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Disease Models & Mechanisms Jun 2024Growing evidence shows that the lung is an organ prone to injury by diabetes mellitus. However, the molecular mechanisms of these pulmonary complications have not yet...
Growing evidence shows that the lung is an organ prone to injury by diabetes mellitus. However, the molecular mechanisms of these pulmonary complications have not yet been characterized comprehensively. To systematically study the effects of insulin deficiency and hyperglycaemia on the lung, we combined proteomics and lipidomics with quantitative histomorphological analyses to compare lung tissue samples from a clinically relevant pig model for mutant INS gene induced diabetes of youth (MIDY) with samples from wild-type (WT) littermate controls. Among others, the level of pulmonary surfactant-associated protein A (SFTPA1), a biomarker of lung injury, was moderately elevated. Furthermore, key proteins related to humoral immune response and extracellular matrix (ECM) organization were significantly altered in abundance. Importantly, a lipoxygenase pathway was dysregulated as indicated by a 2.5-fold reduction of polyunsaturated fatty acid lipoxygenase ALOX15 levels, associated with corresponding changes in the levels of lipids influenced by this enzyme. Our multi-omics study points to an involvement of reduced ALOX15 levels and an associated lack of eicosanoid switching as mechanisms contributing to a proinflammatory milieu in the lungs of subjects suffering from diabetes mellitus.
PubMed: 38900131
DOI: 10.1242/dmm.050650 -
Cancers May 2024This study aimed to assess a four-marker protein panel (4MP)'s performance, including the precursor form of surfactant protein B, cancer antigen 125, carcinoembryonic...
This study aimed to assess a four-marker protein panel (4MP)'s performance, including the precursor form of surfactant protein B, cancer antigen 125, carcinoembryonic antigen, and cytokeratin-19, for predicting lung cancer in a cohort enriched with never- and ever-smokers. Blinded pre-diagnostic plasma samples collected within 2 years prior to a lung cancer diagnosis from 25 cases and 100 sex-, age-, and smoking-matched controls were obtained from the Physicians' Health Study (PHS). The 4MP yielded AUC performance estimates of 0.76 (95% CI: 0.61-0.92) and 0.69 (95% CI: 0.56-0.82) for predicting lung cancer within one year and within two years of diagnosis, respectively. When stratifying into ever-smokers and never-smokers, the 4MP had respective AUCs of 0.77 (95% CI: 0.63-0.92) and 0.72 (95% CI: 0.17-1.00) for a 1-year risk of lung cancer. The AUCs of the 4MP for predicting metastatic lung cancer within one year and two years of the blood draw were 0.95 (95% CI: 0.87-1.00) and 0.78 (95% CI: 0.62-0.94), respectively. Our findings indicate that a blood-based biomarker panel may be useful in identifying ever- and never-smokers at high risk of a diagnosis of lung cancer within one-to-two years.
PubMed: 38893188
DOI: 10.3390/cancers16112070 -
International Journal of Molecular... May 2024Given the various clinical manifestations that characterize Coronavirus Disease 2019 (COVID-19), the scientific community is constantly searching for biomarkers with...
Given the various clinical manifestations that characterize Coronavirus Disease 2019 (COVID-19), the scientific community is constantly searching for biomarkers with prognostic value. Surfactant proteins A (SP-A) and D (SP-D) are collectins that play a crucial role in ensuring proper alveolar function and an alteration of their serum levels was reported in several pulmonary diseases characterized by Acute Respiratory Distress Syndrome (ARDS) and pulmonary fibrosis. Considering that such clinical manifestations can also occur during Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, we wondered if these collectins could act as prognostic markers. In this regard, serum levels of SP-A and SP-D were measured by enzyme immunoassay in patients with SARS-CoV-2 infection (n = 51) at admission (T0) and after seven days (T1) and compared with healthy donors (n = 11). SP-D increased in COVID-19 patients compared to healthy controls during the early phases of infection, while a significant reduction was observed at T1. Stratifying SARS-CoV-2 patients according to disease severity, increased serum SP-D levels were observed in severe compared to mild patients. In light of these results, SP-D, but not SP-A, seems to be an eligible marker of COVID-19 pneumonia, and the early detection of SP-D serum levels could be crucial for preventive clinical management.
Topics: Humans; COVID-19; Male; Female; Pulmonary Surfactant-Associated Protein D; Biomarkers; Middle Aged; Severity of Illness Index; Pulmonary Surfactant-Associated Protein A; SARS-CoV-2; Aged; Adult; Prognosis
PubMed: 38891806
DOI: 10.3390/ijms25115620 -
Cells May 2024Pulmonary surfactants play a crucial role in managing lung lipid metabolism, and dysregulation of this process is evident in various lung diseases. Alternations in lipid... (Review)
Review
Pulmonary surfactants play a crucial role in managing lung lipid metabolism, and dysregulation of this process is evident in various lung diseases. Alternations in lipid metabolism lead to pulmonary surfactant damage, resulting in hyperlipidemia in response to lung injury. Lung macrophages are responsible for recycling damaged lipid droplets to maintain lipid homeostasis. The inflammatory response triggered by external stimuli such as cigarette smoke, bleomycin, and bacteria can interfere with this process, resulting in the formation of lipid-laden macrophages (LLMs), also known as foamy macrophages. Recent studies have highlighted the potential significance of LLM formation in a range of pulmonary diseases. Furthermore, growing evidence suggests that LLMs are present in patients suffering from various pulmonary conditions. In this review, we summarize the essential metabolic and signaling pathways driving the LLM formation in chronic obstructive pulmonary disease, pulmonary fibrosis, tuberculosis, and acute lung injury.
Topics: Humans; Lung Diseases; Lipid Metabolism; Animals; Macrophages; Macrophages, Alveolar; Signal Transduction
PubMed: 38891022
DOI: 10.3390/cells13110889 -
Respiratory Research Jun 2024Sleep-disordered breathing (SDB) is a major comorbidity in idiopathic pulmonary fibrosis (IPF) and is associated with a poor outcome. There is a lack of knowledge...
Treating sleep-disordered breathing of idiopathic pulmonary fibrosis patients with CPAP and nocturnal oxygen treatment. A pilot study : Sleep-disordered breathing treatment in IPF.
INTRODUCTION
Sleep-disordered breathing (SDB) is a major comorbidity in idiopathic pulmonary fibrosis (IPF) and is associated with a poor outcome. There is a lack of knowledge regarding the impact of SDB treatment on IPF. We assessed at one year: (1) the effect of CPAP and/or nocturnal oxygen therapy on IPF regarding lung function, blood mediators, and quality of life; (2) adherence to SDB treatment and SDB changes.
METHODOLOGY
This is a prospective study of consecutive newly diagnosed IPF patients initiating anti-fibrotic treatment. Lung function, polysomnography, blood tests and quality of life questionnaires were performed at inclusion and after one year. Patients were classified as obstructive sleep apnoea (OSA), central sleep apnoea (CSA), and sleep-sustained hypoxemia (SSH). SDB therapy (CPAP and/or nocturnal oxygen therapy) was initiated if needed.
RESULTS
Fifty patients were enrolled (36% had OSA, 22% CSA, and 12% SSH). CPAP was started in 54% of patients and nocturnal oxygen therapy in 16%. At one-year, polysomnography found improved parameters, though 17% of patients had to add nocturnal oxygen therapy or CPAP, while 33% presented SDB onset at this second polysomnography. CPAP compliance at one year was 6.74 h/night (SD 0.74). After one year, matrix metalloproteinase-1 decreased in OSA and CSA (p = 0.029; p = 0.027), C-reactive protein in OSA (p = 0.045), and surfactant protein D in CSA group (p = 0.074). There was no significant change in lung function.
CONCLUSIONS
Treatment of SBD with CPAP and NOT can be well tolerated with a high compliance. IPF patients may exhibit SDB progression and require periodic re-assessment. Further studies to evaluate the impact of SDB treatment on lung function and serological mediators are needed.
Topics: Humans; Continuous Positive Airway Pressure; Female; Male; Idiopathic Pulmonary Fibrosis; Pilot Projects; Aged; Prospective Studies; Sleep Apnea Syndromes; Oxygen Inhalation Therapy; Middle Aged; Treatment Outcome; Polysomnography; Quality of Life
PubMed: 38890648
DOI: 10.1186/s12931-024-02871-6 -
American Journal of Physiology. Lung... Jun 2024COVID-19 syndrome is characterized by acute lung injury, hypoxemic respiratory failure, and high mortality. Alveolar Type 2 (AT2) cells are essential for gas exchange,...
COVID-19 syndrome is characterized by acute lung injury, hypoxemic respiratory failure, and high mortality. Alveolar Type 2 (AT2) cells are essential for gas exchange, repair, and regeneration of distal lung epithelium. We have shown that the causative agent, SARS-CoV-2 and other β-coronavirus genus members induce an ER stress response , however the consequences for host AT2 function are less understood. To study this, two murine models of coronavirus infection were employed- mouse hepatitis virus-1 (MHV-1) in A/J mice and a mouse adapted SARS-CoV-2 strain. MHV-1 infected mice exhibited dose-dependent weight loss with histological evidence of distal lung injury accompanied by elevated bronchoalveolar lavage fluid (BALF) cell counts and total protein. AT2 cells showed evidence of both viral infection and increased BIP/GRP78 expression, consistent with activation of the unfolded protein response (UPR). The AT2 UPR included increased IRE1α signaling and a biphasic response in PERK signaling accompanied marked reductions in AT2 and BALF surfactant protein (SP-B, SP-C) content, increases in surfactant surface tension, and emergence of a re-programmed epithelial cell population (, ). The loss of a homeostatic AT2 endophenotype was attenuated by treatment with the IRE1α inhibitor OPK711. As proof-of-concept, C57BL6 mice infected with mouse-adapted SARS-CoV-2 demonstrated similar lung injury and evidence of disrupted surfactant homeostasis. We conclude that lung injury from β-coronavirus infection results from an aberrant host response activating multiple AT2 UPR pathways, altering surfactant metabolism/function, and changing AT2 endophenotypes offering a mechanistic link between SARS-CoV-2 infection, AT2 cell biology, and acute respiratory failure.
PubMed: 38860845
DOI: 10.1152/ajplung.00324.2023 -
Immunity, Inflammation and Disease Jun 2024Severe cases of COVID-19 often lead to the development of acute respiratory syndrome, a critical condition believed to be caused by the harmful effects of SARS-CoV-2 on... (Review)
Review
BACKGROUND
Severe cases of COVID-19 often lead to the development of acute respiratory syndrome, a critical condition believed to be caused by the harmful effects of SARS-CoV-2 on type II alveolar cells. These cells play a crucial role in producing pulmonary surfactants, which are essential for proper lung function. Specifically focusing on surfactant proteins, including Surfactant protein A (SP-A), Surfactant protein B, Surfactant protein C, and Surfactant protein D (SP-D), changes in the levels of pulmonary surfactants may be a significant factor in the pathological changes seen in COVID-19 infection.
OBJECTIVE
This study aims to gain insights into surfactants, particularly their impacts and changes during COVID-19 infection, through a comprehensive review of current literature. The study focuses on the function of surfactants as prognostic markers, diagnostic factors, and essential components in the management and treatment of COVID-19.
FINDING
In general, pulmonary surfactants serve to reduce the surface tension at the gas-liquid interface, thereby significantly contributing to the regulation of respiratory mechanics. Additionally, these surfactants play a crucial role in the innate immune system within the pulmonary microenvironment. Within the spectrum of COVID-19 infections, a compelling association is observed, characterized by elevated levels of SP-D and SP-A across a range of manifestations from mild to severe pneumonia. The sudden decline in respiratory function observed in COVID-19 patients may be attributed to the decreased synthesis of surfactants by type II alveolar cells.
CONCLUSION
Collectin proteins such as SP-A and SP-D show promise as biomarkers, offering potential avenues for predicting and monitoring pulmonary alveolar injury in the context of COVID-19. This clarification enhances our understanding of the molecular complexities contributing to respiratory complications in severe COVID-19 cases, providing a foundation for targeted therapeutic approaches using surfactants and refined clinical management strategies.
Topics: COVID-19; Humans; SARS-CoV-2; Pulmonary Surfactant-Associated Proteins; Pulmonary Surfactants; Biomarkers; Pulmonary Surfactant-Associated Protein D; Prognosis; Lung
PubMed: 38860749
DOI: 10.1002/iid3.1302 -
PloS One 2024Clear amniotic fluid aspiration syndrome (CAF-AS) is a very rare event occurring in 0.25% of our term clear amniotic fluids deliveries. The study's aims were: 1. to... (Observational Study)
Observational Study
BACKGROUND
Clear amniotic fluid aspiration syndrome (CAF-AS) is a very rare event occurring in 0.25% of our term clear amniotic fluids deliveries. The study's aims were: 1. to characterize the risk factors and outcomes associated with Clear Amniotic Fluid Aspiration Syndrome and 2. to compare the outcomes of Clear Amniotic Fluid Aspiration to Meconium Aspiration.
METHODS
This was an observational study over a 22-year period in a single level-3 medical center. Compared were parturient/labor characteristics and neonatal outcomes in cases with suspected Clear Amniotic Fluid Aspiration to cases suspected for Meconium Aspiration.
RESULTS
Out of 79,620 term deliveries there were 66,705 (83.8%) clear amniotic fluids and 12,915 (16.2%) meconium stained amniotic fluid (MSAF). Of neonates born with clear amniotic fluid, 166 (0.25%) were diagnosed with Clear Amniotic Fluid Aspiration Syndrome (CAF-AS), while 202 (15.7%) of those born with MSAF, were diagnosed with aspiration syndrome (MSAF-AS). Both conditions had comparable rates of mild manifestation (67.5% vs 69.2%, p = 0.63). Persistent pulmonary hypertension (PPH) occurred 5 times less in CAF-AS than MSAF-AS (4% vs 20%, OR 0.17, P< 0.0001) Both conditions presented similar rates of surfactant without PPH (11.1% vs 13.4%, p = 0.87). There was 1 postnatal death in CAF-AS vs 10 in MSAF.
CONCLUSION
CAF-AS were quantitatively quite similar in terms of need of actual active intervention of the neonatologists in the delivery room (166 vs 202, i.e. in terms of numbers of cases and not prevalence) to MSAF-AS.We identified in these cases two major specific causes: hyperkinetic explosive deliveries in multiparas and long-lasting episodes of maternal hypotension due to epidural/spinal anaesthesia during labor. Out of 140 million births per year in the world, it should be of concern that 3 million cases are neglected nowadays. Future studies should evaluate if this CAF-AS should benefit from a more active intervention such as immediate endotracheal suction at birth, this clear fluid being very easy to suction.
Topics: Humans; Female; Amniotic Fluid; Pregnancy; Meconium Aspiration Syndrome; Infant, Newborn; Adult; Risk Factors; Male
PubMed: 38857215
DOI: 10.1371/journal.pone.0301595 -
JCI Insight Jun 2024Progressive pulmonary fibrosis (PPF), defined as the worsening of various interstitial lung diseases (ILDs), currently lacks useful biomarkers. To identify novel...
Progressive pulmonary fibrosis (PPF), defined as the worsening of various interstitial lung diseases (ILDs), currently lacks useful biomarkers. To identify novel biomarkers for early detection of patients at risk of PPF, we performed a proteomic analysis of serum extracellular vesicles (EVs). Notably, the identified candidate biomarkers were enriched for lung-derived proteins participating in fibrosis-related pathways. Among them, pulmonary surfactant-associated protein B (SFTPB) in serum EVs could predict ILD progression better than the known biomarkers, serum KL-6 and SP-D, and it was identified as an independent prognostic factor from ILD-gender-age-physiology index. Subsequently, the utility of SFTPB for predicting ILD progression was evaluated further in 2 cohorts using serum EVs and serum, respectively, suggesting that SFTPB in serum EVs but not in serum was helpful. Among SFTPB forms, pro-SFTPB levels were increased in both serum EVs and lungs of patients with PPF compared with those of the control. Consistently, in a mouse model, the levels of pro-SFTPB, primarily originating from alveolar epithelial type 2 cells, were increased similarly in serum EVs and lungs, reflecting pro-fibrotic changes in the lungs, as supported by single-cell RNA sequencing. SFTPB, especially its pro-form, in serum EVs could serve as a biomarker for predicting ILD progression.
Topics: Extracellular Vesicles; Humans; Animals; Biomarkers; Mice; Male; Female; Pulmonary Fibrosis; Disease Progression; Pulmonary Surfactant-Associated Protein B; Middle Aged; Aged; Lung Diseases, Interstitial; Lung; Proteomics; Disease Models, Animal; Prognosis; Protein Precursors; Pulmonary Surfactant-Associated Proteins
PubMed: 38855869
DOI: 10.1172/jci.insight.177937 -
Translational Pediatrics May 2024Bronchopulmonary dysplasia (BPD), characterized by impaired lung development, remains a leading cause of morbidity and mortality in premature infants. The synthesis and...
BACKGROUND
Bronchopulmonary dysplasia (BPD), characterized by impaired lung development, remains a leading cause of morbidity and mortality in premature infants. The synthesis and metabolism of lipids play a critical role in normal lung development, such as dipalmitoylphosphatidylcholine, a key component of pulmonary surfactant (PS). Therefore, we conducted a lipidomics study of rat lung tissue to explore the changes of pulmonary lipid composition in the progression of BPD disease.
METHODS
In this study, we exposed neonatal Sprague-Dawley (SD) rats to hyperoxia for 14 days. After hyperoxia exposure, the lung tissues of rats were analyzed pathologically, and untargeted lipidomics was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS).
RESULTS
Hematoxylin-eosin (H&E) staining showed that the alveoli enlarged, the number of alveoli decreased and the pulmonary surfactant-associated protein D (SFTPD) decreased in hyperoxia-exposed rats. A total of 620 pulmonary lipids were detected by LC-MS/MS, covering 27 lipid categories. The most common lipids were triacylglycerol (TAG), followed by phosphatidylcholine (PC) and phosphatidylethanolamine (PE).
CONCLUSIONS
Compared with those rats exposed to normoxic conditions, the lipid levels in the lungs of rats exposed to hyperoxia for 14 days generally decreased, with the levels of TAG and PC decreasing most significantly. In short, our results provide a clue for finding therapeutic targets and biomarkers of a BPD rat model lung liposome.
PubMed: 38840687
DOI: 10.21037/tp-23-546