Neurovascular glucocorticoid receptors and glucocorticoids: implications in health, neurological disorders and drug therapy

Establishment of a dexamethasone-induced zebrafish skeletal muscle atrophy model and exploration of its mechanisms

BACKGROUND

Skeletal muscle atrophy is one of the main side effects of high-dose or continuous use of glucocorticoids (such as dexamethasone). However, there are limited studies on dexamethasone-induced skeletal muscle atrophy in zebrafish and even fewer explorations of the underlying molecular mechanisms. This study aimed to construct a model of dexamethasone-induced skeletal muscle atrophy in zebrafish and to investigate the molecular mechanisms.

METHODS

Zebrafish soaked in 0.01 % dexamethasone solution for 10 days. Loli Track (Denmark) and Loligo Swimming Respirometer were used to observe the effect of dexamethasone on swimming ability. The effects of dexamethasone on zebrafish skeletal muscle were observed by Transmission electron microscopy, H&E, and wheat germ agglutinin techniques. Enriched genes and signaling pathways were analyzed using Transcriptome sequencing. Further, the levels of mitochondrial and endoplasmic reticulum-related proteins were examined to investigate possible mechanisms.

RESULTS

0.01 % dexamethasone reduced zebrafish skeletal muscle mass (p < 0.05), myofibre size and cross-sectional area (p < 0.001), and increased protein degradation (ubiquitination and autophagy) (p < 0.05). In addition, 0.01 % dexamethasone reduced the swimming ability of zebrafish, as evidenced by the reluctance to move, fewer movement trajectories, decreased total distance traveled (p < 0.001), average velocity of movement (p < 0.001), oxygen consumption (p < 0.001), critical swimming speed (p < 0.01) and increased exhaustive swimming time (p < 0.001). Further, 0.01 % dexamethasone-induced mitochondrial dysfunction (decreased mitochondrial biogenesis, disturbs kinetic homeostasis, increased autophagy) and endoplasmic reticulum stress.

CONCLUSIONS

0.01 % dexamethasone induces skeletal muscle atrophy and impairs the swimming ability of zebrafish through mitochondrial dysfunction and endoplasmic reticulum stress.

Effect of prednisolone in a kindling model of epileptic seizures in rats on cytokine and intestinal microbiota diversity

Epilepsy is a neurological disease characterized by spontaneous and recurrent seizures. Epileptic seizures can be initiated and facilitated by inflammatory mechanisms. As the dysregulation of the immune system would be involved in epileptogenesis, it is suggested that anti-inflammatory medications could impact epileptic seizures. These medications could potentially have a side effect by altering the structure and composition of the intestinal microbiota. These changes can disrupt microbial homeostasis, leading to dysbiosis and potentially exacerbating intestinal inflammation. We hypothesize that prednisolone may affect the development of epileptic seizures, potentially influencing the diversity of the intestinal microbiota and the regulation of pro-inflammatory cytokines in intestinal tissue. This study aimed to evaluate the effects of prednisolone treatment on epileptic seizures and investigate the effect of this drug on the bacterial diversity of the intestinal microbiota and markers of inflammatory processes in intestinal tissue. We used Male Wistar rat littermates (n = 31, 90-day-old) divided into four groups: positive control treated with 2 mg/kg of diazepam (n = 6), negative control treated with 0.9 g% sodium chloride (n = 6), and the remaining two groups were subjected to treatment with prednisolone, with one receiving 1 mg/kg (n = 9) and the other 5 mg/kg (n = 10). All administrations were performed intraperitoneally (i.p.) over 14 days. To induce the chronic model of epileptic seizures, we administered pentylenetetrazole (PTZ) 25 mg/kg i.p. on alternate days. Seizure latency (n = 6 - 10) and TNF-α and IL-1β concentrations from intestinal samples were measured by ELISA (n = 6 per group), and intestinal microbiota was evaluated with intergenic ribosomal RNA (rRNA) spacer (RISA) analysis (n = 6 per group). The prednisolone treatment demonstrated an increase in the latency time of epileptic seizures and TNF-α and IL-1β concentrations compared to controls. There was no statistically significant difference in intestinal microbiota diversity between the different treatments. However, there was a strong positive correlation between microbial diversity and TNF-α and IL-1β concentrations. The administration of prednisolone yields comparable results to diazepam on increasing latency between seizures, exhibiting promise for its use in clinical studies. Although there were no changes in intestinal microbial diversity, the increase in the TNF-α and IL-1β cytokines in intestinal tissue may be linked to immune system signaling pathways involving the intestinal microbiota. Additional research is necessary to unravel the intricacies of these pathways and to understand their implications for clinical practice.

Peripheral inflammation is associated with impaired sadness recognition in euthymic bipolar patients

BACKGROUND

Inflammation impairs cognitive function in healthy individuals and people with psychiatric disorders, such as bipolar disorder (BD). This effect may also impact emotion recognition, a fundamental element of social cognition. Our study aimed to investigate the relationships between pro-inflammatory cytokines and emotion recognition in euthymic BD patients and healthy controls (HCs).

METHODS

We recruited forty-four euthymic BD patients and forty healthy controls (HCs) and measured their inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and TNF-α. We applied validated cognitive tasks, the Wisconsin Card-Sorting Test (WCST) and Continuous Performance Test (CPT), and a social cognitive task for emotion recognition, Diagnostic Analyses of Nonverbal Accuracy, Taiwanese Version (DANVA-2-TW). We analyzed the relationships between cytokines and cognition and then explored possible predictive factors of sadness recognition accuracy.

RESULTS

Regarding pro-inflammatory cytokines, TNF-α was elevated in euthymic BD patients relative to HCs. In euthymic BD patients only, higher TNF-α levels were associated with lower accuracy of sadness recognition. Regression analysis revealed that TNF-α was an independent predictive factor of sadness recognition in patients with euthymic BD when neurocognition was controlled for.

CONCLUSIONS

We demonstrated that enhanced inflammation, indicated by increased TNF-α, was an independent predictive factor of impaired sadness recognition in BD patients but not in HCs. Our findings suggested a direct influence of TNF-α on sadness recognition and indicated vulnerability to depression in euthymic BD patients with chronic inflammation.

Protective Effect of Glucocorticoids against Symptomatic Disease in CSF1R Variant Carriers

BACKGROUND

There is an unmet need for the treatment of colony-stimulating factor-1 receptor (CSF1R)-related leukoencephalopathy.

OBJECTIVES

To evaluate the association of glucocorticoids (GCs) with disease onset and progression in CSF1R variant carriers.

METHODS

Retrospective cohort study on CSF1R variants carriers (n = 41) whose medical records were collected at Mayo Clinic Florida from 2003 to 2023. We retrieved information on sex, ethnicity, family history, medications, disease onset, course and duration, neuroimaging features, and activities of daily living (ADL).

RESULTS

Risk of developing symptoms was significantly lower for individuals who used GCs (n = 8) compared to individuals who did not (n = 33) (12.5% vs. 81.8%, hazard ratio [HR] = 0.10, P = 0.036). The risk of becoming dependent in ADL was markedly lower for the GCs group (0.0% vs. 43.8%, P = 0.006). White matter lesions and corpus callosum involvement were less common in the GCs group (62.5% vs. 96.6%, P = 0.026; 37.5% vs. 84.6%, P = 0.017; respectively).

CONCLUSIONS

We found a protective association of GCs in CSF1R variant carriers against developing CSF1R-related leukoencephalopathy. We call for further studies to validate our findings and investigate the potential application of GCs in CSF1R-related leukoencephalopathy. © 2023 International Parkinson and Movement Disorder Society.

Physiologic effects of stress dose corticosteroids in in-hospital cardiac arrest (CORTICA): A randomized clinical trial

Aim

Postresuscitation hemodynamics are associated with hospital mortality/functional outcome. We sought to determine whether low-dose steroids started during and continued after cardiopulmonary resuscitation (CPR) affect postresuscitation hemodynamics and other physiological variables in vasopressor-requiring, in-hospital cardiac arrest.

Methods

We conducted a two-center, randomized, double-blind trial of patients with adrenaline (epinephrine)-requiring cardiac arrest. Patients were randomized to receive either methylprednisolone 40 mg (steroids group) or normal saline-placebo (control group) during the first CPR cycle post-enrollment. Postresuscitation shock was treated with hydrocortisone 240 mg daily for 7 days maximum and gradual taper (steroids group), or saline-placebo (control group). Primary outcomes were arterial pressure and central-venous oxygen saturation (ScvO₂) within 72 hours post-ROSC.

Results

Eighty nine of 98 controls and 80 of 86 steroids group patients with ROSC were treated as randomized. Primary outcome data were collected from 100 patients with ROSC (control, n = 54; steroids, n = 46). In intention-to-treat mixed-model analyses, there was no significant effect of group on arterial pressure, marginal mean (95% confidence interval) for mean arterial pressure, steroids vs. control: 74 (68–80) vs. 72 (66–79) mmHg] and ScvO₂ [71 (68–75)% vs. 69 (65–73)%], cardiac index [2.8 (2.5–3.1) vs. 2.9 (2.5–3.2) L/min/m²], and serum cytokine concentrations [e.g. interleukin-6, 89.1 (42.8–133.9) vs. 75.7 (52.1–152.3) pg/mL] determined within 72 hours post-ROSC (P = 0.12–0.86). There was no between-group difference in body temperature, echocardiographic variables, prefrontal blood flow index/cerebral autoregulation, organ failure-free days, and hazard for poor in-hospital/functional outcome, and adverse events (P = 0.08–>0.99).

Conclusions

Our results do not support the use of low-dose corticosteroids in in-hospital cardiac arrest.

Trial Registration:ClinicalTrials.gov number: NCT02790788 (https://www.clinicaltrials.gov).

Ipriflavone as a non-steroidal glucocorticoid receptor antagonist ameliorates diabetic cognitive impairment in mice

Diabetic cognitive impairment (DCI) is a common diabetic complication with hallmarks of loss of learning ability and disorders of memory and behavior. Glucocorticoid receptor (GR) dysfunction is a main reason for neuronal impairment in brain of diabetic patients. Here, we determined that ipriflavone (IP) a clinical anti-osteoporosis drug functioned as a non-steroidal GR antagonist and efficiently ameliorated learning and memory dysfunction in both type 1 and 2 diabetic mice. The underlying mechanism has been intensively investigated by assay against the diabetic mice with GR-specific knockdown in the brain by injection of adeno-associated virus (AAV)-ePHP-si-GR. IP suppressed tau hyperphosphorylation through GR/PI3K/AKT/GSK3β pathway, alleviated neuronal inflammation through GR/NF-κB/NLRP3/ASC/Caspase-1 pathway, and protected against synaptic impairment through GR/CREB/BDNF pathway. To our knowledge, our work might be the first to expound the detailed mechanism underlying the amelioration of non-steroidal GR antagonist on DCI-like pathology in mice and report the potential of IP in treatment of DCI.

Interdisciplinary Approach to Biological and Health Implications in Selected Professional Competences

Everyday life’s hygiene and professional realities, especially in economically developed countries, indicate the need to modify the standards of pro-health programs as well as modern hygiene and work ergonomics programs. These observations are based on the problem of premature death caused by civilization diseases. The biological mechanisms associated with financial risk susceptibility are well described, but there is little data explaining the biological basis of neuroaccounting. Therefore, the aim of the study was to present relationships between personality traits, cognitive competences and biological factors shaping behavioral conditions in a multidisciplinary aspect. This critical review paper is an attempt to compile biological and psychological factors influencing the development of professional competences, especially decent in the area of accounting and finance. We analyzed existing literature from wide range of scientific disciplines (including economics, psychology, behavioral genetics) to create background to pursuit multidisciplinary research models in the field of neuroaccounting. This would help in pointing the best genetically based behavioral profile of future successful financial and accounting specialists.

Trimetazidine attenuates dexamethasone-induced muscle atrophy via inhibiting NLRP3/GSDMD pathway-mediated pyroptosis

Skeletal muscle atrophy is one of the major side effects of high dose or sustained usage of glucocorticoids. Pyroptosis is a novel form of pro-inflammatory programmed cell death that may contribute to skeletal muscle injury. Trimetazidine, a well-known anti-anginal agent, can improve skeletal muscle performance both in humans and mice. We here showed that dexamethasone-induced atrophy, as evidenced by the increase of muscle atrophy F-box (Atrogin-1) and muscle ring finger 1 (MuRF1) expression, and the decrease of myotube diameter in C2C12 myotubes. Dexamethasone also induced pyroptosis, indicated by upregulated pyroptosis-related protein NLR family pyrin domain containing 3 (NLRP3), Caspase-1, and gasdermin-D (GSDMD). Knockdown of NLRP3 or GSDMD attenuated dexamethasone-induced myotube pyroptosis and atrophy. Trimetazidine treatment ameliorated dexamethasone-induced muscle pyroptosis and atrophy both in vivo and in vitro. Activation of NLRP3 using LPS and ATP not only increased the cleavage and activation of Caspase-1 and GSDMD, but also increased the expression levels of atrophy markers MuRF1 and Atrogin-1 in trimetazidine-treated C2C12 myotubes. Mechanically, dexamethasone inhibited the phosphorylation of PI3K/AKT/FoxO3a, which could be attenuated by trimetazidine. Conversely, co-treatment with a PI3K/AKT inhibitor, picropodophyllin, remarkably increased the expression of NLRP3 and reversed the protective effects of trimetazidine against dexamethasone-induced C2C12 myotube pyroptosis and atrophy. Taken together, our study suggests that NLRP3/GSDMD-mediated pyroptosis might be a novel mechanism for dexamethasone-induced skeletal muscle atrophy. Trimetazidine might be developed as a potential therapeutic agent for the treatment of dexamethasone-induced muscle atrophy.

Glucocorticoids as Regulators of Macrophage-Mediated Tissue Homeostasis

Our immune system has evolved as a complex network of cells and tissues tasked with maintaining host homeostasis. This is evident during the inflammatory responses elicited during a microbial infection or traumatic tissue damage. These responses seek to eliminate foreign material or restore tissue integrity. Even during periods without explicit disturbances, the immune system plays prominent roles in tissue homeostasis. Perhaps one of the most studied cells in this regard is the macrophage. Tissue-resident macrophages are a heterogenous group of sensory cells that respond to a variety of environmental cues and are essential for organ function. Endogenously produced glucocorticoid hormones connect external environmental stress signals with the function of many cell types, producing profound changes in immune cells, including macrophages. Here, we review the current literature which demonstrates specific effects of glucocorticoids in several organ systems. We propose that tissue-resident macrophages, through glucocorticoid signaling, may play an underappreciated role as regulators of organ homeostasis.

COVID-19-Associated Neurological Disorders: The Potential Route of CNS Invasion and Blood-Brain Relevance

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel human coronavirus that has sparked a global pandemic of the coronavirus disease of 2019 (COVID-19). The virus invades human cells through the angiotensin-converting enzyme 2 (ACE2) receptor-driven pathway, primarily targeting the human respiratory tract. However, emerging reports of neurological manifestations demonstrate the neuroinvasive potential of SARS-CoV-2. This review highlights the possible routes by which SARS-CoV-2 may invade the central nervous system (CNS) and provides insight into recent case reports of COVID-19-associated neurological disorders, namely ischaemic stroke, encephalitis, encephalopathy, epilepsy, neurodegenerative diseases, and inflammatory-mediated neurological disorders. We hypothesize that SARS-CoV-2 neuroinvasion, neuroinflammation, and blood-brain barrier (BBB) dysfunction may be implicated in the development of the observed disorders; however, further research is critical to understand the detailed mechanisms and pathway of infectivity behind CNS pathogenesis.

Heat Shock Proteins Accelerate the Maturation of Brain Endothelial Cell Glucocorticoid Receptor in Focal Human Drug-Resistant Epilepsy

Pharmacoresistance in epilepsy is a major challenge to successful clinical therapy. Glucocorticoid receptor (GR) dysregulation can affect the underlying disease pathogenesis. We recently reported that local drug biotransformation at the blood-brain barrier is upregulated by GR, which controls drug-metabolizing enzymes (e.g., cytochrome P450s, CYPs) and efflux drug transporters (MDR1) in human epileptic brain endothelial cells (EPI-ECs). Here, we establish that this mechanism is influenced upstream by GR and its association with heat shock proteins/co-chaperones (Hsps) during maturation, which differentially affect human epileptic (EPI) tissue and brain endothelial cells. Overexpressed GR, Hsp90, Hsp70, and Hsp40 were found in EPI vs. NON-EPI brain regions. Elevated neurovascular GR expression and co-localization with Hsps was evident in the EPI regions with cortical dysplasia, predominantly in the brain micro-capillaries and neurons. A corresponding increase in ATPase activity (*p < 0.05) was found in the EPI regions. The GR-Hsp90/Hsp70 binding patterns indicated a faster chaperone-promoted maturation of GR, leading to its overactivation in both the tissue and EPI-ECs derived from EPI/focal regions and GR silencing in EPI-ECs slowed such GR-Hsp interactions. Significantly accelerated GR nuclear translocation was determined in EPI-ECs following treatment with GR modulators/ligands dexamethasone, rifampicin, or phenytoin. Our findings reveal that overexpressed GR co-localizes with Hsps in the neurovasculature of EPI brain, increased GR maturation by Hsps accelerates EPI GR machinery, and furthermore this change in EPI and NON-EPI GR-Hsp interaction alters with the age of seizure onset in epileptic patients, together affecting the pathophysiology and drug regulation in the epileptic brain endothelium.