uPARAP/Endo180 receptor is a gatekeeper of VEGFR-2/VEGFR-3 heterodimerisation during pathological lymphangiogenesis

Abstract

The development of new lymphatic vessels occurs in many cancerous and inflammatory diseases through the binding of VEGF-C to its receptors, VEGFR-2 and VEGFR-3. The regulation of VEGFR-2/VEGFR-3 heterodimerisation and its downstream signaling in lymphatic endothelial cells (LECs) remain poorly understood. Here, we identify the endocytic receptor, uPARAP, as a partner of VEGFR-2 and VEGFR-3 that regulates their heterodimerisation. Genetic ablation of uPARAP leads to hyperbranched lymphatic vasculatures in pathological conditions without affecting concomitant angiogenesis. In vitro, uPARAP controls LEC migration in response to VEGF-C but not VEGF-A or VEGF-CCys156Ser. uPARAP restricts VEGFR-2/VEGFR-3 heterodimerisation and subsequent VEGFR-2-mediated phosphorylation and inactivation of Crk-II adaptor. uPARAP promotes VEGFR-3 signaling through the Crk-II/JNK/paxillin/Rac1 pathway. Pharmacological Rac1 inhibition in uPARAP knockout mice restores the wild-type phenotype. In summary, our study identifies a molecular regulator of lymphangiogenesis, and uncovers novel molecular features of VEGFR-2/VEGFR-3 crosstalk and downstream signaling during VEGF-C-driven LEC sprouting in pathological conditions.

Lymphatic Endothelial Cell Junctions: Molecular Regulation in Physiology and Diseases

“…Further studies will be required for a clear understanding of the roles of VEGFR3 signaling in LEC junction organization in developmental and disease conditions. Additionally, VEGFR3 and VEGFR2 form heterodimers in both BECs and LECs upon VEGF-A or VEGF-C stimulation (Dixelius et al, 2003;Nilsson et al, 2010), and previous studies have underlined the contribution of VEGFR2/VEGFR3 heterodimers to VEGF-C-driven tumor and corneal lymphangiogenesis and pulmonary lymphangiectasia (Yao et al, 2014;Durre et al, 2018). So far no data are available regarding the role of VEGFR2/VEGFR3 dimerization in the regulation of LEC junctions.…”

HEYL Regulates Neoangiogenesis Through Overexpression in Both Breast Tumor Epithelium and Endothelium

“…However, the efficacy of anti-angiogenic therapies, mainly based on blocking VEGF function, has been limited in the clinical setting ( 7 – 12 ). This lack of therapeutic efficacy may be due to compensation by other angiogenic factors thereby resulting in resistance to anti-VEGF therapy ( 3 , 13 , 14 ), or simply due to a lack of sprouting angiogenesis in lymph nodes during early tumor dissemination ( 15 , 16 ).…”

Single-cell transcriptomic profiling and characterization of endothelial progenitor cells: new approach for finding novel markers

“…This system is involved in the migration, proliferation, and adhesion of cells. Moreover, this system is a key orchestrator of angiogenesis besides other cellular processes that include receptor shedding and internalization, protein expression, phenotype modulation and tissue remodeling, cancer progression, and metastasis [47,51,[53][54][55]. In order for angiogenesis to occur, EPCs have to be released from the basement membrane then they migrate to distant regions where there is injury or neovascularization.…”

“…The fifth group is involved in the internalization (of ligands from the extracellular matrix to be recycled back to the endosomal compartment), endocytosis, migratory and/or invasive capacity, and motility. It comprises urokinase plasminogen activator (uPA), urokinase plasminogen activator receptor (uPAR), urokinase plasminogen activator receptorassociated protein (uPARAP), tissue-type plasminogen activator (tPA), Neuropilin-1 NRP1, Neuropilin-2 NRP2, VEGF R1, 2 and 3, PECAM-1, ICAM-1, VE-cadherin, Ephrin-B2, EphB4, and EGFL7 [46][47][48][49][50][51][52][53][54][55][56][57].…”