| 1. |
- Jin, Yi, et al.
(författare)
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Endoglin prevents vascular malformation by regulating flow-induced cell migration and specification through VEGFR2 signalling
- 2017
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Ingår i: Nature Cell Biology. - : NATURE PUBLISHING GROUP. - 1465-7392 .- 1476-4679. ; 19:6, s. 639-652
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Tidskriftsartikel (refereegranskat)abstract
- Loss-of-function (LOF) mutations in the endothelial cell (EC)-enriched gene endoglin (ENG) cause the human disease hereditary haemorrhagic telangiectasia-1, characterized by vascular malformations promoted by vascular endothelial growth factor A (VEGFA). How ENG deficiency alters EC behaviour to trigger these anomalies is not understood. Mosaic ENG deletion in the postnatal mouse rendered Eng LOF ECs insensitive to flow-mediated venous to arterial migration. Eng LOF ECs retained within arterioles acquired venous characteristics and secondary ENG-independent proliferation resulting in arteriovenous malformation (AVM). Analysis following simultaneous Eng LOF and overexpression (OE) revealed that ENG OE ECs dominate tip-cell positions and home preferentially to arteries. ENG knockdown altered VEGFA-mediated VEGFR2 kinetics and promoted AKT signalling. Blockage of PI(3)K/AKT partly normalized flow-directed migration of ENG LOF ECs in vitro and reduced the severity of AVM in vivo. This demonstrates the requirement of ENG in flow-mediated migration and modulation of VEGFR2 signalling in vascular patterning.
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| 2. |
- Alvarez, Alberto, et al.
(författare)
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VEGF Receptor Tyrosine Kinases : Key Regulators of Vascular Function
- 2017
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Ingår i: Protein Kinases In Development And Disease. - : Elsevier. - 9780128015131 ; 123, s. 433-
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Bokkapitel (refereegranskat)abstract
- Vascular endothelial growth factor receptor (VEGFR) tyrosine kinases are key regulators of vascular development in vertebrates. Their activation is regulated through a family of secreted glycoproteins, the vascular endothelial growth factors (VEGFs). Expression, proteolytic processing, and diffusion range of VEGF proteins need to be tightly regulated, due to their crucial roles in development. While some VEGFs form concentration gradients across developing tissues and act as morphogenes, others function as inhibitors of receptor activation and downstream signaling. Ligand-induced receptor dimerization leads to activation of the intrinsic tyrosine kinase activity, which results in autophosphorylation of the receptors and in turn triggers the recruitment of interacting proteins as well as the initiation of downstream signaling. Although many biochemical details of VEGFR signaling have been revealed, the in vivo relevance of certain signaling aspects still remains to be demonstrated. Here, we highlight basic principles of VEGFR signaling and discuss its crucial role during development of the vascular system in mammals.
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| 3. |
- Fernandez-Chacon, Macarena, et al.
(författare)
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Incongruence between transcriptional and vascular pathophysiological cell states
- 2023
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Ingår i: NATURE CARDIOVASCULAR RESEARCH. - : SPRINGERNATURE. - 2731-0590. ; 2:6, s. 530-549
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Tidskriftsartikel (refereegranskat)abstract
- The Notch pathway is a major regulator of endothelial transcriptional specification. Targeting the Notch receptors or Delta-like ligand 4 (Dll4) dysregulates angiogenesis. Here, by analyzing single and compound genetic mutants for all Notch signaling members, we find significant differences in the way ligands and receptors regulate liver vascular homeostasis. Loss of Notch receptors caused endothelial hypermitogenic cell-cycle arrest and senescence. Conversely, Dll4 loss triggered a strong Myc-driven transcriptional switch inducing endothelial proliferation and the tip-cell state. Myc loss suppressed the induction of angiogenesis in the absence of Dll4, without preventing the vascular enlargement and organ pathology. Similarly, inhibition of other pro-angiogenic pathways, including MAPK/ERK and mTOR, had no effect on the vascular expansion induced by Dll4 loss; however, anti-VEGFA treatment prevented it without fully suppressing the transcriptional and metabolic programs. This study shows incongruence between single-cell transcriptional states, vascular phenotypes and related pathophysiology. Our findings also suggest that the vascular structure abnormalization, rather than neoplasms, causes the reported anti-Dll4 antibody toxicity. Fernandez-Chacon et al. use imaging and scRNA-seq after targeting multiple Notch genes and angiogenic signaling pathways to find that the function of these pathways in vascular pathophysiology cannot be predicted by assessing transcriptional states.
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| 4. |
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| 5. |
- Gladh, Hanna, et al.
(författare)
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Mice Lacking Platelet-Derived Growth Factor D Display a Mild Vascular Phenotype
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor D (PDGF-D) is the most recently discovered member of the PDGF family. PDGF-D signals through PDGF receptor beta, but its biological role remains largely unknown. In contrast to other members of the PDGF family of growth factors, which have been extensively investigated using different knockout approaches in mice, PDGF-D has until now not been characterized by gene inactivation in mice. Here, we present the phenotype of a constitutive Pdgfd knockout mouse model (Pdgfd(-/-)), carrying a LacZ reporter used to visualize Pdgfd promoter activity. Inactivation of the Pdgfd gene resulted in a mild phenotype in C57BL/6 mice, and the offspring was viable, fertile and generally in good health. We show that Pdgfd reporter gene activity was consistently localized to vascular structures in both postnatal and adult tissues. The expression was predominantly arterial, often localizing to vascular bifurcations. Endothelial cells appeared to be the dominating source for Pdgfd, but reporter gene activity was occasionally also found in sub-populations of mural cells. Tissue-specific analyses of vascular structures revealed that NG2-expressing pericytes of the cardiac vasculature were disorganized in Pdgfd(-/-) mice. Furthermore, Pdgfd(-/-) mice also had a slightly elevated blood pressure. In summary, the vascular expression pattern together with morphological changes in NG2-expressing cells, and the increase in blood pressure, support a function for PDGF-D in regulating systemic arterial blood pressure, and suggests a role in maintaining vascular homeostasis.
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| 6. |
- Jaff, Nasren, et al.
(författare)
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Transcriptomic analysis of the harvested endothelial cells in a swine model of mechanical thrombectomy
- 2018
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Ingår i: Neuroradiology. - : SPRINGER. - 0028-3940 .- 1432-1920. ; 60:7, s. 759-768
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Tidskriftsartikel (refereegranskat)abstract
- In mechanical thrombectomy (MT) for ischemic stroke, endothelial cells (ECs) from intracranial blood vessels adhere to the stent retriever device and can be harvested. However, understanding the molecular biology and the role of the endothelium in different pathological conditions remains insufficient. The purpose of the study was to characterize and analyze the molecular aspect of harvested ECs using cell culture and transcriptomic techniques in an MT swine model relevant to clinical ischemic stroke. In swine, preformed thrombi were injected into the external carotid and subclavian arteries to occlude their branches. MT was performed according to clinical routine. The stent retriever device and thrombus were treated with cell dissociation buffer. The resulting cell suspension was analyzed by immunohistochemistry and was cultured. Cultured cells were analyzed using single-cell RNA sequencing (scRNA-seq) after fluorescence-activated cell sorting (FACS). A total number of 37 samples were obtained containing CD31-positive cells. Cell culture was successful in 90% of samples, and the cells expressed multiple typical EC protein markers. Eighty-nine percent of the sorted cells yielded high-quality transcriptomes, and single-cell transcriptomes from cultured cells showed that they expressed typical endothelial gene patterns. Gene expression analysis of ECs from an occluded artery did not show distinctive clustering into subtypes. ECs harvested during MT can be cultured and analyzed using single-cell transcriptomic techniques. This analysis can be implemented in clinical practice to study the EC gene expression of comorbidities, such as hypertension, diabetes mellitus, and metabolic syndrome, in patients suffering from acute ischemic stroke.
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| 7. |
- Lendahl, Urban, et al.
(författare)
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Identification, discrimination and heterogeneity of fibroblasts
- 2022
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 13:1
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Forskningsöversikt (refereegranskat)abstract
- Fibroblasts, the principal cell type of connective tissue, secrete extracellular matrix components during tissue development, homeostasis, repair and disease. Despite this crucial role, the identification and distinction of fibroblasts from other cell types are challenging and laden with caveats. Rapid progress in single-cell transcriptomics now yields detailed molecular portraits of fibroblasts and other cell types in our bodies, which complement and enrich classical histological and immunological descriptions, improve cell class definitions and guide further studies on the functional heterogeneity of cell subtypes and states, origins and fates in physiological and pathological processes. In this review, we summarize and discuss recent advances in the understanding of fibroblast identification and heterogeneity and how they discriminate from other cell types. In this review, the authors look at how recent progress in single-cell transcriptomics complement and enrich the classical, largely morphological, portraits of fibroblasts. The detailed molecular information now available provides new insights into fibroblast identity, heterogeneity and function.
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| 8. |
- Liu, Jianping, et al.
(författare)
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A human cell type similar to murine central nervous system perivascular fibroblasts
- 2021
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Ingår i: Experimental Cell Research. - : Elsevier. - 0014-4827 .- 1090-2422. ; 402:2
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Tidskriftsartikel (refereegranskat)abstract
- The brain vasculature has several specific features, one of them being the blood-brain barrier (BBB), which supports and protects the brain by allowing for the passage of oxygen and nutrients, while at the same time preventing passage of pathogens and toxins. The BBB also prevents efficient delivery of drugs to the brain, e.g. for treatment of brain tumors. In the murine brain, perivascular fibroblasts were recently identified as a novel potential constituent of the BBB. Here we present the existence of human cells that could be the equivalent to the murine brain perivascular fibroblasts. Using RNA sequencing, we show a similar transcriptomic profile of cultured human brain cells and murine perivascular fibroblasts. These data open up a window for new hypotheses on cell types involved in human CNS diseases.
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| 9. |
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| 10. |
- Muhl, Lars, et al.
(författare)
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A single-cell transcriptomic inventory of murine smooth muscle cells
- 2022
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Ingår i: Developmental Cell. - : Elsevier. - 1534-5807 .- 1878-1551. ; 57:20, s. 2426-
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Tidskriftsartikel (refereegranskat)abstract
- Smooth muscle cells (SMCs) execute important physiological functions in numerous vital organ systems, including the vascular, gastrointestinal, respiratory, and urogenital tracts. SMC differ morphologically and functionally at these different anatomical locations, but the molecular underpinnings of the differences remain poorly understood. Here, using deep single-cell RNA sequencing combined with in situ gene and pro-tein expression analysis in four murine organs-heart, aorta, lung, and colon-we identify a molecular basis for high-level differences among vascular, visceral, and airway SMC, as well as more subtle differences between, for example, SMC in elastic and muscular arteries and zonation of elastic artery SMC along the direction of blood flow. Arterial SMC exhibit extensive organotypic heterogeneity, whereas venous SMC are similar across organs. We further identify a specific SMC subtype within the pulmonary vasculature. This comparative SMC cross-organ resource offers insight into SMC subtypes and their specific functions.
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