The Transcriptional Signature in Alveolar Macrophages Dictates Acute Respiratory Distress Outcomes.
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ABSTRACT:
SUBMITTER: Tejwani V
PROVIDER: S-EPMC6775879 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Rationale: Serial measurements of alveolar macrophage (AM) transcriptional changes in patients with acute respiratory distress syndrome (ARDS) could identify cell-specific biological programs that are associated with clinical outcomes.Objectives: To determine whether AM transcriptional programs are associated with prolonged mechanical ventilation and 28-day mortality in individuals with ARDS.Methods: We performed genome-wide transcriptional profiling of AMs purified from BAL fluid collected from 35 subjects with ARDS. Cells were obtained at baseline (Day 1), Day 4, and Day 8 after ARDS onset (N = 68 total samples). We identified biological pathways that were enriched at each time point in subjects alive and extubated within 28 days after ARDS onset (alive/extubatedDay28) versus those dead or persistently supported on mechanical ventilation at Day 28 (dead/intubatedDay28).Measurements and Main Results: "M1-like" (classically activated) and proinflammatory gene sets such as IL-6/JAK/STAT5 (Janus kinase/signal transducer and activator of transcription 5) signaling were significantly enriched in AMs isolated on Day 1 in alive/extubatedDay28 versus dead/intubatedDay28 subjects. In contrast, by Day 8, many of these same proinflammatory gene sets were enriched in AMs collected from dead/intubatedDay28 compared with alive/extubatedDay28 subjects. Serially sampled alive/extubatedDay28 subjects were characterized by an AM temporal expression pattern of Day 1 enrichment of innate immune programs followed by prompt downregulation on Days 4 and 8. Dead/intubatedDay28 subjects exhibited an opposite pattern, characterized by progressive upregulation of proinflammatory programs over the course of ARDS. The relationship between AM expression profiles and 28-day clinical status was distinct in subjects with direct (pulmonary) versus indirect (extrapulmonary) ARDS.Conclusions: Clinical outcomes in ARDS are associated with highly distinct AM transcriptional programs.
| S-EPMC6775881 | biostudies-literature
Project description:Background Acute respiratory distress syndrome (ARDS) is a common cause of death in ICU patients and its underlying mechanism remains unclear, which leads to its high mortality rate. This study aimed to identify candidate genes potentially implicating in the pathogenesis of ARDS and provide novel therapeutic targets. Methods Using bioinformatics tools, we searched for differentially expressed genes (DEGs) in an ARDS microarray dataset downloaded from the Gene Expression Omnibus (GEO) database. Afterwards, functional enrichment analysis of GO, KEGG, GSEA and WGCNA were carried out to investigate the potential involvement of these DEGs. Moreover, the Protein–protein interaction (PPI) network was constructed and molecular complexes and hub genes were identified, followed by prognosis analysis of the hub genes. Further, we performed qRT-PCR, Western Blot and flow cytometry analysis to detect candidate genes of CCR2 and FPR3 in macrophage model of LPS-induced ARDS and primary alveolar macrophages(AMs). Macrophage chemotaxis was evaluated using Transwell assay. Results DEGs mainly involved in myeloid leukocyte activation, cell chemotaxis, adenylate cyclase-modulating G protein-coupled receptor signaling pathway and cytokine-cytokine receptor interaction. Basing on the constructed PPI network, we identified five molecular complexes and 10 hub genes potentially participating in the pathogenesis of ARDS. It was observed that candidate genes of CCR2 and FPR3 were significantly over-expressed in primary alveolar macrophages from ARDS patients and macrophgae model of LPS-induced ARDS. Moreover, in vitro transwell assay demonstrated that CCR2 and FPR3 down-regulation, respectively, inhibited LPS-triggered macrophage chemotaxis toward CCL2. Finally, a positive correlation between FPR3 and CCR2 expression was confirmed using pearson correlation analysis and Western Blot assay. Conclusions Our study identified CCR2 and FPR3 as the candidate genes which can promote macrophage chemotaxis through a possible interaction between FPR3 and CCL2/CCR2 axis and provided novel insights into ARDS pathogenesis.
| S-EPMC8555499 | biostudies-literature
Project description:Rationale: Serial measurements of genome-wide transcriptional changes in alveolar macrophages (AM) and peripheral blood monocytes (PBM) from patients with acute respiratory distress (ARDS) could clarify the biologic programs activated in ARDS and the relationship of these changes to clinical outcomes. Objectives: To identify transcriptional programs activated in purified AM and PBM over the course of ARDS, and determine the relationship of these programs with patient outcomes. Methods: We performed transcriptional profiling of total RNA isolated from AMs and PBMs purified from bronchoalveolar lavage fluid (BALF) and peripheral blood respectively, collected from patients (n = 26) with ARDS previously enrolled in a phase-II clinical trial. Cells were obtained at baseline (day 0) after enrollment. Measurements and Main Results: Using an unbiased gene set enrichment analysis (GSEA), we found highly divergent patterns of gene expression in AMs and PBMs. Notably, immuno-inflammatory gene sets were enriched in AMs isolated on day 0 in those who survived and had more ventilator-free days (VFD); however, this association between inflammatory and immune gene sets and good outcomes was not seen in PBMs. Conclusion: Transcriptional responses during ARDS are remarkably different between AMs and PBMs. Rationale: Serial measurements of genome-wide transcriptional changes in alveolar macrophages (AM) and peripheral blood monocytes (PBM) from patients with acute respiratory distress (ARDS) could clarify the biologic programs activated in ARDS and the relationship of these changes to clinical outcomes. Objectives: To identify transcriptional programs activated in purified AM and PBM over the course of ARDS, and determine the relationship of these programs with patient outcomes. Methods: We performed transcriptional profiling of total RNA isolated from AMs and PBMs purified from bronchoalveolar lavage fluid and peripheral blood respectively, collected from patients (n = 26) with ARDS previously enrolled in a phase-II clinical trial. Cells were obtained at baseline (day 0) after enrollment. Measurements and Main Results: Using an unbiased gene set enrichment analysis (GSEA), we found highly divergent patterns of gene expression in AMs and PBMs. Notably, immuno-inflammatory gene sets were enriched in AM isolated on day 0 in those who survived and had more ventilator-free days (VFD); however, this association between inflammatory and immune gene sets and good outcomes was not seen in PBMs. Conclusion: Transcriptional responses during ARDS are remarkably different between AM and PBM.
2017-04-30 | GSE89953 | GEO
Project description:Interleukin-17A is a proinflammatory cytokine known to play a role in host defense and pathologic inflammation in murine models of lung injury. The relationship between interleukin-17A and inflammation in human lung injury is unknown. Our primary objective was to determine whether interleukin-17A levels are associated with alveolar measures of inflammation and injury in patients with acute respiratory distress syndrome. Our secondary objective was to test whether interleukin-17A levels are associated with acute respiratory distress syndrome-related outcomes.Observational study.Six North American medical centers.We studied two groups of patients with acute respiratory distress syndrome: 1) patients previously enrolled in a placebo-controlled clinical trial of omega-3 fatty acids performed at five North American medical centers (n = 86, acute respiratory distress syndrome 1), and 2) patients with systemic inflammatory response syndrome admitted to an ICU who developed acute respiratory distress syndrome (n = 140, acute respiratory distress syndrome 2). In acute respiratory distress syndrome 1, we used paired serum and bronchoalveolar lavage fluid samples obtained within 48 hours of acute respiratory distress syndrome onset, whereas in acute respiratory distress syndrome 2, we used plasma obtained within the first 24 hours of ICU admission.None.We measured circulating interleukin-17A in acute respiratory distress syndrome 1 and acute respiratory distress syndrome 2. We also measured interleukin-17A, neutrophil counts, and total protein in bronchoalveolar lavage fluid from acute respiratory distress syndrome 1. We found that bronchoalveolar lavage interleukin-17A was strongly associated with higher bronchoalveolar lavage percent neutrophils (p < 0.001) and bronchoalveolar lavage total protein (p < 0.01) in acute respiratory distress syndrome1. In both acute respiratory distress syndrome 1 and acute respiratory distress syndrome 2, elevated interleukin-17A was associated with higher Sequential Organ Failure Assessment scores (p < 0.05).Elevated circulating and alveolar levels of interleukin-17A are associated with increased percentage of alveolar neutrophils, alveolar permeability, and organ dysfunction in acute respiratory distress syndrome.
| S-EPMC4764422 | biostudies-literature
Project description:Studies in human peripheral blood monocyte-derived macrophages in vitro have shown clear evidence that multiple macrophage polarization states exist. The extent to which different alveolar macrophage (AM) polarization states exist in homeostasis or in the setting of severe injury such as acute respiratory distress syndrome (ARDS) is largely unknown. We applied single-cell cytometry TOF (CyTOF) to simultaneously measure 36 cell-surface markers on CD45+ cells present in bronchoalveolar lavage from healthy volunteers, as well as mechanically ventilated subjects with and without ARDS. Visualization of the high-dimensional data with the t-distributed stochastic neighbor embedding algorithm demonstrated wide diversity of cell-surface marker profiles among CD33+CD71+CD163+ AMs. We then used a ?-nearest neighbor density estimation algorithm to statistically identify distinct alveolar myeloid subtypes, and we discerned 3 AM subtypes defined by CD169 and PD-L1 surface expression. The percentage of AMs that were classified into one of the 3 AM subtypes was significantly different between healthy and mechanically ventilated subjects. In an independent cohort of subjects with ARDS, PD-L1 gene expression and PD-L1/PD-1 pathway-associated gene sets were significantly decreased in AMs from patients who experienced prolonged mechanical ventilation or death. Unsupervised CyTOF analysis of alveolar leukocytes from human subjects has potential to identify expected and potentially novel myeloid populations that may be linked with clinical outcomes.
| S-EPMC6012519 | biostudies-other
Project description:Rationale: Serial measurements of genome-wide transcriptional changes in alveolar macrophages (AMs) in patients with acute respiratory distress syndrome (ARDS) could identify dynamic biologic processes that are associated with clinical outcomes. Objectives: To identify associations between AM transcriptional programs and the composite endpoint of ventilator-free days (VFDs) over the course of ARDS. Methods: We performed unbiased genome-wide transcriptional profiling of AMs purified from bronchoalveolar lavage fluid collected from patients with ARDS. Cells were obtained at baseline (Day 1), Day 4, and Day 8 after ARDS onset. We assessed pathway enrichment in subjects with VFDs > 0 (VFD-Extubated/Alive) versus VFDs = 0 (VFD-Intubated/Dead) at each time point. Measurements and Main Results: We found highly divergent AM transcriptional patterns at all time points between ARDS patients based on their VFD status (FDR < 0.05). “M1-like” and pro-inflammatory gene sets such as IL-6-JAK-STAT signaling were significantly enriched in AMs isolated on Day 1 in VFD-Extubated/Alive versus VFD-Intubated/Dead subjects. In contrast, many of these same gene sets were associated with the VFD-Intubated/Dead subjects on Day 8. In patients who had samples from each time point, we identified multiple AM gene clusters whose temporal expression patterns were associated with VFD status. The relationship between AM expression profiles and VFDs was distinct in subjects with Direct (pulmonary) versus Indirect (extrapulmonary) ARDS. Conclusion: Clinically meaningful outcomes over the course of ARDS are associated with highly distinct AM transcriptional programs. Our findings suggest that interventions targeting the alveolar immune response should be tested within strictly defined time periods.
2019-03-31 | GSE116560 | GEO
Project description:Acute respiratory distress syndrome (ARDS) consists of uncontrolled inflammation that causes hypoxemia and reduced lung compliance. Since it is a complex process, not all details have been elucidated yet. In a well-controlled experimental murine model of lipopolysaccharide (LPS)-induced ARDS, the activity and viability of macrophages and neutrophils dictate the beginning and end phases of lung inflammation. C-C chemokine receptor type 2 (CCR2) is a critical chemokine receptor that mediates monocyte/macrophage activation and recruitment to the tissues. Here, we used CCR2-deficient mice to explore mechanisms that control lung inflammation in LPS-induced ARDS. CCR2-/- mice presented higher total numbers of pulmonary leukocytes at the peak of inflammation as compared to CCR2+/+ mice, mainly by enhanced influx of neutrophils, whereas we observed two to six-fold lower monocyte or interstitial macrophage numbers in the CCR2-/-. Nevertheless, the time needed to control the inflammation was comparable between CCR2+/+ and CCR2-/-. Interestingly, CCR2-/- mice presented higher numbers and increased proliferative rates of alveolar macrophages from day 3, with a more pronounced M2 profile, associated with transforming growth factor (TGF)-β and C-C chemokine ligand (CCL)22 production, decreased inducible nitric oxide synthase (Nos2), interleukin (IL)-1β and IL-12b mRNA expression and increased mannose receptor type 1 (Mrc1) mRNA and CD206 protein expression. Depletion of alveolar macrophages significantly delayed recovery from the inflammatory insult. Thus, our work shows that the lower number of infiltrating monocytes in CCR2-/- is partially compensated by increased proliferation of resident alveolar macrophages during the inflammation control of experimental ARDS.
| S-EPMC9659255 | biostudies-literature
Project description:OBJECTIVES:Physiologic dead space is associated with mortality in acute respiratory distress syndrome, but its measurement is cumbersome. Alveolar dead space fraction relies on the difference between arterial and end-tidal carbon dioxide (alveolar dead space fraction = (PaCO2 - PetCO2) / PaCO2). We aimed to assess the relationship between alveolar dead space fraction and mortality in a cohort of children meeting criteria for acute respiratory distress syndrome (both the Berlin 2012 and the American-European Consensus Conference 1994 acute lung injury) and pediatric acute respiratory distress syndrome (as defined by the Pediatric Acute Lung Injury Consensus Conference in 2015). DESIGN:Secondary analysis of a prospective, observational cohort. SETTING:Tertiary care, university affiliated PICU. PATIENTS:Invasively ventilated children with pediatric acute respiratory distress syndrome. INTERVENTIONS:None. MEASUREMENTS AND MAIN RESULTS:Of the 283 children with pediatric acute respiratory distress syndrome, 266 had available PetCO2. Alveolar dead space fraction was lower in survivors (median 0.13; interquartile range, 0.06-0.23) than nonsurvivors (0.31; 0.19-0.42; p < 0.001) at pediatric acute respiratory distress syndrome onset, but not 24 hours after (survivors 0.12 [0.06-0.18], nonsurvivors 0.14 [0.06-0.25], p = 0.430). Alveolar dead space fraction at pediatric acute respiratory distress syndrome onset discriminated mortality with an area under receiver operating characteristic curve of 0.76 (95% CI, 0.66-0.85; p < 0.001), better than either initial oxygenation index or PaO2/FIO2. In multivariate analysis, alveolar dead space fraction at pediatric acute respiratory distress syndrome onset was independently associated with mortality, after adjustment for severity of illness, immunocompromised status, and organ failures. CONCLUSIONS:Alveolar dead space fraction at pediatric acute respiratory distress syndrome onset discriminates mortality and is independently associated with nonsurvival. Alveolar dead space fraction represents a single, useful, readily obtained clinical biomarker reflective of pulmonary and nonpulmonary variables associated with mortality.
| S-EPMC4740261 | biostudies-literature
Project description:The alveolar recruitment maneuver (RM) has been reported to improve oxygenation in acute respiratory distress syndrome (ARDS) and may be related to reduced extravascular lung water (EVLW) in animals. This study was designed to investigate the effects of RM on EVLW in patients with ARDS.An open label, prospective, randomized controlled trial including patients with ARDS was conducted in hospitals in North Taiwan between 2010 and 2016. The patients were divided into 2 groups (with and without RM). The primary endpoint was the comparison of the EVLW index between the 2 groups.Twenty-four patients with ARDS on mechanical ventilator support were randomized to receive ventilator treatment with RM (RM group, n?=?12) or without RM (non-RM group, n?=?12). Baseline demographic characteristics were similar between the 2 groups. After recruitment, the day 3 extravascular lung water index (EVLWI) (25.3?±?9.3 vs 15.5?±?7.3?mL/kg, P?=?.008) and the arterial oxygen tension/fractional inspired oxygen ratio (PaO2/FiO2) (132.3?±?43.5 vs 185.6?±?38.8?mL/kg, P?=?.003) both improved over that of day 1. However, both EVLWI and PaO2/FiO2 did not significantly change from day 1 to 3 in the non-RM group.RM is a feasible method for improving oxygenation and the EVLW index in patients with ARDS, as well as for decreasing ventilator days and intensive care unit stay duration.
| S-EPMC5627850 | biostudies-literature
Project description:Acute respiratory distress syndrome (ARDS) is a diffuse, acute, inflammatory lung disease characterized by a severe respiratory failure. Recognizing and promptly treating ARDS is critical to combat the high mortality associated with the disease. Despite a significant progress in the treatment of ARDS, our ability to identify early patients and predict outcomes remains limited. The development of novel biomarkers is crucial. In this study, we profiled microRNA (miRNA) expression of plasma-derived exosomes in ARDS disease by small RNA sequencing. Sequencing of 8 ARDS patients and 10 healthy subjects (HSs) allowed to identify 12 differentially expressed exosomal miRNAs (adjusted p < 0.05). Pathway analysis of their predicted targets revealed enrichment in several biological processes in agreement with ARDS pathophysiology, such as inflammation, immune cell activation, and fibrosis. By quantitative RT-PCR, we validated the alteration of nine exosomal miRNAs in an independent cohort of 15 ARDS patients and 20 HSs, among which seven present high capability in discriminating ARDS patients from HSs (area under the curve > 0.8) (miR-130a-3p, miR-221-3p, miR-24-3p, miR-98-3p, Let-7d-3p, miR-1273a, and miR-193a-5p). These findings highlight exosomal miRNA dysregulation in the plasma of ARDS patients which provide promising diagnostic biomarkers and open new perspectives for the development of therapeutics.
| S-EPMC8319727 | biostudies-literature