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Pediatric Pulmonology Sep 2023Congenital diaphragmatic hernia (CDH) is associated with high mortality rates and significant pulmonary morbidities. The objective of this study was to delineate the...
INTRODUCTION
Congenital diaphragmatic hernia (CDH) is associated with high mortality rates and significant pulmonary morbidities. The objective of this study was to delineate the histopathological features observed in necropsies of CDH patients and correlate these with their clinical manifestations.
METHODS
We retrospectively reviewed the postmortem findings and corresponding clinical characteristics in eight CDH cases from 2017 to July 2022.
RESULTS
The median survival time was 46 (8-624) hours. Autopsy reports showed that diffuse alveolar damage (congestion and hemorrhage) and hyaline membrane formation were the primary pathological lung changes observed. Notably, despite significant reduction in lung volume, the lung development appeared normal in 50% of the cases, while lobulated deformities were present in three (37.5%) cases. All patients displayed a large patent ductus arteriosus (PDA) and a patent foramen ovale, resulting in increased right ventricle (RV) volume, and myocardial fibers appeared slightly congested and swollen. The pulmonary vessels indicated thickening of the arterial media and adventitia. Lung hypoplasia and diffuse lung damage resulted in impaired gas exchange, while PDA and pulmonary hypertension led to RV failure, subsequent organ dysfunction and ultimately death.
CONCLUSIONS
Patients with CDH typically succumb to cardiopulmonary failure, a condition driven by a complex interplay of pathophysiological factors. This complexity accounts for the unpredictable response to currently available vasodilators and ventilation therapies.
Topics: Humans; Hernias, Diaphragmatic, Congenital; Retrospective Studies; Lung; Hypertension, Pulmonary; Research Design
PubMed: 37378468
DOI: 10.1002/ppul.26565 -
Nature Communications Jun 2024Dexamethasone is the standard of care for critically ill patients with COVID-19, but the mechanisms by which it decreases mortality and its immunological effects in this...
Dexamethasone is the standard of care for critically ill patients with COVID-19, but the mechanisms by which it decreases mortality and its immunological effects in this setting are not understood. Here we perform bulk and single-cell RNA sequencing of samples from the lower respiratory tract and blood, and assess plasma cytokine profiling to study the effects of dexamethasone on both systemic and pulmonary immune cell compartments. In blood samples, dexamethasone is associated with decreased expression of genes associated with T cell activation, including TNFSFR4 and IL21R. We also identify decreased expression of several immune pathways, including major histocompatibility complex-II signaling, selectin P ligand signaling, and T cell recruitment by intercellular adhesion molecule and integrin activation, suggesting these are potential mechanisms of the therapeutic benefit of steroids in COVID-19. We identify additional compartment- and cell- specific differences in the effect of dexamethasone that are reproducible in publicly available datasets, including steroid-resistant interferon pathway expression in the respiratory tract, which may be additional therapeutic targets. In summary, we demonstrate compartment-specific effects of dexamethasone in critically ill COVID-19 patients, providing mechanistic insights with potential therapeutic relevance. Our results highlight the importance of studying compartmentalized inflammation in critically ill patients.
Topics: Dexamethasone; Humans; COVID-19 Drug Treatment; COVID-19; SARS-CoV-2; Lung; Cytokines; Critical Illness; Male; Single-Cell Analysis; Female; Middle Aged; T-Lymphocytes; Aged; Lymphocyte Activation
PubMed: 38942804
DOI: 10.1038/s41467-024-49756-2 -
Frontiers in Immunology 2023Sarcoidosis is a granulomatous interstitial lung disease involving a complex interplay among different cluster of differentiation 4 (CD4) thymus cell (T-cell) subsets....
Imbalanced distribution of regulatory T cells and Th17.1 cells in the peripheral blood and BALF of sarcoidosis patients: relationship to disease activity and the fibrotic radiographic phenotype.
RATIONALE
Sarcoidosis is a granulomatous interstitial lung disease involving a complex interplay among different cluster of differentiation 4 (CD4) thymus cell (T-cell) subsets. Originally described as a type 1 T-helper (Th1) inflammatory disease, recent evidence suggests that both effector and regulatory T-cell subgroups play a critical role in sarcoidosis, but this remains controversial.
OBJECTIVES
We aimed to investigate the distribution of CD4 T-cell subpopulations in sarcoidosis patients and its potential associations with clinical disease activity and a radiographic fibrotic phenotype.
METHODS
We measured the frequencies of regulatory T cells (Tregs), Th1, Th17, and Th17.1 cells in the peripheral blood and/or bronchoalveolar lavage fluid (BALF) of 62 sarcoidosis patients, 66 idiopathic pulmonary fibrosis (IPF) patients, and 41 healthy volunteers using flow cytometry. We also measured the changes in these T-cell subpopulations in the blood at the follow-up visits of 11 sarcoidosis patients.
MEASUREMENTS AND RESULTS
An increased percentage of Tregs was observed in the peripheral blood of sarcoidosis patients, with a positive association to disease activity and a fibrotic radiographic phenotype. We found a higher frequency of Tregs, a lower proportion of Th17.1 cells, and a lower ratio of Th17.1 cells to total Tregs in the peripheral blood of both active and fibrotic sarcoidosis patients, compared with IPF patients or healthy donors. In contrast, a lower frequency of Tregs and a higher proportion of Th17.1 cells was found in the BALF of sarcoidosis patients than in that of IPF patients. There was an imbalance of Tregs and Th17.1 cells between the peripheral blood and BALF in sarcoidosis patients. Following immunoregulatory therapy, the proportion of circulating Tregs in sarcoidosis patients decreased.
CONCLUSION
A higher proportion of Tregs in the peripheral blood of sarcoidosis patients was related to disease activity, fibrotic phenotype, and the need for immunoregulatory therapy. The imbalanced distribution of Tregs and Th17.1 cells in patients' peripheral blood and BALF suggests that the lung microenvironment has an effect on the immunological pathogenesis of sarcoidosis. Therefore, further studies on the functional analysis of Tregs and Th17.1 cells in sarcoidosis patients are warranted.
Topics: Humans; T-Lymphocytes, Regulatory; Bronchoalveolar Lavage Fluid; Sarcoidosis; Lung; Phenotype; Idiopathic Pulmonary Fibrosis
PubMed: 37520566
DOI: 10.3389/fimmu.2023.1185443 -
Science Translational Medicine Dec 2023Tobacco smoking doubles the risk of active tuberculosis (TB) and accounts for up to 20% of all active TB cases globally. How smoking promotes lung microenvironments...
Tobacco smoking doubles the risk of active tuberculosis (TB) and accounts for up to 20% of all active TB cases globally. How smoking promotes lung microenvironments permissive to () growth remains incompletely understood. We investigated primary bronchoalveolar lavage cells from current and never smokers by performing single-cell RNA sequencing (scRNA-seq), flow cytometry, and functional assays. We observed the enrichment of immature inflammatory monocytes in the lungs of smokers compared with nonsmokers. These monocytes exhibited phenotypes consistent with recent recruitment from blood, ongoing differentiation, increased activation, and states similar to those with chronic obstructive pulmonary disease. Using integrative scRNA-seq and flow cytometry, we identified CD93 as a marker for a subset of these newly recruited smoking-associated lung monocytes and further provided evidence that the recruitment of monocytes into the lung was mediated by CCR2-binding chemokines, including CCL11. We also show that these cells exhibit elevated inflammatory responses upon exposure to and accelerated intracellular growth of compared with mature macrophages. This elevated growth could be inhibited by anti-inflammatory small molecules, providing a connection between smoking-induced pro-inflammatory states and permissiveness to growth. Our findings suggest a model in which smoking leads to the recruitment of immature inflammatory monocytes from the periphery to the lung, which results in the accumulation of these -permissive cells in the airway. This work defines how smoking may lead to increased susceptibility to and identifies host-directed therapies to reduce the burden of TB among those who smoke.
Topics: Humans; Monocytes; Mycobacterium tuberculosis; Tobacco Smoke Pollution; Macrophages; Tuberculosis; Lung
PubMed: 38055798
DOI: 10.1126/scitranslmed.adg3451 -
ACS Nano Jul 2023-loaded white blood cells (WBC) can transfer cargo to pathological foci in the central nervous system (CNS). Here we tested affinity ligand driven loading of WBC in...
-loaded white blood cells (WBC) can transfer cargo to pathological foci in the central nervous system (CNS). Here we tested affinity ligand driven loading of WBC in order to bypass the need for WBC manipulation. We used a mouse model of acute brain inflammation caused by local injection of tumor necrosis factor alpha (TNF-α). We intravenously injected nanoparticles targeted to intercellular adhesion molecule 1 (anti-ICAM/NP). We found that (A) at 2 h, >20% of anti-ICAM/NP were localized to the lungs; (B) of the anti-ICAM/NP in the lungs >90% were associated with leukocytes; (C) at 6 and 22 h, anti-ICAM/NP pulmonary uptake decreased; (D) anti-ICAM/NP uptake in brain increased up to 5-fold in this time interval, concomitantly with migration of WBCs into the injured brain. Intravital microscopy confirmed transport of anti-ICAM/NP beyond the blood-brain barrier and flow cytometry demonstrated complete association of NP with WBC in the brain (98%). Dexamethasone-loaded anti-ICAM/liposomes abrogated brain edema in this model and promoted anti-inflammatory M2 polarization of macrophages in the brain. targeted loading of WBC in the intravascular pool may provide advantages of coopting WBC predisposed to natural rapid mobilization from the lungs to the brain, connected directly via conduit vessels.
Topics: Mice; Animals; Drug Delivery Systems; Lung; Brain; Liposomes; Leukocytes; Intercellular Adhesion Molecule-1
PubMed: 37432926
DOI: 10.1021/acsnano.2c08275 -
American Journal of Respiratory Cell... Jun 2024
Topics: T-Lymphocytes, Regulatory; Animals; Macrophages, Alveolar; Humans; Mice; Lung
PubMed: 38445963
DOI: 10.1165/rcmb.2024-0049ED -
Journal of Ethnopharmacology Feb 2024Radiation-induced lung injury (RILI) is a common complication during thoracic radiotherapy which impairs the quality of life in patients and limits radiation doses....
ETHNOPHARMACOLOGICAL RELEVANCE
Radiation-induced lung injury (RILI) is a common complication during thoracic radiotherapy which impairs the quality of life in patients and limits radiation doses. Jiawei Maxing Shigan Tang (JMST), which is a modified decoction made of Ephedra, Apricot Kernel, Gypsum, and Licorice, can alleviate the symptoms of RILI in patients. Previous studies and preliminary findings suggested a potential molecular mechanism of JMST in the treatment of RILI. Further studies are needed.
AIM OF THE STUDY
To elucidate the mechanisms of how regulatory T cells (Tregs) promote RILI and the effect of JMST on Tregs, as well as the corresponding pathway.
MATERIALS AND METHODS
CD4CD25 Tregs were isolated from rats, and the supernatant's TGF-β1 level was examined by using enzyme-linked immunosorbent assay (ELISA). Type II alveolar epithelial cells (AECs) were co-cultured with the supernatant of Tregs, and the expression levels of epithelial-to-mesenchymal transition (EMT)-related and TGF-β1/Smad signaling pathway-related proteins were analyzed by using western blotting (WB). Afterward, the Tregs were incubated with different concentrations of JMST. The cell viability and TGF-β1 concentration were confirmed by cell counting kit-8 (CCK-8) assay and ELISA, respectively. The optimized concentration of JMST was applied in vitro and vivo experiments. The specific mechanism was investigated through the combination of using flow cytometry, lung histopathology analysis, ELISA, and WB.
RESULTS
Radiation could promote Tregs to secrete TGF-β1. After radiation, the expression levels of Smad2/3, phosphorylated Smad2/3 (p-Smad2/3), Smad4 and mesenchymal markers Vimentin and α-SMA were all increased, while the expression level of epithelial markers E-cadherin was decreased. The expression levels of these proteins were reversed after interventions involving Treg cell activation inhibition or TGF-β1 receptor inhibitor. JMST reduced the number of Tregs in lung tissue and alleviated the degree of pulmonary fibrosis. The expression of Smad2/3, p-Smad2/3, Smad4, TGF-β1, Vimentin, and α-SMA were significantly downregulated, while the E-cadherin was upregulated, through the intervention of JMST.
CONCLUSION
Tregs could mediate EMT through TGF-β1/Smad pathway. JMST inhibits EMT via TGF-β1/Smad pathway by regulating Tregs, therefore alleviating RILI.
Topics: Humans; Rats; Animals; Transforming Growth Factor beta1; Vimentin; T-Lymphocytes, Regulatory; Lung Injury; Quality of Life; Lung; Signal Transduction; Epithelial-Mesenchymal Transition; Cadherins
PubMed: 37944875
DOI: 10.1016/j.jep.2023.117389 -
International Journal of Molecular... Aug 2023COVID-19 progression often involves severe lung injury, inflammation, coagulopathy, and leukocyte infiltration into pulmonary tissues. The pathogenesis of these...
SARS-CoV-2 Spike Proteins and Cell-Cell Communication Induce P-Selectin and Markers of Endothelial Injury, NETosis, and Inflammation in Human Lung Microvascular Endothelial Cells and Neutrophils: Implications for the Pathogenesis of COVID-19 Coagulopathy.
COVID-19 progression often involves severe lung injury, inflammation, coagulopathy, and leukocyte infiltration into pulmonary tissues. The pathogenesis of these complications is unknown. Because vascular endothelium and neutrophils express angiotensin-converting enzyme-2 and spike (S)-proteins, which are present in bodily fluids and tissues of SARS-CoV-2-infected patients, we investigated the effect of S-proteins and cell-cell communication on human lung microvascular endothelial cells and neutrophils expression of P-selectin, markers of coagulopathy, NETosis, and inflammation. Exposure of endothelial cells or neutrophils to S-proteins and endothelial-neutrophils co-culture induced P-selectin transcription and expression, significantly increased expression/secretion of IL-6, von Willebrand factor (vWF, pro-coagulant), and citrullinated histone H3 (cit-H3, NETosis marker). Compared to the SARS-CoV-2 Wuhan variant, Delta variant S-proteins induced 1.4-15-fold higher P-selectin and higher IL-6 and vWF. Recombinant tissue factor pathway inhibitor (rTFPI), 5,5'-dithio-bis-(2-nitrobenzoic acid) (thiol blocker), and thrombomodulin (anticoagulant) blocked S-protein-induced vWF, IL-6, and cit-H3. This suggests that following SARS-CoV-2 contact with the pulmonary endothelium or neutrophils and endothelial-neutrophil interactions, S-proteins increase adhesion molecules, induce endothelial injury, inflammation, NETosis and coagulopathy via the tissue factor pathway, mechanisms involving functional thiol groups, and/or the fibrinolysis system. Using rTFPI, effectors of the fibrinolysis system and/or thiol-based drugs could be viable therapeutic strategies against SARS-CoV-2-induced endothelial injury, inflammation, NETosis, and coagulopathy.
Topics: Humans; Endothelial Cells; Spike Glycoprotein, Coronavirus; Neutrophils; SARS-CoV-2; P-Selectin; von Willebrand Factor; Interleukin-6; COVID-19; Endothelium, Vascular; Inflammation; Lung
PubMed: 37628764
DOI: 10.3390/ijms241612585 -
Journal of Thrombosis and Haemostasis :... Jan 2024During infection, neutrophil extracellular traps (NETs) are associated with severity of pulmonary diseases such as acute respiratory disease syndrome. NETs induce...
BACKGROUND
During infection, neutrophil extracellular traps (NETs) are associated with severity of pulmonary diseases such as acute respiratory disease syndrome. NETs induce subsequent immune responses, are directly cytotoxic to pulmonary cells, and are highly procoagulant. Anticoagulation treatment was shown to reduce in-hospital mortality, indicating thromboinflammatory complications. However, data are sparsely available on the involvement of NETs in secondary events after virus clearance, which can lead to persistent lung damage and postacute sequelae with chronic fatigue and dyspnea.
OBJECTIVES
This study focuses on late-phase events using a murine model of viral lung infection with postacute sequelae after virus resolution.
METHODS
C57BL/6JRj mice were infected intranasally with the betacoronavirus murine coronavirus (MCoV, strain MHV-A95), and tissue samples were collected after 2, 4, and 10 days. For NET modulation, mice were pretreated with OM-85 or GSK484 and DNase I were administered intraperitoneally between days 2 to 5 and days 4 to 7, respectively.
RESULTS
Rapid, platelet-attributed thrombus formation was followed by a second, late phase of thromboinflammation. This phase was characterized by negligible virus titers but pronounced tissue damage, apoptosis, oxidative DNA damage, and presence of NETs. Inhibition of NETs during the acute phase did not impact virus burden but decreased lung cell apoptosis by 67% and oxidative stress by 94%. Prevention of neutrophil activation by immune training before virus infection reduced damage by 75%, NETs by 31%, and pulmonary thrombi by 93%.
CONCLUSION
NETs are detrimental inducers of tissue damage during respiratory virus infection but do not contribute to virus clearance.
Topics: Animals; Mice; Extracellular Traps; Neutrophils; Coronavirus; Thromboinflammation; Disease Models, Animal; Inflammation; Thrombosis; Mice, Inbred C57BL; Lung; Coronavirus Infections
PubMed: 37748582
DOI: 10.1016/j.jtha.2023.09.014 -
Blood Dec 2023Viral hemorrhagic fevers (HF) are a group of acute febrile diseases with high mortality rates. Although hemostatic dysfunction appears to be a major determinant of the...
Viral hemorrhagic fevers (HF) are a group of acute febrile diseases with high mortality rates. Although hemostatic dysfunction appears to be a major determinant of the severity of the disease, it is still unclear what pathogenic mechanisms lead to it. In clinical studies it is found that arenaviruses, such as Lassa, Machupo, and Guanarito viruses cause HF that vary in symptoms and biological alterations. In this study we aimed to characterize the hemostatic dysfunction induced by arenaviral HF to determine its implication in the severity of the disease and to elucidate the origin of this syndrome. We found that lethal infection with Machupo, Guanarito, and Lassa viruses is associated with cutaneomucosal, cerebral, digestive, and pulmonary hemorrhages. The affected animals developed a severe alteration of the coagulation system, which was concomitant with acute hepatitis, minor deficit of hepatic factor synthesis, presence of a plasmatic inhibitor of coagulation, and dysfunction of the fibrinolytic system. Despite signs of increased vascular permeability, endothelial cell infection was not a determinant factor of the hemorrhagic syndrome. There were also alterations of the primary hemostasis during lethal infection, with moderate to severe thrombocytopenia and platelet dysfunction. Finally, we show that lethal infection is accompanied by a reduced hematopoietic potential of the bone marrow. This study provides an unprecedented characterization of the hemostasis defects induced by several highly pathogenic arenaviruses.
Topics: Animals; Arenaviridae; Arenavirus; Hemorrhagic Fevers, Viral; Hemorrhage; Hemostasis; Hemostatics; Macaca
PubMed: 37699247
DOI: 10.1182/blood.2023020351