A role for MCP-1/CCR2 in interstitial lung disease in children

Vistusertib improves pulmonary inflammation and fibrosis by modulating inflammatory/oxidative stress mediators via suppressing the mTOR signalling

INTRODUCTION

Inflammation and oxidative stress are key factors in the development of pulmonary fibrosis (PF) by promoting the differentiation of fibroblasts through modulating various pathways including Wnt/β-catenin, TGF-β and mTOR signalling.

OBJECTIVE AND METHODS

This study aimed to evaluate the effects and elucidate the mechanisms of vistusertib (VSB) in treating pulmonary inflammation/fibrosis, specifically by targeting the mTOR pathway using various in vitro and in vivo models.

RESULTS

Lipopolysaccharide (LPS)-induced inflammation model in macrophages (RAW 264.7), epithelial (BEAS-2B) and endothelial (HMVEC-L) cells revealed that treatment with VSB significantly reduced the IL-6, TNF-α, CCL2, and CCL7 expression. TGF-β induced differentiation was also significantly reduced upon VSB treatment in fibrotic cells (LL29 and DHLF). Further, bleomycin-induced inflammation and fibrosis models demonstrated that treatment with VSB significantly ameliorated the severe inflammation, and lung architectural distortion, by reducing the inflammatory markers expression/levels, inflammatory cells and oxidative stress indicators. Further, fibrosis model results exhibited that, VSB treatment significantly reduced the α-SMA, collagen and TGF-β expressions, improved the lung architecture and restored lung functions.

CONCLUSION

Overall, this study uncovers the anti-inflammatory/anti-fibrotic effects of VSB by modulating the mTOR activation. Although VSB was tested for lung fibrosis, it can be tested for other fibrotic disorders to improve the patient's survival and quality of life.

Literature mining discerns latent disease-gene relationships

MOTIVATION

Dysregulation of a gene's function, either due to mutations or impairments in regulatory networks, often triggers pathological states in the affected tissue. Comprehensive mapping of these apparent gene-pathology relationships is an ever-daunting task, primarily due to genetic pleiotropy and lack of suitable computational approaches. With the advent of high throughput genomics platforms and community scale initiatives such as the Human Cell Landscape project, researchers have been able to create gene expression portraits of healthy tissues resolved at the level of single cells. However, a similar wealth of knowledge is currently not at our finger-tip when it comes to diseases. This is because the genetic manifestation of a disease is often quite diverse and is confounded by several clinical and demographic covariates.

RESULTS

To circumvent this, we mined ∼18 million PubMed abstracts published till May 2019 and automatically selected ∼4.5 million of them that describe roles of particular genes in disease pathogenesis. Further, we fine-tuned the pretrained bidirectional encoder representations from transformers (BERT) for language modeling from the domain of natural language processing to learn vector representation of entities such as genes, diseases, tissues, cell-types, etc., in a way such that their relationship is preserved in a vector space. The repurposed BERT predicted disease-gene associations that are not cited in the training data, thereby highlighting the feasibility of in silico synthesis of hypotheses linking different biological entities such as genes and conditions.

AVAILABILITY AND IMPLEMENTATION

PathoBERT pretrained model: https://github.com/Priyadarshini-Rai/Pathomap-Model. BioSentVec-based abstract classification model: https://github.com/Priyadarshini-Rai/Pathomap-Model. Pathomap R package: https://github.com/Priyadarshini-Rai/Pathomap.

Inflammatory Patterns Associated with Legionella in HIV and Pneumonia Coinfections

Legionella infections have a propensity for occurring in HIV-infected individuals, with immunosuppressed individuals tending to present with more severe disease. However, understanding regarding the Legionella host response in immune compromised individuals is lacking. This study investigated the inflammatory profiles associated with Legionella infection in patients hospitalized with HIV and pneumonia in Medellín, Colombia from February 2007 to April 2014, and correlated these profiles with clinical outcomes. Sample aliquots from the Colombian cohort were shipped to Canada where Legionella infections and systemic cytokine profiles were determined using real-time PCR and bead-based technology, respectively. To determine the effect of Legionella coinfection on clinical outcome, a patient database was consulted, comparing laboratory results and outcomes between Legionella-positive and -negative individuals. Principal component analysis revealed higher plasma concentrations of eotaxin, IP-10 and MCP-1 (p = 0.0046) during Legionella infection. Individuals with this immune profile also had higher rates of intensive care unit admissions (adjusted relative risk 1.047 [95% confidence interval 1.027-1.066]). Results demonstrate that systemic markers of monocyte/macrophage activation and differentiation (eotaxin, MCP-1, and IP-10) are associated with Legionella infection and worse patient outcomes. Further investigations are warranted to determine how this cytokine profile may play a role in Legionella pneumonia pathogenesis or immunity.

Wild-type S100A3 and S100A13 restore calcium homeostasis and mitigate mitochondrial dysregulation in pulmonary fibrosis patient-derived cells

Patients with digenic S100A3 and S100A13 mutations exhibited an atypical and progressive interstitial pulmonary fibrosis, with impaired intracellular calcium homeostasis and mitochondrial dysfunction. Here we provide direct evidence of a causative effect of the mutation on receptor mediated calcium signaling and calcium store responses in control cells transfected with mutant S100A3 and mutant S100A13. We demonstrate that the mutations lead to increased mitochondrial mass and hyperpolarization, both of which were reversed by transfecting patient-derived cells with the wild type S100A3 and S100A13, or extracellular treatment with the recombinant proteins. In addition, we demonstrate increased secretion of inflammatory mediators in patient-derived cells and in control cells transfected with the mutant-encoding constructs. These findings indicate that treatment of patients' cells with recombinant S100A3 and S100A13 proteins is sufficient to normalize most of cellular responses, and may therefore suggest the use of these recombinant proteins in the treatment of this devastating disease.

Inhibition of CCR2 attenuates neuroinflammation and neuronal apoptosis after subarachnoid hemorrhage through the PI3K/Akt pathway

BACKGROUND

Neuroinflammation and neuronal apoptosis are closely associated with a poor prognosis in patients with subarachnoid hemorrhage (SAH). We investigated the role of C-C motif chemokine receptor 2 (CCR2) in SAH.

METHODS

Pre-processed RNA-seq transcriptome datasets GSE167110 and GSE79416 from the Gene Expression Omnibus (GEO) database were screened for genes differentially expressed between mice with SAH and control mice, using bioinformatics analysis. The endovascular perforation model was performed to establish SAH. RS504393 (a CCR2 antagonist) and LY294002 (PI3K inhibitor) were administered to explore the mechanism of neuroinflammation after SAH. SAH grading, neurological scoring, brain water content and blood-brain barrier (BBB) permeability determination, enzyme-linked immunosorbent assay (ELISA), western blotting, and immunofluorescence were performed. An in vitro model of SAH was induced in H22 cells by hemin treatment. The protective mechanism of CCR2 inhibition was studied by adding RS504393 and LY294002. Clinical cerebrospinal fluid (CST) samples were detected by ELISA.

RESULTS

Expression of CCR2 was upregulated in both datasets and was identified as a hub gene. CCR2 expression was significantly upregulated in the cytoplasm of neurons after SAH, both in vitro and in vivo. RS significantly reduced the brain water content and blood-brain barrier permeability, alleviated neuroinflammation, and reduced neuronal apoptosis after SAH. Additionally, the protective effects of CCR2 inhibition were abolished by LY treatment. Finally, the levels of CCR2, inflammatory factors, and apoptotic factors were elevated in the CSF of patients with SAH. CCR2 levels were associated with patient outcomes at the 6-month follow-up.

CONCLUSION

CCR2 expression was upregulated in both in vitro and in vivo SAH models. Additionally, inhibition of CCR2, at least partly through the PI3K/AKT pathway, alleviated neuroinflammation and neuronal apoptosis in vivo and in vitro. CCR2 levels in the CSF have a moderate diagnostic value for 6-month outcome prediction in patients with SAH.

Experimental Models to Study the Pathogenesis of Malaria-Associated Acute Respiratory Distress Syndrome

Malaria-associated acute respiratory distress syndrome (MA-ARDS) is increasingly gaining recognition as a severe malaria complication because of poor prognostic outcomes, high lethality rate, and limited therapeutic interventions. Unfortunately, invasive clinical studies are challenging to conduct and yields insufficient mechanistic insights. These limitations have led to the development of suitable MA-ARDS experimental mouse models. In patients and mice, MA-ARDS is characterized by edematous lung, along with marked infiltration of inflammatory cells and damage of the alveolar-capillary barriers. Although, the pathogenic pathways have yet to be fully understood, the use of different experimental mouse models is fundamental in the identification of mediators of pulmonary vascular damage. In this review, we discuss the current knowledge on endothelial activation, leukocyte recruitment, leukocyte induced-endothelial dysfunction, and other important findings, to better understand the pathogenesis pathways leading to endothelial pulmonary barrier lesions and increased vascular permeability. We also discuss how the advances in imaging techniques can contribute to a better understanding of the lung lesions induced during MA-ARDS, and how it could aid to monitor MA-ARDS severity.

Overview of positron emission tomography in functional imaging of the lungs for diffuse lung diseases

Positron emission tomography (PET) is a quantitative molecular imaging modality increasingly used to study pulmonary disease processes and drug effects on those processes. The wide range of drugs and other entities that can be radiolabeled to study molecularly targeted processes is a major strength of PET, thus providing a noninvasive approach for obtaining molecular phenotyping information. The use of PET to monitor disease progression and treatment outcomes in DLD has been limited in clinical practice, with most of such applications occurring in the context of research investigations under clinical trials. Given the high costs and failure rates for lung drug development efforts, molecular imaging lung biomarkers are needed not only to aid these efforts but also to improve clinical characterization of these diseases beyond canonical anatomic classifications based on computed tomography. The purpose of this review article is to provide an overview of PET applications in characterizing lung disease, focusing on novel tracers that are in clinical development for DLD molecular phenotyping, and briefly address considerations for accurately quantifying lung PET signals.

Nifuroxazide-loaded cubosomes exhibit an advancement in pulmonary delivery and attenuate bleomycin-induced lung fibrosis by regulating the STAT3 and NF-κB signaling: A new challenge for unmet therapeutic needs

Pulmonary fibrosis (PF) is a chronic progressive disease that portends a very poor prognosis. It has been suggested that STAT3 is a potential target in PF. This study highlights the importance of cubosomes as a drug delivery system in enhancing the bioavailability of nifuroxazide (NXZD), a poorly soluble STAT3 inhibitor. NXZD-loaded cubosomes (NXZD-LC) were in vitro and in vivo evaluated. In vitro, cubosomes presented a poly-angular nanosized particles with a mean size and zeta potential of 223.73 ± 4.73 nm and - 20.93 ± 2.38 mV, respectively. The entrapment efficiency of nifuroxazide was 90.56 ± 4.25%. The in vivo pharmacokinetic study and the lung tissue accumulation of NXZD were performed by liquid chromatography-tandem mass spectrometry after oral administration to rats. The nanoparticles exhibited a two-fold increase and 1.33 times of bioavailability and lung tissue concentration of NXZD compared to NXZD dispersion, respectively. In view of this, NXZD-LC effectively attenuated PF by targeting STAT3 and NF-κB signals. As a result, NXZD-LC showed a potential anti-inflammatory effect as revealed by the significant decrease in MCP-1, ICAM-1, IL-6, and TNF-α and suppressed fibrogenic mediators as indicated by the significant reduction in TGF-β, TIMP-1, and PDGF-BB in lung tissues. Besides, NXZD-LC improved antioxidant defense mechanisms and decreased LDH and BALF total protein. These effects contributed to decreased collagen deposition. To conclude, cubosomes represent an advantageous pharmaceutical delivery system for enhancing pulmonary delivery of poorly soluble drugs. Additionally, repurposing NXZD as an antifibrotic agent is a promising challenge and new therapeutic approach for unmet therapeutic needs.

Obesity and the Development of Lung Fibrosis

Obesity is an epidemic worldwide and the obese people suffer from a range of respiratory complications including fibrotic changes in the lung. The influence of obesity on the lung is multi-factorial, which is related to both mechanical injury and various inflammatory mediators produced by excessive adipose tissues, and infiltrated immune cells. Adiposity causes increased production of inflammatory mediators, for example, cytokines, chemokines, and adipokines, both locally and in the systemic circulation, thereby rendering susceptibility to respiratory diseases, and altered responses. Lung fibrosis is closely related to chronic inflammation in the lung. Current data suggest a link between lung fibrosis and diet-induced obesity, although the mechanism remains incomplete understood. This review summarizes findings on the association of lung fibrosis with obesity, highlights the role of several critical inflammatory mediators (e.g., TNF-α, TGF-β, and MCP-1) in obesity related lung fibrosis and the implication of obesity in the outcomes of idiopathic pulmonary fibrosis patients.

Non-Invasive Systemic Biomarker of E-cigarette or Vaping use-Associated Lung Injury (EVALI): A pilot study

Background

Electronic cigarette (e-cigarette) vaping, containing nicotine and/or Δ⁸, Δ⁹ or Δ¹⁰ or Δ^o tetrahydrocannabinol (Δⁿ-THC), is associated with an outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI). Despite thousands being hospitalised with EVALI, much remains unknown about diagnosis, treatment and disease pathogenesis. Biomarkers of inflammation, oxidative stress and lipid mediators may help identify e-cigarette users with EVALI.

Methods

We collected plasma and urine along with demographic and vaping-related data of EVALI subjects (age 18–35 years) and non-users matched for sex and age in a pilot study. Biomarkers were assessed by ELISA/EIA and Luminex-based assays.

Results

Elevated levels of THC metabolite (11-nor-9-carboxy-Δ⁹-THC) were found in plasma from EVALI subjects compared to non-users. Levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), an oxidative DNA damage biomarker, and 8-isoprostane, an oxidative stress marker, were slightly increased in urine samples from EVALI subjects compared to non-users. Conversely, plasma levels of lipid mediators, including resolvin D₁ (RvD₁) and prostaglandin E₂ (PGE₂), were significantly lower in EVALI subjects compared to non-users. Both pro-inflammatory biomarkers, such as tumour necrosis factor-α, macrophage inflammatory protein-1β, RANTES (regulated on activation, normal T-cell expressed and secreted) and granulocyte–macrophage colony-stimulating factor, as well as anti-inflammatory biomarkers, such as interleukin-9 and CC10/16, were decreased in plasma from EVALI subjects compared to non-users, supportive of a possible dysregulated inflammatory response in EVALI subjects.

Conclusions

Significant elevations in urine and plasma biomarkers of oxidative stress, as well as reductions in lipid mediators, were shown in EVALI subjects. These noninvasive biomarkers (8-OHdG, 8-isoprostane, RvD₁ and CC10/16), either individually or collectively, may serve as tools in diagnosing future EVALI subjects.

Biomarkers 8-OHdG, 8-isoprostane, RvD₁ and CC10/16 are associated with electronic cigarettes and vapinghttps://bit.ly/3tJJV71

An in vitro assessment of the toxicity of two-dimensional synthetic and natural layered silicates

Natural Layered Silicates (NLS) and Synthetic Layered Silicates (SLS) are a diverse group of clay minerals that have attracted great interest in various branches of industry. However, despite growing demand for this class of material, their impact on human health has not been fully investigated. Therefore, the aim of this study was to evaluate and compare the potential toxic effects of a wide range of commercially available SLS and NLS of varying physicochemical properties (lithium (Li) or fluoride (F) content and size). Mouse BALB/c monocyte macrophage (J774A.1) and human monocyte-derived macrophages (MDMs) were chosen as in vitro models of alveolar macrophages. Montmorillonite, hectorite, Medium (med) F/High Li and Low F/Med Li particles, were cytotoxic to cells and induced potent pro-inflammatory responses. The remaining particles (No F/Very (V)Low Li, No F/Med Li, No F/Low Li, High F/Med Li and High F/Med Li washed) were non- to relatively low- cytotoxic and inflammogenic, in both type of cells. In an acellular condition none of the tested samples increased reactive oxygen species (ROS), while ROS generation was observed following exposure to sublethal concentrations of Med F/High Li, Low F/Med Li, montmorillonite and hectorite samples, in J774A.1 cells. Based on the results obtained in this study the toxic potency of tested samples was not associated with lithium or fluoride content, but appeared to be dependent on particle size, with the platelets of larger dimension and lower surface area being more potent than the smaller platelet particles with higher surface area. In addition, the increased bioactivity of Med F/High Li and Low F/Med Li was associated with endotoxin contamination. Obtained results demonstrated that layered silicate materials have different toxicological profiles and suggest that toxicological properties of a specific layered silicate should be investigated on an individual basis.

Metoprolol in Critically Ill Patients With COVID-19

BACKGROUND

Severe coronavirus disease-2019 (COVID-19) can progress to an acute respiratory distress syndrome (ARDS), which involves alveolar infiltration by activated neutrophils. The beta-blocker metoprolol has been shown to ameliorate exacerbated inflammation in the myocardial infarction setting.

OBJECTIVES

The purpose of this study was to evaluate the effects of metoprolol on alveolar inflammation and on respiratory function in patients with COVID-19-associated ARDS.

METHODS

A total of 20 COVID-19 patients with ARDS on invasive mechanical ventilation were randomized to metoprolol (15 mg daily for 3 days) or control (no treatment). All patients underwent bronchoalveolar lavage (BAL) before and after metoprolol/control. The safety of metoprolol administration was evaluated by invasive hemodynamic and electrocardiogram monitoring and echocardiography.

RESULTS

Metoprolol administration was without side effects. At baseline, neutrophil content in BAL did not differ between groups. Conversely, patients randomized to metoprolol had significantly fewer neutrophils in BAL on day 4 (median: 14.3 neutrophils/µl [Q1, Q3: 4.63, 265 neutrophils/µl] vs median: 397 neutrophils/µl [Q1, Q3: 222, 1,346 neutrophils/µl] in the metoprolol and control groups, respectively; P = 0.016). Metoprolol also reduced neutrophil extracellular traps content and other markers of lung inflammation. Oxygenation (PaO2:FiO2) significantly improved after 3 days of metoprolol treatment (median: 130 [Q1, Q3: 110, 162] vs median: 267 [Q1, Q3: 199, 298] at baseline and day 4, respectively; P = 0.003), whereas it remained unchanged in control subjects. Metoprolol-treated patients spent fewer days on invasive mechanical ventilation than those in the control group (15.5 ± 7.6 vs 21.9 ± 12.6 days; P = 0.17).

CONCLUSIONS

In this pilot trial, intravenous metoprolol administration to patients with COVID-19-associated ARDS was safe, reduced exacerbated lung inflammation, and improved oxygenation. Repurposing metoprolol for COVID-19-associated ARDS appears to be a safe and inexpensive strategy that can alleviate the burden of the COVID-19 pandemic.

Novel associations between cytokines and pulmonary involvement in juvenile dermatomyositis - a cross-sectional study of long-term disease

OBJECTIVES

To examine associations between cytokines and pulmonary involvement in patients with medium- to long-term JDM.

METHODS

In a cross-sectional study, 58 patients examined median (range) 16.8 (6.6-27.0) years after symptom onset were stratified in inactive (JDM-inactive) and active (JDM-active) disease (updated PRINTO criteria); 56 age/sex matched controls were included. Twenty-nine cytokines (in serum) were analysed (Luminex technology/ELISA). Pulmonary function test included forced vital capacity, total lung capacity (TLC) and diffusing capacity for carbon monoxide reported as % of predicted and low forced vital capacity/TLC/diffusing capacity for carbon monoxide. In patients, the presence of clinical pulmonary damage was assessed and high resolution computed tomography scans were scored for interstitial lung disease, chest wall calcinosis and airways disease.

RESULTS

Median age of patients was 21 (7-55) years, 59% were female and 36% inactive. In JDM-active and all patients, higher MCP-1, IP-10 and eotaxin correlated with high-resolution computed tomography findings (rs 0.34-0.61; P < 0.05). MCP-1 and eotaxin correlated with pulmonary damage in JDM-active and all patients (rs 0.41-0.49; P < 0.01). Higher TGF-β1 and PDGF (growth factors) were associated with lower lung volumes (forced vital capacity/TLC measures) in all patients; PDGF in JDM-active and TGF-β1 in JDM-inactive patients. IP-10 correlated with TLC% in JDM-active patients. No associations between cytokines and pulmonary function test were found in controls.

CONCLUSIONS

In JDM, we found a novel association (not previously described in myositis) between eotaxin and pulmonary involvement; we have previously shown an association between eotaxin and cardiac dysfunction. The associations between IP-10/growth factors/MCP-1 and pulmonary involvement are novel in JDM and were mostly seen in JDM-active patients.

The Organ Trail: A Review of Biomarkers of Organ Failure

Pediatric organ failure and transplant populations face significant risks of morbidity and mortality. The risk of organ failure itself may be disproportionately higher among pediatric oncology patients, as cancer may originate within and/or metastasize to organs and adversely affect their function. Additionally, cancer directed therapies are frequently toxic to organs and may contribute to failure. Recent reports suggest that nearly half of providers find it difficult to provide prognostic information regarding organ failure due to unknown disease trajectories. Unfortunately, there is a lack of uniform methodology in detecting the early symptoms of organ failure, which may delay diagnosis, initiation of treatment and hinder prognostic planning. There remains a wide array of outstanding scientific questions regarding organ failure in pediatrics but emerging data may change the landscape of prognostication. Liquid biopsy, in which disease biomarkers are detected in bodily fluids, offers a noninvasive alternative to tissue biopsy and may improve prompt detection of organ failure and prognostication. Here, we review potential liquid biopsy biomarkers for organ failure, which may be particularly useful among pediatric oncology patients. We synthesized information from publications obtained on PubMed, Google Scholar, clinicaltrials.gov, and Web of Science and categorized our findings based on the type of biomarker used to detect organ failure. We highlight the advantages and disadvantages specific to each type of organ failure biomarker. While much work needs to be done to advance this field and validate its applicability to pediatric cancer patients facing critical care complications, herein, we highlight promising areas for future discovery.

CCR2 Mediates Chronic LPS-Induced Pulmonary Inflammation and Hypoalveolarization in a Murine Model of Bronchopulmonary Dysplasia

The histopathology of bronchopulmonary dysplasia (BPD) includes hypoalveolarization and interstitial thickening due to abnormal myofibroblast accumulation. Chorioamnionitis and sepsis are major risk factors for BPD development. The cellular mechanisms leading to these lung structural abnormalities are poorly understood. We used an animal model with repeated lipopolysaccharide (LPS) administration into the airways of immature mice to simulate prolonged airway exposure to gram-negative bacteria, focusing on the role of C-C chemokine receptor type 2-positive (CCR2+) exudative macrophages (ExMf). Repetitive LPS exposure of immature mice induced persistent hypoalveolarization observed at 4 and 18 days after the last LPS administration. LPS upregulated the expression of lung pro-inflammatory cytokines (TNF-α, IL-17a, IL-6, IL-1β) and chemokines (CCL2, CCL7, CXCL1, and CXCL2), while the expression of genes involved in lung alveolar and mesenchymal cell development (PDGFR-α, FGF7, FGF10, and SPRY1) was decreased. LPS induced recruitment of ExMf, including CCR2+ ExMf, as well as other myeloid cells like DCs and neutrophils. Lungs of LPS-exposed CCR2−/− mice showed preserved alveolar structure and normal patterns of α-actin and PDGFRα expression at the tips of the secondary alveolar crests. Compared to wild type mice, a significantly lower number of ExMf, including TNF-α+ ExMf were recruited to the lungs of CCR2−/− mice following repetitive LPS exposure. Further, pharmacological inhibition of TLR4 with TAK-242 also blocked the effect of LPS on alveolarization, α-SMA and PDGFRα expression. TNF-α and IL-17a induced α-smooth muscle actin expression in the distal airspaces of E16 fetal mouse lung explants. In human preterm lung mesenchymal stromal cells, TNF-α reduced mRNA and protein expression of PDGFR-α and decreased mRNA expression of WNT2, FOXF2, and SPRY1. Collectively, our findings demonstrate that in immature mice repetitive LPS exposure, through TLR4 signaling increases lung inflammation and impairs lung alveolar growth in a CCR2-dependent manner.

Trained immunity modulates inflammation-induced fibrosis

Chronic inflammation and fibrosis can result from inappropriately activated immune responses that are mediated by macrophages. Macrophages can acquire memory-like characteristics in response to antigen exposure. Here, we show the effect of BCG or low-dose LPS stimulation on macrophage phenotype, cytokine production, chromatin and metabolic modifications. Low-dose LPS training alleviates fibrosis and inflammation in a mouse model of systemic sclerosis (SSc), whereas BCG-training exacerbates disease in this model. Adoptive transfer of low-dose LPS-trained or BCG-trained macrophages also has beneficial or harmful effects, respectively. Furthermore, coculture with low-dose LPS trained macrophages reduces the fibro-inflammatory profile of fibroblasts from mice and patients with SSc, indicating that trained immunity might be a phenomenon that can be targeted to treat SSc and other autoimmune and inflammatory fibrotic disorders.

Innate immune cells can be trained by some stimuli or pathogen exposures to be metabolically and epigenetically altered such that they have different responses to subsequent exposures. Here the authors show that low-dose LPS trained macrophages and BCG-trained macrophages have opposing effects on fibrosis and inflammation in the context of systemic sclerosis.

Using evasins to target the chemokine network in inflammation

Inflammation, is driven by a network comprising cytokines, chemokines, their target receptors and leukocytes, and is a major pathologic mechanism that adversely affects organ function in diverse human diseases. Despite being supported by substantial target validation, no successful anti-chemokine therapeutic to treat inflammatory disease has yet been developed. This is in part because of the robustness of the chemokine network, which emerges from a large total chemokine load in disease, promiscuous expression of receptors on leukocytes, promiscuous and synergistic interactions between chemokines and receptors, and feedforward loops created by secretion of chemokines by leukocytes themselves. Many parasites, including viruses, helminths and ticks, evade the chemokine network by producing proteins that bind promiscuously to chemokines or their receptors. Evasins - three small glycoproteins identified in the saliva of the brown dog tick - bind multiple chemokines, and are active in several animal models of inflammatory disease. Over 50 evasin homologs have recently been identified from diverse tick species. Characterization of the chemokine binding patterns of evasins show that several have anti-chemokine activities that extend substantially beyond those previously described. These studies indicate that evasins function at the site of the tick bite by reducing total chemokine load. This not only reduces chemokine signaling to receptors, but also interrupts feedforward loops, thus disabling the chemokine network. Taking the lead from nature, a goal for the development of new anti-chemokine therapeutics would be to reduce the total chemokine load in disease. This could be achieved by administering appropriate evasin combinations or by smaller peptides that mimic evasin action.

Pulmonary CCR2+CD4+ T cells are immune regulatory and attenuate lung fibrosis development

BACKGROUND

Animal models have suggested that CCR2-dependent signalling contributes to the pathogenesis of pulmonary fibrosis, but global blockade of CCL2 failed to improve the clinical course of patients with lung fibrosis. However, as levels of CCR2⁺CD4⁺ T cells in paediatric lung fibrosis had previously been found to be increased, correlating with clinical symptoms, we hypothesised that distinct CCR2⁺ cell populations might either increase or decrease disease pathogenesis depending on their subtype.

OBJECTIVE

To investigate the role of CCR2⁺CD4⁺ T cells in experimental lung fibrosis and in patients with idiopathic pulmonary fibrosis and other fibrosis.

METHODS

Pulmonary CCR2⁺CD4⁺ T cells were analysed using flow cytometry and mRNA profiling, followed by in silico pathway analysis, in vitro assays and adoptive transfer experiments.

RESULTS

Frequencies of CCR2⁺CD4⁺ T cells were increased in experimental fibrosis-specifically the CD62L^-CD44⁺ effector memory T cell phenotype, displaying a distinct chemokine receptor profile. mRNA profiling of isolated CCR2⁺CD4⁺ T cells from fibrotic lungs suggested immune regulatory functions, a finding that was confirmed in vitro using suppressor assays. Importantly, adoptive transfer of CCR2⁺CD4⁺ T cells attenuated fibrosis development. The results were partly corroborated in patients with lung fibrosis, by showing higher percentages of Foxp3⁺ CD25⁺ cells within bronchoalveolar lavage fluid CCR2⁺CD4⁺ T cells as compared with CCR2^-CD4⁺ T cells.

CONCLUSION

Pulmonary CCR2⁺CD4⁺ T cells are immunosuppressive, and could attenuate lung inflammation and fibrosis. Therapeutic strategies completely abrogating CCR2-dependent signalling will therefore also eliminate cell populations with protective roles in fibrotic lung disease. This emphasises the need for a detailed understanding of the functions of immune cell subsets in fibrotic lung disease.

PET-based Imaging of Chemokine Receptor 2 in Experimental and Disease-related Lung Inflammation

Purpose To characterize a chemokine receptor type 2 (CCR2)-binding peptide adapted for use as a positron emission tomography (PET) radiotracer for noninvasive detection of lung inflammation in a mouse model of lung injury and in human tissues from subjects with lung disease. Materials and Methods The study was approved by institutional animal and human studies committees. Informed consent was obtained from patients. A 7-amino acid CCR2 binding peptide (extracellular loop 1 inverso [ECL1i]) was conjugated to tetraazacyclododecane tetraacetic acid (DOTA) and labeled with copper 64 (64Cu) or fluorescent dye. Lung inflammation was induced with intratracheal administration of lipopolysaccharide (LPS) in wild-type (n = 19) and CCR2-deficient (n = 4) mice, and these mice were compared with wild-type mice given control saline (n = 5) by using PET performed after intravenous injection of 64Cu-DOTA-ECL1i. Lung immune cells and those binding fluorescently labeled ECL1i in vivo were detected with flow cytometry. Lung inflammation in tissue from subjects with nondiseased lungs donated for lung transplantation (n = 11) and those with chronic obstructive pulmonary disease (COPD) who were undergoing lung transplantation (n = 16) was evaluated for CCR2 with immunostaining and autoradiography (n = 6, COPD) with 64Cu-DOTA-ECL1i. Groups were compared with analysis of variance, the Mann-Whitney U test, or the t test. Results Signal on PET images obtained in mouse lungs after injury with LPS was significantly greater than that in the saline control group (mean = 4.43% of injected dose [ID] per gram of tissue vs 0.99% of injected dose per gram of tissue; P < .001). PET signal was significantly diminished with blocking studies using nonradiolabeled ECL1i in excess (mean = 0.63% ID per gram of tissue; P < .001) and in CCR2-deficient mice (mean = 0.39% ID per gram of tissue; P < .001). The ECL1i signal was associated with an elevated level of mouse lung monocytes. COPD lung tissue displayed significantly elevated CCR2 levels compared with nondiseased tissue (median = 12.8% vs 1.2% cells per sample; P = .002), which was detected with 64Cu-DOTA-ECL1i by using autoradiography. Conclusion 64Cu-DOTA-ECL1i is a promising tool for PET-based detection of CCR2-directed inflammation in an animal model and in human tissues as a step toward clinical translation. © RSNA, 2017 Online supplemental material is available for this article.

Transforming growth factor-beta 1 in humidifier disinfectant-associated children's interstitial lung disease

BACKGROUND

Humidifier disinfectant-associated children's interstitial lung disease has an unpredictable clinical course with a high morbidity and mortality.

OBJECTIVES

To evaluate the differences in clinical findings between survivors and non-survivors of humidifier disinfectant-associated children's interstitial lung disease. To evaluate dynamic changes in serum cytokines related to inflammation and fibrosis in lung injury, and to determine whether these changes are predictive of survival in this disease.

METHODS

We evaluated 17 children with humidifier disinfectant-associated children's interstitial lung disease, from whom serum samples were obtained weekly during hospitalization. The severity of chest tomographic and lung pathologic findings was scored. Levels of several cytokines were measured in the serial serum samples.

RESULTS

Seven of the 17 children were survivors. Compared to survivors, non-survivors had greater ground-glass attenuation on follow-up chest tomography, higher admission neutrophil counts, and more macrophages on pathologic findings. Transforming growth factor-beta 1 persisted at an elevated level (1,000-1,500 pg/ml) in survivors, whereas it decreased abruptly in non-survivors. At the time of this decrease, non-survivors had clinical worsening of their respiratory failure. Transforming growth factor-beta 1 was positively correlated with PaO2 /FiO2 (r = 0.481, P < 0.0001).

CONCLUSIONS

Non-survivors exhibited more inflammatory clinical findings than survivors. Transforming growth factor-beta 1 remained elevated in survivors, suggesting that it affected the clinical course of humidifier disinfectant-associated children's interstitial lung disease. The prognosis of this lung disease may depend more on controlling excessive inflammation and repairing damaged lung than on fibrosis, and transforming growth factor-beta 1 may play a key role in this process.

Plasma Monocyte Chemoattractant Protein-1 Level as a Predictor of the Severity of Community-Acquired Pneumonia

Monocyte chemoattractant protein (MCP)-1 increases in the serum of immunocompetent patients with community-acquired pneumonia (CAP). However, the correlation between the circulating level of MCP-1 and severity of CAP remains unclear. This study investigated differential changes in the plasma MCP-1 levels of patients with CAP before and after an antibiotic treatment and further analyzes the association between the CAP severity and MCP-1 levels. We measured the plasma MCP-1 levels of 137 patients with CAP and 74 healthy controls by using a commercial enzyme-linked immunosorbent assay. Upon initial hospitalization, Acute Physiology and Chronic Health Evaluation II (APACHE II); confusion, urea level, respiratory rate, blood pressure, and age of >64 years (CURB-65); and pneumonia severity index (PSI) scores were determined for assessing the CAP severity in these patients. The antibiotic treatment reduced the number of white blood cells (WBCs) and neutrophils as well as the level of C-reactive protein (CRP) and MCP-1. The plasma MCP-1 level, but not the CRP level or WBC count, correlated with the CAP severity according to the PSI (r = 0.509, p < 0.001), CURB-65 (r = 0.468, p < 0.001), and APACHE II (r = 0.360, p < 0.001) scores. We concluded that MCP-1 levels act in the development of CAP and are involved in the severity of CAP.

Tracking and Therapeutic Value of Human Adipose Tissue-derived Mesenchymal Stem Cell Transplantation in Reducing Venous Neointimal Hyperplasia Associated with Arteriovenous Fistula

PURPOSE

To determine if adventitial transplantation of human adipose tissue-derived mesenchymal stem cells (MSCs) to the outflow vein of B6.Cg-Foxn1(nu)/J mice with arteriovenous fistula (AVF) at the time of creation would reduce monocyte chemoattractant protein-1 (Mcp-1) gene expression and venous neointimal hyperplasia. The second aim was to track transplanted zirconium 89 ((89)Zr)-labeled MSCs serially with positron emission tomography (PET) for 21 days.

MATERIALS AND METHODS

All animal experiments were performed according to protocols approved by the institutional animal care and use committee. Fifty B6.Cg-Foxn1(nu)/J mice were used to accomplish the study aims. Green fluorescent protein was used to stably label 2.5 × 10(5) MSCs, which were injected into the adventitia of the outflow vein at the time of AVF creation in the MSC group. Eleven mice died after AVF placement. Animals were sacrificed on day 7 after AVF placement for real-time polymerase chain reaction (n = 6 for MSC and control groups) and histomorphometric (n = 6 for MSC and control groups) analyses and on day 21 for histomorphometric analysis only (n = 6 for MSC and control groups). In a separate group of experiments (n = 3), animals with transplanted (89)Zr-labeled MSCs were serially imaged with PET for 3 weeks. Multiple comparisons were performed with two-way analysis of variance, followed by the Student t test with post hoc Bonferroni correction.

RESULTS

In vessels with transplanted MSCs compared with control vessels, there was a significant decrease in Mcp-1 gene expression (day 7: mean reduction, 62%; P = .029), with a significant increase in the mean lumen vessel area (day 7: mean increase, 176% [P = .013]; day 21: mean increase, 415% [P = .011]). Moreover, this was accompanied by a significant decrease in Ki-67 index (proliferation on day 7: mean reduction, 81% [P = .0003]; proliferation on day 21: mean reduction, 60%, [P = .016]). Prolonged retention of MSCs at the adventitia was evidenced by serial PET images of (89)Zr-labeled cells.

CONCLUSION

Adventitial transplantation of MSCs decreases Mcp-1 gene expression, accompanied by a reduction in venous neointimal hyperplasia.

The Role of Chemokines in Fibrotic Wound Healing

Significance: Main dermal forms of fibroproliferative disorders are hypertrophic scars (HTS) and keloids. They often occur after cutaneous wound healing after skin injury, or keloids even form spontaneously in the absence of any known injury. HTS and keloids are different in clinical performance, morphology, and histology, but they all lead to physical and psychological problems for survivors. Recent Advances: Although the mechanism of wound healing at cellular and tissue levels has been well described, the molecular pathways involved in wound healing, especially fibrotic healing, is incompletely understood. Critical Issues: Abnormal scars not only lead to increased health-care costs but also cause significant psychological problems for survivors. A plethora of therapeutic strategies have been used to prevent or attenuate excessive scar formation; however, most therapeutic approaches remain clinically unsatisfactory. Future Directions: Effective care depends on an improved understanding of the mechanisms that cause abnormal scars in patients. A thorough understanding of the roles of chemokines in cutaneous wound healing and abnormal scar formation will help provide more effective preventive and therapeutic strategies for dermal fibrosis as well as for other proliferative disorders.

Affect of Early Life Oxygen Exposure on Proper Lung Development and Response to Respiratory Viral Infections

Children born preterm often exhibit reduced lung function and increased severity of response to respiratory viruses, suggesting that premature birth has compromised proper development of the respiratory epithelium and innate immune defenses. Increasing evidence suggests that premature birth promotes aberrant lung development likely due to the neonatal oxygen transition occurring before pulmonary development has matured. Given that preterm infants are born at a point of time where their immune system is also still developing, early life oxygen exposure may also be disrupting proper development of innate immunity. Here, we review current literature in hopes of stimulating research that enhances understanding of how the oxygen environment at birth influences lung development and host defense. This knowledge may help identify those children at risk for disease and ideally culminate in the development of novel therapies that improve their health.

Following the path of CCL2 from prostaglandins to periostin in lung fibrosis

Without question, the greatest and most humbling honor of my scientific career was to learn that I was nominated for the American Thoracic Society Recognition Award for Scientific Accomplishments. On the occasion of this award, as I look back on the progress made in the last 15 years, I am pleased by the scientific insights; however, I am also saddened that we still have no internationally recognized efficacious therapy. This perspective will highlight the areas my laboratory has addressed regarding the pathogenesis of idiopathic pulmonary fibrosis in hopes of identifying new therapeutic targets.

Translational research in pediatrics III: bronchoalveolar lavage

The role of flexible bronchoscopy and bronchoalveolar lavage (BAL) for the care of children with airway and pulmonary diseases is well established, with collected BAL fluid most often used clinically for microbiologic pathogen identification and cellular analyses. More recently, powerful analytic research methods have been used to investigate BAL samples to better understand the pathophysiological basis of pediatric respiratory disease. Investigations have focused on the cellular components contained in BAL fluid, such as macrophages, lymphocytes, neutrophils, eosinophils, and mast cells, as well as the noncellular components such as serum molecules, inflammatory proteins, and surfactant. Molecular techniques are frequently used to investigate BAL fluid for the presence of infectious pathologies and for cellular gene expression. Recent advances in proteomics allow identification of multiple protein expression patterns linked to specific respiratory diseases, whereas newer analytic techniques allow for investigations on surfactant quantification and function. These translational research studies on BAL fluid have aided our understanding of pulmonary inflammation and the injury/repair responses in children. We review the ethics and practices for the execution of BAL in children for translational research purposes, with an emphasis on the optimal handling and processing of BAL samples.

Serum monocyte chemoattractant protein-1 is a biomarker in patients with diabetes and periodontitis

INTRODUCTION

The role of serum Monocyte Chemoattractant Protein-1 (MCP-1) as a biomarker of periodontitis is well documented; however, its role in diabetic patients with periodontitis is unknown.

AIM

This study was conducted to determine the presence and concentration of serum MCP-1 in diabetic patients with and without periodontitis and correlate it glycemic status with periodontitis.

MATERIALS AND METHODS

Adult diabetic patients were enrolled and grouped into group I, II, and III based on their glycemic status and serum MCP-1 estimated by ELISA. Linear regression and correlation tests were performed using R statistical software, Medcalc software to observe correlation between the serum MCP-1 and glycated hemoglobin level among different groups.

RESULTS

Serum samples obtained from 37 patients tested positive for MCP-1. Mean serum MCP-1 concentration was highest (482.3 pg/ml) in group III, lowest (149.3 pg/ml) in group I, and intermediate 398.8 pg/ml in group II. Correlation and regression analysis was done between HbA1c and serum MCP-1. A significant positive correlation (P < 0.001) was observed. Serum MCP-1 increased by 37.278 pg/ml for every 1% rise in HbA1c, and the levels were raised in group II and group III than in group I irrespective of their glycemic status. With an HbA1c range of 6.5-6.9% (group II), the serum MCP-1 values cluster around 380-410 pg/ml. Elevated levels of serum MCP-1 (>500 pg/ml) in three subjects corresponded to HbA1c values more than 12.2% (group III).

CONCLUSION

To our knowledge, this is the first study to document serum MCP-1 levels in diabetic patients with periodontitis. Glycemic status influences serum MCP-1, and lack of glycemic control contributes to increased serum MCP-1 levels. Serum MCP-1 may thus serve as a biomarker of inflammation and disease progression in diabetes with periodontitis.

Evaluation of cytotoxic, genotoxic and inflammatory responses of nanoparticles from photocopiers in three human cell lines

Background

Photocopiers emit nanoparticles with complex chemical composition. Short-term exposures to modest nanoparticle concentrations triggered upper airway inflammation and oxidative stress in healthy human volunteers in a recent study. To further understand the toxicological properties of copier-emitted nanoparticles, we studied in-vitro their ability to induce cytotoxicity, pro-inflammatory cytokine release, DNA damage, and apoptosis in relevant human cell lines.

Methods

Three cell types were used: THP-1, primary human nasal- and small airway epithelial cells. Following collection in a large volume photocopy center, nanoparticles were extracted, dispersed and characterized in the cell culture medium. Cells were doped at 30, 100 and 300 μg/mL administered doses for up to 24 hrs. Estimated dose delivered to cells, was ~10% and 22% of the administered dose at 6 and 24 hrs, respectively. Gene expression analysis of key biomarkers was performed using real time quantitative PCR (RT-qPCR) in THP-1 cells at 5 μg nanoparticles/mL for 6-hr exposure for confirmation purposes.

Results

Multiple cytokines, GM-CSF, IL-1β, IL-6, IL-8, IFNγ, MCP-1, TNF-α and VEGF, were significantly elevated in THP-1 cells in a dose-dependent manner. Gene expression analysis confirmed up-regulation of the TNF-α gene in THP-1 cells, consistent with cytokine findings. In both primary epithelial cells, cytokines IL-8, VEGF, EGF, IL-1α, TNF-α, IL-6 and GM-CSF were significantly elevated. Apoptosis was induced in all cell lines in a dose-dependent manner, consistent with the significant up-regulation of key apoptosis-regulating genes P53 and Casp8 in THP-1 cells. No significant DNA damage was found at any concentration with the comet assay. Up-regulation of key DNA damage and repair genes, Ku70 and Rad51, were also observed in THP-1 cells, albeit not statistically significant. Significant up-regulation of the key gene HO1 for oxidative stress, implicates oxidative stress induced by nanoparticles.

Conclusions

Copier-emitted nanoparticles induced the release of pro-inflammatory cytokines, apoptosis and modest cytotoxicity but no DNA damage in all three-human cell lines. Taken together with gene expression data in THP-1 cells, we conclude that these nanoparticles are directly responsible for inflammation observed in human volunteers. Further toxicological evaluations of these nanoparticles, including across different toner formulations, are warranted.

Neonatal hyperoxia alters the host response to influenza A virus infection in adult mice through multiple pathways

Exposing preterm infants or newborn mice to high concentrations of oxygen disrupts lung development and alters the response to respiratory viral infections later in life. Superoxide dismutase (SOD) has been separately shown to mitigate hyperoxia-mediated changes in lung development and attenuate virus-mediated lung inflammation. However, its potential to protect adult mice exposed to hyperoxia as neonates against viral infection is not known. Here, transgenic mice overexpressing extracellular (EC)-SOD in alveolar type II epithelial cells are used to test whether SOD can alleviate the deviant pulmonary response to influenza virus infection in adult mice exposed to hyperoxia as neonates. Fibrotic lung disease, observed following infection in wild-type (WT) mice exposed to hyperoxia as neonates, was prevented by overexpression of EC-SOD. However, leukocyte recruitment remained excessive, and levels of monocyte chemoattractant protein (MCP)-1 remained modestly elevated following infection in EC-SOD Tg mice exposed to hyperoxia as neonates. Because MCP-1 is often associated with pulmonary inflammation and fibrosis, the host response to infection was concurrently evaluated in adult Mcp-1 WT and Mcp-1 knockout mice exposed to neonatal hyperoxia. In contrast to EC-SOD, excessive leukocyte recruitment, but not lung fibrosis, was dependent upon MCP-1. Our findings demonstrate that neonatal hyperoxia alters the inflammatory and fibrotic responses to influenza A virus infection through different pathways. Therefore, these data suggest that multiple therapeutic strategies may be needed to provide complete protection against diseases attributed to prematurity and early life exposure to oxygen.

CCR2 Antagonists for the Treatment of Diseases Associated with Inflammation

The CCR2 and MCP-1 pathway has become one of the most-studied chemokine systems for therapeutic use in inflammatory diseases and conditions. It plays a pivotal role in inflammatory diseases, especially those that are characterized by monocyte-rich infiltration. This chapter reviews the biology of CCR2 and MCP-1, and their roles in diseases and conditions related to inflammation such as rheumatoid arthritis, multiple sclerosis, asthma, obesity, type 2 diabetes, atherosclerosis, nephropathy, cancer, pulmonary fibrosis and pain. Intense drug-discovery efforts over the past 15 years have generated a large number of CCR2 antagonists in diverse structural classes. Mutagenesis studies have elucidated important residues on CCR2 that interact with many classes of these CCR2 antagonists. To facilitate understanding of CCR2 antagonist SAR, a simple pharmacophore model is used to summarize the large number of diverse chemical structures. The majority of published compounds are classified based on their central core structures using this model. Key SAR points in the published literature are briefly discussed for most of the series. Lead compounds in each chemical series are highlighted where information is available. The challenges in drug discovery and development of CCR2 antagonists are briefly discussed. Clinical candidates in various diseases in the public domain are summarized with a brief discussion about the clinical challenges.

Lung development and the host response to influenza A virus are altered by different doses of neonatal oxygen in mice

Oxygen exposure in preterm infants has been associated with altered lung development and increased risk for respiratory viral infections later in life. Although the dose of oxygen sufficient to exert these changes in humans remains unknown, adult mice exposed to 100% oxygen between postnatal days 1-4 exhibit alveolar simplification and increased sensitivity to influenza virus infection. Additionally, two nonlinear thresholds of neonatal oxygen exposures were previously identified that promote modest (between 40% and 60% oxygen) and severe (between 80% and 100% oxygen) changes in lung development. Here, we investigate whether these two thresholds correlate with the severity of lung disease following respiratory viral infection. Adult mice exposed to 100% oxygen at birth, and to a lesser extent 80% oxygen, demonstrated enhanced body weight loss, persistent inflammation, and fibrosis following infection compared with infected siblings exposed to room air at birth. In contrast, the host response to infection was indistinguishable between mice exposed to room air and 40% or 60% oxygen. Interestingly, levels of monocyte chemoattractant protein (MCP)-1 were equivalently elevated in infected mice that had been exposed to 80% or 100% oxygen as neonates. However, reducing levels of MCP-1 using heterozygous Mcp-1 mice did not affect oxygen-dependent changes in the response to infection. Thus lung development and the host response to respiratory viral infection are disrupted by different doses of oxygen. Our findings suggest that measuring lung function alone may not be sufficient to identify individuals born prematurely who have increased risk for respiratory viral infection.

Molecular and cellular characteristics of ABCA3 mutations associated with diffuse parenchymal lung diseases in children

ABCA3 (ATP-binding cassette subfamily A, member 3) is expressed in the lamellar bodies of alveolar type II cells and is crucial to pulmonary surfactant storage and homeostasis. ABCA3 gene mutations have been associated with neonatal respiratory distress (NRD) and pediatric interstitial lung disease (ILD). The objective of this study was to look for ABCA3 gene mutations in patients with severe NRD and/or ILD. The 30 ABCA3 coding exons were screened in 47 patients with severe NRD and/or ILD. ABCA3 mutations were identified in 10 out of 47 patients, including 2 homozygous, 5 compound heterozygous and 3 heterozygous patients. SP-B and SP-C expression patterns varied across patients. Among patients with ABCA3 mutations, five died shortly after birth and five developed ILD (including one without NRD). Functional studies of p.D253H and p.T1173R mutations revealed that p.D253H and p.T1173R induced abnormal lamellar bodies. Additionally, p.T1173R increased IL-8 secretion in vitro. In conclusion, we identified new ABCA3 mutations in patients with life-threatening NRD and/or ILD. Two mutations associated with ILD acted via different pathophysiological mechanisms despite similar clinical phenotypes.

The role of rigid and flexible bronchoscopy in children

Bronchoscopy for paediatric respiratory disease is a routine procedure in paediatric pulmonology. Rigid bronchoscopy is now much less commonly used than flexible bronchoscopy. Technological advances have brought better picture quality and easier storage of video documentation. Indications with clear clinical benefit are congenital or acquired unexplained airway obstruction. In pulmonary infections or infiltrates in immunodeficient or immunosuppressed children not responding to empirical treatment a pathogen may be identified by bronchoscopy and bronchoalveolar lavage (BAL). Bronchoscopy and BAL can be indicated in children with unusual presentations of chronic cough or wheeze, and cystic fibrosis. The use of transbronchial biopsies (TBB) is established in paediatric lung transplantation. New applications and techniques are being developed, such as endobronchial ultrasound and transbronchial needle biopsy of lymph nodes and the role of airway stent placement have become better understood.

Intramural coronary lipid injection induces atheromatous lesions expressing proinflammatory chemokines: implications for the development of a porcine model of atherosclerosis

BACKGROUND

Intramural delivery of lipids into the coronaries of pigs fed high-cholesterol diet results in the formation of localized atherosclerotic-like lesions within 12 weeks. These lesions are located in positively remodeled vessels and are associated to the development of abundant adventitial vasa vasorum and mononuclear cell infiltrate. In this study, we aimed to analyze the degree of expression of various inflammatory chemokines within the developed lesions compared with control segments injected with saline.

METHODS

Balloon injury was performed in 15 coronary arteries of pigs fed high-cholesterol diet for 12 weeks. Two weeks after procedure, 60 coronary segments were randomized to either intramural injections of complex lipids (n=30) or normal saline (n=30). Neovessel density in the lesions was analyzed by lectin stain. Segments were processed for RNA expression of inflammatory chemokines such as monocyte chemoattractant protein-1 and vascular endothelial growth factor.

RESULTS

At 12 weeks, the percentage area of stenosis seen in histological sections was modest in both groups (lipids: 17.3±15 vs. saline: 32.4±22.8, P=.017). The lipid group showed higher vasa vasorum (VV) quantity (saline: 18.2±14.9 VV/section vs. lipids: 30.6±21.6 VV/section, P<.05) and vasa vasorum density (saline: 7.3±4.6 VV/mm(2) vs. lipids: 16.5±9 VV/mm(2), P<.001). In addition, monocyte chemoattractant protein-1 expression was higher in the lipid group (1.5±1.12) compared with saline control group (0.83±0.34, P<.01). Vascular endothelial growth factor expression was also higher in the lipid group (1.36±0.9) compared with saline group (0.87±0.33, P<.05).

CONCLUSION

The intramural injection of complex lipids into the coronary arteries of pigs maintained in a high-cholesterol diet results in focal lesions located in positively remodeled vessels that have a high neovessel count and express proinflammatory chemokines.

Enhanced MCP-1 release by keloid CD14+ cells augments fibroblast proliferation: role of MCP-1 and Akt pathway in keloids

Keloids are fibrous overgrowth induced by cutaneous injury. The pathogenesis of keloids is poorly understood, and no convincing animal model exists. Current hypotheses of the pathogenesis classify keloids as an entity of aberrant fibrosis. Hyperactivation of the MCP-1/CCR2 axis reportedly causes fibrosis in liver cirrhosis, atherosclerosis and lung fibrosis. Circulating CD14+ monocytes are precursors of circulating fibrocytes and contribute to fibrogenesis by a MCP-1/CCR2-dependent loop. As there is an increase in monocyte lineages in keloids, the aim of this study is to determine whether peripheral CD14+ monocytes in keloid patients trigger fibroblast proliferation through MCP-1. Expressions of MCP-1 and its receptor CCR2 in keloid lesions were measured by immunohistochemistry and real-time PCR. The results revealed an increase in MCP-1 and CCR2 in the keloid tissues. Co-culture of keloid CD14+ cells and normal fibroblasts enhanced fibroblast proliferation and a parallel increase in extracellular MCP-1. We further found that MCP-1 modest enhanced fibroblast proliferation via Akt activation. Blockade of either MCP-1 or Akt signaling suppressed the mediation of fibroblast proliferation by CD14+ cells from patients. These results demonstrated that enhanced MCP-1 release by keloid CD14+ cells augments fibroblast proliferation via Akt pathway in keloids. We concluded that enhanced MCP-1 release by keloid CD14+ cells augments fibroblast proliferation, which might initiate keloid development.

Serum levels of monocyte chemoattractant protein-1 in periodontal health and disease

OBJECTIVES

Initial research has reported high levels of monocyte chemoattractant protein-1 (MCP-1) in gingival crevicular fluid (GCF) of periodontitis patients. Present study has been carried out to assess its concentration in serum and to find its association with periodontal health and disease.

DESIGN

60 subjects were divided into three groups (n=20) based on gingival index (GI), probing pocket depth (PPD) and clinical attachment loss (CAL): healthy (group I), gingivitis (group II) and chronic periodontitis (group III). A fourth group (group IV) consisted of 20 subjects from group III, 6-8 weeks after treatment [i.e. scaling and root planing (SRP)]. Serum samples obtained from each patient were quantified for MCP-1 using enzyme-linked immunosorbent assay (ELISA).

RESULTS

The mean MCP-1 concentration in serum was found to be the highest in group III i.e. 465.80 pg/ml and lowest in group I i.e. 155.20 pg/ml. For group II (251.60 pg/ml) and group IV (263.20 pg/ml) the mean MCP-1 concentrations were found to lie in between the concentrations obtained in group I and III.

CONCLUSIONS

Serum MCP-1 concentration was found to be, approximately one and half folds higher in gingivitis patients (group II) and three folds higher in chronic periodontitis patients (group III) as compared to healthy subjects (group I). Further, the MCP-1 concentration increased proportionally with the severity of disease in group II and III showing positive correlation with clinical parameters. Thus, its role as an inflammatory biomarker in periodontal disease can be proposed.

Gingival crevicular fluid levels of monocyte chemoattractant protein-1 in periodontal health and disease

OBJECTIVES

Monocyte chemoattractant protein-1 (MCP-1) stimulates the chemotaxis of monocytes and also several cellular events associated with chemotaxis thus causes recruitment of inflammatory cells. Its increased gingival crevicular fluid (GCF) levels in periodontal disease have been reported in previous studies. The present study has been carried out to assess the role of MCP-1 in periodontal disease progression and also to determine the effect of periodontal treatment on MCP-1 concentration in GCF.

DESIGN

A total of 60 subjects were divided into three groups (n=20) based on gingival index (GI), probing pocket depth (PPD) and clinical attachment loss (CAL): healthy (group I), gingivitis (group II) and chronic periodontitis (group III). A fourth group (group IV) consisted of 20 subjects from group III, 6-8 weeks after treatment (i.e. scaling and root planing). GCF samples collected from each patient were quantified for MCP-1 using ELISA.

RESULTS

The mean MCP-1 concentration in GCF was found to be the highest in group III, i.e. 72.60 pg/microl. The mean MCP-1 concentration in group I was 19.70 pg/microl and in group IV was 8.50 pg/microl. The mean MCP-1 concentration (37.00 pg/microl) in group II was found to lie in between the concentrations obtained in groups I and III.

CONCLUSIONS

GCF MCP-1 levels increased progressively with the progression of disease and decreased after treatment. Levels of MCP-1 correlated positively with clinical parameters like GI, PPD and CAL thus it can be considered as an inflammatory biomarker in periodontal disease and also deserves further consideration as a therapeutic target.

A polymorphism in the CCL2 chemokine gene is associated with asthma risk: a case-control and a family study in Tunisia

Asthma is a complex genetic disorder characterized by chronic airway inflammation. We hypothesized that genetic polymorphisms in chemokines and their receptors alter leukocyte mobilization and may thus influence the risk and severity of childhood asthma. Distributions of the chemokine CCL2-2578G, CCL2-927C, CCR2-V64I, CX3CR1-V249I and CX3CR1-T280M receptor polymorphisms were examined in a case-control study of 121 children with asthma and 226 age-matched healthy controls and then replicated in a family study of 99 simplex families (297 individuals). The case-control study revealed that the CCL2-2578G allele was less frequent in children with than in those without asthma (P=0.0012). No association with asthma was found for the CCL2-927, CCR2 or CX3CR1 polymorphisms. The finding in the family study that the CCL2-2578G allele was transmitted less often by heterozygous parents to their children with asthma (P=0.0016) confirms the association of CCL2-2578G with asthma risk. Biochemical studies indicated that plasma CCL2 concentrations were higher in both patients (P=0.0214) and controls (P=0.001) carrying the G allele than in subjects with other polymorphisms. Both case-control and family-based studies suggest a protective effect of allele CCL2-2578G in Tunisian asthmatic children.

Neonatal hyperoxia enhances the inflammatory response in adult mice infected with influenza A virus

RATIONALE

Lungs of adult mice exposed to hyperoxia as newborns are simplified and exhibit reduced function much like that observed in people who had bronchopulmonary dysplasia (BPD) as infants. Because survivors of BPD also show increased risk for symptomatic respiratory infections, we investigated how neonatal hyperoxia affected the response of adult mice infected with influenza A virus infection.

OBJECTIVES

To determine whether neonatal hyperoxia increased the severity of influenza A virus infection in adult mice.

METHODS

Adult female mice exposed to room air or hyperoxia between Postnatal Days 1 and 4 were infected with a sublethal dose of influenza A virus.

MEASUREMENTS AND MAIN RESULTS

The number of macrophages, neutrophils, and lymphocytes observed in airways of infected mice that had been exposed to hyperoxia as neonates was significantly greater than in infected siblings that had been exposed to room air. Enhanced inflammation correlated with increased levels of monocyte chemotactic protein-1 (CCL2) in lavage fluid, whereas infection-associated changes in IFN-gamma, IL-1beta, IL-6, tumor necrosis factor-alpha, KC, granulocyte-macrophage colony-stimulating factor, and macrophage inflammatory protein-1alpha, and production of virus-specific antibodies, were largely unaffected. Increased mortality of mice exposed to neonatal hyperoxia occurred by Day 14 of infection, and was associated with persistent inflammation and fibrosis.

CONCLUSIONS

These data suggest that the disruptive effect of hyperoxia on neonatal lung development also reprograms key innate immunoregulatory pathways in the lung, which may contribute to exacerbated pathology and poorer resistance to respiratory viral infections typically seen in people who had BPD.

Identification of unique gene expression patterns within different lesional sites of keloids

Keloid disease is a significant clinical problem, especially in black populations, with an estimated incidence of 4-16%. Keloids are fibroproliferative dermal tumors developing as a result of deregulated wound healing. The dynamic nature of keloids is illustrated by clinical regression in the center, while the margin remains active growing into the surrounding healthy skin. Therefore, the gene expression profiles of fibroblasts from different sites of the keloids were characterized using Affymetrix microarrays covering the whole human genome. This study revealed 105 genes that were differentially regulated (79 genes were up-regulated and 26 down-regulated) in a unique gene expression profile in different sites of keloids where progression or regression of the process was in progress. The apoptosis inhibitor AVEN was found to be up-regulated at the active margin of keloids, while apoptosis-inducing genes such as ADAM12 and genes inducing extracellular matrix (ECM) degradation such as matrix metalloproteinase-19 were up-regulated in the regressing keloid center. We identified genes previously not described in the development of keloids. Activating proapoptotic genes or inhibiting ECM-inducing genes as INHBA or monocyte chemoattractant protein-1 might be possible target genes for new treatment strategies for keloid disease.

Chemokines and their receptors in respiratory disease: a therapeutic target for respiratory syncytial virus infection

Cell recruitment is a multistep process orchestrated by chemokines and their receptors. The chemokine/receptor system is central to many inflammatory diseases, making it a key target for therapeutic intervention. Despite complexity and redundancy within the system, effective antagonists are in development and undergoing clinical trials, for example, maraviroc, for use in HIV treatment. Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infection in infants, with global annual infection estimated at 64 million people. Current treatment is purely supportive, with no effective vaccine available. RSV pathology is partly due to excessive airway inflammation. Evidence is growing for a key role for chemokine receptors. Receptor blockade may therefore provide a feasible therapeutic option to inhibit RSV-induced inflammation and thereby reduce disease severity.

Lung cells from neonates show a mesenchymal stem cell phenotype

RATIONALE

Mesenchymal stem cells have been isolated from adult bone marrow, peripheral blood, adipose tissue, trabecular bone, articular synovium, and bronchial submucosa.

OBJECTIVES

We hypothesized that the lungs of premature infants undergoing mechanical ventilation contain fibroblast-like cells with features of mesenchymal stem cells.

METHODS

Tracheal aspirate fluid from mechanically ventilated, premature (< 30 wk gestation) infants 7 days old or younger was obtained from routine suctioning and plated on plastic culture dishes.

MEASUREMENTS AND MAIN RESULTS

A total of 11 of 20 patients studied demonstrated fibroblast-like cells, which were identified as early as 6 hours after plating. Cells were found to express the mesenchymal stem cell markers STRO-1, CD73, CD90, CD105, and CD166, as well as CCR2b, CD13, prolyl 4-hydroxylase, and alpha-smooth muscle actin. Cells were negative for the hematopoietic and endothelial cell markers CD11b, CD31, CD34, or CD45. Tracheal aspirate monocyte chemoattractant protein-1/CCL2 levels were ninefold higher in aspirates in which fibroblast-like cells were found, and cells demonstrated chemotaxis in response to monocyte chemoattractant protein. Placement of cells into appropriate media resulted in adipogenic, osteogenic, and myofibroblastic differentiation. Patients from whom mesenchymal stem cells were isolated tended to require more days of mechanical ventilation and supplemental oxygen.

CONCLUSIONS

Together, these data demonstrate that tracheal aspirate fluid from premature, mechanically ventilated infants contains fibroblasts with cell markers and differentiation potential typically found in mesenchymal stem cells.