The endosomal RIN2/Rab5C machinery prevents VEGFR2 degradation to control gene expression and tip cell identity during angiogenesis

Abstract

Sprouting angiogenesis is key to many pathophysiological conditions, and is strongly regulated by vascular endothelial growth factor (VEGF) signaling through VEGF receptor 2 (VEGFR2). Here we report that the early endosomal GTPase Rab5C and its activator RIN2 prevent lysosomal routing and degradation of VEGF-bound, internalized VEGFR2 in human endothelial cells. Stabilization of endosomal VEGFR2 levels by RIN2/Rab5C is crucial for VEGF signaling through the ERK and PI3-K pathways, the expression of immediate VEGF target genes, as well as specification of angiogenic ‘tip’ and ‘stalk’ cell phenotypes and cell sprouting. Using overexpression of Rab mutants, knockdown and CRISPR/Cas9-mediated gene editing, and live-cell imaging in zebrafish, we further show that endosomal stabilization of VEGFR2 levels is required for developmental angiogenesis in vivo. In contrast, the premature degradation of internalized VEGFR2 disrupts VEGF signaling, gene expression, and tip cell formation and migration. Thus, an endosomal feedforward mechanism maintains receptor signaling by preventing lysosomal degradation, which is directly linked to the induction of target genes and cell fate in collectively migrating cells during morphogenesis.

A miRNA-Based Prognostic Model to Trace Thyroid Cancer Recurrence

“…ZEB2 can trigger the induction of genes associated with epithelial–mesenchymal transition [ 73 ], activate the Wnt/beta-catenin pathway [ 74 ], and regulate invasion and metastasis [ 72 ]. Endosomal RAB5C was reported to prevent VEGFR2 degradation during angiogenesis [ 75 ], regulate focal adhesion-mediated cell migration [ 76 ], and enhance resistance to ionizing radiation [ 77 ]. DUSP6, a member of the MAPK phosphatase family, is highly expressed in PTC and plays a pro-oncogenic role in thyroid tumorigenesis by regulating the ERK1/2 pathway, cell proliferation, and invasiveness [ 78 ].…”

HSPA12A Stimulates p38/ERK-AP-1 Signaling to Promote Angiogenesis and Is Required for Functional Recovery Postmyocardial Infarction

“…HUVECs. Angiogenesis is strongly regulated by VEGF signaling through VEGF receptors such as VFGFR2 [32]. Overexpression of HSPA12A in HUVECs for 24 h significantly increased VEGF expression compared to the NC group (Figures 4(a) and 4(b)).…”

Trafficking in blood vessel development

“…Thereafter, the receptor is plugged into a recycling holding pattern, being cyclically internalized and inserted back into the membrane [ 2 ]. Upon ligand binding, VEGFR2 is endocytosed and degraded via the lysosome [ 3 ]. In this example, it is obvious that alterations in any trafficking step of an important protein such as VEGFR2 would have profound effects on blood vessel function independent of transcriptional activity.…”

“…In the absence of RabEP2, Rab4-positive vesicles were diverted to a Rab7 lysosomal pathway, significantly attenuating VEGF signaling [ 41 ]. It was also reported that Rab5c partners with RIN2 to delay lysosomal degradation to increase downstream VEGFR2 signaling [ 3 ]. In this article, loss of RIN2 or Rab5c-mediated endosomal stabilization blunted VEGFR2 signaling of Akt and ERK leading to defects in sprouting parameters in culture and zebrafish blood vessel development.…”