Project description:To determine whether dural fibroblasts (DuF) under IL-1β-mediated wound conditions, release pro-angiogenic factors, and promote angiogenic properties in human endothelial cells (ECs). DuF were stimulated by pro-inflammatory cytokines interleukin (IL)-1β, and transcriptome sequencing was then used to identify the differentially expressed genes in the DuF with/without IL-1β stimulation (DuFCon/DuFIL1b)
Project description:Encephaloduroarteriosynangiosis (EDAS), an indirect anastomosis procedure, is widely accepted as a primary treatment for moyamoya disease (MMD) to improve collateral blood flow. During surgical intervention, dural fibroblasts (DuF) are thought to produce various proteins that create an angiogenic microenvironment. However, the biophysiological evidence supporting the angiogenic properties of this surgical technique has not been thoroughly elucidated. The purpose of these studies was to determine whether DuF releases pro-angiogenic factors and chemokines and promotes angiogenic properties in human endothelial cells (ECs) under IL-1β-mediated wound conditions, which are expected to occur during the process of neo-vascularization within the dura mater. Furthermore, a microfluidic chemotaxis platform was implemented to investigate the angiogenic activity of ECs in response to a reconstituted dura model. Transcriptome sequencing revealed that IL-1β stimulation on DuF induced a significant upregulation of various pro-angiogenic genes, including IL-6, IL-8, CCL-2, CCL-5, SMOC-1, and SCG-2 (p < 0.05). Moreover, compared to ECs cultured in naïve media or naïve DuF media, those exposed to IL-1β-DuF conditioned media expressed higher mRNA and protein levels of these pro-angiogenic factors (p < 0.001). ECs co-cultured with IL-1β-DuF also exhibited considerable migration on the microfluidic chemotaxis platform. Furthermore, the chemotactic effects on the ECs were reduced upon neutralization of IL-8 or inhibition of NF-κB signaling. Our findings demonstrate that IL-1β-DuFs release factors that activate and enhance the angiogenic properties of ECs. These results suggest a potential interaction between DuF and ECs following EDAS for MMD, and these components could be targeted for the development of therapeutic biomarkers.
Project description:The aim of our study was to determin if papillary and reticular fibroblasts cell sheets expressed distinct genes involved in angiogenesis regulation and extracellular matrix. Thanks to our RNAseq analyssis, we demonstrated that papillary and reticular fibroblasts express specific signature of genes related to secreted angiogenic regulators and matrisome genes, suggesting that each subtype of fibroblasts differently regulate the formation of capillary via secreted factors and the microenvironment they generate. We confirmed this hypothesis with functional angiogenesis model in vitro. Overall, we show that papillary fibroblasts have a greater angiogenic potential and support the formation of dense branched vascular netword. On the other hand, reticular fibroblasts allow the formation of fewer vessel of larger diameter. This resultats are coherent with native skin vasculature and suggest that each fibroblasts subtypes play a role in regulating skin vascularisation.
Project description:To investigate cellular landscape of dural immune cells, dural immune cells from 30 P28 male mice and 30 P7 male mice were FACS sorted and single-cell RNA seqs were performed
Project description:Each organ of the human body requires locally-adapted blood vessels1–3. The gain of such organotypic vessel specializations is often deemed molecularly unrelated to the process of organ vascularization. Opposing this model, we reveal a molecular mechanism for brain-specific angiogenesis that operates under the control of Wnt7a/b ligands, well-known blood-brain barrier maturation signals4–6. The control mechanism relies on Wnt7a/b-dependent expression of Mmp25 in brain endothelial cells. This hitherto poorly characterized GPI-anchored matrix metalloproteinase is selectively required in endothelial tip cells to enable their initial migration across the pial basement membrane which lines the brain surface, and whose distinctive molecular composition is controlled by embryonic pial fibroblasts. Mechanistically, Mmp25 confers brain invasive competence by cleaving the pial basement membrane-enriched Col4a5/6 within a short non-collagenous region of the central helical part of the heterotrimer. Upon genetic interference with pial basement membrane composition, the Wnt/β-catenin-dependent organotypic control of brain angiogenesis is lost, resulting in a properly patterned, yet blood-brain barrier-defective cerebrovasculature. This work reveals an organ-specific angiogenesis mechanism, sheds light on tip cell mechanistic angiodiversity, and thereby illustrates how organs, by imposing local constraints on angiogenic tip cells, can select vessels matching their distinctive physiological requirements.
Project description:To investigate different responses of dural macrophage subsets to systemic viral infection, we collected the dura mater from mice 12 h after systemic LCMV infection and macrophages were sorted
Project description:While macrophages in the meningeal compartments of the central nervous system (CNS) has been comprehensively characterized under steady state, studying their contribution to physiological and pathological processes has been severely hampered by the lack of specific targeting tools in vivo. Recent findings have shown that the dural sinus and its adjacent lymphatic vessels act as a neuroimmune interface. Notably, the cellular and functional heterogeneity of extrasinusoidal dural macrophages outside this immune hub is currently unclear. Therefore, we comprehensively characterized these cells using single-cell transcriptomics, fate mapping, confocal imaging, clonal analysis and transgenic mouse lines. Extrasinusoidal dural macrophages were clearly distinct from leptomeningeal and CNS parenchymal macrophages in terms of their origin, expansion kinetics and transcriptional profiles. Lastly, functional studies demonstrated that during autoimmune neuroinflammation, extrasinusoidal dural macrophages perform efferocytosis of granulocytes. Our results highlight a previously unappreciated myeloid cell diversity and provide insights into the brain’s innate immune system.