Editorial: Progressive fibrosing interstitial lung disease: from bench to bedside

peer reviewe

A new nucleosomic-based model to identify and diagnose SSc-ILD

peer reviewedBACKGROUND: Systemic sclerosis (SSc) is a rare connective tissue disease associated with rapid evolving interstitial lung disease (SSc-ILD), driving its mortality. Specific biomarkers associated with the evolution of the lung disease are highly needed. We aimed to identify specific biomarkers of SSc-ILD to predict the evolution of the disease. Nucleosomes are stable DNA/protein complexes that are shed into the blood stream making them ideal candidates for biomarkers. METHODS: We studied circulating cell-free nucleosomes (cf-nucleosomes) in SSc patients, 31 with ILD (SSc-ILD) and 67 without ILD. We analyzed plasma levels for cf-nucleosomes and investigated whether global circulating nucleosome levels in association with or without other biomarkers of interest for systemic sclerosis or lung fibrosis (e.g., serum growth factors: IGFBP-1 and the MMP enzyme: MMP-9), could be suitable potential biomarkers for the correct identification of SSc-ILD disease. RESULTS: We found that H3.1 nucleosome levels were significantly higher in patients with SSc-ILD compared SSc patients without ILD (p < 0.05) and levels of MMP-9 were significantly increased in patients with SSc-ILD compared to SSc patients without ILD (p < 0.05). Conversely, IGFBP-1 was significantly reduced in patients with SSc-ILD compared to SSc without ILD (p < 0.001). The combination of cf-nucleosomes H3.1 coupled to MMP-9 and IGFBP-1 increased the sensitivity for the differential detection of SSc-ILD. High levels of accuracy were reached with this combined model: its performances are strong with 68.4% of positive predictive value and 77.2% of negative predictive value for 90% of specificity. With our model, we identified a significant negative correlation with FVC % pred (r = -0.22) and TLC % pred (r = -0.31). The value of our model at T1 (baseline) has a predictive power over the Rodnan score at T2 (after 6-18 months), showed by a significant linear regression with R2 = 19% (p = 0.013). We identified in the sole group of SSc-ILD patients a significant linear regression with a R2 = 54.4% with the variation of DLCO between T1 and T2 (p < 0.05). CONCLUSION: In our study, we identified a new blood-based model with nucleosomic biomarker in order to diagnose SSc-ILD in a SSc cohort. This model is correlated with TLC and FVC at baseline and predictive of the skin evolution and the DLCO. Further longitudinal exploration studies should be performed in order to evaluate the potential of such diagnostic and predictive model

Sorting and packaging of RNA into extracellular vesicles shape intracellular transcript levels.

peer reviewed[en] BACKGROUND: Extracellular vesicles (EVs) are released by nearly every cell type and have attracted much attention for their ability to transfer protein and diverse RNA species from donor to recipient cells. Much attention has been given so far to the features of EV short RNAs such as miRNAs. However, while the presence of mRNA and long noncoding RNA (lncRNA) transcripts in EVs has also been reported by multiple different groups, the properties and function of these longer transcripts have been less thoroughly explored than EV miRNA. Additionally, the impact of EV export on the transcriptome of exporting cells has remained almost completely unexamined. Here, we globally investigate mRNA and lncRNA transcripts in endothelial EVs in multiple different conditions. RESULTS: In basal conditions, long RNA transcripts enriched in EVs have longer than average half-lives and distinctive stability-related sequence and structure characteristics including shorter transcript length, higher exon density, and fewer 3' UTR A/U-rich elements. EV-enriched long RNA transcripts are also enriched in HNRNPA2B1 binding motifs and are impacted by HNRNPA2B1 depletion, implicating this RNA-binding protein in the sorting of long RNA to EVs. After signaling-dependent modification of the cellular transcriptome, we observed that, unexpectedly, the rate of EV enrichment relative to cells was altered for many mRNA and lncRNA transcripts. This change in EV enrichment was negatively correlated with intracellular abundance, with transcripts whose export to EVs increased showing decreased abundance in cells and vice versa. Correspondingly, after treatment with inhibitors of EV secretion, levels of mRNA and lncRNA transcripts that are normally highly exported to EVs increased in cells, indicating a measurable impact of EV export on the long RNA transcriptome of the exporting cells. Compounds with different mechanisms of inhibition of EV secretion affected the cellular transcriptome differently, suggesting the existence of multiple EV subtypes with different long RNA profiles. CONCLUSIONS: We present evidence for an impact of EV physiology on the characteristics of EV-producing cell transcriptomes. Our work suggests a new paradigm in which the sorting and packaging of transcripts into EVs participate, together with transcription and RNA decay, in controlling RNA homeostasis and shape the cellular long RNA abundance profile

Sputum IL-25, IL-33 and TSLP, IL-23 and IL-36 in airway obstructive diseases. Reduced levels of IL-36 in eosinophilic phenotype.

peer reviewedINTRODUCTION: Alarmins ((IL-25, IL-33 and thymic stromal lymphopoietin (TSLP)) are known to promote Th2 inflammation and could be associated with eosinophilic airway infiltration. They may also play a role in airway remodeling in chronic airway obstructive diseases such as asthma and chronic obstructive pulmonary disease (COPD). IL-23 and IL-36 were shown to mediate the neutrophilic airway inflammation as seen in chronic airway obstructive diseases. OBJECTIVES: The purpose of this project was to determine the expression and the production of these cytokines from induced sputum (IS) in patients with chronic airway obstructive diseases including asthmatics and COPD. The relationship of the mediators with sputum inflammatory cellular profile and the severity of airway obstruction was assessed. METHODS: The alarmins (IL-25, IL-33 and TSLP) as well as IL-23 and IL-36 concentrations were measured in IS from 24 asthmatics and 20 COPD patients compared to 25 healthy volunteers. The cytokines were assessed by ELISA in the IS supernatant and by RT-qPCR in the IS cells. RESULTS: At protein level, no difference was observed between controls and patients suffering from airway obstructive diseases regarding the different mediators. IL-36 protein level was negatively correlated with sputum eosinophil and appeared significantly decreased in patients with an eosinophilic airway inflammation compared to those with a neutrophilic profile and controls. At gene level, only IL-36, IL-23 and TSLP were measurable but none differed between controls and patients with airway obstructive diseases. IL-36 and IL-23 were significantly increased in patients with an neutrophilic inflammatory profile compared to those with an eosinophilic inflammation and were correlated with sputum neutrophil proportions. None of the mediators were linked to airway obstruction. CONCLUSIONS: The main finding of our study is that patients with eosinophilic airway inflammation exhibited a reduced IL-36 level which could make them more susceptible to airway infections as IL-36 is implicated in antimicrobial defense. This study showed also an implication of IL-36 and IL-23 in airway neutrophilic inflammation in chronic airway obstructive diseases

Increased KL-6 levels in moderate to severe COVID-19 infection.

peer reviewed[en] BACKGROUND: The global coronavirus disease 2019 (COVID-19) has presented significant challenges and created concerns worldwide. Besides, patients who have experienced a SARS-CoV-2 infection could present post-viral complications that can ultimately lead to pulmonary fibrosis. Serum levels of Krebs von den Lungen 6 (KL-6), high molecular weight human MUC1 mucin, are increased in the most patients with various interstitial lung damage. Since its production is raised during epithelial damages, KL-6 could be a helpful non-invasive marker to monitor COVID-19 infection and predict post-infection sequelae. METHODS: We retrospectively evaluated KL-6 levels of 222 COVID-19 infected patients and 70 healthy control. Serum KL-6, fibrinogen, lactate dehydrogenase (LDH), platelet-lymphocytes ratio (PLR) levels and other biological parameters were analyzed. This retrospective study also characterized the relationships between serum KL-6 levels and pulmonary function variables. RESULTS: Our results showed that serum KL-6 levels in COVID-19 patients were increased compared to healthy subjects (470 U/ml vs 254 U/ml, P 453.5 U/ml was associated with COVID-19 (AUC = 0.8415, P < 0.0001). KL-6 level was positively correlated with other indicators of disease severity such as fibrinogen level (r = 0.1475, P = 0.0287), LDH level (r = 0,31, P = 0,004) and PLR level (r = 0.23, P = 0.0005). However, KL-6 levels were not correlated with pulmonary function tests (r = 0.04, P = 0.69). CONCLUSIONS: KL-6 expression was correlated with several disease severity indicators. However, the association between mortality and long-term follow-up outcomes needs further investigation. More extensive trials are required to prove that KL-6 could be a marker of disease severity in COVID-19 infection

Mechanisms of endothelial microparticle generation : influence of the vascular bed on microparticle release

En réponse à l'activation et/ou une apoptose, les cellules endothéliales (CE) libèrent dans le milieu environnant des microparticules endothéliales (MPE). Les microparticules sont des vésicules de petite taille résultant d'évènements membranaires liés à une perte de l'asymétrie des phospholipides. Peu de travaux concernent l'étude des mécanismes de génération des MPE et l'influence du territoire vasculaire sur la capacité de vésiculation des CE n'est pas connue. Nous avons montré que la thrombine induit la génération de MPE par un mécanisme complexe impliquant un lien entre coagulation et inflammation sur les CE macro et microvasculaires. A partir de l'étude du transcriptome, nous avons mis en évidence l'implication de TRAIL dans la génération des MPE procoagulantes par la thrombine. A l'état basal, les CE issues de différents territoires vasculaires présentent des capacités différentes de vésiculation, les CE microvasculaires présentant une plus grande capacité à libérer des MPE. L'étude du transcriptome a permis de déterminer des signatures moléculaires représentatives des territoires macro et microvasculaires. Nos travaux mettent en évidence une génération différentielle de MPE en fonction du calibre des vaisseaux et les signatures spécifiques pourraient permettre une meilleure caractérisation du territoire endothélial lésé.In response to activation and/or apoptosis, endothelial cells (EC) release endothelial microparticles (EMP) in the extracellular space. Microparticles are small-sized vesicles resulting from membrane events leading to a loss of phospholipid asymmetry. Few works have documented the mechanisms underlying EMP generation and the influence of vascular bed on EMP release remains largely unknown. Our works showed that thrombin induced EMP generation through a complex mechanism involving a cross-talk between coagulation and inflammation in macro and microvascular EC. Using a global gene expression study, we have evidenced the involvement of TRAIL in the procoagulant EMP generation induced by thrombin. In a basal state, EC from various vascular beds showed different capacities of EMP release, with microvascular EC displaying the highest capacity. Gene expression study identified molecular signatures representative of EC from macro and microvascular beds. Our works highlight the role of the vascular beds in the capacity of EC to generate EMP according to the vessel caliber. The specific gene signatures could improve our knowledge the endothelial dysfunction and a better characterization of the damaged vascular beds

Mécanismes de génération des microparticules endothélialesmicroparticules endotheliales (influence du territoire vasculaire sur la capacité des cellules endothéliales à libérer les microparticules)

En réponse à l'activation et/ou une apoptose, les cellules endothéliales (CE) libèrent dans le milieu environnant des microparticules endothéliales (MPE). Les microparticules sont des vésicules de petite taille résultant d'évènements membranaires liés à une perte de l'asymétrie des phospholipides. Peu de travaux concernent l'étude des mécanismes de génération des MPE et l'influence du territoire vasculaire sur la capacité de vésiculation des CE n'est pas connue. Nous avons montré que la thrombine induit la génération de MPE par un mécanisme complexe impliquant un lien entre coagulation et inflammation sur les CE macro et microvasculaires. A partir de l'étude du transcriptome, nous avons mis en évidence l'implication de TRAIL dans la génération des MPE procoagulantes par la thrombine. A l'état basal, les CE issues de différents territoires vasculaires présentent des capacités différentes de vésiculation, les CE microvasculaires présentant une plus grande capacité à libérer des MPE. L'étude du transcriptome a permis de déterminer des signatures moléculaires représentatives des territoires macro et microvasculaires. Nos travaux mettent en évidence une génération différentielle de MPE en fonction du calibre des vaisseaux et les signatures spécifiques pourraient permettre une meilleure caractérisation du territoire endothélial lésé.In response to activation and/or apoptosis, endothelial cells (EC) release endothelial microparticles (EMP) in the extracellular space. Microparticles are small-sized vesicles resulting from membrane events leading to a loss of phospholipid asymmetry. Few works have documented the mechanisms underlying EMP generation and the influence of vascular bed on EMP release remains largely unknown. Our works showed that thrombin induced EMP generation through a complex mechanism involving a cross-talk between coagulation and inflammation in macro and microvascular EC. Using a global gene expression study, we have evidenced the involvement of TRAIL in the procoagulant EMP generation induced by thrombin. In a basal state, EC from various vascular beds showed different capacities of EMP release, with microvascular EC displaying the highest capacity. Gene expression study identified molecular signatures representative of EC from macro and microvascular beds. Our works highlight the role of the vascular beds in the capacity of EC to generate EMP according to the vessel caliber. The specific gene signatures could improve our knowledge the endothelial dysfunction and a better characterization of the damaged vascular beds.AIX-MARSEILLE2-Bib.electronique (130559901) / SudocSudocFranceF

Endothelial miRNAs as Cellular Messengers in Cardiometabolic Diseases.

peer reviewedaudience: researcher, studentMetabolic syndrome is a clustering of risk factors that increases susceptibility to serious cardiometabolic complications, including type 2 diabetes (T2D) and myocardial infarction. Understanding the underlying mechanisms will advance the development of diagnostic and therapeutic approaches. A prominent feature of cardiometabolic diseases is endothelial dysfunction. Endothelial cell (EC) homeostasis and response to pathological stimuli are controlled by gene regulatory networks in which miRNAs play a critical role. Recently, miRNAs have been implicated as cell-cell messengers that can influence cellular function. This review investigates the known and potential roles for miRNA-based cell-cell communication in the control of cardiovascular health and explores the value of identifying miRNA biomarkers and developing therapeutics that harness or antagonize miRNA-based communication