glucocorticoid sensitivity and resistance.

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Glucocorticoids can induce rapid and persistent chromatin decompaction

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Transcription is not essential for chromatin decompaction

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Large-scale chromatin organization may modulate the glucocorticoid response

Development of a Molecular Signature to Monitor Pharmacodynamic Responses Mediated by In Vivo Administration of Glucocorticoids

OBJECTIVE

To develop an objective, readily measurable pharmacodynamic biomarker of glucocorticoid (GC) activity.

METHODS

Genes modulated by prednisolone were identified from in vitro studies using peripheral blood mononuclear cells from normal healthy volunteers. Using the criteria of a >2-fold change relative to vehicle controls and an adjusted P value cutoff of less than 0.05, 64 up-regulated and 18 down-regulated genes were identified. A composite score of the up-regulated genes was generated using a single-sample gene set enrichment analysis algorithm.

RESULTS

GC gene signature expression was significantly elevated in peripheral blood leukocytes from normal healthy volunteers following oral administration of prednisolone. Expression of the signature increased in a dose-dependent manner, peaked at 4 hours postadministration, and returned to baseline levels by 48 hours after dosing. Lower expression was detected in normal healthy volunteers who received a partial GC receptor agonist, which is consistent with the reduced transactivation potential of this compound. In cohorts of patients with systemic lupus erythematosus and patients with rheumatoid arthritis, expression of the GC signature was negatively correlated with the percentages of peripheral blood lymphocytes and positively correlated with peripheral blood neutrophil counts, which is consistent with the known biology of the GC receptor. Expression of the signature largely agreed with reported GC use in these populations, although there was significant interpatient variability within the dose cohorts.

CONCLUSION

The GC gene signature identified in this study represents a pharmacodynamic marker of GC exposure.

Using the inbred mouse strain SPRET/EiJ to provide novel insights in inflammation and infection research

Inbred mouse strains derived from the species Mus spretus have been very informative in the study of certain gene polymorphisms in inflammation and infection. Based on our interest in sepsis, we used SPRET/EiJ mice and mapped several critical loci that are linked to sensitivity to cytokine-induced inflammation and endotoxemia. These studies were based on prominent phenotypes that have never been observed in strains derived from Mus musculus and we mapped them at a resolution that enables us to draw conclusions on the mechanisms. Now that the genome of SPRET/EiJ has been sequenced, and other tools have become available, it is time to revisit this strain and emphasize its advantages and disadvantages as a research tool and a discovery platform.

Glucocorticoid receptor isoform-specific regulation of development, circadian rhythm, and inflammation in mice

Glucocorticoids are primary stress hormones, and their synthetic derivatives are widely used clinically. The therapeutic efficacy of these steroids is limited by side effects and glucocorticoid resistance. Multiple glucocorticoid receptor (GR) isoforms are produced from a single gene by alternative translation initiation; however, the role individual isoforms play in tissue-specific responses to glucocorticoids is unknown. We have generated knockin mice that exclusively express the most active receptor isoform, GR-C3. GR-C3 knockin mice die at birth due to respiratory distress. Microarray analysis of fibroblasts from wild-type and GR-C3 mice indicated that most genes regulated by GR-C3 were unique to this isoform. Antenatal glucocorticoid administration rescued GR-C3 knockin mice from neonatal death. Dual-energy X-ray absorptiometry revealed no major alterations in body composition for rescued knockin mice. Rescued female, but not male, GR-C3 mice exhibited increased wheel running activity in the light portion of the day. LPS administration induced premature mortality in rescued GR-C3 knockin mice, and gene expression studies revealed a deficiency in the ability of GR-C3 to repress a large cohort of immune and inflammatory response genes. These findings demonstrate that specific GR translational isoforms can influence development, circadian rhythm, and inflammation through the regulation of distinct gene networks.-Oakley, R. H., Ramamoorthy, S., Foley, J. F., Busada, J. T., Lu, N. Z., Cidlowski, J. A. Glucocorticoid receptor isoform-specific regulation of development, circadian rhythm, and inflammation in mice.

Combination of icariin and oleanolic acid attenuates in vivo and in vitro glucocorticoid resistance through protecting dexamethasone-induced glucocorticoid receptor impairment

Glucocorticoid resistance (GCR) remains a significant problem and is the most important reason for treatment failure of glucocorticoids (GCs).

Therapeutic Mechanisms of Glucocorticoids

Glucocorticoids (GCs) have been used clinically for decades as potent anti-inflammatory and immunosuppressive agents. Nevertheless, their use is severely hampered by the risk of developing side effects and the occurrence of glucocorticoid resistance (GCR). Therefore, efforts to understand the complex mechanisms underlying GC function and GCR are ongoing. The goal is to generate new glucocorticoid receptor (GR) ligands that can dissociate anti-inflammatory from metabolic side effects and/or overcome GCR. In this review paper we discuss recent insights into GR-mediated actions in GCR and novel therapeutic strategies for acute and chronic inflammatory diseases.