Aberrant fibroblast function plays a key role in the pathogenesis of idiopathic pulmonary fibrosis, a devastating disease of unrelenting extracellular matrix deposition in response to lung injury. Platelet-derived growth factor α–positive ( Pdgfra ⁺ ) lipofibroblasts (LipoFBs) are essential for lung injury response and maintenance of a functional alveolar stem cell niche. Little is known about the effects of lung injury on LipoFB function. Here, we used single-cell RNA-Seq (scRNA-Seq) technology and Pdgfra ^GFP lineage tracing to generate a transcriptomic profile of Pdgfra ⁺ fibroblasts in normal and injured mouse lungs 14 days after bleomycin exposure, generating 11 unique transcriptomic clusters that segregated according to treatment. While normal and injured LipoFBs shared a common gene signature, injured LipoFBs acquired fibrogenic pathway activity with an attenuation of lipogenic pathways. In a 3D organoid model, injured Pdgfra ⁺ fibroblast–supported organoids were morphologically distinct from those cultured with normal fibroblasts, and scRNA-Seq analysis suggested distinct transcriptomic changes in alveolar epithelia supported by injured Pdgfra ⁺ fibroblasts. In summary, while LipoFBs in injured lung have not migrated from their niche and retain their lipogenic identity, they acquire a potentially reversible fibrogenic profile, which may alter the kinetics of epithelial regeneration and potentially contribute to dysregulated repair, leading to fibrosis.

Pulmonary fibrosis (PF) is a heterogeneous disease with a poor prognosis. Therefore, identifying additional therapeutic modalities is required to improve outcome. However, the lack of biomarkers of disease progression hampers the preclinical to clinical translational process. Here, this work assesses and identifies progressive alterations in pulmonary function, transcriptomics, and metabolomics in the mouse lung at 7, 14, 21, and 28 days after a single dose of oropharyngeal bleomycin. By integrating multi‐omics data, this work identifies two central gene subnetworks associated with multiple critical pathological changes in transcriptomics and metabolomics as well as pulmonary function. This work presents a multi‐omics‐based framework to establish a translational link between the bleomycin‐induced PF model in mice and human idiopathic pulmonary fibrosis to identify druggable targets and test therapeutic candidates. This work also indicates peripheral cannabinoid receptor 1 (CB₁R) antagonism as a rational therapeutic target for clinical translation in PF. Mouse Lung Fibrosis Atlas can be accessed freely at https://niaaa.nih.gov/mouselungfibrosisatlas.

Pulmonary fibrosis (PF) is a life-threatening disease that requires effective and well-tolerated therapeutic modalities. Previously, the distinct pathogenic roles of cannabinoid receptor 1 (CB ₁ R) and inducible nitric oxide synthase (iNOS) in the lungs and their joint therapeutic targeting were highlighted in PF. However, the cell-specific role of CB ₁ R in PF has not been explored. Here, we demonstrate that CB ₁ R in alveolar macrophages (AMs) mediates the release of anandamide into the alveoli, which promotes PF by inducing pro-fibrotic macrophages that are accessible to locally delivered antifibrotic therapy. A multitargeted therapy may improve therapeutic efficacy in PF. Pulmonary delivery of 0.5 mg/kg/d MRI-1867 (zevaquenabant), a peripherally acting hybrid CB ₁ R/iNOS inhibitor, was as effective as systemic delivery of 10 mg/kg/d and also matched the efficacy of nintedanib in mitigating bleomycin-induced PF. A systems pharmacology approach revealed that zevaquenabant and nintedanib treatments reversed pathologic changes in both distinct and shared PF-related pathways, which are conserved in human and mouse. Moreover, zevaquenabant treatment also attenuated fibrosis and pro-fibrotic mediators in human precision-cut lung slices. These findings establish CB ₁ R-expressing AMs as a therapeutic target and support local delivery of dual CB ₁ R/iNOS inhibitor zevaquenabant by inhalation as an effective, well-tolerated, and safe strategy for PF.

The inhibition of soluble epoxide hydrolase (sEH) can reduce the level of dihydroxyeicosatrienoic acids (DHETs) effectively maintaining endogenous epoxyeicosatrienoic acids (EETs) levels, resulting in the amelioration of inflammation and pain. Consequently, the development of sEH inhibitors has been a prominent research area for over two decades. In the present study, we synthesized and evaluated sulfonyl urea derivatives for their potential to inhibit sEH. These compounds underwent extensive in vitro investigation, revealing their potency against human and mouse sEH, with 4f showing the most promising sEH inhibitory potential. When subjected to lipopolysaccharide (LPS)-induced acute lung injury (ALI) in studies in mice, compound 4f manifested promising anti-inflammatory efficacy. We investigated the analgesic efficacy of sEH inhibitor 4f in a murine pain model of tail-flick reflex. These results validate the role of sEH inhibition in inflammatory diseases and pave the way for the rational design and optimization of sEH inhibitors based on a sulfonyl urea template.

La fibrose pulmonaire idiopathique (FPI) est une maladie rare, qui constitue la forme la plus fréquence de pneumopathie interstitielle diffuse de l’adulte. Elle se caractérise par une accumulation massive de matrice extracellulaire, principalement de collagène, dans le parenchyme pulmonaire, ce qui entraine une altération dramatique et irréversible de la fonction respiratoire. La FPI est une pathologie mortelle qui survient principalement après 60 ans, et sa médiane de survie est d’environ 5 ans après diagnostic. Il n’existe aucun traitement curatif. A ce jour seuls 2 médicaments, la pirfénidone et le nintédanib ont été validés dans cette indication, mais ils ne permettent que de ralentir très modérément son évolution. La recherche visant à mieux caractériser les mécanismes physiopathologiques de la FPI ainsi que le développement de nouveaux traitements est donc crucial pour les patients.La maladie se caractérise par la production massive de cellules myofibroblastiques issus de la transformation des autres cellules pulmonaires. Le TGF-b1; est une cytokine clée stimulant cette transformation. On sait que ce processus est régulé, notamment par les cellules de l’immunité dont les macrophages. Les protéines de choc thermique (HSP) et en particulier HSP27 et aB-crystallin sont d’autres modulateurs connus des mécanismes de fibrogenèse.Mon travail de thèse a consisté 1) à étudier l’intérêt de l’utilisation du récepteur macrophagique CD206 comme marqueur diagnostique et comme cible à inhiber pour limiter le développement de la fibrose, 2) à étudier le rôle d’HSP27 présente spécifiquement dans le compartiment extracellulaire dans le développement de la fibrose pulmonaire, 3) à tester les effets d’un oligonucléotide antisens dirigé contre aB-crystallin pour s’opposer au développement de la maladie.Nos travaux ont permis de montrer l’augmentation de l’expression du récepteur macrophagique CD206 en cas de fibrose dans les macrophages pulmonaires humains et murins. Le traitement des macrophages par un radiotraceur dirigé sur le CD206, le tilmanocept permet de quantifier son expression, et celle-ci est diminuée par le nintédanib, et par un inhibiteur des macrophages M2, le tofacitinib. Le traitement par tofacitinib permet aussi de limiter le développement de la fibrose chez la souris, tout en limitant le recrutement des macrophages. Ce travail suggère l’utilité du CD206 pour le diagnostic de la FPI et l’intérêt de développer des inhibiteurs pour le traitement de la fibrose. Dans la 2è partie, mes travaux montrent qu’HSP27 est sécrétée par les cellules pulmonaires en conditions pro-fibrosantes, qu’elle est capable alors d’interagir avec les récepteurs TLR2 et TLR4. La conséquence est une potentialisation de la transformation myofibroblastique des cellules pulmonaires induite par le TGF-b1;. HSP27 sécrétée par les cellules pulmonaires induit aussi une activation des cellules macrophagiques et l’expression de cytokines pro-fibrosantes. Nous avons montré qu’HSP27 se comporterait comme un médiateur intercellulaire pro-fibrosant, et que son inhibition constituait un intérêt pour limiter le développement de la maladie. Dans la 3ème partie de ce travail, nous avons testé un oligonucléotide antisens dirigé contre aB-crystallin et modifié par conjugaison lipidique. Ce travail n’a pas montré l’intérêt de ce composé vis-à-vis de l’oligonucléotide de première génération pour limiter les processus profibrosants.En conclusion, mon travail a permis d’ouvrir de nouvelles pistes de diagnostic et de traitement en relation avec un récepteur macrophagique le CD206 et une protéine de choc thermique HSP27.

Heavy alcohol drinking alters lung immunity increasing the susceptibility to inflammatory and fibroproliferative conditions with poor prognoses. Although a sexually dimorphic effect was demonstrated in different organs, gender difference was not clearly demonstrated in lung immunity. Here, we focused on investigating the molecular and cellular effects of alcohol ingestion on lung immunity in male and female subjects using population-based human lung transcriptomics analysis and an experimental mouse model of chronic alcohol drinking. Human lung transcriptomics data were analyzed from 328 alcohol drinkers (249 males and 79 females) and 110 nondrinkers (53 males and 57 females) using Genotype-Tissue Expression (GTEx) project data. The translational relevance was established with the NIAAA alcohol-feeding model in mice. Flow cytometry and transcriptomics analyses in mice revealed a sexually dimorphic effect of chronic alcohol drinking on the lung immunity of both humans and mice. Dose dependently chronic alcohol drinking significantly down-regulated immune-related pathways only in male human subjects. Both myeloid and lymphoid cells were altered only in male lungs. In addition, the different subpopulations of lung macrophages, as well as their polarization (CD206/CD80), were impaired in male mice with a moderate effect in females. Transcriptomics analysis from humans and mice provided evidence that immunometabolic change is a central driver. The Branch Chain Amino Acid-mTOR signaling axis may serve as an upstream regulator of alcohol-induced dysregulation in lung immunity.