Association of Preoperative Lung Function with Complications after Lobectomy Using Race-Neutral and Race-Specific Normative Equations.

Rationale: Pulmonary function testing (PFT) is performed to aid patient selection before surgical resection for non-small cell lung cancer (NSCLC). The interpretation of PFT data relies on normative equations, which vary by race, but the relative strength of association of lung function using race-specific or race-neutral normative equations with postoperative pulmonary complications is unknown. Objectives: To compare the strength of association of lung function, using race-neutral or race-specific equations, with surgical complications after lobectomy for NSCLC. Methods: We studied 3,311 patients who underwent lobectomy for NSCLC and underwent preoperative PFT from 2001 to 2021. We used Global Lung Function Initiative equations to generate race-specific and race-neutral normative equations to calculate percentage predicted forced expiratory volume in 1 second (FEV1%). The primary outcome of interest was the occurrence of postoperative pulmonary complications within 30 days of surgery. We used unadjusted and race-adjusted logistic regression models and least absolute shrinkage and selection operator analyses adjusted for relevant comorbidities to measure the association of race-specific and race-neutral FEV1% with pulmonary complications. Results: Thirty-one percent of patients who underwent surgery experienced pulmonary complications. Higher FEV1, whether measured with race-neutral (odds ratio [OR], 0.98 per 1% change in FEV1% [95% confidence interval (CI), 0.98-0.99]; P < 0.001) or race-specific (OR, 0.98 per 1% change in FEV1% [95% CI, 0.98-0.98]; P < 0.001) normative equations, was associated with fewer postoperative pulmonary complications. The area under the receiver operator curve for pulmonary complications was similar for race-adjusted race-neutral (0.60) and race-specific (0.60) models. Using least absolute shrinkage and selection operator regression, higher FEV1% was similarly associated with a lower rate of pulmonary complications in race-neutral (OR, 0.99 per 1% [95% CI, 0.98-0.99]) and race-specific (OR, 0.99 per 1%; 95% CI, 0.98-0.99) models. The marginal effect of race on pulmonary complications was attenuated in all race-specific models compared with all race-neutral models. Conclusions: The choice of race-specific or race-neutral normative PFT equations does not meaningfully affect the association of lung function with pulmonary complications after lobectomy for NSCLC, but the use of race-neutral equations unmasks additional effects of self-identified race on pulmonary complications.

Interstitial lung abnormalities after hospitalization for COVID-19 in patients with cancer: A prospective cohort study.

INTRODUCTION: Survivors of SARS-CoV-2 pneumonia often develop persistent respiratory symptom and interstitial lung abnormalities (ILAs) after infection. Risk factors for ILA development and duration of ILA persistence after SARS-CoV-2 infection are not well described in immunocompromised hosts, such as cancer patients. METHODS: We conducted a prospective cohort study of 95 patients at a major cancer center and 45 patients at a tertiary referral center. We collected clinical and radiographic data during the index hospitalization for COVID-19 pneumonia and measured pneumonia severity using a semi-quantitative radiographic score, the Radiologic Severity Index (RSI). Patients were evaluated in post-COVID-19 clinics at 3 and 6 months after discharge and underwent comprehensive pulmonary evaluations (symptom assessment, chest computed tomography, pulmonary function tests, 6-min walk test). The association of clinical and radiological factors with ILAs at 3 and 6 months post-discharge was measured using univariable and multivariable logistic regression. RESULTS: Sixty-six (70%) patients of cancer cohort had ILAs at 3 months, of whom 39 had persistent respiratory symptoms. Twenty-four (26%) patients had persistent ILA at 6 months after hospital discharge. In adjusted models, higher peak RSI at admission was associated with ILAs at 3 (OR 1.5 per 5-point increase, 95% CI 1.1-1.9) and 6 months (OR 1.3 per 5-point increase, 95% CI 1.1-1.6) post-discharge. Fibrotic ILAs (reticulation, traction bronchiectasis, and architectural distortion) were more common at 6 months post-discharge. CONCLUSIONS: Post-COVID-19 ILAs are common in cancer patients 3 months after hospital discharge, and peak RSI and older age are strong predictors of persistent ILAs.

Toll-like receptors 2, 4, and 9 modulate promoting effect of COPD-like airway inflammation on K-ras-driven lung cancer through activation of the MyD88/NF-ĸB pathway in the airway epithelium.

Introduction: Toll-like receptors (TLRs) are an extensive group of proteins involved in host defense processes that express themselves upon the increased production of endogenous damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs) due to the constant contact that airway epithelium may have with pathogenic foreign antigens. We have previously shown that COPD-like airway inflammation induced by exposure to an aerosolized lysate of nontypeable Haemophilus influenzae (NTHi) promotes tumorigenesis in a K-ras mutant mouse model of lung cancer, CCSPCre/LSL-K-rasG12D (CC-LR) mouse. Methods: In the present study, we have dissected the role of TLRs in this process by knocking out TLR2, 4, and 9 and analyzing how these deletions affect the promoting effect of COPD-like airway inflammation on K-ras-driven lung adenocarcinoma. Results: We found that knockout of TLR 2, 4, or 9 results in a lower tumor burden, reduced angiogenesis, and tumor cell proliferation, accompanied by increased tumor cell apoptosis and reprogramming of the tumor microenvironment to one that is antitumorigenic. Additionally, knocking out of downstream signaling pathways, MyD88/NF-κB in the airway epithelial cells further recapitulated this initial finding. Discussion: Our study expands the current knowledge of the roles that TLR signaling plays in lung cancer, which we hope, can pave the way for more reliable and efficacious prevention and treatment modalities for lung cancer.

Immunocompromised Host Pneumonia: Definitions and Diagnostic Criteria: An Official American Thoracic Society Workshop Report.

Pneumonia imposes a significant clinical burden on people with immunocompromising conditions. Millions of individuals live with compromised immunity because of cytotoxic cancer treatments, biological therapies, organ transplants, inherited and acquired immunodeficiencies, and other immune disorders. Despite broad awareness among clinicians that these patients are at increased risk for developing infectious pneumonia, immunocompromised people are often excluded from pneumonia clinical guidelines and treatment trials. The absence of a widely accepted definition for immunocompromised host pneumonia is a significant knowledge gap that hampers consistent clinical care and research for infectious pneumonia in these vulnerable populations. To address this gap, the American Thoracic Society convened a workshop whose participants had expertise in pulmonary disease, infectious diseases, immunology, genetics, and laboratory medicine, with the goal of defining the entity of immunocompromised host pneumonia and its diagnostic criteria.

Effect of epithelial-specific MyD88 signaling pathway on airway inflammatory response to organic dust exposure.

The Toll-like receptor (TLR) adaptor protein MyD88 is integral to airway inflammatory response to microbial-enriched organic dust extract (ODE) exposures. ODE-induced airway neutrophil influx and release of pro-inflammatory cytokines was essentially abrogated in global MyD88-deficient mice, yet these mice demonstrate an increase in airway epithelial cell mucin expression. To further elucidate the role of MyD88-dependent responses specific to lung airway epithelial cells in response to ODE in vivo, the surfactant protein C protein (SPC) Cre+ embryologic expressing airway epithelial cells floxed for MyD88 to disrupt MyD88 signaling were utilized. The inducible club cell secretory protein (CCSP) Cre+, MyD88 floxed, were also developed. Using an established protocol, mice were intranasally instilled with ODE or saline once or daily up to 3 weeks. Mice with MyD88-deficient SPC+ lung epithelial cells exhibited decreased neutrophil influx following ODE exposure once and repetitively for 1 week without modulation of classic pro-inflammatory mediators including tumor necrosis factor (TNF)-α, interleukin (IL)-6, and neutrophil chemoattractants. This protective response was lost after 3 weeks of repetitive exposure. ODE-induced Muc5ac mucin expression at 1 week was also reduced in MyD88-deficient SPC+ cells. Acute ODE-induced IL-33 was reduced in MyD88-deficient SPC+ cells whereas serum IgE levels were increased at one week. In contrast, mice with inducible MyD88-deficient CCSP+ airway epithelial cells demonstrated no significant difference in experimental indices following ODE exposure. Collectively, these findings suggest that MyD88-dependent signaling targeted to all airway epithelial cells plays an important role in mediating neutrophil influx and mucin production in response to acute organic dust exposures.

TNIK regulation of interferon signaling and endothelial cell response to virus infection.

Background: Traf2 and Nck-interacting kinase (TNIK) is known for its regulatory role in various processes within cancer cells. However, its role within endothelial cells (ECs) has remained relatively unexplored. Methods: Leveraging RNA-seq data and Ingenuity Pathway Analysis (IPA), we probed the potential impact of TNIK depletion on ECs. Results: Examination of RNA-seq data uncovered more than 450 Differentially Expressed Genes (DEGs) in TNIK-depleted ECs, displaying a fold change exceeding 2 with a false discovery rate (FDR) below 0.05. IPA analysis unveiled that TNIK depletion leads to the inhibition of the interferon (IFN) pathway [-log (p-value) >11], downregulation of IFN-related genes, and inhibition of Hypercytokinemia/Hyperchemokinemia [-log (p-value) >8]. The validation process encompassed qRT-PCR to evaluate mRNA expression of crucial IFN-related genes, immunoblotting to gauge STAT1 and STAT2 protein levels, and ELISA for the quantification of IFN and cytokine secretion in siTNIK-depleted ECs. These assessments consistently revealed substantial reductions upon TNIK depletion. When transducing HUVECs with replication incompetent E1-E4 deleted adenovirus expressing green fluorescent protein (Ad-GFP), it was demonstrated that TNIK depletion did not affect the uptake of Ad-GFP. Nonetheless, TNIK depletion induced cytopathic effects (CPE) in ECs transduced with wild-type human adenovirus serotype 5 (Ad-WT). Summary: Our findings suggest that TNIK plays a crucial role in regulating the EC response to virus infections through modulation of the IFN pathway.

Alternative adenosine Receptor activation: The netrin-Adora2b link.

During hypoxia or inflammation, extracellular adenosine levels are elevated. Studies using pharmacologic approaches or genetic animal models pertinent to extracellular adenosine signaling implicate this pathway in attenuating hypoxia-associated inflammation. There are four distinct adenosine receptors. Of these, it is not surprising that the Adora2b adenosine receptor functions as an endogenous feedback loop to control hypoxia-associated inflammation. First, Adora2b activation requires higher adenosine concentrations compared to other adenosine receptors, similar to those achieved during hypoxic inflammation. Second, Adora2b is transcriptionally induced during hypoxia or inflammation by hypoxia-inducible transcription factor HIF1A. Studies seeking an alternative adenosine receptor activation mechanism have linked netrin-1 with Adora2b. Netrin-1 was originally discovered as a neuronal guidance molecule but also functions as an immune-modulatory signaling molecule. Similar to Adora2b, netrin-1 is induced by HIF1A, and has been shown to enhance Adora2b signaling. Studies of acute respiratory distress syndrome (ARDS), intestinal inflammation, myocardial or hepatic ischemia and reperfusion implicate the netrin-Adora2b link in tissue protection. In this review, we will discuss the potential molecular linkage between netrin-1 and Adora2b, and explore studies demonstrating interactions between netrin-1 and Adora2b in attenuating tissue inflammation.

SARS-CoV-2 Infection: Host Response, Immunity, and Therapeutic Targets.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has resulted in a global pandemic with severe socioeconomic effects. Immunopathogenesis of COVID-19 leads to acute respiratory distress syndrome (ARDS) and organ failure. Binding of SARS-CoV-2 spike protein to human angiotensin-converting enzyme 2 (hACE2) on bronchiolar and alveolar epithelial cells triggers host inflammatory pathways that lead to pathophysiological changes. Proinflammatory cytokines and type I interferon (IFN) signaling in alveolar epithelial cells counter barrier disruption, modulate host innate immune response to induce chemotaxis, and initiate the resolution of inflammation. Here, we discuss experimental models to study SARS-CoV-2 infection, molecular pathways involved in SARS-CoV-2-induced inflammation, and viral hijacking of anti-inflammatory pathways, such as delayed type-I IFN response. Mechanisms of alveolar adaptation to hypoxia, adenosinergic signaling, and regulatory microRNAs are discussed as potential therapeutic targets for COVID-19.

How Are Indeterminate Pulmonary Nodules at Diagnosis Associated with Survival in Patients with High-Grade Osteosarcoma?

BACKGROUND: Pulmonary metastases are a poor prognostic factor in patients with osteosarcoma; however, the clinical significance of subcentimeter lung nodules and whether they represent a tumor is not fully known. Because the clinician is faced with decisions regarding biopsy, resection, or observation of lung nodules and the potential impact they have on decisions about resection of the primary tumor, this remains an area of uncertainty in patient treatment. Surgical management of the primary tumor is tailored to prognosis, and it is unclear how aggressively patients with indeterminate pulmonary nodules (IPNs), defined as nodules smaller than 1 cm at presentation, should be treated. There is a clear need to better understand the clinical importance of these nodules. QUESTIONS/PURPOSES: (1) What percentage of patients with high-grade osteosarcoma and spindle cell sarcoma of bone have IPNs at diagnosis? (2) Are IPNs at diagnosis associated with worse metastasis-free and overall survival? (3) Are there any clinical or radiologic factors associated with worse overall survival in patients with IPN? METHODS: Between 2008 and 2016, 484 patients with a first presentation of osteosarcoma or spindle cell sarcoma of bone were retrospectively identified from an institutional database. Patients with the following were excluded: treatment at another institution (6%, 27 of 484), death related to complications of neoadjuvant chemotherapy (1%, 3 of 484), Grade 1 or 2 on final pathology (4%, 21 of 484) and lack of staging chest CT available for review (0.4%, 2 of 484). All patients with abnormalities on their staging chest CT underwent imaging re-review by a senior radiology consultant and were divided into three groups for comparison: no metastases (70%, 302 of 431), IPN (16%, 68 of 431), and metastases (14%, 61 of 431) at the time of diagnosis. A random subset of CT scans was reviewed by a senior radiology registrar and there was very good agreement between the two reviewers (κ = 0.88). Demographic and oncologic variables as well as treatment details and clinical course were gleaned from a longitudinally maintained institutional database. The three groups did not differ with regard to age, gender, subtype, presence of pathological fracture, tumor site, or chemotherapy-induced necrosis. They differed according to local control strategy and tumor size, with a larger proportion of patients in the metastases group presenting with larger tumor size and undergoing nonoperative treatment. There was no differential loss to follow-up among the three groups. Two percent (6 of 302) of patients with no metastases, no patients with IPN, and 2% (1 of 61) of patients with metastases were lost to follow-up at 1 year postdiagnosis but were not known to have died. Individual treatment decisions were determined as part of a multidisciplinary conference, but in general, patients without obvious metastases received (neo)adjuvant chemotherapy and surgical resection for local control. Patients in the no metastases and IPN groups did not differ in local control strategy. For patients in the IPN group, staging CT images were inspected for IPN characteristics including number, distribution, size, location, presence of mineralization, and shape. Subsequent chest CT images were examined by the same radiologist to reevaluate known nodules for interval change in size and to identify the presence of new nodules. A random subset of chest CT scans were re-reviewed by a senior radiology resident (κ = 0.62). The association of demographic and oncologic variables with metastasis-free and overall survival was first explored using the Kaplan-Meier method (log-rank test) in univariable analyses. All variables that were statistically significant (p < 0.05) in univariable analyses were entered into Cox regression multivariable analyses. RESULTS: Following re-review of staging chest CTs, IPNs were found in 16% (68 of 431) of patients, while an additional 14% (61 of 431) of patients had lung metastases (parenchymal nodules 10 mm or larger). After controlling for potential confounding variables like local control strategy, tumor size, and chemotherapy-induced necrosis, we found that the presence of an IPN was associated with worse overall survival and a higher incidence of metastases (hazard ratio 1.9 [95% CI 1.3 to 2.8]; p = 0.001 and HR 3.6 [95% CI 2.5 to 5.2]; p < 0.001, respectively). Two-year overall survival for patients with no metastases, IPN, or metastases was 83% [95% CI 78 to 87], 65% [95% CI 52 to 75] and 45% [95% CI 32 to 57], respectively (p = 0.001). In 74% (50 of 68) of patients with IPNs, it became apparent that they were true metastatic lesions at a median of 5.3 months. Eighty-six percent (43 of 50) of these patients had disease progression by 2 years after diagnosis. In multivariable analysis, local control strategy and tumor subtype correlated with overall survival for patients with IPNs. Patients who were treated nonoperatively and who had a secondary sarcoma had worse outcomes (HR 3.6 [95% CI 1.5 to 8.3]; p = 0.003 and HR 3.4 [95% CI 1.1 to 10.0]; p = 0.03). The presence of nodule mineralization was associated with improved overall survival in the univariable analysis (87% [95% CI 39 to 98] versus 57% [95% CI 43 to 69]; p = 0.008), however, because we could not control for other factors in a multivariable analysis, the relationship between mineralization and survival could not be determined. We were unable to detect an association between any other nodule radiologic features and survival. CONCLUSION: The findings show that the presence of IPNs at diagnosis is associated with poorer survival of affected patients compared with those with normal staging chest CTs. IPNs noted at presentation in patients with high-grade osteosarcoma and spindle cell sarcoma of bone should be discussed with the patient and be considered when making treatment decisions. Further work is required to elucidate how the nodules should be managed. LEVEL OF EVIDENCE: Level III, prognostic study.

Immune Modulation to Improve Survival of Viral Pneumonia in Mice.

Viral pneumonias remain global health threats, as exemplified in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, requiring novel treatment strategies both early and late in the disease process. We have reported that mice treated before or soon after infection with a combination of inhaled Toll-like receptor (TLR) 2/6 and 9 agonists (Pam2-ODN) are broadly protected against microbial pathogens including respiratory viruses, but the mechanisms remain incompletely understood. The objective of this study was to validate strategies for immune modulation in a preclinical model of viral pneumonia and determine their mechanisms. Mice were challenged with the Sendai paramyxovirus in the presence or absence of Pam2-ODN treatment. Virus burden and host immune responses were assessed to elucidate Pam2-ODN mechanisms of action and to identify additional opportunities for therapeutic intervention. Enhanced survival of Sendai virus pneumonia with Pam2-ODN treatment was associated with reductions in lung virus burden and with virus inactivation before internalization. We noted that mortality in sham-treated mice corresponded with CD8+ T-cell lung inflammation on days 11-12 after virus challenge, after the viral burden had declined. Pam2-ODN blocked this injurious inflammation by minimizing virus burden. As an alternative intervention, depleting CD8+ T cells 8 days after viral challenge also decreased mortality. Stimulation of local innate immunity within the lungs by TLR agonists early in disease or suppression of adaptive immunity by systemic CD8+ T-cell depletion late in disease improves outcomes of viral pneumonia in mice. These data reveal opportunities for targeted immunomodulation to protect susceptible human subjects.

Inducible epithelial resistance against acute Sendai virus infection prevents chronic asthma-like lung disease in mice.

BACKGROUND AND PURPOSE: Respiratory viral infections play central roles in the initiation, exacerbation and progression of asthma in humans. An acute paramyxoviral infection in mice can cause a chronic lung disease that resembles human asthma. We sought to determine whether reduction of Sendai virus lung burden in mice by stimulating innate immunity with aerosolized Toll-like receptor (TLR) agonists could attenuate the severity of chronic asthma-like lung disease. EXPERIMENTAL APPROACH: Mice were treated by aerosol with 1-µM oligodeoxynucleotide (ODN) M362, an agonist of the TLR9 homodimer, and 4-µM Pam2CSK4 (Pam2), an agonist of the TLR2/6 heterodimer, within a few days before or after Sendai virus challenge. KEY RESULTS: Treatment with ODN/Pam2 caused ~75% reduction in lung Sendai virus burden 5 days after challenge. The reduction in acute lung virus burden was associated with marked reductions 49 days after viral challenge in eosinophilic and lymphocytic lung inflammation, airway mucous metaplasia, lumenal mucus occlusion and hyperresponsiveness to methacholine. Mechanistically, ODN/Pam2 treatment attenuated the chronic asthma phenotype by suppressing IL-33 production by type 2 pneumocytes, both by reducing the severity of acute infection and by down-regulating Type 2 (allergic) inflammation. CONCLUSION AND IMPLICATIONS: These data suggest that treatment of susceptible human hosts with aerosolized ODN and Pam2 at the time of a respiratory viral infection might attenuate the severity of the acute infection and reduce initiation, exacerbation and progression of asthma.

Distinct Immunophenotypes of T Cells in Bronchoalveolar Lavage Fluid From Leukemia Patients With Immune Checkpoint Inhibitors-Related Pulmonary Complications.

Patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) treated with immune checkpoint inhibitors (ICIs) are at risk of pneumonitis as well as pneumonia (combined henceforth as ICI-related pulmonary complications). Little is known about the cellular and molecular mechanisms underlying ICI-related pulmonary complications. We characterized lymphocytes from bronchoalveolar lavage (BAL) fluid and peripheral blood from seven AML/MDS patients with pulmonary symptoms after ICI-based therapy (ICI group) and four ICI-naïve AML/MDS patients with extracellular bacterial or fungal pneumonias (controls). BAL T cells in the ICI group were clonally expanded, and BAL IFNγ+ IL-17- CD8+ T and CXCR3+ CCR6+ Th17/Th1 cells were enriched in the ICI group. Our data suggest that these cells may play a critical role in the pathophysiology of ICI-related pulmonary complications. Understanding of these cell populations may also provide predictive and diagnostic biomarkers of ICI-related pulmonary complications, eventually enabling differentiation of pneumonitis from pneumonia in AML/MDS patients receiving ICI-based therapies.

Refinement of estimates of mortality risk using the Radiologic Severity Index in hematologic malignancy patients with respiratory syncytial virus infection.

BACKGROUND: Immunocompromised hematologic malignancy (HM) patients experience high mortality after respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI). We measured radiologic severity to determine whether it could improve the performance of 60-day mortality models based only upon immunodeficiency severity. METHODS: We studied 155 HM patients, including 84 hematopoietic cell transplant recipients, who developed RSV LRTI from 2001 to 2013. We measured immunodeficiency using lymphopenia (lymphocyte count <200 cells/mm3 ), Immunodeficiency Severity Index (ISI), and Severe Immunodeficiency (SID) criteria. Radiologic severity was measured by the Radiologic Severity Index (RSI, range 0-72) at time of LRTI (baseline-RSI) and peak severity (peak-RSI). Delta-RSI was defined as the difference between baseline-RSI and peak-RSI. We used logistic regression models to measure the association of immunodeficiency and RSI with 60-day all-cause mortality, and measured model discrimination using areas under the receiver-operating characteristics curves, calibration using Brier scores, and explained variance using pseudo-R2 values. RESULTS: Forty-one patients died within 60 days of RSV LRTI. Severe immunodeficiency was associated with higher mortality. Peak-RSI (odds ratio [OR] 1.06/point, 95% confidence interval [CI] 1.04-1.08), and delta-RSI (OR 1.07/point, 95% CI 1.05-1.10) were associated with 60-day mortality after RSV LRTI, but not baseline-RSI. Addition of peak-RSI or delta-RSI to baseline immunodeficiency improved the discrimination, calibration, and explained variance (P < 0.001) of 60-day mortality models. CONCLUSIONS: Although baseline immunodeficiency in HM patients helps predict 60-day mortality after RSV LRTI, mortality risk estimates can be further refined by also measuring LRTI progression using RSI. RSI is well-suited as a marker of LRTI severity in RSV infection.

MAGI1 as a link between endothelial activation and ER stress drives atherosclerosis.

The possible association between the membrane-associated guanylate kinase with inverted domain structure-1 (MAGI1) and inflammation has been suggested, but the molecular mechanisms underlying this link, especially during atherogenesis, remain unclear. In endothelial cells (ECs) exposed to disturbed flow (d-flow), p90 ribosomal S6 kinase (p90RSK) bound to MAGI1, causing MAGI1-S741 phosphorylation and sentrin/SUMO-specific protease 2 T368 phosphorylation-mediated MAGI1-K931 deSUMOylation. MAGI1-S741 phosphorylation upregulated EC activation via activating Rap1. MAGI1-K931 deSUMOylation induced both nuclear translocation of p90RSK-MAGI1 and ATF-6-MAGI1 complexes, which accelerated EC activation and apoptosis, respectively. Microarray screening revealed key roles for MAGI1 in the endoplasmic reticulum (ER) stress response. In this context, MAGI1 associated with activating transcription factor 6 (ATF-6). MAGI1 expression was upregulated in ECs and macrophages found in atherosclerotic-prone regions of mouse aortas as well as in the colonic epithelia and ECs of patients with inflammatory bowel disease. Further, reduced MAGI1 expression in Magi1-/+ mice inhibited d-flow-induced atherogenesis. In sum, EC activation and ER stress-mediated apoptosis are regulated in concert by two different types of MAGI1 posttranslational modifications, elucidating attractive drug targets for chronic inflammatory disease, particularly atherosclerosis.

Inducible lung epithelial resistance requires multisource reactive oxygen species generation to protect against bacterial infections.

Pneumonia remains a global health threat, in part due to expanding categories of susceptible individuals and increasing prevalence of antibiotic resistant pathogens. However, therapeutic stimulation of the lungs' mucosal defenses by inhaled exposure to a synergistic combination of Toll-like receptor (TLR) agonists known as Pam2-ODN promotes mouse survival of pneumonia caused by a wide array of pathogens. This inducible resistance to pneumonia relies on intact lung epithelial TLR signaling, and inducible protection against viral pathogens has recently been shown to require increased production of epithelial reactive oxygen species (ROS) from multiple epithelial ROS generators. To determine whether similar mechanisms contribute to inducible antibacterial responses, the current work investigates the role of ROS in therapeutically-stimulated protection against Pseudomonas aerugnosa challenges. Inhaled Pam2-ODN treatment one day before infection prevented hemorrhagic lung cytotoxicity and mouse death in a manner that correlated with reduction in bacterial burden. The bacterial killing effect of Pam2-ODN was recapitulated in isolated mouse and human lung epithelial cells, and the protection correlated with inducible epithelial generation of ROS. Scavenging or targeted blockade of ROS production from either dual oxidase or mitochondrial sources resulted in near complete loss of Pam2-ODN-induced bacterial killing, whereas deficiency of induced antimicrobial peptides had little effect. These findings support a central role for multisource epithelial ROS in inducible resistance against a bacterial pathogen and provide mechanistic insights into means to protect vulnerable patients against lethal infections.

Lipocalin-2 is dispensable in inflammation-induced sickness and depression-like behavior.

RATIONALE: While the relationship between inflammation and depression is well-established, the molecular mechanisms mediating this relationship remain unclear. RNA sequencing analysis comparing brains of vehicle- and lipopolysaccharide-treated mice revealed LCN2 among the most dysregulated genes. As LCN2 is known to be an important regulator of the immune response to bacterial infection, we investigated its role in the behavioral response to lipopolysaccharide. OBJECTIVE: To explore the role of LCN2 in modulating behavior following lipopolysaccharide administration using wild type (WT) and lcn2-/- mice. METHODS: Using a within-subjects design, mice were treated with 0.33 mg/kg liposaccharide (LPS) and vehicle. Primary outcome measures included body weight, food consumption, voluntary wheel running, sucrose preference, and the tail suspension test. To evaluate the inflammatory response, 1 week later, mice were re-administered either vehicle or LPS and terminated at 6 h. RESULTS: While lcn2-/- mice had increased baseline food consumption and body weight, they showed a pattern of reduced food consumption and weight loss similar to WT mice in response to LPS. WT and lcn2-/- mice both recovered voluntary activity on the fourth day following LPS. LPS induced equivalent reductions in sucrose preference and TST immobility in the WT and lcn2-/- mice. Finally, there were no significant effects of genotype on inflammatory markers. CONCLUSIONS: Our data demonstrate that lcn2 is dispensable for sterile inflammation-induced sickness and depression-like behavior. Specifically, lcn2-/- mice displayed sickness and immobility in the tail suspension test comparable to that of WT mice both in terms of intensity and duration.

Progression of the Radiologic Severity Index is associated with increased mortality and healthcare resource utilisation in acute leukaemia patients with pneumonia.

Background: Pneumonia is a major cause of mortality and morbidity, but the development of new antimicrobials is lacking. Radiological assessment of pneumonia severity may serve as an effective intermediate endpoint to reduce barriers to successful completion of antimicrobial trials. We sought to determine whether the Radiologic Severity Index (RSI) correlated with mortality and healthcare resource utilisation in patients with acute leukaemia undergoing induction chemotherapy. Methods: We measured RSI (range 0-72) on all chest radiographs performed within 33 days of induction chemotherapy in 165 haematological malignancy patients with pneumonia. Peak RSI was defined as the highest RSI score within 33 days of induction. We used extended Cox proportional hazards models to measure the association of time-varying RSI with all-cause mortality within the first 33 days after induction chemotherapy, and logistic regression or generalised models to measure the association of RSI with total daily cost and healthcare resource utilisation. Results: After adjustment for clinical variables, each one-point increase in RSI was associated with a 7% increase in all-cause 33-day mortality (HR 1.07, 95% CI 1.05 to 1.09, p<0.0001). Peak RSI values of 37.5 or higher were associated with 86% higher daily direct costs (p<0.0001), more days in intensive care unit (9.9 vs 4.8 days, p=0.001) and higher odds for mechanical ventilation (OR 12.1, p<0.0001). Conclusions: Greater radiological severity as measured by RSI was associated with increased mortality and morbidity in acute leukaemia patients with pneumonia. RSI is a promising intermediate marker of pneumonia severity and is well suited for use in antimicrobial trials.