Project description:Asthma is a chronic inflammatory respiratory disease well-known to demonstrate sexual dimorphism in incidence and severity, although the mechanisms causing these differ-ences remains incompletely understood. RPS4X and RPS4Y1 are X and Y-chromosome-linked genes coding ribosomal subunits previously associated with in-flammation, airway remodelling and asthma medication efficacy. Particularly, RPS4Y1 has been under-investigated within the context of disease, with little examination of molecular mechanisms and pathways regulated by this gene. The ribosome, a vital cellular machinery, facilitates the translation of mRNA into peptides and then proteins. Imbalance or dysfunction in ribosomal components may lead to malfunctioning proteins. Using CRISPR-Cas9 knockout cellular models for RPS4Y1 and RPS4X, we characterised the function of RPS4Y1 in the context of the asthma-relevant processes, inflammation and fibrosis. No viable RPS4X knockouts could be generated. We highlight novel molecular mechanisms such as specific translation of IL6 and tenascin-C mRNA by RPS4Y1 con-taining ribosomes. Furthermore, an RPS4Y1-centric gene signature correlates with clinical lung function measurements specifically in adult male asthma patients. These findings inform the current understanding of sex differences in asthma, as females do not produce the RPS4Y1 protein. Therefore, the pathologically relevant functions of RPS4Y1 may contribute to the complex sexually dimorphic pattern of asthma susceptibility and pro-gression.
Project description:Pentraxin-2 (PTX-2) is a constitutive, anti-inflammatory, innate immune plasma protein whose circulating level is decreased in chronic human fibrotic diseases. Recent studies indicate that systemic delivery of recombinant PTX-2 inhibits inflammatory diseases associated with fibrosis by blocking pro-fibrotic macrophage activation and promoting anti-inflammatory and regulatory macrophages. Here we show that recombinant human PTX-2 (rhPTX-2) retards the progression of chronic kidney disease in Col4a3 mutant mice that develop Alport syndrome, reducing blood markers of kidney failure, enhancing lifespan by 20%, and improving histological signs of disease. Exogenously-delivered rhPTX-2 is detected in macrophages but is also found in tubular epithelial cells where it counteracts macrophage activation and is cytoprotective for the epithelium. We performed transcriptional profiling of whole kidney homogenates and human proximal tubule epithelial cells (PTECs) to identify pathways differentially activated or suppressed in response to treatment with PTX-2. Computational analysis of genes regulated by rhPTX-2 identified the transcriptional regulator c-Jun and its binding partners, which form AP-1 complexes, as a central target for the function of rhPTX-2. Accordingly, PTX-2 attenuates c-Jun activation and reduces expression of AP-1 dependent inflammatory genes in both monocytes and epithelium. Our studies therefore identify rhPTX-2 as a potential therapy for chronic fibrotic disease of the kidney and an important inhibitor of pathological c-Jun signaling in this setting. 1. Total RNA from whole kidney homogenates of wildtype (Col4a3+/+) and knockout (Col4a3-/-) mice treated with PTX-2 was isolated and hybidized to Illumina Mouse WG-6 v2 Expression BeadChips. 2. Total RNA from human proximal tubules treated with plasma and PTX-2 was isolated and hybidized to Illumina HumanHT-12 v4 Expression BeadChips.
Project description:We isolated non-hematopoietic cells from fibrotic and non-fibrotic mouse bone marrow and perfomed scRNAseq on them. We identified 8 different stromal populations. Our analysis revealed two distinct mesenchymal stromal cells (MSC) subsets as pro-fibrotic cells. MSCs were functionally reprogrammed in a stagedependent manner with loss of their progenitor status and initiation of differentiation in the prefibrotic stage and acquisition of a pro-fibrotic and inflammatory phenotype in the fibrotic stage. In parallel, IL-33-expressing myelinating Schwann cell progenitors expanded, likely as a repair mechanism for the previously described neuropathy in MPN.
Project description:We isolated non-hematopoietic cells from fibrotic and non-fibrotic human bone marrow and perfomed scRNAseq on them. We identified 3 different stromal populations and 2 populations of hematopoietic progenitors. Our analysis revealed mesenchymal stromal cells (MSC) as pro-fibrotic cells. MSCs were functionally reprogrammed with loss of their progenitor status and acquisition of a pro-fibrotic phenotype in the fibrotic bone marrow. Additionally, stromal cells exhibited an upregulation of pro-inflammatory mediators like S100A8/A9.
Project description:YAP/TAZ are transcription co-factors recently described responsive to pro-inflammatory cytokines and involved in inflammatory-related disorders. However, the role of tumor necrosis factor (TNF), a major pro-inflammatory cytokine, on YAP signaling is not well understood and controversial. Here, we observe in vitro, using wild type and YAP knockout HEK293 cells, that TNF triggers YAP nuclear translocation and transcriptional activity, thus being dependent on Rho family of GTPases. In response to TNF, YAP transcriptional activity orientates cell fate toward survival. Transcriptional analysis with Nanostring technology reveals that YAP modulates TNF-induced increase in fibro-inflammatory pathways such as NF-κB, inflammasomes, cytokines or chemokines signaling as well as pro-fibrotic pathways involving TGF-β and extracellular matrix remodeling. Therefore, in response to TNF, YAP acts as a sustainer of the inflammatory response and as a molecular link between inflammation and fibrotic processes. This work identifies that YAP is critical to drive several biological effects of TNF which are involved in cancer and inflammatory disorders.
Project description:Fibrosis is a hallmark feature of airway remodeling in asthma. However, the exact molecular mechanisms driving its development and progression remain inadequately understood. Interleukin-5 (IL-5) plays a potent role in the inflammatory response associated with eosinophils and asthma pathophysiology, but its direct impact on lung fibroblasts and contribution to fibrosis have yet to be fully explored. In our study, we investigated the pro-fibrotic effects of IL-5 on human lung fibroblasts derived from asthmatic and normal subjects. Following IL-5 stimulation, these fibroblasts were subjected to a series of experiments to assess IL-5’s impact on fibrosis. Our findings reveal that IL-5 triggers the release of several extracellular matrix (ECM) components, and disrupts the balance of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) . This imbalance further disrupts the MMP/TIMP ratio. Additionally, IL-5 stimulation promotes the release of pro-inflammatory and pro-fibrotic cytokines, Overall, these findings indicate a novel pro-fibrotic role of IL-5 through its direct action on lung fibroblasts, offering valuable insights into the therapeutic potential of targeting IL-5 to mitigate or possibly reverse airway remodeling in asthma.
Project description:Rationale: Fibrotic hypersensitivity pneumonitis is a debilitating interstitial lung disease driven by incompletely understood immune mechanisms. Objectives: To elucidate immune aberrations in fibrotic hypersensitivity pneumonitis in single-cell resolution. Methods: Single-cell 5’ RNA sequencing was conducted on peripheral blood mononuclear cells and bronchoalveolar lavage cells obtained from 45 patients with fibrotic hypersensitivity pneumonitis, 63 idiopathic pulmonary fibrosis, 4 non-fibrotic hypersensitivity pneumonitis, and 36 healthy controls in the United States and Mexico. Analyses included differential gene expression (Seurat), transcription factor activity imputation (DoRothEA-VIPER), and trajectory analyses (Monocle3/Velocyto-scVelo-CellRank). Measurements and Main Results: Overall, 501,534 peripheral blood mononuclear cells from 110 patients and controls and 88,336 bronchoalveolar lavage cells from 19 patients were profiled. Compared to controls, fibrotic hypersensitivity pneumonitis has elevated classical monocytes (adjusted-p=2.5e-3) and are enriched in CCL3hi/CCL4hi and S100Ahi classical monocytes (adjusted-p<2.2e-16). Trajectory analyses demonstrate that S100Ahi classical monocytes differentiate into SPP1hi lung macrophages associated with fibrosis. Compared to both controls and idiopathic pulmonary fibrosis, fibrotic hypersensitivity pneumonitis patient cells are significantly enriched in GZMhi cytotoxic T cells. These cells exhibit transcription factor activities indicative of TGFb and TNFa/NFkB pathways. These results are publicly available at https://ildimmunecellatlas.org. Conclusions: Single-cell transcriptomics of fibrotic hypersensitivity pneumonitis patients uncovered novel immune perturbations, including previously undescribed increases in GZMhi cytotoxic CD4+ and CD8+ T cells – reflecting this disease’s unique inflammatory T-cell driven nature – as well as increased S100Ahi and CCL3hi/CCL4hi classical monocytes also observed in idiopathic pulmonary fibrosis. Both cell populations may guide the development of new biomarkers and therapeutic interventions.
Project description:Objective: To evaluate gene expression profiles in patients with advanced cirrhosis compared with healthy controls (HC). Results: Patients with advanced cirrhosis exhibit an unbalanced systemic response involving pro-fibrotic / protective signatures that could be contributing to the pathogenesis of cirrhosis and also to that of the extra-hepatic complications of this disease.
Project description:Peripheral serotonin (5-hydroxytryptamine, 5HT) regulates cell growth and differentiation in numerous cell types through engagement of seven types of cell surface receptors (HTR1-7). Deregulated 5HT/HTR levels contribute to pathology in chronic inflammatory diseases, with macrophages being relevant targets for the physio-pathological effects of 5HT. In fact, 5HT skews human macrophage polarization through engagement of HTR2B and HTR7 receptors. We now report that 5HT primes macrophages for reduced pro-inflammatory cytokine production and IFN type I-mediated signalling, and promotes an anti-inflammatory and pro-fibrotic gene signature in human macrophages. The acquisition of the 5HT-dependent gene profile primarily depends on the HTR7 receptor and HTR7-initiated PKA-dependent signaling. In line with the transcriptional results, 5HT upregulates TGFb1 production by human macrophages in an HTR7- and PKA-dependent manner, whereas the absence of Htr7 in vivo results in diminished macrophage infiltration and collagen deposition in a mouse model of skin fibrosis. Our results indicate that the anti-inflammatory and pro-fibrotic activity of 5HT is primarily mediated through the HTR7-PKA axis, and that HTR7 contributes to pathology in fibrotic diseases.