Project description:Connective tissues support organs and play crucial roles in development, homeostasis and fibrosis, yet our understanding of their formation is still limited. To gain insight into the molecular mechanisms of connective tissue specification, we selected five zinc finger transcription factors - OSR1, OSR2, EGR1, KLF2 and KLF4 - based on their expression patterns and/or known involvement in connective tissue subtype differentiation. RNA-seq and ChIP-seq profiling revealed a set of common genes regulated by all five transcription factors, which we propose as connective tissue core expression set. This common core was enriched in genes associated with axon guidance and myofibroblast signature, including fibrosis-related genes. In addition, each transcription factor regulated a specific set of signalling molecules and extracellular matrix components. This suggests a concept whereby local molecular niches can be created via the expression of specific transcription factors impinging on the specification of local microenvironments. The regulatory network established here identifies common and distinct molecular signatures of limb connective tissue subtypes, provides novel insight into the signalling pathways governing connective tissue specification, and serves as a resource for connective tissue development.
Project description:Connective tissues support organs and play crucial roles in development, homeostasis and fibrosis, yet our understanding of their formation is still limited. To gain insight into the molecular mechanisms of connective tissue specification, we selected five zinc finger transcription factors - OSR1, OSR2, EGR1, KLF2 and KLF4 - based on their expression patterns and/or known involvement in connective tissue subtype differentiation. RNA-seq and ChIP-seq profiling revealed a set of common genes regulated by all five transcription factors, which we propose as connective tissue core expression set. This common core was enriched in genes associated with axon guidance and myofibroblast signature, including fibrosis-related genes. In addition, each transcription factor regulated a specific set of signalling molecules and extracellular matrix components. This suggests a concept whereby local molecular niches can be created via the expression of specific transcription factors impinging on the specification of local microenvironments. The regulatory network established here identifies common and distinct molecular signatures of limb connective tissue subtypes, provides novel insight into the signalling pathways governing connective tissue specification, and serves as a resource for connective tissue development.
Project description:Patients with cystic fibrosis (CF) experience severe lung disease, including persistent infections, inflammation, and irreversible fibrotic remodelling of the airways. Although therapy with transmembrane conductance regulator (CFTR) protein modulators reached optimal results in terms of CFTR rescue, lung transplant remains the best line of care for patients in an advanced stage of CF. Indeed, chronic inflammation and tissue remodelling still represent stumbling blocks during treatment, and underlying mechanisms are still unclear. Nowadays, animal models are not able to replicate clinical features of the human disease and the conventional in vitro models lack a stromal compartment undergoing fibrotic remodelling. To address this gap, we show the development of a 3D full-thickness model of CF with a human bronchial epithelium differentiated on a connective airway tissue. We demonstrated that the epithelial cells not only underwent mucociliary differentiation but also migrated in the connective tissue and formed glandular structures. The presence of the connective tissue stimulated the pro-inflammatory behaviour of the epithelium, which activated the fibroblasts embedded into their own extracellular matrix (ECM). By varying the composition of the model with CF epithelial cells and a CF or healthy connective tissue, it was possible to replicate different moments of CF disease, as demonstrated by the differences in the transcriptome of the CF epithelium in the different conditions. The possibility to faithfully represent the crosstalk between epithelial and connective in CF through the full thickness model, along with inflammation and stromal activation, makes the model suitable to better understand mechanisms of disease genesis, progression, and response to therapy.
Project description:Although connective tissues play critical roles in development, our understanding of connective tissue fibroblast developmental programs lag behind that of other components of the musculoskeletal system mainly because fibroblasts are highly heterogeneous and poorly characterized. Combining single-cell RNA-sequencing-based strategies, including trajectory inference, and in situ hybridization analyses, we address the diversity of connective tissue fibroblasts and their developmental trajectories during chicken limb foetal development. We show that fibroblasts switch from a positional information to a lineage diversification program during their development. Muscle connective tissue and tendon contain several fibroblast populations that emerge asynchronously. In fine, these populations map to distinct layers, prefiguring the adult fibroblast layers. Populations that are close in transcriptional identity are found in neighboring layers. Altogether, we propose that the limb connective tissue is organised in a continuum of promiscuous fibroblasts identities, allowing for the robust and efficient connection of highly different tissues such as muscle, bone and skin.
2024-07-19 | GSE261503 | GEO
Project description:orbital adipose/connective tissue of thyroid-associated orbitopathy sequencing
Project description:Connective tissues support organs and play crucial roles in development, homeostasis and fibrosis, yet our understanding of their formation is still limited. To gain insight into the molecular mechanisms of connective tissue specification, we selected five zinc finger transcription factors - OSR1, OSR2, EGR1, KLF2 and KLF4 - based on their expression patterns and/or known involvement in connective tissue subtype differentiation. RNA-seq and ChIP-seq profiling revealed a set of common genes regulated by all five transcription factors, which we propose as connective tissue core expression set. This common core was enriched in genes associated with axon guidance and myofibroblast signature, including fibrosis-related genes. In addition, each transcription factor regulated a specific set of signalling molecules and extracellular matrix components. This suggests a concept whereby local molecular niches can be created via the expression of specific transcription factors impinging on the specification of local microenvironments. The regulatory network established here identifies common and distinct molecular signatures of limb connective tissue subtypes, provides novel insight into the signalling pathways governing connective tissue specification, and serves as a resource for connective tissue development.
Project description:After tissue injury mesenchymal progenitor subsets undergo a transient proliferative expansion, morphological transition and migration from their perivascular niche. Some of these subsets contribute enduring populations to connective tissue structures adjacent to muscle. To gain insights into gene accessibility to complement the single cell RNA seq expression data previously obtained and to uncover the lineage potential of MPs in this context, tdTomato positive cells were profiled by single cell ATAC sequencing.
Project description:Systemic sclerosis (SSc) is an autoimmune, connective tissue disease characterized by vasculopathy and fibrosis of the skin and internal organs. Trends in efficacy outcome measures favored tofacitnib. Baseline gene expression in fibroblast and keratinocyte subpopulations indicates interferon (IFN) activated gene expression.