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- Benedito, Rui, et al.
(författare)
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Notch as a hub for signaling in angiogenesis
- 2013
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827 .- 1090-2422. ; 319:9, s. 1281-1288
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Forskningsöversikt (refereegranskat)
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| 2. |
- Castro, Marco
(författare)
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Cellular and molecular roles for CDC42 in angiogenesis
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Angiogenesis is the physiological process by which new blood vessels grow and critically depends on the interplay between the major vascular units: endothelial cells, pericytes and smooth muscle cells. Dysfunction and mispatterning of blood vessels are associated with the progression of many vascular complications, and therefore, understanding the causes of vascular dysmorphia is a central question in vascular biology. CDC42 is a small GTPase known to regulate a diverse array of cellular functions in endothelial cells, however, its contribution to vascular development in vivo remains incompletely understood. The overall aim of this thesis work is to investigate the role of CDC42 during angiogenesis in the central nervous system, using an inducible endothelial-specific Cdc42 knockout model.In Paper I, I investigate which CDC42-dependent functions operational in vivo are of relevance for angiogenic sprouting, and how they contribute to blood vessel morphogenesis. Analysis of distinct cellular behaviours shows that CDC42 is critically required for proper EC dispersion in the vasculature and that it regulates sprouting angiogenesis and endothelial axial polarity.In Paper II, I explore the in vivo consequences of Cdc42 deletion for vascular morphogenesis, leading to the appearance of capillary-venous malformations in the brain, resembling the human disease of cerebral cavernous malformations. I aimed to understand how this type of vascular malformations arise and was been able to identify the MEKK3-ERK5-KLF2/4 molecular signalling pathway and other cellular events as the trigger factors that may be responsible for these malformations.Paper III redirects focus to the physiological roles of another protein, GPR116, in modulating blood-brain barrier permeability and pathologic angiogenesis in the central nervous system.In summary, these findings reveal crucial roles of endothelial CDC42 during angiogenesis and further uncover its potential relevance in the molecular pathogenesis of cerebrovascular malformations.
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| 3. |
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| 4. |
- 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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| 5. |
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| 6. |
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| 7. |
- Monelli, Erika, et al.
(författare)
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Angiocrine polyamine production regulates adiposity
- 2022
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Ingår i: Nature Metabolism. - : Springer Nature. - 2522-5812. ; 4:3, s. 327-
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Tidskriftsartikel (refereegranskat)abstract
- Reciprocal interactions between endothelial cells (ECs) and adipocytes are fundamental to maintain white adipose tissue (WAT) homeostasis, as illustrated by the activation of angiogenesis upon WAT expansion, a process that is impaired in obesity. However, the molecular mechanisms underlying the crosstalk between ECs and adipocytes remain poorly understood. Here, we show that local production of polyamines in ECs stimulates adipocyte lipolysis and regulates WAT homeostasis in mice. We promote enhanced cell-autonomous angiogenesis by deleting Pten in the murine endothelium. Endothelial Pten loss leads to a WAT-selective phenotype, characterized by reduced body weight and adiposity in pathophysiological conditions. This phenotype stems from enhanced fatty acid beta-oxidation in ECs concomitant with a paracrine lipolytic action on adipocytes, accounting for reduced adiposity. Combined analysis of murine models, isolated ECs and human specimens reveals that WAT lipolysis is mediated by mTORC1-dependent production of polyamines by ECs. Our results indicate that angiocrine metabolic signals are important for WAT homeostasis and organismal metabolism. Endothelial cells in white adipose tissue are shown to produce polyamines, which regulate adipocyte lipolysis, thus demonstrating how local angiocrine signals contribute to healthy adipose tissue homeostasis.
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| 8. |
- Zarkada, Georgia, et al.
(författare)
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Chylomicrons Regulate Lacteal Permeability and Intestinal Lipid Absorption
- 2023
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Ingår i: Circulation Research. - : Lippincott Williams & Wilkins. - 0009-7330 .- 1524-4571. ; 133:4, s. 333-349
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Tidskriftsartikel (refereegranskat)abstract
- Background: Lymphatic vessels are responsible for tissue drainage, and their malfunction is associated with chronic diseases. Lymph uptake occurs via specialized open cell-cell junctions between capillary lymphatic endothelial cells (LECs), whereas closed junctions in collecting LECs prevent lymph leakage. LEC junctions are known to dynamically remodel in development and disease, but how lymphatic permeability is regulated remains poorly understood.Methods: We used various genetically engineered mouse models in combination with cellular, biochemical, and molecular biology approaches to elucidate the signaling pathways regulating junction morphology and function in lymphatic capillaries.Results: By studying the permeability of intestinal lacteal capillaries to lipoprotein particles known as chylomicrons, we show that ROCK (Rho-associated kinase)-dependent cytoskeletal contractility is a fundamental mechanism of LEC permeability regulation. We show that chylomicron-derived lipids trigger neonatal lacteal junction opening via ROCK-dependent contraction of junction-anchored stress fibers. LEC-specific ROCK deletion abolished junction opening and plasma lipid uptake. Chylomicrons additionally inhibited VEGF (vascular endothelial growth factor)-A signaling. We show that VEGF-A antagonizes LEC junction opening via VEGFR (VEGF receptor) 2 and VEGFR3-dependent PI3K (phosphatidylinositol 3-kinase)/AKT (protein kinase B) activation of the small GTPase RAC1 (Rac family small GTPase 1), thereby restricting RhoA (Ras homolog family member A)/ROCK-mediated cytoskeleton contraction.Conclusions: Our results reveal that antagonistic inputs into ROCK-dependent cytoskeleton contractions regulate the interconversion of lymphatic junctions in the intestine and in other tissues, providing a tunable mechanism to control the lymphatic barrier.
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