Similar Datasets
Project description:Tight control of cell fate choices is crucial for proper vessel development. Here we show that Rnf20, the major E3 ubiquitin ligase of histone H2B, plays a key role in the tight control of VEGF-Notch signaling, which is crucial for proper vessel growth and patterning, as well as for the dynamic tip-stalk cell fate at the vascular front. We demonstrate that Rnf20 is dynamically expressed in the developing retina and controls vessel growth through two distinct modes of action. On the one hand, it restricts gene activation by the endothelial transcription factor ERG and on the other, it orchestrates large-scale mRNA processing events, which change the bioavailability and function of critical pro-angiogenic factors. We show that Rnf20 plays a key role for the upregulation of both VEGFR2 through alternative polyadenylation and VEGFA through intron inclusion, as well as for suppressing the ability of Notch1 to bind to chromatin. Interestingly, perturbations of RNF20 have been associated with complex cardiovascular malformations in human patients, suggesting that delineating the mechanisms that control Rnf20 expression and activity may provide new insights into diseases caused by vascular dysfunction.
2024-08-18 | GSE212522 | GEO
Project description:Tight control of cell fate choices is crucial for proper vessel development. Here we show that Rnf20, the major E3 ubiquitin ligase of histone H2B, plays a key role in the tight control of VEGF-Notch signaling, which is crucial for proper vessel growth and patterning, as well as for the dynamic tip-stalk cell fate at the vascular front. We demonstrate that Rnf20 is dynamically expressed in the developing retina and controls vessel growth through two distinct modes of action. On the one hand, it restricts gene activation by the endothelial transcription factor ERG and on the other, it orchestrates large-scale mRNA processing events, which change the bioavailability and function of critical pro-angiogenic factors. We show that Rnf20 plays a key role for the upregulation of both VEGFR2 through alternative polyadenylation and VEGFA through intron inclusion, as well as for suppressing the ability of Notch1 to bind to chromatin. Interestingly, perturbations of RNF20 have been associated with complex cardiovascular malformations in human patients, suggesting that delineating the mechanisms that control Rnf20 expression and activity may provide new insights into diseases caused by vascular dysfunction.
2024-08-18 | GSE212520 | GEO
Project description:Tight control of cell fate choices is crucial for proper vessel development. Here we show that Rnf20, the major E3 ubiquitin ligase of histone H2B, plays a key role in the tight control of VEGF-Notch signaling, which is crucial for proper vessel growth and patterning, as well as for the dynamic tip-stalk cell fate at the vascular front. We demonstrate that Rnf20 is dynamically expressed in the developing retina and controls vessel growth through two distinct modes of action. On the one hand, it restricts gene activation by the endothelial transcription factor ERG and on the other, it orchestrates large-scale mRNA processing events, which change the bioavailability and function of critical pro-angiogenic factors. We show that Rnf20 plays a key role for the upregulation of both VEGFR2 through alternative polyadenylation and VEGFA through intron inclusion, as well as for suppressing the ability of Notch1 to bind to chromatin. Interestingly, perturbations of RNF20 have been associated with complex cardiovascular malformations in human patients, suggesting that delineating the mechanisms that control Rnf20 expression and activity may provide new insights into diseases caused by vascular dysfunction.
2024-08-18 | GSE225943 | GEO
Project description:Tight control of cell fate choices is crucial for proper vessel development. Here we show that Rnf20, the major E3 ubiquitin ligase of histone H2B, plays a key role in the tight control of VEGF-Notch signaling, which is crucial for proper vessel growth and patterning, as well as for the dynamic tip-stalk cell fate at the vascular front. We demonstrate that Rnf20 is dynamically expressed in the developing retina and controls vessel growth through two distinct modes of action. On the one hand, it restricts gene activation by the endothelial transcription factor ERG and on the other, it orchestrates large-scale mRNA processing events, which change the bioavailability and function of critical pro-angiogenic factors. We show that Rnf20 plays a key role for the upregulation of both VEGFR2 through alternative polyadenylation and VEGFA through intron inclusion, as well as for suppressing the ability of Notch1 to bind to chromatin. Interestingly, perturbations of RNF20 have been associated with complex cardiovascular malformations in human patients, suggesting that delineating the mechanisms that control Rnf20 expression and activity may provide new insights into diseases caused by vascular dysfunction.
2024-08-18 | GSE212523 | GEO
Project description:Vascular endothelial growth factor (VEGF) is the master regulator of angiogenesis, whose best-understood mechanism is sprouting. However, therapeutic VEGF delivery to ischemic muscle induces angiogenesis by the alternative process of intussusception, or vascular splitting, whose molecular regulation is essentially unknown. Here, we identify ephrinB2/EphB4 signaling as a key regulator of intussusceptive angiogenesis and its outcome under therapeutically relevant conditions. EphB4 signaling fine-tunes the degree of endothelial proliferation induced by specific VEGF doses during the initial stage of circumferential enlargement of vessels, thereby limiting their size and subsequently enabling successful splitting into normal capillary networks. Mechanistically, EphB4 neither inhibits VEGF-R2 activation by VEGF nor its internalization, but it modulates VEGF-R2 downstream signaling through phospho-ERK1/2. In vivo inhibitor experiments show that ERK1/2 activity is required for EphB4 regulation of VEGF-induced intussusceptive angiogenesis. Lastly, after clinically relevant VEGF gene delivery with adenoviral vectors, pharmacological stimulation of EphB4 normalizes dysfunctional vascular growth in both normoxic and ischemic muscle. These results identify EphB4 as a druggable target to modulate the outcome of VEGF gene delivery and support further investigation of its therapeutic potential.
| S-EPMC5934775 | biostudies-literature
Project description:Cerebral cavernous malformations (CCM) are frequent vascular abnormalities caused by mutations in one of the CCM genes. CCM1 (also known as KRIT1) stabilizes endothelial junctions and is essential for vascular morphogenesis in mouse embryos. However, cellular functions of CCM1 during the early steps of the CCM pathogenesis remain unknown. We show here that CCM1 represents an antiangiogenic protein to keep the human endothelium quiescent. CCM1 inhibits endothelial proliferation, apoptosis, migration, lumen formation, and sprouting angiogenesis in primary human endothelial cells. CCM1 strongly induces DLL4-NOTCH signaling, which promotes AKT phosphorylation but reduces phosphorylation of the mitogen-activated protein kinase ERK. Consistently, blocking of NOTCH activity alleviates CCM1 effects. ERK phosphorylation is increased in human CCM lesions. Transplantation of CCM1-silenced human endothelial cells into SCID mice recapitulates hallmarks of the CCM pathology and serves as a unique CCM model system. In this setting, the multikinase inhibitor Sorafenib can ameliorate loss of CCM1-induced excessive microvascular growth, reducing the microvessel density to levels of normal wild-type endothelial cells. Collectively, our data suggest that the origin of CCM lesions is caused by perturbed Notch signaling-induced excessive capillary sprouting, which can be therapeutically targeted.
| S-EPMC2906569 | biostudies-literature
Project description:Heparan sulfate proteoglycans regulate key steps of blood vessel formation. The present study was undertaken to investigate if there is a functional overlap between heparan sulfate proteoglycans and chondroitin sulfate proteoglycans during sprouting angiogenesis.Using cultures of genetically engineered mouse embryonic stem cells, we show that angiogenic sprouting occurs also in the absence of heparan sulfate biosynthesis. Cells unable to produce heparan sulfate instead increase their production of chondroitin sulfate that binds key angiogenic growth factors such as vascular endothelial growth factor A, transforming growth factor ?, and platelet-derived growth factor B. Lack of heparan sulfate proteoglycan production however leads to increased pericyte numbers and reduced adhesion of pericytes to nascent sprouts, likely due to dysregulation of transforming growth factor ? and platelet-derived growth factor B signal transduction.The present study provides direct evidence for a previously undefined functional overlap between chondroitin sulfate proteoglycans and heparan sulfate proteoglycans during sprouting angiogenesis. Our findings provide information relevant for potential future drug design efforts that involve targeting of proteoglycans in the vasculature.
| S-EPMC3331918 | biostudies-literature
Project description:Angiogenesis is coordinated by VEGF and Notch signaling. DLL4-induced Notch signaling inhibits tip cell formation and vessel branching. To ensure proper Notch signaling, receptors and ligands are clustered at adherens junctions. However, little is known about factors that control Notch activity by influencing the cellular localization of Notch ligands. Here, we show that the multiple PDZ domain protein (MPDZ) enhances Notch signaling activity. MPDZ physically interacts with the intracellular carboxyterminus of DLL1 and DLL4 and enables their interaction with the adherens junction protein Nectin-2. Inactivation of the MPDZ gene leads to impaired Notch signaling activity and increased blood vessel sprouting in cellular models and the embryonic mouse hindbrain. Tumor angiogenesis was enhanced upon endothelial-specific inactivation of MPDZ leading to an excessively branched and poorly functional vessel network resulting in tumor hypoxia. As such, we identified MPDZ as a novel modulator of Notch signaling by controlling ligand recruitment to adherens junctions.
| S-EPMC5933922 | biostudies-literature
Project description:In this study, we investigated the roles of Epac1 in pathological angiogenesis and its potential as a novel therapeutic target for the treatment of vasoproliferative diseases. Genetic deletion of Epac1 ameliorated pathological angiogenesis in mouse models of oxygen-induced retinopathy (OIR) and carotid artery ligation. Moreover, genetic deletion or pharmacological inhibition of Epac1 suppressed microvessel sprouting from ex vivo aortic ring explants. Mechanistic studies revealed that Epac1 acted as a previously unidentified inhibitor of the ?-secretase/Notch signaling pathway via interacting with ?-secretase and regulating its intracellular trafficking while enhancing vascular endothelial growth factor signaling to promote pathological angiogenesis. Pharmacological administration of an Epac-specific inhibitor suppressed OIR-induced neovascularization in wild-type mice, recapitulating the phenotype of genetic Epac1 knockout. Our results demonstrate that Epac1 signaling is critical for the progression of pathological angiogenesis but not for physiological angiogenesis and that the newly developed Epac-specific inhibitors are effective in combating proliferative retinopathy.
| S-EPMC6938696 | biostudies-literature
Project description:Vascular endothelial growth factor (VEGF) is a major mediator of pathologic angiogenesis, a process necessary for the formation of new blood vessels to support tumor growth. Historically, VEGF has been thought to signal via receptor tyrosine kinases, which are not typically considered to be G protein dependent. Here, we show that targeted knockdown of the G protein gng2 gene (Ggamma2) blocks the normal angiogenic process in developing zebrafish embryos. Moreover, loss of gng2 function inhibits the ability of VEGF to promote the angiogenic sprouting of blood vessels by attenuating VEGF induced phosphorylation of phospholipase C-gamma1 (PLCgamma1) and serine/threonine kinase (AKT). Collectively, these results demonstrate a novel interaction between Ggamma2- and VEGF-dependent pathways to regulate the angiogenic process in a whole-animal model. Blocking VEGF function using a humanized anti-VEGF antibody has emerged as a promising treatment for colorectal, non-small lung cell, and breast cancers. However, this treatment may cause considerable side effects. Our findings provide a new opportunity for cotargeting G protein- and VEGF-dependent pathways to synergistically block pathologic angiogenesis, which may lead to a safer and more efficacious therapeutic regimen to fight cancer.
| S-EPMC1895829 | biostudies-literature