Project description:Vascular endothelial growth factor (VEGF) regulates vasculogenesis by using its tyrosine kinase receptors. However, little is known about whether Sec14-like phosphatidylinositol transfer proteins (PTP) are involved in this process. Here, we show that zebrafish sec14l3, one of the family members, specifically participates in artery and vein formation via regulating angioblasts and subsequent venous progenitors' migration during vasculogenesis. Vascular defects caused by sec14l3 depletion are partially rescued by restoration of VEGFR2 signaling at the receptor or downstream effector level. Biochemical analyses show that Sec14l3/SEC14L2 physically bind to VEGFR2 and prevent it from dephosphorylation specifically at the Y1175 site by peri-membrane tyrosine phosphatase PTP1B, therefore potentiating VEGFR2 signaling activation. Meanwhile, Sec14l3 and SEC14L2 interact with RAB5A/4A and facilitate the formation of their GTP-bound states, which might be critical for VEGFR2 endocytic trafficking. Thus, we conclude that Sec14l3 controls vasculogenesis in zebrafish via the regulation of VEGFR2 activation.
Project description:We isolated GFP-positive and negative cell populations, by fluorescence-activated cell sorting (FACS), from Tg(fli1a:EGFP)y1 embryos at 22-24 hpf, then extracted their RNAs for high-through put sequencing based on Illumina HiSeq2000 to find out enriched genes in vascular, hematopoietic and pharyngeal arch cells
Project description:Hypoxia controls reparative angiogenesis. MiRNAs are master regulators of gene expression in hypoxia and angiogenesis. However, we do not yet have a clear understanding of how hypoxia-induced miRNAs modulate vasoreparative processes. Here, we identify miR-130a as a mediator of the hypoxic response in human primary endothelial colony forming cells (ECFCs), a well-characterized subtype of endothelial progenitor. Under hypoxic conditions, miR-130a overexpression enhances ECFC pro-angiogenic capacity in vitro and potentiates their vasoreparative properties in vivo. Mechanistically, miR-130a orchestrates upregulation of VEGFR2, activation of STAT3-dependent transcription, and accumulation of HIF1α via translational inhibition of DDX6. These findings unveil a new role for miR-130a in hypoxia, whereby it modulates the VEGFR2/STAT3/HIF1α axis to increase the vasoregenerative capacity of ECFCs.
Project description:The project concerns vascular endothelial growth factor (VEGF) signaling, which is dependent on binding of VEGF to VEGF receptor-2 (VEGFR2) and leads to activation of the receptor kinase and autophosphorylation. Previous mouse studies with the VEGFR-2 phosphorylation site mutation Y1212F showed reduced vascular stability. We here investigate with LC-MS proteomics which signal transduction pathway(s) are lost in the mutant by identifying proteins that bind to the Y1212F site.
Project description:RNA sequencing of lung tissue from transgenic mice in order to investigate the effect of a single tyrosine to phenylalanine exchange in the endothelial receptor VEGFR2 at position Y949. This exchange creates a mouse with unleaky blood vessels which is an advantage in several diseases such as cancer and cardiovascular disease.