Corticosteroids in the treatment of rheumatologic diseases

Repression of transcription by the glucocorticoid receptor: A parsimonious model for the genomics era

Glucocorticoids are potent anti-inflammatory drugs that are used to treat an extraordinary range of human disease, including COVID-19, underscoring the ongoing importance of understanding their molecular mechanisms. Early studies of GR signaling led to broad acceptance of models in which glucocorticoid receptor (GR) monomers tether repressively to inflammatory transcription factors, thus abrogating inflammatory gene expression. However, newer data challenge this core concept and present an exciting opportunity to reframe our understanding of GR signaling. Here, we present an alternate, two-part model for transcriptional repression by glucocorticoids. First, widespread GR-mediated induction of transcription results in rapid, primary repression of inflammatory gene transcription and associated enhancers through competition-based mechanisms. Second, a subset of GR-induced genes, including targets that are regulated in coordination with inflammatory transcription factors such as NF-κB, exerts secondary repressive effects on inflammatory gene expression. Within this framework, emerging data indicate that the gene set regulated through the cooperative convergence of GR and NF-κB signaling is central to the broad clinical effectiveness of glucocorticoids in terminating inflammation and promoting tissue repair.

Nascent transcript analysis of glucocorticoid crosstalk with TNF defines primary and cooperative inflammatory repression

The glucocorticoid receptor (NR3C1, also known as GR) binds to specific DNA sequences and directly induces transcription of anti-inflammatory genes that contribute to cytokine repression, frequently in cooperation with NF-kB. Whether inflammatory repression also occurs through local interactions between GR and inflammatory gene regulatory elements has been controversial. Here, using global run-on sequencing (GRO-seq) in human airway epithelial cells, we show that glucocorticoid signaling represses transcription within 10 min. Many repressed regulatory regions reside within "hyper-ChIPable" genomic regions that are subject to dynamic, yet nonspecific, interactions with some antibodies. When this artifact was accounted for, we determined that transcriptional repression does not require local GR occupancy. Instead, widespread transcriptional induction through canonical GR binding sites is associated with reciprocal repression of distal TNF-regulated enhancers through a chromatin-dependent process, as evidenced by chromatin accessibility and motif displacement analysis. Simultaneously, transcriptional induction of key anti-inflammatory effectors is decoupled from primary repression through cooperation between GR and NF-kB at a subset of regulatory regions. Thus, glucocorticoids exert bimodal restraints on inflammation characterized by rapid primary transcriptional repression without local GR occupancy and secondary anti-inflammatory effects resulting from transcriptional cooperation between GR and NF-kB.

THE EFFECTS OF VARIOUS DOSES OF PREDNISOLONE ADMINISTRATION ON SERUM VASPIN LEVELS IN RATS

AIM

The aim of this study was to investigate the dose-dependent effects of prednisolone administration on serum vaspin levels and correlate this with changes in the BMI and lipogenesis in rats.

MATERIALS AND METHODS

Twenty-four albino Wistar male rats weighing between 190-240 g were divided into four groups, three experimental (5 mg/kg, 10 mg/kg, and 20 mg/kg prednisolone) and one control. The prednisolone groups were given once-daily doses for 30 days, orally. In addition, the rats were weighed, and their height and waist circumferences were measured once a week. At the end of 30 days, vaspin and glucose levels were measured from blood samples.

RESULTS

In the prednisolone groups, the vaspin levels significantly increased when compared with the control group. The control group has a serum vaspin level of 155 ± 20.99 pg/mL and this level has been increased by prednisolone administration in a dose dependent manner. In the prednisolone groups, especially the 10 mg/kg and 20 mg/kg groups, the glucose levels increased in a dose dependent fashion.

CONCLUSION

Prednisolone administration significantly increased serum glucose and vaspin levels in a dose dependent manner, indicating that the increase in the serum vaspin levels could be related to the increase in the serum glucose concentration. Vaspin can be a molecule that is released in response to increased glucose and can be a rebound defense mechanism to modulate the blood glucose concentration. We suggest vaspin as a potential target for the treatment and diagnosis of diabetes mellitus and other metabolic disorders.

Genetic Approaches to Hypothalamic-Pituitary-Adrenal Axis Regulation

The normal function of the hypothalamic-pituitary-adrenal (HPA) axis, and resultant glucocorticoid (GC) secretion, is essential for human health. Disruption of GC regulation is associated with pathologic, psychological, and physiological disease states such as depression, post-traumatic stress disorder, hypertension, diabetes, and osteopenia, among others. As such, understanding the mechanisms by which HPA output is tightly regulated in its responses to environmental stressors and circadian cues has been an active area of investigation for decades. Over the last 20 years, however, advances in gene targeting and genome modification in rodent models have allowed the detailed dissection of roles for key molecular mediators and brain regions responsible for this control in vivo to emerge. Here, we summarize work done to elucidate the function of critical neuropeptide systems, GC-signaling targets, and inflammation-associated pathways in HPA axis regulation and behavior, and highlight areas for future investigation.

Incidence of Symptomatic Vertebral Fractures Among Newly Diagnosed Autoimmune Diseases Initiating Glucocorticoid Therapy

Few data are available regarding vertebral fracture risk in patients treated with corticosteroids including patients with interstitial lung disease (ILD). The aim of the present study was to identify risk factors for symptomatic vertebral fracture analyzed in patients with newly diagnosed autoimmune diseases.This was an observational cohort study conducted in the National Hospital Organization-EBM study group from 2006 to 2008. The study subjects were autoimmune disease patients who were newly treated with glucocorticoids (GCs). The primary endpoint was the first occurrence of vertebral fracture diagnosed by x-rays. Cox proportional-hazards regression was used to determine independent risk factors for vertebral fracture with covariates including sex, age, comorbidity, laboratory data, use of immunosuppressants, and dose of GCs. Survival was analyzed according to the Kaplan-Meier method and assessed by the log-rank test.Among 604 patients of mean age 59.5 years and mean GC dose 50.4 mg/d (first 1 months), 19 patient (3.1%) had at least 1 symptomatic vertebral fracture during 1.9 years of follow-up period. Cox regression model demonstrated that the relative risk for symptomatic vertebral fracture was independently higher in patient with ILD (hazard ratio [HR] = 2.86, 95% confidence interval [CI] = 1.10-7.42, P = 0.031) and in every 10-year increment of the age of disease onset (HR = 1.57, 95% CI = 1.09-2.26, P = 0.015). Kaplan-Meier analyses demonstrated that the incidence of vertebral fractures in patients with ILD was significantly higher in comparison with those without ILD.Our results indicate a higher risk of vertebral facture in patients with ILD and elderly patients during the initial GC treatment against autoimmune diseases. There is a need for further, even longer-term, prospective studies subjected patients with autoimmune disease, including ILD, under GC treatment.

Glucocorticoid Therapy and the Risk of Infection in Patients With Newly Diagnosed Autoimmune Disease

Glucocorticoid (GC) therapy is associated with the risk of life-threatening adverse events in patients with autoimmune disease. To determine accurately the incidence and predictors of GC-related adverse events during initial GC treatment, we conducted a cohort study. Patients with autoimmune disease who were initially treated with GCs in Japan National Hospital Organization (NHO) hospitals were enrolled. Cox proportional hazard regression was used to determine the independent risks for GC-related serious adverse events and mortality. Survival was analyzed according to the Kaplan-Meier method and was assessed with the log-rank test.The 604 patients had a total follow-up of 1105.8 person-years (mean, 1.9 year per patient). One hundred thirty-six patients had at least 1 infection with objective confirmation, and 71 patients had serious infections. Twenty-two cardiovascular events, 55 cases of diabetes, 30 fractures, 23 steroid psychosis events, and 4 avascular bone necrosis events occurred during the follow-up period. The incidence of serious infections was 114.8 (95% confidence interval, 95.7-136.6) per 1000 person-years. After adjustment for covariates, the following independent risk factors for serious infection were found: elderly age (hazard ratio [HR], 1.25/10-yr age increment; p = 0.016), presence of interstitial lung disease (HR, 2.01; p = 0.011), high-dose GC use (≥29.9 mg/d) (HR, 1.71; p = 0.047), and low performance status (Karnofsky score, HR, 0.98/1-score increment; p = 0.002). During the follow-up period, 73 patients died, 35 of whom died of infection. Similarly, elderly age, the presence of interstitial lung disease, and high-dose GC use were found to be significant independent risk factors for mortality. The incidence of serious and life-threatening infection was higher in patients with autoimmune disease who were initially treated with GCs. Although the primary diseases are important confounding factors, elderly age, male sex, the presence of interstitial lung diseases, high-dose GCs, and low performance status were shown to be risk factors for serious infection and mortality.

Treatment of acute transverse myelitis and its early complications

Acute transverse myelitis (ATM) has many potential etiologies, but a significant proportion of cases are categorized as idiopathic despite thorough evaluation. Clinical presentation of ATM typically includes some combination of motor weakness, sensory symptoms, and bowel and bladder dysfunction. Prompt recognition, even before a final etiologic diagnosis is reached, is critical to initiating early therapeutic intervention to reduce the harmful effects of inflammation. Acute therapeutic options for ATM include corticosteroids, plasma exchange, IV immunoglobulin, and chemotherapeutic agents such as cyclophosphamide. In some instances, combinations of these therapies are used. This article examines the therapeutic approach to ATM and its various acute clinical manifestations.

Successful factorial design for the optimization of methylprednisolone encapsulation in biodegradable nanoparticles

Due to their crystalline nature, the encapsulation of hydrophobic corticosteroids within polymeric nanoparticles by o/w solvent evaporation method is often difficult to achieve. The aim of this study was to evaluate the effect of both process and formulation parameters on the encapsulation of a model corticosteroid: methylprednisolone (MP). For this purpose, a 3(2)factorial design was performed evaluating the effects of the concentration of emulsifiers and sonication time on the manufactured nanoparticles, followed by a multiresponse optimization. The study also included the evaluation of other parameters such as the type of organic solvent used, polymer characteristics and the initial mass of drug. The optimal nanoparticle formulation using 0.25% (w/v) of emulsifying agent (Polyvinyl-alcohol, PVA) and 5 min of sonication was then characterized. The highest encapsulation was obtained with an organic phase consisting of acetone: dichloromethane (1:1), polyD,L-lactide-co-glycolide (PLGA) 50:50 as polymer and an initial mass of 6.6 mg of methylprednisolone. Nanoparticles size and ζ potential of optimized formulation were respectively around 230 nm and -14 mV. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) demonstrated that the drug was molecularly dispersed within the nanoparticles. Release study showed that MP-loaded nanoparticles sustained drug release for up to 120 h. This study reflects the importance of factorial design to optimize the manufacture of nanoparticles encapsulating hydrophobic drugs.