Elevated cardiac hemoglobin expression is associated with a pro-oxidative and inflammatory environment in primary mitral regurgitation

BACKGROUND

Primary mitral regurgitation (PMR) is associated with oxidative and inflammatory myocardial damage. We reported greater exosome hemoglobin (Hb) in pericardial fluid (PCF) versus plasma, suggesting a cardiac source of Hb.

OBJECTIVE

Test the hypothesis that Hb is produced in the PMR heart and is associated with increased inflammation.

METHODS AND RESULTS

Hb gene expression for subunits alpha (HBA) and beta (HBB) was assessed in right atria (RA), left atria (LA) and left ventricular (LV) tissue from donor hearts (n = 10) and PMR patient biopsies at surgery (n = 11). PMR patients (n = 22) had PCF and blood collected for macrophage markers, pro-inflammatory cytokines, and matrix metalloproteinases (MMPs). In-situ hybridization for HBA mRNA and immunohistochemistry for Hb-alpha (Hbα) and Hb-beta (Hbβ) protein was performed on PMR tissue.

RESULTS

HBA and HBB genes are significantly increased (>4-fold) in RA, LA, and LV in PMR vs. normal hearts. In PMR tissue, HBA mRNA is expressed in both LV cardiomyocytes and interstitial cells by in-situ hybridization; however, Hbα and Hbβ protein is only expressed in interstitial cells by immunohistochemistry. PCF oxyHb is significantly increased over plasma along with low ratios (<1.0) of haptoglobin:oxyHb and hemopexin:heme supporting a highly oxidative environment. Macrophage chemotactic protein-1, tumor necrosis factor-α, interleukin-6, and MMPs are significantly higher in PCF vs. plasma.

CONCLUSION

There is increased Hb production in the PMR heart coupled with the inflammatory state of the heart, suggests a myocardial vulnerability of further Hb delivery and/or production during cardiac surgery that could adversely affect LV functional recovery.

Chitinase-3-like 1 regulates TH2 cells, TFH cells and IgE responses to helminth infection

Introduction

Data from patient cohorts and mouse models of atopic dermatitis, food allergy and asthma strongly support a role for chitinase-3-like-1 protein (CHI3L1) in allergic disease.

Methods

To address whether Chi3l1 also contributes to TH2 responses following nematode infection, we infected Chi3l1 -/- mice with Heligmosomoides polygyrus (Hp) and analyzed T cell responses.

Results

As anticipated, we observed impaired TH2 responses in Hp-infected Chi3l1 -/- mice. However, we also found that T cell intrinsic expression of Chi3l1 was required for ICOS upregulation following activation of naïve CD4 T cells and was necessary for the development of the IL-4+ TFH subset, which supports germinal center B cell reactions and IgE responses. We also observed roles for Chi3l1 in TFH, germinal center B cell, and IgE responses to alum-adjuvanted vaccination. While Chi3l1 was critical for IgE humoral responses it was not required for vaccine or infection-induced IgG1 responses.

Discussion

These results suggest that Chi3l1 modulates IgE responses, which are known to be highly dependent on IL-4-producing TFH cells.

Loss of the mammalian G-protein coupled receptor, G2A, modulates severity of invasive pulmonary aspergillosis

Background

Aspergillus fumigatus is a well-known opportunistic pathogen that causes a range of diseases including the often-fatal disease, invasive pulmonary aspergillosis (IPA), in immunocompromised populations. The severity of IPA is dependent on both host- and pathogen-derived signaling molecules that mediate host immunity and fungal growth. Oxylipins are bioactive oxygenated fatty acids known to influence host immune response and Aspergillus developmental programs. Aspergillus synthesizes 8-HODE and 5,8-diHODE that have structural similarities to 9-HODE and 13-HODE, which are known ligands of the host G-protein-coupled receptor G2A (GPR132).

Materials and methods

Oxylipins were extracted from infected lung tissue to assess fungal oxylipin production and the Pathhunter β-arrestin assay was used to assess agonist and antagonist activity by fungal oxylipins on G2A. An immunocompetent model of A. fumigatus infection was used to assess changes in survival and immune responses for G2A-/- mice.

Results

Here we report that Aspergillus oxylipins are produced in lung tissue of infected mice and in vitro ligand assays suggest 8-HODE is a G2A agonist and 5,8-diHODE is a partial antagonist. To address the hypothesis that G2A could be involved in the progression of IPA, we assessed the response of G2A-/- mice to A. fumigatus infection. G2A-/- mice showed a survival advantage over wild-type mice; this was accompanied by increased recruitment of G2A-/- neutrophils and increased levels of inflammatory markers in A. fumigatus-infected lungs.

Conclusions

We conclude that G2A suppresses host inflammatory responses to Aspergillus fumigatus although it remains unclear if fungal oxylipins are involved in G2A activities.

Feasibility study of intraoperative pericardial fluid biomarkers and length of stay after cardiac surgery

Objective

Pericardial fluid biomarkers reflect the physiologic state of the myocardium. Previously, we showed a sustained increase in pericardial fluid biomarkers compared with blood in the 48 hours after cardiac surgery. We assess the feasibility of analyzing 9 common cardiac biomarkers from pericardial fluid collected during cardiac surgery and test a preliminary hypothesis of association between the most common biomarkers, troponin and brain natriuretic peptide, and length of stay after surgery.

Methods

We prospectively enrolled 30 patients aged 18 years or more undergoing coronary artery or valvular surgery. Patients with ventricular assist devices, atrial fibrillation surgery, thoracic aorta surgery, redo surgery, concomitant noncardiac surgery, and preoperative inotropic support were excluded. Before pericardial excision during surgery, a 1-cm pericardial incision was made to insert an 18-gauge catheter and collect 10 mL of pericardial fluid. Concentrations of 9 established biomarkers of cardiac injury or inflammation including brain natriuretic peptide and troponin were measured. Zero truncated Poisson regression adjusted for Society of Thoracic Surgery Preoperative Risk of Mortality tested for a preliminary association between pericardial fluid biomarkers and length of stay.

Results

Pericardial fluid was collected and pericardial fluid biomarkers resulted for all patients. Adjusted for Society of Thoracic Surgery risk, brain natriuretic peptide, and troponin were associated with increased intensive care unit and overall hospital length of stay.

Conclusions

In 30 patients, pericardial fluid was obtained and analyzed for cardiac biomarkers. Adjusting for Society of Thoracic Surgery risk, pericardial fluid troponin and brain natriuretic peptide were preliminarily associated with increased length of stay. Further investigation is needed to validate this finding and to investigate the potential clinical utility of pericardial fluid biomarkers.

Hematopoietic 12/15-lipoxygenase activity negatively contributes to fungal-associated allergic asthma

Asthma is one of the most common non-communicable diseases in the world. Approximately 30% of severe cases are associated with fungal sensitization, often associated with allergy to the opportunistic mold Aspergillus fumigatus. Leukotrienes, immunopathogenic mediators derived from the metabolism of arachidonic acid (AA) by 5-lipoxygenase (5-LOX), are often elevated in severe asthma. As such, these mediators are FDA-approved therapeutic targets of the anti-asthmatic drugs Zileuton®/Zyflo® and Singulair®/Montelukast®. A second enzyme involved in AA metabolism is 12/15-lipoxygenase (12/15-LOX; Alox15). Here, C57BL/6 wild-type mice subjected to experimental fungal asthma had increased expression of Alox15 mRNA as well as increased levels of 12-HETE, a product of 12/15-LOX activity, in the lung when compared to naïve and vehicle-treated mice. Mice deficient in 12/15-LOX (Alox15-/-) demonstrated better lung function, as measured by airway hyperresponsiveness (AHR), during fungal asthma. Histological assessment revealed reduced inflammation in the lungs of Alox15-/- mice compared to WT mice, which was corroborated by flow cytometric analysis of multiple myeloid (eosinophils, neutrophils) and lymphoid (CD4+ T, γδ T) cell populations. This was further supported by decreased levels of specific chemokines that promote the recruitment of these cells. Likewise, type 1 and 2, but not type 17 cytokines, were significantly lower in the lungs of Alox15-/- mice. Bone marrow chimera studies revealed that the presence of 12/15-LOX in hematopoietic cells contributed to AHR during fungal asthma. Taken together, our data supports the hypothesis that hematopoietic-associated 12/15-LOX contributes to type 2 responses and exacerbation of allergic fungal asthma.

Exosomes and Microvesicles From Adipose-derived Mesenchymal Stem Cells Protects the Endothelial Glycocalyx From LPS Injury

INTRODUCTION

Endothelial glycocalyx damage occurs in numerous pathological conditions and results in endotheliopathy. Extracellular vesicles, including exosomes and microvesicles, isolated from adipose-derived mesenchymal stem cells (ASC) have therapeutic potential in multiple disease states, however, their role in preventing glycocalyx shedding has not been defined. We hypothesized that ASC-derived exosomes and microvesicles would protect the endothelial glycocalyx from damage by LPS injury in cultured endothelial cells.

METHODS

Exosomes and microvesicles were collected from ASC conditioned media by centrifugation (10,000 g for microvesicles, 100,000 g for exosomes). Human umbilical vein endothelial cells (HUVECs) were exposed to 1 μg/mL lipopolysaccharide (LPS). LPS injured cells (n = 578) were compared to HUVECS with concomitant LPS injury plus 1.0 μg/mL of exosomes (n = 540) or microvesicles (n = 510) for 24 hours. These two cohorts were compared to control HUVECs that received phosphate-buffered saline only (n = 786) and HUVECs exposed to exosomes (n = 505) or microvesicles (n = 500) alone. Cells were fixed and stained with FITC-labelled wheat germ agglutinin (WGA) to quantify EGX. Real-time quantitative reverse-transcription polymerase chain reaction were used on HUVECs cell lystate to quantify Hyaluron Synthase-1 (HAS1) expression.

RESULTS

Exosomes alone decreased endothelial glycocalyx staining intensity when compared to control (4.94 vs. 6.41 AU, p < 0.001), while microvesicles did not cause a change glycocalyx staining intensity (6.39 vs. 6.41, p = 0.99). LPS injury resulted in decreased glycocalyx intensity as compared to control (5.60 vs. 6.41, p < 0.001). Exosomes (6.85 vs. 5.60, p < 0.001) and microvesicles (6.35 vs. 5.60, p < 0.001) preserved endothelial glycocalyx staining intensity after LPS injury. HAS1 levels were found to be higher in the exosome (1.14 vs. 3.67 RE, p = 0.02) and microvesicle groups (1.14 vs. 3.59 RE, p = 0.02) when compared to LPS injury. Hyaluron Synthase-2 and -3 expression were not different in the various experimental groups.

CONCLUSIONS

Exosomes alone can damage the endothelial glycocalyx. However, in the presence of LPS injury, both exosomes and microvesicles protect the glycocalyx layer. This effect appears to be mediated by HAS1.

LEVEL OF EVIDENCE

Basic Science study.

Impact of early pericardial fluid chymase activation after cardiac surgery

Introduction

Chymase is a highly destructive serine protease rapidly neutralized in the circulation by protease inhibitors. Here we test whether pericardial fluid (PCF) chymase activation and other inflammatory biomarkers determine intensive care unit length of stay, and explore mechanisms of chymase delivery by extracellular vesicles to the heart.

Methods

PCF was collected from adult patients (17 on-pump; 13 off-pump) 4 h after cardiac surgery. Extracellular vesicles (EVs) containing chymase were injected into Sprague-Dawley rats to test for their ability to deliver chymase to the heart.

Results

The mean intensive care unit (ICU) stay and mean total length of stay was 2.17 ± 3.8 days and 6.41 ± 1.3 days respectively. Chymase activity and 32 inflammatory markers did not differ in on-pump vs. off-pump cardiac surgery. Society of Thoracic Surgeons Predicted Risk of Morbidity and Mortality Score (STS-PROM), 4-hour post-surgery PCF chymase activity and C-X-C motif chemokine ligand 6 (CXCL6) were all independent predictors of ICU and total hospital length of stay by univariate analysis. Mass spectrometry of baseline PCF shows the presence of serine protease inhibitors that neutralize chymase activity. The compartmentalization of chymase within and on the surface of PCF EVs was visualized by immunogold labeling and transmission electron microscopy. A chymase inhibitor prevented EV chymase activity (0.28 fmol/mg/min vs. 14.14 fmol/mg/min). Intravenous injection of PCF EVs obtained 24 h after surgery into Sprague Dawley rats shows diffuse human chymase uptake in the heart with extensive cardiomyocyte damage 4 h after injection.

Discussion

Early postoperative PCF chymase activation underscores its potential role in cardiac damage soon after on- or off-pump cardiac surgery. In addition, chymase in extracellular vesicles provides a protected delivery mechanism from neutralization by circulating serine protease inhibitors.

Glycocalyx degradation and the endotheliopathy of viral infection

The endothelial glycocalyx (EGX) contributes to the permeability barrier of vessels and regulates the coagulation cascade. EGX damage, which occurs in numerous disease states, including sepsis and trauma, results in endotheliopathy. While influenza and other viral infections are known to cause endothelial dysfunction, their effect on the EGX has not been described. We hypothesized that the H1N1 influenza virus would cause EGX degradation. Human umbilical vein endothelial cells (HUVECs) were exposed to varying multiplicities of infection (MOI) of the H1N1 strain of influenza virus for 24 hours. A dose-dependent effect was examined by using an MOI of 5 (n = 541), 15 (n = 714), 30 (n = 596), and 60 (n = 653) and compared to a control (n = 607). Cells were fixed and stained with FITC-labelled wheat germ agglutinin to quantify EGX. There was no difference in EGX intensity after exposure to H1N1 at an MOI of 5 compared to control (6.20 vs. 6.56 Arbitrary Units (AU), p = 0.50). EGX intensity was decreased at an MOI of 15 compared to control (5.36 vs. 6.56 AU, p<0.001). The degree of EGX degradation was worse at higher doses of the H1N1 virus; however, the decrease in EGX intensity was maximized at an MOI of 30. Injury at MOI of 60 was not worse than MOI of 30. (4.17 vs. 4.47 AU, p = 0.13). The H1N1 virus induces endothelial dysfunction by causing EGX degradation in a dose-dependent fashion. Further studies are needed to characterize the role of this EGX damage in causing clinically significant lung injury during acute viral infection.

Secondary Risk Reduction Strategies in Breast Cancer Care

Over the past three decades breast cancer survival rates have increased in Ireland. This is due to advances in cancer diagnostics and therapeutics. Cure is now anticipated for most newly diagnosed patients. Cancer survivorship however is associated with an increased risk of additional cancers and the development of other non-communicable diseases such as cardiovascular disease. At present, secondary risk reduction strategies are an integral part of cardiovascular disease management. Given the improvements in breast cancer survival, similar strategies should be implemented as part of routine early-stage breast cancer care treatment plan. Herein, we present compelling evidence to support the integration of secondary risk reduction strategies for patients as a standard of care.

A Novel Controlled PTEN-Knockout Mouse Model for Prostate Cancer Study

Prostate cancer (PCa) is associated with advanced age, but how age contributes to prostate carcinogenesis remains unknown. The prostate-specific Pten conditional knockout mouse model closely imitates human PCa initiation and progression. To better understand how age impacts PCa in an experimental model, we have generated a spatially and temporally controlled Pten-null PCa murine model at different ages (aged vs. non-aged) of adult mice. Here, we present a protocol to inject the Cre-expressing adenovirus with luciferin tag, intraductally, into the prostate anterior lobes of Pten-floxed mice; Pten-loss will be triggered post-Cre expression at different ages. In vivo imaging of luciferin signal following viral infection confirmed successful delivery of the virus and Cre activity. Immunohistochemical staining confirmed prostate epithelial-specific expression of Cre recombinase and the loss of Pten and activation of P-Akt, P-S6, and P-4E-BP1. The Cre-expression, Pten ablation, and activated PI3K/AKT/mTOR pathways were limited to the prostate epithelium. All mice developed prostatic epithelial hyperplasia within 4 weeks after Pten ablation and prostatic intraepithelial neoplasia (PIN) within 8 weeks post-Pten ablation. Some PINs had progressed to invasive adenocarcinoma at 8-16 weeks post-Pten ablation. Aged mice exhibited significantly accelerated PI3K/AKT/mTOR signaling and increased PCa onset and progression compared to young mice. The viral infection success rate is ∼80%. This model will be beneficial for investigations of cancer-related to aging.

320 A Closed Loop Audit of Surgical Site Infection Rate in Elective Colorectal Laparotomies, Pre and Post Introduction of Jubilee Dressing Method

Introduction

Surgical site infections (SSI) are responsible for one third of all inpatient infections and are associated with increased morbidity and extended hospital stay. The colorectal department at Glasgow Royal Infirmary introduced the Jubilee dressing method in August 2019 with the aim of reducing SSI incidence.

Method

Closed loop audit of all elective colorectal laparotomies at Glasgow Royal Infirmary pre- and post-introduction of Jubilee dressing method (March – July & August – December 2019). Literature reviews informed selection of baseline characteristics relevant to SSI. Analysis by logistic regression of SSI incidence by characteristic and Jubilee dressing use.

Results

A total of 193 patients were included. There was 52% uptake of Jubilee dressing method in the implementation phase and reduction in total SSI rate from 18.25% to 14.93%. Operation duration and smoking history were the only significant factors at univariate analysis and were put forward to multivariate analysis. Of these, only operation duration made a significant contribution to SSI incidence.

Conclusions

Jubilee dressing use did not make a significant difference to SSI incidence in this sample. This intervention is likely to have small effect size and there were probable confounding factors. Multifactorial influence in SSI incidence suggests larger datasets are required to isolate independent factors.

A Comparison of Growth Factors and Cytokines in Fresh Frozen Plasma and Never Frozen Plasma

BACKGROUND

Fresh frozen plasma (FFP) contains proinflammatory mediators released from cellular debris during frozen storage. In addition, recent studies have shown that transfusion of never-frozen plasma (NFP), instead of FFP, may be superior in trauma patients. We hypothesized that FFP would have higher levels of inflammatory mediators when compared to NFP.

MATERIALS AND METHODS

FFP (n = 8) and NFP (n = 8) samples were obtained from an urban, level 1 trauma center blood bank. The cytokines in these samples were compared using a Milliplex (Milliplex Sigma) human cytokine magnetic bead panel multiplex assay for 41 different biomarkers.

RESULTS

Growth factors that were higher in NFP included platelet-derived growth factor-AA (PDGF-AA; 8.09 versus 108.00 pg/mL, P < 0.001) and PDGF-AB (0.00 versus 215.20, P= 0.004). Soluble CD40-ligand (sCD40L), a platelet activator and pro-coagulant, was higher in NFP (31.81 versus 80.45 pg/mL, P< 0.001). RANTES, a leukocyte chemotactic cytokine was higher in NFP (26.19 versus 1418.00 pg/mL, P< 0.001). Interleukin-4 (5.70 versus 0.00 pg/mL, P= 0.03) and IL-8 (2.20 versus 0.52 pg/ml, P= 0.03) levels were higher in were higher in FFP.

CONCLUSIONS

Frozen storage of plasma may result in decrease of several growth factors and/or pro-coagulants found in NFP. In addition, the freezing and thawing process may induce release of pro-inflammatory chemokines. Further studies are needed to determine if these cytokines result in improved outcomes with NFP over FFP in transfusion of trauma patients.

Age-Related Increased Onset and Progression of Prostate Cancer Is Revealed in Novel Pten-Null Mouse Models

Prostate cancer (PCa) is associated with advanced age. To better understand how age impacts PCa, it is critical to use PCa animal models generated at different ages (aged vs. non-aged). The PB-Cre4 driven phosphatase and tensin homolog (Pten) conditional knockout mouse model, which closely imitates human PCa initiation and progression. However, the Pten deletion is triggered in a 2-week-old prostate, when comparing the extent of PCa between aged and non-aged mice, it is difficult to distinguish the extent to which the onset and progression of PCa are due to the acceleration of the normal aging process or due to the manifestation of PCa pathologies over time. We present here a protocol to inject Cre-expressing adenovirus with luciferin tag intraductally into the prostate anterior lobes of Pten floxed mice, thus, the Pten-loss will be triggered at different ages post-Cre expression. The in vivo imaging of luciferin signals following viral infection was conducted to confirm the Cre expression and activity. Immunohistochemical staining was performed to confirm the Cre expression, Pten loss, and p-Akt and p-S6 activation. Prostate weight and histopathology were compared between aged and non-aged mice. The results showed that the virus infection was limited in the prostate glands and aged mice had significantly increased PCa onset and progression compared to young mice. Although technical skill is required to carry out this procedure and the success rate of viral infection is about 80%, this model of PCa is of great use to all investigators in the aging and cancer research field.

The chemokine CX3CL1/fractalkine regulates immunopathogenesis during fungal-associated allergic airway inflammation

Individuals that present with difficult-to-control asthma and sensitivity to one or more fungal species are categorized as a subset of severe asthma patients belonging to a group herein referred to as severe asthma with fungal sensitization (SAFS). We have previously reported the identification of numerous cytokines and chemokines that were elevated in human asthmatics that were sensitized to fungi vs. nonfungal sensitized asthmatics. Here, we show that the unique chemokine CX3CL1 (fractalkine) is elevated in both bronchoalveolar lavage fluid and sputum from human asthmatics sensitized to fungi, implicating an association with CX3CL1 in fungal asthma severity. In an experimental model of fungal-associated allergic airway inflammation, we demonstrate that the absence of CX3CR1 signaling unexpectedly resulted in a profound impairment in lung function. Histological assessment of lung tissue revealed an unrestricted inflammatory response that was subsequently characterized by enhanced levels of neutrophils, eosinophils, and inflammatory monocytes. Neutrophilic inflammation correlated with elevated IL-17A, proinflammatory cytokines (TNF-α, IL-1α, and IL-1β), neutrophil survival factors (granulocyte colony-stimulating factor), and neutrophil-targeting chemokines (CCL3 and CCL4). Eosinophilia correlated with elevated type 2 responses (IL-5 and IL-13) whereas inflammatory monocyte levels correlated with elevated type 1 responses (IFN-γ and CXCL9) and survival factors (macrophage colony-stimulating factor). Despite enhanced inflammatory responses, the immunoregulatory cytokine IL-10 and the natural inhibitor of IL-1 signaling, IL-1RA, were significantly elevated rather than impaired. Regulatory T-cell levels were unchanged, as were levels of the anti-inflammatory cytokines IL-35 and IL-38. Taken together, the CX3CL1/CX3CR1 axis preserves lung function during fungal-associated allergic airway inflammation through a nonclassical immunoregulatory mechanism.

A Case of Colonic Ischaemia Masquerading as a Colonic Mass

Intestinal ischaemia is an uncommon vascular syndrome resulting from an acute or chronic drop in blood supply to the bowel, with varied clinical presentations. Intestinal ischaemia can present similarly to other conditions, leaving the clinician with a diagnostic dilemma. In this case report, we present a 69-year-old male who presented with abdominal pain, distention, anorexia and per rectal bleeding. Endoscopy showed a left-sided mass-like, ulcerated lesion, endoscopically thought to be colonic carcinoma. Histology later revealed this mass to be intestinal ischaemia, with no features of invasive carcinoma. This was confirmed at an interval endoscopy, which showed a largely healed mucosa and nil evidence of a mass. Raising awareness of this disease and its ability to mimic other presentations, both clinically and endoscopically, is key to establishing an early diagnosis and intervention.

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) and receptors in type 1, type 2 and type 17 inflammation in cross-sectional asthma study

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) reportedly promotes, or conversely, resolves inflammation in asthma. In this study of TRAIL and cell receptors in sputum, bronchoalveolar lavage and biopsy from subjects in the Severe Asthma Research Program at Wake Forest, the high TRAIL group had significant increases in all leucocytes, and was associated with increased type 1, type 2 and type 17 cytokines, but not type 9 interleukin 9. Two variants at loci in the TRAIL gene were associated with higher sputum levels of TRAIL. Increased TRAIL decoy receptor R3/DcR1 was observed on sputum leucocytes compared with death receptor R1/DR4, suggesting reduced apoptosis and prolonged cellular inflammation.

CD4+ T helper 17 cell response of aged mice promotes prostate cancer cell migration and invasion

BACKGROUND

Aging is the most important risk factor for prostate cancer (PCa), but how age contributes to PCa is poorly understood. Aging is characterized by low-grade systemic inflammation (i.e., inflammaging) that is often attributed to the progressive activation of immune cells over time, which may play an important role in prostate carcinogenesis. Th17 response is elevated in aging humans and mice, but it remains unknown whether it is increased in prostate tissue or contributes to prostate carcinogenesis during aging. In this study, we aimed to determine the role of age-related Th17 response in PCa cell growth, migration, and invasion.

METHODS

C57BL/6J (B6) mouse was used as an aging animal model and the prostate histopathology during aging was analyzed. Splenic CD4⁺ T cells were isolated from young (16-20 weeks old) and aged (96-104 weeks old) mice, and cultured in the presence of plate-bound anti-CD3/anti-CD28, with or without Th17 differentiation conditions. The cells were collected and used for subsequent flow cytometry or quantitative reverse transcription polymerase chain reaction. The supernatant was collected and used to treat PCa cell lines. The treated PCa cells were analyzed for cell viability, migration, invasion, and nuclear factor kappa B (NF-κB) signaling.

RESULTS

Aged mice had enlarged prostate glands and increased morphological alterations, with not only increased inflammatory cell infiltration but also increased Th17 cytokines in prostate tissue, compared to young mice. Naïve CD4⁺ T cells from aged mice differentiated increased interleukin (IL)-17-expressing cells. CD4⁺ T cells from aged mice spleen had increased Th17 cells, Th17 cytokines and Th17/Treg ratio compared to young mice. Factors secreted from aged CD4⁺ T cells, especially from ex vivo differentiated Th17 cells, not only promoted PCa cell viability, migration, and invasion but also activated the NF-κB signaling in PCa cells compared to young mice.

CONCLUSIONS

These results indicate that age-related CD4⁺ T cells, especially Th17 cells-secreted factors have the potential to contribute to prostate carcinogenesis. Our work could prompt further research using autochthonous PCa mouse models at different ages to elucidate the functional role of Th17 response in prostate carcinogenesis during aging.

12/15-Lipoxygenase Deficiency Impairs Neutrophil Granulopoiesis and Lung Proinflammatory Responses to Aspergillus fumigatus

Development of invasive aspergillosis correlates with impairments in innate immunity. We and others have recently shown that arachidonic acid metabolism pathways, specifically the cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) pathways, participate in the induction of protective innate immune responses during invasive aspergillosis. Based on the high degree of cooperation and interconnection within the eicosanoid network, we hypothesized that 12/15-LOX is also active during invasive aspergillosis. We report in this study that mice deficient in the gene encoding 12/15-LOX (Alox15) are profoundly susceptible to invasive aspergillosis. Decreased survival correlated with increased fungal burden and evidence of increased lung damage. These defects were associated with very early (6 and 12 h) 12/15-LOX-dependent inflammatory cytokine (IL-1α, IL-1β, and TNF-α) and chemokine (CCL3 and CCL4) production. Neutrophil levels in the lung were blunted in the absence of 12/15-LOX, although neutrophil antifungal activity was intact. However, lower neutrophil levels in the lungs of Alox15^−/− mice were not a result of impaired recruitment or survival; rather, Alox15^−/− mice demonstrated impaired neutrophil granulopoiesis in the bone marrow intrinsically and after fungal exposure. Employing a lower inoculum to allow for better survival allowed the identification of 12/15-LOX-dependent induction of IL-17A and IL-22. Impaired IL-17A and IL-22 production correlated with reduced invariant NKT cell numbers as well as lower IL-23 levels. Together, these data indicate that 12/15-LOX is a critical player in induction of the earliest aspects of the innate immune response to Aspergillus fumigatus.

Sorting Beef Subprimals by Ribeye Size at the Packer Level to Maximize Utility and Product Uniformity in Foodservice and Retail Sectors

ObjectivesTo determine the impact of sorting beef carcasses at the packer level by ribeye area, instead of sorting subprimals by weight, to provide more consistent products for the end user via foodservice and retail channelsMaterials and MethodsInstrument grading technology was used to select 100 USDA Choice, yield grade 2 or 3 sides, and 100 USDA Select, yield grade 2 or 3 sides. Carcass sides were sorted into one of five ribeye area (REA) categories, as outlined in Tabsle 6.USDA Choice carcass sides were fabricated to remove beef rib, ribeye, lip-on (IMPS 112A) and beef loin, strip loin, boneless (IMPS 180) from each USDA Choice. Beef loin, tenderloin, full, side muscle on, partially defatted (IMPS 189B) subprimals were procured from each USDA Select side. Subprimals were weighed, trimmed to specification, and passed through a 3-D visual analysis portioning machine and to obtain scan data for a variety of portioning outcomes generated by simulation software.ResultsBased on input from our foodservice collaborators, 1.25 inches (3.18 cm) was identified, for ribeye and strip loin steaks, as the targeted optimal thickness to meet consumer expectations. After evaluation of multiple portioning outcomes, it was determined that a 14.00-ounce (396.89 g) portion, for each REA category, most consistently delivered the preferred steak thickness identified previously. REA categories 1 and 2 most frequently produced desirable thickness and portion weight outcomes in ribeye and strip loin steaks. Statistical analysis of number of portions per subprimal stratified by portion weight and portion thickness revealed differences (P < 0.05) across all REA area categories in both ribeyes and strip loins. As portion weight and thickness increased, steak portion number tended to decrease. In tenderloins, an optimal steak thickness of 1.75 to 2.00 in (4.45 to 5.08 cm) was identified as optimal. Most frequently, 8, 9, and 10-ounce (226.80, 255.15, and 283.50 g) portions met the targets for optimal portion weight and thickness parameters. For tenderloins, number of portions by portion weight showed significant differences (P < 0.05) in all ribeye area categories with the exception of 7-ounces (198.45 g) and showed no differences when stratified by portion thickness. In this investigation, USDA Choice carcasses (r = 0.76) and USDA Select carcasses (r = 0.56) expressed moderate correlation between REA area and hot carcass weight.ConclusionResults of the present study suggest strip loin, ribeye, and tenderloin subprimals from carcasses possessing a ribeye area ranging from 74.8 cm2 to 87.1 cm2 offered the greatest level of utility when portioned for use in foodservice and retail sectors. Further research is warranted to continue examining the merit of sorting carcasses by ribeye area at the packer level, but results of this study suggest that there is potential for improved consistency and utility of subprimals in the foodservice and retail sectors.Table 6.Ribeye area (REA) categories and associated acceptable REA ranges.

AGE-RELATED ELEVATED CD4+ T HELPER 17 CELL RESPONSE PROMOTES PROSTATE CANCER CELL GROWTH, MIGRATION, AND INVASION

Age is the most important risk factor for prostate cancer (PCa). But, how age contributes to PCa remains unknown. Interleukin-17 (IL-17) -producing CD4+ T helper 17 (Th17) cells play a critical role in inflammatory diseases. It is often elevated in aging humans and mice, however, whether aging affects Th17 cell function and subsequent PCa risk increase is unclear. In this study, we investigated the role of CD4+ T cells in PCa cell growth during the aging process. Splenic T cells were isolated and purified into CD4+CD25- T cells from young and old mice, then cultured in the presence of plate-bound anti-CD3/anti-CD28. Four days later, the cells were re-stimulated with PMA and ionomycin in the presence of brefeldin A for 4 hours and then were collected and used for flow cytometry and/or qPCR. The supernatant (conditioned media) from young and old cultures was collected and used in subsequent experiments. Flow and qPCR results showed that 17-producing T cells and associated cytokines were significantly increased in old mice compared to young mice. When PCa cell lines (LNCaP, DU-145, and PC3) were treated by the conditioned media for 48 and 72 hours. The cell proliferation, migration, and invasion, as well as the activation of NF-B signaling in PCa cells, were significantly increased after exposure to the conditioned media from aged mice, compared to that from young mice. These results indicated that age-related CD4+ Th17 cell responses are elevated in mice in the aging process and play an important role in PCa growth.

IL-1RA regulates immunopathogenesis during fungal-associated allergic airway inflammation

Severe asthma with fungal sensitization (SAFS) defines a subset of human asthmatics with allergy to 1 or more fungal species and difficult-to-control asthma. We have previously reported that human asthmatics sensitized to fungi have worse lung function and a higher degree of atopy, which was associated with higher IL-1 receptor antagonist (IL-1RA) levels in bronchoalveolar lavage fluid. IL-1RA further demonstrated a significant negative association with bronchial hyperresponsiveness to methacholine. Here, we show that IL-1α and IL-1β are elevated in both bronchoalveolar lavage fluid and sputum from human asthmatics sensitized to fungi, implicating an association with IL-1α, IL-1β, or IL-1RA in fungal asthma severity. In an experimental model of fungal-associated allergic airway inflammation, we demonstrate that IL-1R1 signaling promotes type 1 (IFN-γ, CXCL9, CXCL10) and type 17 (IL-17A, IL-22) responses that were associated with neutrophilic inflammation and increased airway hyperreactivity. Each of these were exacerbated in the absence of IL-1RA. Administration of human recombinant IL-1RA (Kineret/anakinra) during fungal-associated allergic airway inflammation improved airway hyperreactivity and lowered type 1 and type 17 responses. Taken together, these data suggest that IL-1R1 signaling contributes to fungal asthma severity via immunopathogenic type 1 and type 17 responses and can be targeted for improving allergic asthma severity.

An extracellular matrix fragment drives epithelial remodeling and airway hyperresponsiveness

It is anticipated that bioactive fragments of the extracellular matrix (matrikines) can influence the development and progression of chronic diseases. The enzyme leukotriene A₄ hydrolase (LTA₄H) mediates opposing proinflammatory and anti-inflammatory activities, through the generation of leukotriene B₄ (LTB₄) and degradation of proneutrophilic matrikine Pro-Gly-Pro (PGP), respectively. We show that abrogation of LTB₄ signaling ameliorated inflammation and airway hyperresponsiveness (AHR) in a murine asthma model, yet global loss of LTA₄H exacerbated AHR, despite the absence of LTB₄ This exacerbated AHR was attributable to a neutrophil-independent capacity of PGP to promote pathological airway epithelial remodeling. Thus, we demonstrate a disconnect between airway inflammation and AHR and the ability of a matrikine to promote an epithelial remodeling phenotype that negatively affects lung function. Subsequently, we show that substantial quantities of PGP are detectable in the sputum of moderate-severe asthmatics in two distinct cohorts of patients. These studies have implications for our understanding of remodeling phenotypes in asthma and may rationalize the failure of LTA₄H inhibitors in the clinic.

The United Kingdom Primary Immune Deficiency (UKPID) registry 2012 to 2017

This is the second report of the United Kingdom Primary Immunodeficiency (UKPID) registry. The registry will be a decade old in 2018 and, as of August 2017, had recruited 4758 patients encompassing 97% of immunology centres within the United Kingdom. This represents a doubling of recruitment into the registry since we reported on 2229 patients included in our first report of 2013. Minimum PID prevalence in the United Kingdom is currently 5·90/100 000 and an average incidence of PID between 1980 and 2000 of 7·6 cases per 100 000 UK live births. Data are presented on the frequency of diseases recorded, disease prevalence, diagnostic delay and treatment modality, including haematopoietic stem cell transplantation (HSCT) and gene therapy. The registry provides valuable information to clinicians, researchers, service commissioners and industry alike on PID within the United Kingdom, which may not otherwise be available without the existence of a well-established registry.

Host defense mechanisms against Aspergillus fumigatus lung colonization and invasion

The human lung is continually exposed to airborne conidia of the fungus Aspergillus fumigatus (AF) and related species. The innate immune system efficiently eliminates inhaled AF conidia from the lung in normal individuals, but immunocompromised patients are at risk for highly lethal invasive aspergillosis (IA). Some individuals not at risk for IA may still suffer from failed clearance of AF in the form of noninvasive colonization associated with conditions such as allergic bronchopulmonary aspergillosis. Understanding of normal innate immune function against AF as well as failures of these functions will enable better treatment of these patient groups. In this review, we will focus on recent research that elucidates mechanisms of host defense and their failures resulting in colonization as well as tissue invasion.

C-X3-C Chemokine Receptor 1 (CX3CR1) Regulates Immunopathogenesis During Fungal Asthma

Severe asthma with fungal sensitization (SAFS) defines a subset of severe asthmatics with allergy to multiple fungal species, including A. fumigatus. The C-X3-C chemokine receptor 1 (CX3CR1) is primarily expressed on monocytes, macrophages, and dendridic cells while expression of its ligand, CX3CL1 is increased in the presence of pro-inflammatory cytokines. Here, we show that bronchoalveolar lavage fluid (BALF) and induced sputum from human asthmatics sensitized to fungi demonstrate increased levels of CX3CL1 compared to fungal negative asthmatics, suggesting that CX3CL1 may contribute to fungal asthma severity. To this end, we examined fungal asthma severity in mice deficient in the CX3CL1 receptor (CX3CR1 -/-). The absence of CX3CR1 yielded no significant impact on type 2 biomarkers of asthma severity (e.g., levels of pro-allergic CCL17, CCL22, and IL-33) or lung eosinophil numbers. Rather, CX3CR1 deficiency was associated with heightened type 17 responses (characterized by increased production of IL-1α, IL-1β, IL-6, IL-17A, IL-22, G-CSF and CXCL2) and type 1 responses (characterized by increased IFNγ and CXCL9 production). Moreover, this inflammatory profile correlated with worse lung physiologic responses (e.g., increased dynamic and airway resistance). Taken together, these preliminary results suggest a critical role for CX3CL1 in regulating the immune response (immunopathogenesis) in fungal asthma independent of its role in cell recruitment.

12/15-lipoxygenase supports inflammatory cytokine production and PMN recruitment during invasive aspergillosis

Eicosanoids are a family of inflammatory lipid mediators produced via the metabolism of arachidonic acid by a network of biosynthetic enzymes. We and others have recently shown that pathways within this network, specifically the cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) pathways, participate in induction of protective immune responses during invasive aspergillosis (IA). Based on the high degree of cooperation and interconnection within the eicosanoid network, we hypothesized that a third core enzyme, 12/15-lipoxygenase (12/15-LOX), also may support innate antifungal responses. We report here that mice deficient in the gene encoding 12/15-LOX, Alox15, exhibit decreased survival and increased fungal burden in a model of IA. These defects were associated with decreased PMN numbers in the lung and decreased levels of PMN chemokines (CXCL1, CXCL2, CCL3) in Alox15−/− mice, while fungal killing by PMNs in vitro was unaffected. Alox15−/− mice produced lower levels of the inflammatory cytokines IL-17A, IL-22, IL-1α and IL-6 during infection. iNKT cells, which we have reported to be a major cell source of IL-22 during IA, were present in decreased numbers in Alox15−/− mice. This reduction was associated with lower levels of IL-7, a cytokine we have recently shown to be required for optimal numbers of iNKT cells during IA. Decreased IL-22 levels were further associated with decreased levels of IL-23. Together, these data indicate that 12/15-LOX is a critical player in induction of multiple aspects of the innate immune response to A. fumigatus.

Treating the troponin: adverse consequences of over-treatment of elevated troponin in non-coronary presentations

BACKGROUND AND AIMS

Anti-platelet and anti-thrombotic therapy are well-established treatments in acute coronary syndromes. Highly sensitive assays have diminished the positive predictive value of troponin in acute coronary syndromes and increased the importance of the clinical assessment in interpreting positive results. This cohort study sought to investigate over-treatment of non-coronary troponin rises and associated adverse outcomes.

METHODS AND RESULTS

We reviewed 223 consecutive patients presenting to Queen Elizabeth University Hospital, Glasgow, with suspected acute coronary syndromes over a six-week period. Of these, 27 (12%) met our 'inappropriate therapy' criteria. This group had a low ischaemic risk (HEART score: 4.2 ± 1.4) (GRACE score: 117 ± 30.8) but an intermediate-high bleeding risk (CRUSADE score: 34 ± 14.5). Approximately half of the patients (14/27, 52%) reported chest pain, with only 4/27 (15%) having ischaemic ECG changes. There were three intracranial haemorrhages, each after the patient had received a single dose of aspirin, ticagrelor and fondaparinux.

CONCLUSION

The combination of injudicious high-sensitivity troponin testing with potent anti-platelet and anti-thrombotic therapy was associated with possible over-treatment of patients and associated harm. Emphasis on interpretation of troponin in the context of clinical presentation and improved awareness of type 2 myocardial infarction are essential to limit iatrogenic pharmacological harm.

Glucagon Receptor Signaling Regulates Energy Metabolism via Hepatic Farnesoid X Receptor and Fibroblast Growth Factor 21

Glucagon, an essential regulator of glucose and lipid metabolism, also promotes weight loss, in part through potentiation of fibroblast growth factor 21 (FGF21) secretion. However, FGF21 is only a partial mediator of metabolic actions ensuing from glucagon receptor (GCGR) activation, prompting us to search for additional pathways. Intriguingly, chronic GCGR agonism increases plasma bile acid levels. We hypothesized that GCGR agonism regulates energy metabolism, at least in part, through farnesoid X receptor (FXR). To test this hypothesis, we studied whole-body and liver-specific FXR-knockout (Fxr∆liver) mice. Chronic GCGR agonist (IUB288) administration in diet-induced obese (DIO) Gcgr, Fgf21, and Fxr whole-body or liver-specific knockout (∆liver) mice failed to reduce body weight when compared with wild-type (WT) mice. IUB288 increased energy expenditure and respiration in DIO WT mice, but not Fxr∆liver mice. GCGR agonism increased [14C]palmitate oxidation in hepatocytes isolated from WT mice in a dose-dependent manner, an effect blunted in hepatocytes from Fxr∆liver mice. Our data clearly demonstrate that control of whole-body energy expenditure by GCGR agonism requires intact FXR signaling in the liver. This heretofore-unappreciated aspect of glucagon biology has implications for the use of GCGR agonism in the therapy of metabolic disorders.

Unique Lipid Signatures of Extracellular Vesicles from the Airways of Asthmatics

Asthma is a chronic inflammatory disease process involving the conductive airways of the human lung. The dysregulated inflammatory response in this disease process may involve multiple cell-cell interactions mediated by signaling molecules, including lipid mediators. Extracellular vesicles (EVs) are lipid membrane particles that are now recognized as critical mediators of cell-cell communication. Here, we compared the lipid composition and presence of specific lipid mediators in airway EVs purified from the bronchoalveolar lavage (BAL) fluid of healthy controls and asthmatic subjects with and without second-hand smoke (SHS) exposure. Airway exosome concentrations were increased in asthmatics, and correlated with blood eosinophilia and serum IgE levels. Frequencies of HLA-DR⁺ and CD54⁺ exosomes were also significantly higher in asthmatics. Lipidomics analysis revealed that phosphatidylglycerol, ceramide-phosphates, and ceramides were significantly reduced in exosomes from asthmatics compared to the non-exposed control groups. Sphingomyelin 34:1 was more abundant in exosomes of SHS-exposed asthmatics compared to healthy controls. Our results suggest that chronic airway inflammation may be driven by alterations in the composition of lipid mediators within airway EVs of human subjects with asthma.

Exosomal transfer of mitochondria from airway myeloid-derived regulatory cells to T cells

Chronic inflammation involving both innate and adaptive immune cells is implicated in the pathogenesis of asthma. Intercellular communication is essential for driving and resolving inflammatory responses in asthma. Emerging studies suggest that extracellular vesicles (EVs) including exosomes facilitate this process. In this report, we have used a range of approaches to show that EVs contain markers of mitochondria derived from donor cells which are capable of sustaining a membrane potential. Further, we propose that these participate in intercellular communication within the airways of human subjects with asthma. Bronchoalveolar lavage fluid of both healthy volunteers and asthmatics contain EVs with encapsulated mitochondria; however, the % HLA-DR⁺ EVs containing mitochondria and the levels of mitochondrial DNA within EVs were significantly higher in asthmatics. Furthermore, mitochondria are present in exosomes derived from the pro-inflammatory HLA-DR⁺ subsets of airway myeloid-derived regulatory cells (MDRCs), which are known regulators of T cell responses in asthma. Exosomes tagged with MitoTracker Green, or derived from MDRCs transduced with CellLight Mitochondrial GFP were found in recipient peripheral T cells using a co-culture system, supporting direct exosome-mediated cell-cell transfer. Importantly, exosomally transferred mitochondria co-localize with the mitochondrial network and generate reactive oxygen species within recipient T cells. These findings support a potential novel mechanism of cell-cell communication involving exosomal transfer of mitochondria and the bioenergetic and/or redox regulation of target cells.

Complex association patterns for inflammatory mediators in induced sputum from subjects with asthma

BACKGROUND

The release of various inflammatory mediators into the bronchial lumen is thought to reflect both the type and degree of airway inflammation, eosinophilic Th2, and Th9, or neutrophilic Th1, and Th17, in patients with asthma.

AIMS

We investigated whether cytokines and chemokines differed in sputum from subjects with more severe compared with milder asthma and whether unbiased factor analysis of cytokine and chemokine groupings indicates specific inflammatory pathways.

METHODS

Cell-free supernatants from induced sputum were obtained from subjects with a broad range of asthma severity (n = 158) and assessed using Milliplex^® Cytokines/Chemokine kits I, II and III, measuring 75 individual proteins. Each cytokine, chemokine or growth factor concentration was examined for differences between asthma severity groups, for association with leucocyte counts, and by factor analysis.

RESULTS

Severe asthma subjects had 9 increased and 4 decreased proteins compared to mild asthma subjects and fewer differences compared to moderate asthma. Twenty-six mediators were significantly associated with an increasing single leucocyte type: 16 with neutrophils (3 interleukins [IL], 3 CC chemokines, 4 CXC chemokines, 4 growth factors, TNF-α and CX3CL1/Fractalkine); 5 with lymphocytes (IL-7, IL-16, IL-23, IFN-α2 and CCL4/MIP1β); IL-15 and CCL15/MIP1δ with macrophages; IL-5 with eosinophils; and IL-4 and TNFSF10/TRAIL with airway epithelial cells. Factor analysis grouped 43 cytokines, chemokines and growth factors which had no missing data onto the first 10 factors, containing mixes of Th1, Th2, Th9 and Th17 inflammatory and anti-inflammatory proteins.

CONCLUSIONS

Sputum cytokines, chemokines and growth factors were increased in severe asthma, primarily with increased neutrophils. Factor analysis identified complex inflammatory protein interactions, suggesting airway inflammation in asthma is characterized by overlapping immune pathways. Thus, focus on a single specific inflammatory mediator or pathway may limit understanding the complexity of inflammation underlying airway changes in asthma and selection of appropriate therapy.

Proceedings of resources for optimal care of acute care and emergency surgery consensus summit Donegal Ireland

BACKGROUND

Opportunities to improve emergency surgery outcomes exist through guided better practice and reduced variability. Few attempts have been made to define optimal care in emergency surgery, and few clinically derived key performance indicators (KPIs) have been published. A summit was therefore convened to look at resources for optimal care of emergency surgery. The aim of the Donegal Summit was to set a platform in place to develop guidelines and KPIs in emergency surgery.

METHODS

The project had multidisciplinary global involvement in producing consensus statements regarding emergency surgery care in key areas, and to assess feasibility of producing KPIs that could be used to monitor process and outcome of care in the future.

RESULTS

Forty-four key opinion leaders in emergency surgery, across 7 disciplines from 17 countries, composed evidence-based position papers on 14 key areas of emergency surgery and 112 KPIs in 20 acute conditions or emergency systems.

CONCLUSIONS

The summit was successful in achieving position papers and KPIs in emergency surgery. While position papers were limited by non-graded evidence and non-validated KPIs, the process set a foundation for the future advancement of emergency surgery.

IL-33 Signaling Regulates Innate IL-17A and IL-22 Production via Suppression of Prostaglandin E2 during Lung Fungal Infection

Members of the IL-1 family play protective and regulatory roles in immune defense against the opportunistic mold Aspergillus fumigatus In this study, we investigated the IL-1 family member IL-33 in lung defense against A. fumigatus IL-33 was detected in the naive lung, which further increased after exposure to A. fumigatus in a dectin-1-independent manner. Mice deficient in the receptor for IL-33 (Il1rl1-/-) unexpectedly demonstrated enhanced lung clearance of A. fumigatus IL-33 functioned as a negative regulator of multiple inflammatory cytokines, as IL-1α, IL-1β, IL-6, IL-17A, and IL-22 were significantly elevated in fungal-exposed Il1rl1-/- mice. Subsequently, IL-33 administration to normal mice attenuated fungal-induced IL-17A and IL-22, but not IL-1α, IL-1β, or IL-6, production. IL-33-mediated regulation of IL-17A and IL-22 did not involve the modulation of IL-23 but rather PGE2; PGE2 was significantly increased in fungal-exposed Il1rl1-/- mice, and normal mice produced less PGE2 after fungal exposure when administered IL-33, suggesting that IL-33-mediated regulation of IL-17A and IL-22 occurred at the level of PGE2 This was confirmed by in vivo cyclooxygenase 2 inhibition, which attenuated fungal-induced IL-17A and IL-22, as well as IL-1α, IL-1β, and IL-6, production in Il1rl1-/- mice, resulting in impaired fungal clearance. We also show that a PGE2 receptor agonist increased, whereas a PGE2 synthase inhibitor decreased, the levels of IL-17A and IL-22 but not IL-1α, IL-1β, or IL-6. This study establishes novel mechanisms of innate IL-17A/IL-22 production via PGE2 and regulation of the PGE2/IL-17A/IL-22 axis via IL-33 signaling during lung fungal exposure.

The contribution of acidic mammalian chitinase to disease severity in experimental fungal asthma

Chitin is a polysaccharide that provides structure and rigidity to the fungal cell wall. Exposure to A. fumigatus cell wall moieties such as chitin has been linked to fungal sensitization and allergic inflammation. Chitin is not present in mammals, however, mammals possess enzymes that function to degrade chitin known as chitinases. Mammals possess two functional chitinases, acidic mammalian chitinase (AMCase) and chitotriosidase. Although chitinase expression has been linked to Th2 respiratory disorders, their exact role in fungal sensitization and fungal asthma has not been determined. In an allergic asthma model associated with chronic A. fumigatus exposure, mice deficient in AMCase displayed attenuated levels of the proallergic/pro-type 2 factors CCL22, CCL17, and IL-33. Furthermore, a deficiency in AMCase led to improved total lung function. Surprisingly, examination of inflammatory responses revealed attenuated IL-17 and IL-22 responses, but not type 2 responses (IL-4, IL-5, IL-13), in the absence of AMCase. Collectively, these data suggest that expression of AMCase during allergic fungal asthma is associated with increased severity that is putatively associated with IL-17A and IL-22 responses.

LDB1 Regulates Energy Homeostasis During Diet-Induced Obesity

The broadly expressed transcriptional coregulator LDB1 is essential for β-cell development and glucose homeostasis. However, it is unclear whether LDB1 has metabolic roles beyond the β-cell, especially under metabolic stress. Global Ldb1 deletion results in early embryonic lethality; thus, we used global heterozygous Ldb1+/- and inducible β-cell-specific Ldb1-deficient (Ldb1Δβ-cell) mice. We assessed glucose and insulin tolerance, body composition, feeding, and energy expenditure during high-fat diet exposure. Brown adipose tissue (BAT) biology was evaluated by thermogenic gene expression and LDB1 chromatin immunoprecipitation analysis. We found that partial loss of Ldb1 does not impair the maintenance of glucose homeostasis; rather, we observed improved insulin sensitivity in these mice. Partial loss of Ldb1 also uncovered defects in energy expenditure in lean and diet-induced obese (DIO) mice. This decreased energy expenditure during DIO was associated with significantly altered BAT gene expression, specifically Cidea, Elovl3, Cox7a1, and Dio2. Remarkably, the observed changes in energy balance during DIO were absent in Ldb1Δβ-cell mice, despite a similar reduction in plasma insulin, suggesting a role for LDB1 in BAT. Indeed, LDB1 is expressed in brown adipocytes and occupies a regulatory domain of Elovl3, a gene crucial to normal BAT function. We conclude that LDB1 regulates energy homeostasis, in part through transcriptional modulation of critical regulators in BAT function.

IL-1R and IL-1RA differentially contribute to immunopathogenesis during fungal asthma

Severe asthma with fungal sensitization defines a subset of asthmatics with allergy to multiple fungal species, including Aspergillus fumigatus. We have previously shown genetic deficiency in or neutralization of IL-22 improves fungal asthma severity, which correlated with lower levels of IL-1α and IL-1β. Here, we show that bronchoalveolar lavage fluid (BALF) and induced sputum from human asthmatics sensitized to fungi demonstrate increased levels of IL-1α, IL-1β and IL-1 Receptor Antagonist (IL-1RA) compared to fungal negative asthmatics, suggesting that members of the IL-1 cytokine family may contribute to fungal asthma severity. To this end, we examined fungal asthma severity in mice deficient in IL-1R and IL-1RA with the hypothesis being that severity would be decreased and increased in these animals respectively. Surprisingly, the absence of IL-1R signaling had no impact on biomarkers of asthma severity (i.e. levels of proallergic CCL17, CCL22, and IL-33), yet Il1r−/−mice demonstrated better lung function compared to WT mice. Interestingly, the absence of IL-1R signaling resulted in a profound defect in the production of IL-22, suggesting a mechanism of improved lung function in Il1r−/− mice. In direct contrast, Il1rn−/− mice exhibited elevated proallergic biomarker levels, but no changes in the levels of IL-22. These preliminary results identify differential roles for IL-1R signaling (IL-22 mediated immunopathogenesis) and IL-1RA signaling (type 2 mediated immunopathogenesis) in fungal asthma severity.