Cell-Specific Immune Regulation by Glucocorticoids in Murine Models of Infection and Inflammation

Glucocorticoids treatment and adverse infectious events in rheumatic diseases

It is well known that rheumatic diseases are characterized by an increased infection risk, due to several factors, such as an intrinsically dysfunctional immune system, disease activity, and the use of immunosuppressive drugs. Glucocorticoids are widely used therapeutic agents for treating several chronic inflammatory and immune diseases, due to their anti-inflammatory and immunosuppressive effects. Their use is burdened by well-known side effects in dose- and duration of use-dependent manner. Physicians need to be aware of the mechanism of action of glucocorticoids, their side effects, particularly infectious side effects, and the significance of cumulative dose and duration of glucocorticoid treatment. Additionally, physicians shoultdleveld have knowledge of each patient and their comorbidities. They could use appropriate tools for assessing glucocorticoid-related toxicity and morbidity, particularly in the context of chronic glucocorticoid administration. This comprehensive understanding is crucial for ensuring the proper and safe use of these drugs, particularly in terms of minimizing infectious risks. The aim of this review is to focus on available data concerning the infectious risk associated to glucocorticoid treatment in rheumatic diseases, highlighting the role of the correct drug management in clinical practice and the role of the disease itself in the occurrence of this worthy side effect. We conducted a review of randomized controlled trials and observational studies about glucocorticoid use in autoimmune/rheumatic diseases, analyzing the infectious risk during glucocorticoid therapy, and its relationship with the used dose and duration of treatment.

Looking Back to Move Forward: Research in Stress, Behavior, and Immune Function

BACKGROUND

From the original studies investigating the effects of adrenal gland secretion to modern high-throughput multidimensional analyses, stress research has been a topic of scientific interest spanning just over a century.

SUMMARY

The objective of this review was to provide historical context for influential discoveries, surprising findings, and preclinical models in stress-related neuroimmune research. Furthermore, we summarize this work and present a current understanding of the stress pathways and their effects on the immune system and behavior. We focus on recent work demonstrating stress-induced immune changes within the brain and highlight studies investigating stress effects on microglia. Lastly, we conclude with potential areas for future investigation concerning microglia heterogeneity, bone marrow niches, and sex differences.

KEY MESSAGES

Stress is a phenomenon that ties together not only the central and peripheral nervous system, but the immune system as well. The cumulative effects of stress can enhance or suppress immune function, based on the intensity and duration of the stressor. These stress-induced immune alterations are associated with neurobiological changes, including structural remodeling of neurons and decreased neurogenesis, and these contribute to the development of behavioral and cognitive deficits. As such, research in this field has revealed important insights into neuroimmune communication as well as molecular and cellular mediators of complex behaviors relevant to psychiatric disorders.

Development and Validation of a Risk Mortality Prediction Model for Patients with Pulmonary Tuberculosis Complicated by Severe Community-Acquired Pneumonia in the Intensive Care Unit

Purpose

The mortality rate from pulmonary tuberculosis (PTB) complicated by severe community-acquired pneumonia (SCAP) in the intensive care unit (ICU) remains high. We aimed to develop a rapid and simple model for the early assessment and stratification of prognosis in these patients.

Patients and Methods

All adult patients with PTB complicated by SCAP admitted to the ICU of a tertiary hospital in Chengdu, Sichuan, China between 2019 and 2021 (development cohort) and 2022 (validation cohort) were retrospectively included. Data on demographics, comorbidities, laboratory values, and interventions were collected. The outcome was the 28-day mortality. Stepwise backward multivariate Cox analysis was used to develop a mortality risk prediction score model. Receiver operating characteristic (ROC) and calibration curves were used to evaluate the model's predictive efficiency. Decision curve analysis (DCA) was used to validate the model's clinical value and impact on decision making.

Results

Overall, 357 and 168 patients were included in the development and validation cohorts, respectively. The Pulmonary Tuberculosis Severity Index (PTSI) score included long-term use of glucocorticoid, body mass index (BMI) <18.5 kg/m2, diabetes, blood urea nitrogen (BUN) ≥7.14 mmol/L, PO2/FiO2 <150 mmHg, and vasopressor use. The area under the ROC curve (AUC) values were 0.817 (95% CI: 0.772-0.863) and 0.814 for the development and validation cohorts, respectively. The PTSI score had a higher AUC than the APACHE II, SOFA, and CURB-65 score. The calibration curves indicated good calibration in both cohorts. The DCA of the PTSI score indicated the high clinical application of the model compared with the APACHE II and SOFA scores.

Conclusion

This prognostic tool was designed to rapidly evaluate the 28-day mortality risk in individuals with PTB complicated by SCAP. It can stratify this patient group into relevant risk categories, guide targeted interventions, and enhance clinical decision making, thereby optimizing patient care and improving outcomes.

Deficiency of glucocorticoid receptor in bone marrow adipocytes has mild effects on bone and hematopoiesis but does not influence expansion of marrow adiposity with caloric restriction

Introduction

Unlike white adipose tissue depots, bone marrow adipose tissue (BMAT) expands during caloric restriction (CR). Although mechanisms for BMAT expansion remain unclear, prior research suggested an intermediary role for increased circulating glucocorticoids.

Methods

In this study, we utilized a recently described mouse model (BMAd-Cre) to exclusively target bone marrow adipocytes (BMAds) for elimination of the glucocorticoid receptor (GR) (i.e. Nr3c1) whilst maintaining GR expression in other adipose depots.

Results

Mice lacking GR in BMAds (BMAd-Nr3c1 -/-) and control mice (BMAd-Nr3c1 +/+) were fed ad libitum or placed on a 30% CR diet for six weeks. On a normal chow diet, tibiae of female BMAd-Nr3c1-/- mice had slightly elevated proximal trabecular metaphyseal bone volume fraction and thickness. Both control and BMAd-Nr3c1-/- mice had increased circulating glucocorticoids and elevated numbers of BMAds in the proximal tibia following CR. However, no significant differences in trabecular and cortical bone were observed, and quantification with osmium tetroxide and μCT revealed no difference in BMAT accumulation between control or BMAd-Nr3c1 -/- mice. Differences in BMAd size were not observed between BMAd-Nr3c1-/- and control mice. Interestingly, BMAd-Nr3c1-/- mice had decreased circulating white blood cell counts 4 h into the light cycle.

Discussion

In conclusion, our data suggest that eliminating GR from BMAd has minor effects on bone and hematopoiesis, and does not impair BMAT accumulation during CR.

Photochemical reaction of glucocorticoids in aqueous solution: Influencing factors and photolysis products

Glucocorticoids (GCs), as endocrine disruptors, have attracted widespread attention due to their impacts on organisms' growth, development, and reproduction. In the current study, the photodegradation of budesonide (BD) and clobetasol propionate (CP), as targeted GCs, was investigated including the effects of initial concentrations and typical environmental factors (Cl^-, NO₂^-, Fe³⁺, and fulvic acid (FA)). The results showed that the degradation rate constants (k) were 0.0060 and 0.0039 min^-1 for BD and CP at concentration of 50 μg·L^-1, and increased with the initial concentrations. Under the addition of Cl^-, NO₂^-, and Fe³⁺ to the GCs/water system, the photodegradation rate was decreased with increasing Cl^-, NO₂^-, and Fe³⁺ concentrations, which were in contrast to the addition of FA. Electron resonance spectroscopy (EPR) analysis and the radical quenching experiments verified that GCs could transition to the triplet excited states of GCs (³GCs*) for direct photolysis under irradiation to undergo, while NO₂^-, Fe³⁺, and FA could generate ·OH to induce indirect photolysis. According to HPLC-Q-TOF MS analysis, the structures of the three photodegradation products of BD and CP were elucidated, respectively, and the phototransformation pathways were inferred based on the product structures. These findings help to grasp the fate of synthetic GCs in the environment and contribute to the understanding of their ecological risks.

Focusing COVID-19-associated mucormycosis: a major threat to immunocompromised COVID-19

COVID-19 disease has been identified to cause remarkable increase of mucormycosis infection cases in India, with the majority of cases being observed in individuals recovering from COVID-19. Mucormycosis has emanated as an outcome of the recent COVID-19 pandemic outbreak as rapidly developing fatal illness which was acquired by Mucorales fungus which is a subcategory of molds known as mucormycetes. Mucormycosis is one of the serious, sporadic mycotic illnesses which is a great threat to immunocompromised COVID-19 patients and affects people of all ages, including children with COVID-19 infections. This is associated with tissue damaging property and, therefore, causes serious clinical complications and elevated death rate. The COVID-19-associated mucormycosis or "black fungus" are the terms used interchangeably. The rapid growth of tissue necrosis presenting as "rhino-orbital-cerebral, pulmonary, cutaneous, gastrointestinal, and disseminated disease" are various clinical forms of mucormycosis. The patient's prognosis and survival can be improved with proper surgeries using an endoscopic approach for local tissue protection in conjunction with course of appropriate conventional antifungal drug like Amphotericin-B and novel drugs like Rezafungin, encochleated Amphotericin B, Orolofim, and SCY-078 which have been explored in last few years. This review provides an overview of mucormycosis including its epidemiology, pathophysiology, risk factors, its clinical forms, and therapeutic approaches for disease management like antifungal therapy, surgical debridement, and iron chelators. The published patents and ongoing clinical trials related to mucormycosis have also been mentioned in this review.

Immune Modulations by Glucocorticoids: From Molecular Biology to Clinical Research

Due to their potent anti-inflammatory and immune-suppressive actions, glucocorticoids have been used in the treatment of inflammatory and autoimmune disease for more than 70 years [...].