Transmembrane protein ESDN promotes endothelial VEGF signaling and regulates angiogenesis

Abstract

Aberrant blood vessel formation contributes to a wide variety of pathologies, and factors that regulate angiogenesis are attractive therapeutic targets. Endothelial and smooth muscle cell-derived neuropilin-like protein (ESDN) is a neuropilin-related transmembrane protein expressed in ECs; however, its potential effect on VEGF responses remains undefined. Here, we generated global and EC-specific Esdn knockout mice and demonstrated that ESDN promotes VEGF-induced human and murine EC proliferation and migration. Deletion of Esdn in the mouse interfered with adult and developmental angiogenesis, and knockdown of the Esdn homolog (dcbld2) in zebrafish impaired normal vascular development. Loss of ESDN in ECs blunted VEGF responses in vivo and attenuated VEGF-induced VEGFR-2 signaling without altering VEGF receptor or neuropilin expression. Finally, we found that ESDN associates with VEGFR-2 and regulates its complex formation with negative regulators of VEGF signaling, protein tyrosine phosphatases PTP1B and TC-PTP, and VEcadherin. These findings establish ESDN as a regulator of VEGF responses in ECs that acts through a mechanism distinct from neuropilins. As such, ESDN may serve as a therapeutic target for angiogenesis regulation.

MicroRNA-486 regulates normal erythropoiesis and enhances growth and modulates drug response in CML progenitors

“…39,40 Finally, DCBLD2 is a membrane protein cloned from vascular cells, which is upregulated after vascular injury and considered to regulate vascular cell growth and have a variety of functions in other tissues. 41 Additional studies are warranted to determine the role of these genes in erythroid development.…”

The neuropilin-like protein ESDN regulates insulin signaling and sensitivity

“…DNA synthesis was quantified by measuring [ 3 H]thymidine incorporation as described (28). Briefly, 10,000 WT or Esdn Ϫ/Ϫ VSMCs were seeded on 24-well culture plates, and the medium was switched to medium 199 containing 1% FBS after 24 h. The next day, cells were treated with insulin or control buffer in triplicates for 18 h, at which point [ 3 H]thymidine (0.074 MBq; GE Healthcare) was added to each well for 6 h. To account for baseline differences in cell proliferation in 1% FBS, the data with insulin are shown as relative to [ 3 H]thymidine incorporation in nonstimulated cells.…”

“…The modified Boyden chamber migration assay was performed as described (28). Medium 199 with 0.5% bovine serum albumin (BSA) containing insulin (70 nM) or control buffer was added in the lower well, and cell migration was quantified after 6 h in triplicates.…”

“…Endothelial and smooth muscle cell-derived neuropilin-like protein (ESDN), also called DCBLD2 or CLCP1, is a widely expressed transmembrane protein with a domain structure reminiscent of neuropilins (18,19). Recent work by our groups has identified ESDN as a novel regulator of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) signaling in vascular cells (13,28). In the case of VEGF signaling, in endothelial cells ESDN interferes with VEGF receptor (VEGFR)-2 interaction with negative regulators of VEGF signaling, including protein tyrosine phosphatases protein-tyrosine phosphatase 1B (PTP1B) and T cell protein tyrosine phosphatase, and promotes downstream signaling and angiogenesis (28).…”

“…Recent work by our groups has identified ESDN as a novel regulator of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) signaling in vascular cells (13,28). In the case of VEGF signaling, in endothelial cells ESDN interferes with VEGF receptor (VEGFR)-2 interaction with negative regulators of VEGF signaling, including protein tyrosine phosphatases protein-tyrosine phosphatase 1B (PTP1B) and T cell protein tyrosine phosphatase, and promotes downstream signaling and angiogenesis (28). The inhibitory effect of ESDN on PDGF signaling in vascular smooth muscle cells (VSMCs) is through regulation of ligand-induced PDGF receptor (PDGFR)-␤ ubiquitination (13).…”