Controlled dual release of dihydrotestosterone and flutamide from polycaprolactone electrospun scaffolds accelerate burn wound healing.

Wound healing is a complex process involving multiple independent and overlapping sequential physiological mechanisms. In addition to cutaneous injury, a severe burn stimulates physiological derangements that induce a systemic hypermetabolic response resulting in impaired wound healing. Topical application of the anti-androgen drug, flutamide accelerates cutaneous wound healing, whereas paradoxically systemic dihydrotestosterone (DHT) improves burn wound healing. We developed and characterized a PCL scaffold that is capable of controlled release of androgen (DHT) and anti-androgen (F) individually or together. This study aims to investigate whether local modification of androgen actions has an impact on burn injury wound healing. In a full-thickness burn wound healing, mouse model, DHT/F-scaffold showed a significantly faster wound healing compared with F-scaffold or DHT-scaffold. Histology analysis confirmed that DHT/F-scaffold exhibited higher re-epithelization, cell proliferation, angiogenesis, and collagen deposition. Dual release of DHT and F from PCL scaffolds promoted cell proliferation of human keratinocytes and alters the keratinocyte cell cycle. Lastly, no adverse effects on androgen-dependent organs, spleen and liver were observed. In conclusion, we demonstrated DHT plus F load PCL scaffolds accelerated burn wound healing when loading alone did not. These findings point to a complex role of androgens in burn wound healing and open novel therapeutic avenues for treating severe burn patients.

Efficient, multi-hundred-gram scale access to E3 ubiquitin ligase ligands for degrader development.

Small molecule heterobifunctional degraders (commonly also known as PROTACs) offer tremendous potential to deliver new therapeutics in areas of unmet medical need. To deliver on this promise, a new discipline directed at degrader design and optimization has emerged within medicinal chemistry to address a central challenge, namely how to optimize relatively large, heterobifunctional molecules for activity, whilst maintaining drug-like properties. This process involves simultaneous optimization of the three principle degrader components: E3 ubiquitin ligase ligand, linker, and protein of interest (POI) ligand. A substantial degree of commonality exists with the E3 ligase ligands typically used at the early stages of degrader development, resulting in demand for these compounds as chemical building blocks in degrader research programs. We describe herein a collation of large scale, high-yielding syntheses to access the most utilized E3 ligase ligands to support early-stage degrader development.

11ß-Hydroxysteroid Dehydrogenase Type 1 within Osteoclasts Mediates the Bone Protective Properties of Therapeutic Corticosteroids in Chronic Inflammation.

Therapeutic glucocorticoids (GCs) are powerful anti-inflammatory tools in the management of chronic inflammatory diseases such as rheumatoid arthritis (RA). However, their actions on bone in this context are complex. The enzyme 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) is a mediator of the anti-inflammatory actions of therapeutic glucocorticoids (GCs) in vivo. In this study we delineate the role of 11ß-HSD1 in the effects of GC on bone during inflammatory polyarthritis. Its function was assessed in bone biopsies from patients with RA and osteoarthritis, and in primary osteoblasts and osteoclasts. Bone metabolism was assessed in the TNF-tg model of polyarthritis treated with oral GC (corticosterone), in animals with global (TNF-tg11ßKO), mesenchymal (including osteoblast) (TNF-tg11ßflx/tw2cre) and myeloid (including osteoclast) (TNF-tg11ßflx/LysMcre) deletion. Bone parameters were assessed by micro-CT, static histomorphometry and serum metabolism markers. We observed a marked increase in 11ß-HSD1 activity in bone in RA relative to osteoarthritis bone, whilst the pro-inflammatory cytokine TNFα upregulated 11ß-HSD1 within osteoblasts and osteoclasts. In osteoclasts, 11ß-HSD1 mediated the suppression of bone resorption by GCs. Whilst corticosterone prevented the inflammatory loss of trabecular bone in TNF-tg animals, counterparts with global deletion of 11ß-HSD1 were resistant to these protective actions, characterised by increased osteoclastic bone resorption. Targeted deletion of 11ß-HSD1 within osteoclasts and myeloid derived cells partially reproduced the GC resistant phenotype. These data reveal the critical role of 11ß-HSD1 within bone and osteoclasts in mediating the suppression of inflammatory bone loss in response to therapeutic GCs in chronic inflammatory disease.

Global Deletion of 11ß-HSD1 Prevents Muscle Wasting Associated with Glucocorticoid Therapy in Polyarthritis.

Glucocorticoids provide indispensable anti-inflammatory therapies. However, metabolic adverse effects including muscle wasting restrict their use. The enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) modulates peripheral glucocorticoid responses through pre-receptor metabolism. This study investigates how 11ß-HSD1 influences skeletal muscle responses to glucocorticoid therapy for chronic inflammation. We assessed human skeletal muscle biopsies from patients with rheumatoid arthritis and osteoarthritis for 11ß-HSD1 activity ex vivo. Using the TNF-α-transgenic mouse model (TNF-tg) of chronic inflammation, we examined the effects of corticosterone treatment and 11ß-HSD1 global knock-out (11ßKO) on skeletal muscle, measuring anti-inflammatory gene expression, muscle weights, fiber size distribution, and catabolic pathways. Muscle 11ß-HSD1 activity was elevated in patients with rheumatoid arthritis and correlated with inflammation markers. In murine skeletal muscle, glucocorticoid administration suppressed IL6 expression in TNF-tg mice but not in TNF-tg11ßKO mice. TNF-tg mice exhibited reductions in muscle weight and fiber size with glucocorticoid therapy. In contrast, TNF-tg11ßKO mice were protected against glucocorticoid-induced muscle atrophy. Glucocorticoid-mediated activation of catabolic mediators (FoxO1, Trim63) was also diminished in TNF-tg11ßKO compared to TNF-tg mice. In summary, 11ß-HSD1 knock-out prevents muscle atrophy associated with glucocorticoid therapy in a model of chronic inflammation. Targeting 11ß-HSD1 may offer a strategy to refine the safety of glucocorticoids.

Cumulative dispensing of high oral corticosteroid doses for treating asthma in Australia.

OBJECTIVE: To estimate the level of dispensing of oral corticosteroids (OCS) for managing asthma in Australia, with a particular focus on the cumulative dispensing of doses associated with long term toxicity (≥ 1000 mg prednisolone-equivalent). DESIGN: Retrospective cohort study; analysis of 10% random sample of Pharmaceutical Benefits Scheme (PBS) dispensing data. PARTICIPANTS, SETTING: People aged 12 years or more treated for asthma during 2014-2018, according to dispensing of controller inhaled corticosteroids (ICS). MAIN OUTCOME MEASURES: Number of people dispensed OCS for managing asthma during 2014-2018; proportion who were cumulatively dispensed at least 1000 mg prednisolone-equivalent. The secondary outcome was the number of people dispensed at least 1000 mg prednisolone-equivalent during 2018, stratified by inhaler controller dose and use. RESULTS: 124 011 people had been dispensed at least two prescriptions of ICS during 2014-2018 and met the study definition for asthma, of whom 64 112 (51.7%) had also been dispensed OCS, including 34 580 (27.9% of the asthma group) cumulatively dispensed 1000 mg prednisolone-equivalent or more. Of 138 073 people dispensed OCS at this level, 68 077 (49%) were patients with airway diseases. Dispensing of diabetes and osteoporosis medications was more common for people cumulatively dispensed 1000 mg prednisolone-equivalent or more. During 2018, 4633 people with asthma using high dose ICS controllers were dispensed 1000 mg prednisolone-equivalent or more, for 2316 of whom (50%) controller use was inadequate. CONCLUSIONS: Cumulative exposure to OCS in Australia reaches levels associated with toxicity in one-quarter of patients with asthma using ICS. Cumulative dispensing of potentially toxic OCS amounts often accompanies inadequate inhaler controller dispensing. Better approaches are needed to improve adherence to controller therapy, improve outcomes for people with asthma, and to minimise the use and toxicity of OCS.

Dihydrotestosterone (DHT) Enhances Wound Healing of Major Burn Injury by Accelerating Resolution of Inflammation in Mice.

Androgens have been known to inhibit cutaneous wound healing in men and male mice. However, in children with major burn injuries, a synthetic androgen was reported clinically to improve wound healing. The aim of this study is to investigate the role of dihydrotestosterone (DHT) as a new therapeutic approach in treating major burn injury. In the present study, mice received systemic androgen treatment post major burn injury. Wound healing rate and body weight were monitored over 21 days. The serum level of inflammatory cytokines/chemokines were measured using multiplex immunoassays. In addition, splenocyte enumeration was performed by flow cytometry. Healing phases of inflammation, re-epithelialization, cell proliferation and collagen deposition were also examined. In results, DHT treated mice lost less weight and displayed accelerated wound healing but has no impact on hypermetabolism. Mice, after burn injury, displayed acute systemic inflammatory responses over 21 days. DHT treatment shortened the systemic inflammatory response with reduced splenic weight and monocyte numbers on day 14 and 21. DHT treatment also reduced wound infiltrating macrophage numbers. In conclusion, DHT treatment facilitates local wound healing by accelerating the resolution of inflammation, but not through alterations of post-burn hypermetabolic response.

Endogenous glucocorticoid signaling in chondrocytes attenuates joint inflammation and damage.

Previous studies demonstrated that endogenous glucocorticoid signaling in osteoblasts promotes inflammation in murine immune arthritis. The current study determined whether disruption of endogenous glucocorticoid signaling in chondrocytes also modulates the course and severity of arthritis. Tamoxifen-inducible chondrocyte-targeted glucocorticoid receptor-knockout (chGRKO) mice were generated by breeding GRflox/flox mice with tamoxifen-inducible collagen 2a1 Cre (Col2a1-CreERT2) mice. Antigen-induced arthritis (AIA) and K/BxN serum transfer-induced arthritis (STIA) were induced in both chGRKO mice and their Cre-negative GRflox/flox littermates [wild type (WT)]. Arthritis was assessed by measurement of joint swelling and histology of joints collected at d 14. Neutrophil activity and gene expression patterns associated with cartilage damage were also evaluated. In both arthritis models clinical (joint swelling) and histologic indices of inflammatory activity were significantly greater in chGRKO than in WT mice. The STIA model was characterized by early up-regulation of CXCR2/CXCR2 ligand gene expression in ankle tissues, and significant and selective expansion of splenic CXCR2+ neutrophils in chGRKO arthritic compared to WT arthritic mice. At later stages, gene expression of enzymes involved in cartilage degradation was up-regulated in chGRKO but not WT arthritic mice. Therefore, we summarize that chondrocytes actively mitigate local joint inflammation, cartilage degradation and systemic neutrophil activity via a glucocorticoid-dependent pathway.-Tu, J., Stoner, S., Fromm, P. D., Wang, T., Chen, D., Tuckermann, J., Cooper, M. S., Seibel, M. J., Zhou, H. Endogenous glucocorticoid signaling in chondrocytes attenuates joint inflammation and damage.

Vitamin D to Prevent Lung Injury Following Esophagectomy-A Randomized, Placebo-Controlled Trial.

OBJECTIVES: Observational studies suggest an association between vitamin D deficiency and adverse outcomes of critical illness and identify it as a potential risk factor for the development of lung injury. To determine whether preoperative administration of oral high-dose cholecalciferol ameliorates early acute lung injury postoperatively in adults undergoing elective esophagectomy. DESIGN: A double-blind, randomized, placebo-controlled trial. SETTING: Three large U.K. university hospitals. PATIENTS: Seventy-nine adult patients undergoing elective esophagectomy were randomized. INTERVENTIONS: A single oral preoperative (3-14 d) dose of 7.5 mg (300,000 IU; 15 mL) cholecalciferol or matched placebo. MEASUREMENTS AND MAIN RESULTS: Primary outcome was change in extravascular lung water index at the end of esophagectomy. Secondary outcomes included PaO2:FIO2 ratio, development of lung injury, ventilator and organ-failure free days, 28 and 90 day survival, safety of cholecalciferol supplementation, plasma vitamin D status (25(OH)D, 1,25(OH)2D, and vitamin D-binding protein), pulmonary vascular permeability index, and extravascular lung water index day 1 postoperatively. An exploratory study measured biomarkers of alveolar-capillary inflammation and injury. Forty patients were randomized to cholecalciferol and 39 to placebo. There was no significant change in extravascular lung water index at the end of the operation between treatment groups (placebo median 1.0 [interquartile range, 0.4-1.8] vs cholecalciferol median 0.4 mL/kg [interquartile range, 0.4-1.2 mL/kg]; p = 0.059). Median pulmonary vascular permeability index values were significantly lower in the cholecalciferol treatment group (placebo 0.4 [interquartile range, 0-0.7] vs cholecalciferol 0.1 [interquartile range, -0.15 to -0.35]; p = 0.027). Cholecalciferol treatment effectively increased 25(OH)D concentrations, but surgery resulted in a decrease in 25(OH)D concentrations at day 3 in both arms. There was no difference in clinical outcomes. CONCLUSIONS: High-dose preoperative treatment with oral cholecalciferol was effective at increasing 25(OH)D concentrations and reduced changes in postoperative pulmonary vascular permeability index, but not extravascular lung water index.

Critical Illness-Related Corticosteroid Insufficiency (CIRCI): A Narrative Review from a Multispecialty Task Force of the Society of Critical Care Medicine (SCCM) and the European Society of Intensive Care Medicine (ESICM).

OBJECTIVE: To provide a narrative review of the latest concepts and understanding of the pathophysiology of critical illness-related corticosteroid insufficiency (CIRCI). PARTICIPANTS: A multi-specialty task force of international experts in critical care medicine and endocrinology and members of the Society of Critical Care Medicine and the European Society of Intensive Care Medicine. DATA SOURCES: Medline, Database of Abstracts of Reviews of Effects (DARE), Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Database of Systematic Reviews. RESULTS: Three major pathophysiologic events were considered to constitute CIRCI: dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, altered cortisol metabolism, and tissue resistance to glucocorticoids. The dysregulation of the HPA axis is complex, involving multidirectional crosstalk between the CRH/ACTH pathways, autonomic nervous system, vasopressinergic system, and immune system. Recent studies have demonstrated that plasma clearance of cortisol is markedly reduced during critical illness, explained by suppressed expression and activity of the primary cortisol-metabolizing enzymes in the liver and kidney. Despite the elevated cortisol levels during critical illness, tissue resistance to glucocorticoids is believed to occur due to insufficient glucocorticoid alpha-mediated anti-inflammatory activity. CONCLUSIONS: Novel insights into the pathophysiology of CIRCI add to the limitations of the current diagnostic tools to identify at-risk patients and may also impact how corticosteroids are used in patients with CIRCI.

Guidelines for the Diagnosis and Management of Critical Illness-Related Corticosteroid Insufficiency (CIRCI) in Critically Ill Patients (Part I): Society of Critical Care Medicine (SCCM) and European Society of Intensive Care Medicine (ESICM) 2017.

OBJECTIVE: To update the 2008 consensus statements for the diagnosis and management of critical illness-related corticosteroid insufficiency (CIRCI) in adult and pediatric patients. PARTICIPANTS: A multispecialty task force of 16 international experts in critical care medicine, endocrinology, and guideline methods, all of them members of the Society of Critical Care Medicine and/or the European Society of Intensive Care Medicine. DESIGN/METHODS: The recommendations were based on the summarized evidence from the 2008 document in addition to more recent findings from an updated systematic review of relevant studies from 2008 to 2017 and were formulated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The strength of each recommendation was classified as strong or conditional, and the quality of evidence was rated from high to very low based on factors including the individual study design, the risk of bias, the consistency of the results, and the directness and precision of the evidence. Recommendation approval required the agreement of at least 80% of the task force members. RESULTS: The task force was unable to reach agreement on a single test that can reliably diagnose CIRCI, although delta cortisol (change in baseline cortisol at 60 min of < 9 µg/dL) after cosyntropin (250 µg) administration and a random plasma cortisol of < 10 µg/dL may be used by clinicians. We suggest against using plasma-free cortisol or salivary cortisol level over plasma total cortisol (conditional, very low quality of evidence). For treatment of specific conditions, we suggest using IV hydrocortisone < 400 mg/day for ≥ 3 days at full dose in patients with septic shock that is not responsive to fluid and moderate- to high-dose vasopressor therapy (conditional, low quality of evidence). We suggest not using corticosteroids in adult patients with sepsis without shock (conditional recommendation, moderate quality of evidence). We suggest the use of IV methylprednisolone 1 mg/kg/day in patients with early moderate to severe acute respiratory distress syndrome (PaO2/FiO2 < 200 and within 14 days of onset) (conditional, moderate quality of evidence). Corticosteroids are not suggested for patients with major trauma (conditional, low quality of evidence). CONCLUSIONS: Evidence-based recommendations for the use of corticosteroids in critically ill patients with sepsis and septic shock, acute respiratory distress syndrome, and major trauma have been developed by a multispecialty task force.

Transgenic Disruption of Glucocorticoid Signaling in Osteoblasts Attenuates Joint Inflammation in Collagen Antibody-Induced Arthritis.

The role of endogenous glucocorticoids (GCs) in rheumatoid arthritis remains unclear. Herein, we examined the role of osteoblastic GC signaling in collagen antibody-induced arthritis. Intracellular GC signaling was abrogated exclusively in mature osteoblasts via transgenic (tg) expression of 11ß-hydroxysteroid dehydrogenase type 2. Arthritis was induced in 8-week-old male tg mice and their wild-type (WT) littermates. Paw swelling was scored daily from induction to end point (day 14). Inflammation, cartilage degradation, and local bone erosion were assessed at the wrist, knee, and ankle joints. Systemic skeletal changes were determined by microcomputed tomography and histomorphometrical analysis of the tibiae. Both tg and WT mice developed acute arthritis in response to the administration of collagen antibodies. However, compared with WT mice, both clinical and histological indexes of joint inflammation were significantly mitigated in animals with disrupted osteoblastic GC signaling. In WT mice, arthritis was associated with increased bone resorption, decreased bone formation, and significant bone loss. In contrast, bone turnover and bone mass remained unchanged in tg arthritic mice. Disruption of GC signaling in osteoblasts significantly reduces joint inflammation and prevents structural bone and cartilage damage in collagen antibody-induced arthritis. These data corroborate the concept that osteoblasts modulate the inflammatory response in immune-mediated arthritis via a GC-dependent pathway.

11ß-Hydroxysteroid dehydrogenase type 1 within muscle protects against the adverse effects of local inflammation.

Muscle wasting is a common feature of inflammatory myopathies. Glucocorticoids (GCs), although effective at suppressing inflammation and inflammatory muscle loss, also cause myopathy with prolonged administration. 11ß-Hydroxysteroid dehydrogenase type 1 (11ß-HSD1) is a bidirectional GC-activating enzyme that is potently upregulated by inflammation within mesenchymal-derived tissues. We assessed the regulation of this enzyme with inflammation in muscle, and examined its functional impact on muscle. The expression of 11ß-HSD1 in response to proinflammatory stimuli was determined in a transgenic murine model of chronic inflammation (TNF-Tg) driven by overexpression of tumour necrosis factor (TNF)-α within tissues, including muscle. The inflammatory regulation and functional consequences of 11ß-HSD1 expression were examined in primary cultures of human and murine myotubes and human and murine muscle biopsies ex vivo. The contributions of 11ß-HSD1 to muscle inflammation and wasting were assessed in vivo with the TNF-Tg mouse on an 11ß-HSD1 null background. 11ß-HSD1 was significantly upregulated within the tibialis anterior and quadriceps muscles from TNF-Tg mice. In human and murine primary myotubes, 11ß-HSD1 expression and activity were significantly increased in response to the proinflammatory cytokine TNF-α (mRNA, 7.6-fold, p < 0.005; activity, 4.1-fold, p < 0.005). Physiologically relevant levels of endogenous GCs activated by 11ß-HSD1 suppressed proinflammatory cytokine output (interkeukin-6, TNF-α, and interferon-γ), but had little impact on markers of muscle wasting in human myotube cultures. TNF-Tg mice on an 11ß-11ß-HSD1 knockout background developed greater muscle wasting than their TNF-Tg counterparts (27.4% less; p < 0.005), with smaller compacted muscle fibres and increased proinflammatory gene expression relative to TNF-Tg mice with normal 11ß-HSD1 activity. This study demonstrates that inflammatory stimuli upregulate 11ß-HSD1 expression and GC activation within muscle. Although concerns have been raised that excess levels of GCs may be detrimental to muscle, in this inflammatory TNF-α-driven model, local endogenous GC activation appears to be an important anti-inflammatory response that protects against inflammatory muscle wasting in vivo. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Vitamin D deficiency contributes directly to the acute respiratory distress syndrome (ARDS).

RATIONALE: Vitamin D deficiency has been implicated as a pathogenic factor in sepsis and intensive therapy unit mortality but has not been assessed as a risk factor for acute respiratory distress syndrome (ARDS). Causality of these associations has never been demonstrated. OBJECTIVES: To determine if ARDS is associated with vitamin D deficiency in a clinical setting and to determine if vitamin D deficiency in experimental models of ARDS influences its severity. METHODS: Human, murine and in vitro primary alveolar epithelial cell work were included in this study. FINDINGS: Vitamin D deficiency (plasma 25(OH)D levels <50 nmol/L) was ubiquitous in patients with ARDS and present in the vast majority of patients at risk of developing ARDS following oesophagectomy. In a murine model of intratracheal lipopolysaccharide challenge, dietary-induced vitamin D deficiency resulted in exaggerated alveolar inflammation, epithelial damage and hypoxia. In vitro, vitamin D has trophic effects on primary human alveolar epithelial cells affecting >600 genes. In a clinical setting, pharmacological repletion of vitamin D prior to oesophagectomy reduced the observed changes of in vivo measurements of alveolar capillary damage seen in deficient patients. CONCLUSIONS: Vitamin D deficiency is common in people who develop ARDS. This deficiency of vitamin D appears to contribute to the development of the condition, and approaches to correct vitamin D deficiency in patients at risk of ARDS should be developed. TRIAL REGISTRATION: UKCRN ID 11994.

TNFα regulates cortisol metabolism in vivo in patients with inflammatory arthritis.

OBJECTIVE: To determine the relationship between inflammation and glucocorticoid metabolism in vivo, in a clinical study of patients with inflammatory arthritis treated with anti-TNFα therapy. METHODS: Urine samples were collected from patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA) as part of a multicentre study assessing responses to infliximab and etanercept. Systemic measures of glucocorticoid metabolism were assessed by gas chromatography/mass spectrometry at weeks 0 (baseline), 4 and 12 after anti-TNFα therapy. Clinical data including DAS28 and C-reactive protein were also collected. RESULTS: Systemic measures of 11ß-HSD1 activity in patients with inflammatory arthritis decreased significantly following anti-TNFα therapy in patients with RA and PsA. Additionally, the activity of the glucocorticoid inactivating enzyme 5α-reductase appeared to increase significantly. CONCLUSIONS: This study demonstrates, for the first time, that the increased 11ß-HSD1 activity seen in patients with inflammatory arthritis is mediated through TNFα. Furthermore, the changes in related glucocorticoid metabolising enzymes suggest that there is a coordinated change in glucocorticoid metabolism which promotes higher tissue glucocorticoid levels.

Association between bone mineral density and C-reactive protein in a large population-based sample.

OBJECTIVE: Several studies suggest that bone mineral density (BMD) is reduced in chronic inflammatory diseases. Higher serum levels of C-reactive protein (CRP) have been associated with lower BMD in women and older adults. However, it is not clear whether this association holds in a representative sample of the general population. The purpose of this study was to examine the relationship between BMD and CRP level in a large representative US population-based sample from the National Health and Nutrition Examination Survey (NHANES). METHODS: We included participants age ≥20 years with BMD (total and subregions) measured by dual x-ray absorptiometry scans and complete information on covariates from NHANES. The association between CRP level and BMD was evaluated using multivariate linear regression models, adjusting for potential confounders and further adjusting for comorbid diseases, medications, and serum vitamin D levels. RESULTS: The study sample included 10,475 participants (53% Caucasian, 22% Mexican American, 18% African American, and 7% other races). Men had higher BMD and lower CRP concentrations than women. BMD (total body BMD as well as subtotal BMD and BMD of the extremities, ribs, and trunk subregions) was inversely associated with quintiles of CRP concentration both in men and in women in a dose-dependent manner (for total BMD, P for trend < 0.0001 for men, P for trend = 0.0005 for women). The associations were independent of medications, comorbidities, and other potential confounders. The results remained largely unchanged with further adjustment for serum vitamin D levels. CONCLUSION: Among men and women in a large representative population-based sample, the CRP level was inversely and independently associated with total BMD in a dose-dependent manner.

The mesenchymal stem cell marker CD248 (endosialin) is a negative regulator of bone formation in mice.

OBJECTIVE: CD248 (tumor endothelial marker 1/endosialin) is found on stromal cells and is highly expressed during malignancy and inflammation. Studies have shown a reduction in inflammatory arthritis in CD248-knockout (CD248(-/-) ) mice. The aim of the present study was to investigate the functional effect of genetic deletion of CD248 on bone mass. METHODS: Western blotting, polymerase chain reaction, and immunofluorescence were used to investigate the expression of CD248 in humans and mice. Micro-computed tomography and the 3-point bending test were used to measure bone parameters and mechanical properties of the tibiae of 10-week-old wild-type (WT) or CD248(-/-) mice. Human and mouse primary osteoblasts were cultured in medium containing 10 mM ß-glycerophosphate and 50 µg/ml ascorbic acid to induce mineralization, and then treated with platelet-derived growth factor BB (PDGF-BB). The mineral apposition rate in vivo was calculated by identifying newly formed bone via calcein labeling. RESULTS: Expression of CD248 was seen in human and mouse osteoblasts, but not osteoclasts. CD248(-/-) mouse tibiae had higher bone mass and superior mechanical properties (increased load required to cause fracture) compared to WT mice. Primary osteoblasts from CD248(-/-) mice induced increased mineralization in vitro and produced increased bone over 7 days in vivo. There was no decrease in bone mineralization and no increase in proliferation of osteoblasts in response to stimulation with PDGF-BB, which could be attributed to a defect in PDGF signal transduction in the CD248(-/-) mice. CONCLUSION: There is an unmet clinical need to address rheumatoid arthritis-associated bone loss. Genetic deletion of CD248 in mice results in high bone mass due to increased osteoblast-mediated bone formation, suggesting that targeting CD248 in rheumatoid arthritis may have the effect of increasing bone mass in addition to the previously reported effect of reducing inflammation.

Inflammatory regulation of glucocorticoid metabolism in mesenchymal stromal cells.

OBJECTIVE: Tissue glucocorticoid (GC) levels are regulated by the GC-activating enzyme 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1). This enzyme is expressed in cells and tissues arising from mesenchymal stromal cells. Proinflammatory cytokines dramatically increase expression of 11ß-HSD1 in stromal cells, an effect that has been implicated in inflammatory arthritis, osteoporosis, obesity, and myopathy. Additionally, GCs act synergistically with proinflammatory cytokines to further increase enzyme expression. The present study was undertaken to investigate the mechanisms underlying this regulation. METHODS: Gene reporter analysis, rapid amplification of complementary DNA ends (RACE), chemical inhibition experiments, and genetic disruption of intracellular signaling pathways in mouse embryonic fibroblasts (MEFs) were used to define the molecular mechanisms underlying the regulation of 11ß-HSD1 expression. RESULTS: Gene reporter, RACE, and chemical inhibitor studies demonstrated that the increase in 11ß-HSD1 expression with tumor necrosis factor α (TNFα)/interleukin-1ß (IL-1ß) occurred via the proximal HSD11B1 gene promoter and depended on NF-κB signaling. These findings were confirmed using MEFs with targeted disruption of NF-κB signaling, in which RelA (p65) deletion prevented TNFα/IL-1ß induction of 11ß-HSD1. GC treatment did not prevent TNFα-induced NF-κB nuclear translocation. The synergistic enhancement of TNFα-induced 11ß-HSD1 expression with GCs was reproduced by specific inhibitors of p38 MAPK. Inhibitor and gene deletion studies indicated that the effects of GCs on p38 MAPK activity occurred primarily through induction of dual-specificity phosphatase 1 expression. CONCLUSION: The mechanism by which stromal cell expression of 11ß-HSD1 is regulated is novel and distinct from that in other tissues. These findings open new opportunities for development of therapeutic interventions aimed at inhibiting or stimulating local GC levels in cells of mesenchymal stromal lineage during inflammation.

Recycling glucocorticoids: therapeutic implications of the 11ß-HSD1 enzyme system.

Endogenous glucocorticoids and commonly used oral glucocorticoids have the property of existing in an inactive and active form in vivo. The inactive form can be converted back to the active form, or 'recycled' in cells and tissues that express the 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) enzyme. This recycling provides an important contribution to the action of glucocorticoids. This review examines the literature relating to the importance of 11ß-HSD1 activity during glucocorticoid treatment, with an emphasis on studies examining bone and joint disease and the ability of glucocorticoids to suppress inflammatory damage in models of arthritis. Animal models with global or selective deletion of 11ß-HSD1 have determined the extent to which this recycling is important in normal physiology and during treatment with oral glucocorticoids. These studies demonstrate that 11ß-HSD1-mediated recycling of inactive glucocorticoids has a substantial action and indeed is responsible for the majority of the effects of orally administered glucocorticoids on a range of tissues. Importantly, the anti-inflammatory actions of glucocorticoids appear largely through this mechanism such that mice that lack 11ß-HSD1 are resistant to the anti-inflammatory actions of glucocorticoids. The recognition that to a large extent the circulating inactive counterpart of these glucocorticoids is more important to anti-inflammatory effects than the active glucocorticoid presents novel opportunities to more selectively target glucocorticoids to tissues or to reduce the likely side effects.

Glucocorticoid-Induced Psychosis in Children and Adolescents: A Systematic Review.

Objectives: Knowledge is limited regarding the adverse effects of therapeutic glucocorticoids on pediatric mental health outcomes. Glucocorticoid-induced psychosis (GIP) is a rare but severe side effect of high-dose glucocorticoid therapy in children and adolescents. This study identified reported pediatric cases of GIP, based on DSM-5 criteria, and defined its presentation, treatments, and outcomes. Methods: A systematic review was completed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, including pediatric patients with incident psychosis following glucocorticoid treatment. Patient demographics, clinical presentation, interventions, outcomes, and long-term management were extracted from individual cases. Results: Of 1131 articles screened, 28 reports were included, comprising of 31 patients. The mean age was 13 years, and 61% of patients were male. The most common medical illnesses requiring administration of high dose glucocorticoids were asthma (23%) and acute lymphoblastic leukemia (23%). The most common glucocorticoid used was prednisone (35%), and most patients (91%) received doses greater than or equal to 40 mg/day of prednisone. The range of time to symptom onset was 1 day to 7 months. Hallucinations alone (45%) were the most reported feature of GIP. Glucocorticoids were discontinued in 52% of cases, reduced in dosage in 32%, and 81% of affected patients were prescribed psychotropic medications. Long-term management plans and prophylactic psychotropic use were not mentioned in 52% of cases. Symptoms resolved in 90% of patients, and the majority (71%) had no recurrence of psychiatric symptoms. Conclusions: GIP can generally be managed by tapering the causative agent with adjunctive second-generation antipsychotics if psychotic symptoms persist. All patients in this review had complete resolution or improvement of their psychotic symptoms; however, there is likely reporting bias due to the expected underreporting of negative outcomes. Managing clinicians must take a circumspect approach when prescribing high-dose glucocorticoids to minimize the risk of serious but preventable side effects.