Nuclear localization of vascular endothelial growth factor-D and regulation of c-Myc–dependent transcripts in human lung fibroblasts

S El-Chemaly, G Pacheco-Rodriguez… - American journal of …, 2014 - atsjournals.org
S El-Chemaly, G Pacheco-Rodriguez, D Malide, V Meza-Carmen, J Kato, Y Cui, PI Padilla
American journal of respiratory cell and molecular biology, 2014atsjournals.org
Lymphangiogenesis and angiogenesis are processes that are, in part, regulated by vascular
endothelial growth factor (VEGF)-D. The formation of lymphatic structures has been
implicated in multiple lung diseases, including pulmonary fibrosis. VEGF-D is a secreted
protein produced by fibroblasts and macrophages, which induces lymphangiogenesis by
signaling via VEGF receptor-3, and angiogenesis through VEGF receptor-2. VEGF-D
contains a central VEGF homology domain, which is the biologically active domain, with …
Lymphangiogenesis and angiogenesis are processes that are, in part, regulated by vascular endothelial growth factor (VEGF)-D. The formation of lymphatic structures has been implicated in multiple lung diseases, including pulmonary fibrosis. VEGF-D is a secreted protein produced by fibroblasts and macrophages, which induces lymphangiogenesis by signaling via VEGF receptor-3, and angiogenesis through VEGF receptor-2. VEGF-D contains a central VEGF homology domain, which is the biologically active domain, with flanking N- and C-terminal propeptides. Full-length VEGF-D (∼ 50 kD) is proteolytically processed in the extracellular space, to generate VEGF homology domain that contains the VEGF-D receptor–binding sites. Here, we report that, independent of its cell surface receptors, full-length VEGF-D accumulated in nuclei of fibroblasts, and that this process appears to increase with cell density. In nuclei, full-length VEGF-D associated with RNA polymerase II and c-Myc. In cells depleted of VEGF-D, the transcriptionally regulated genes appear to be modulated by c-Myc. These findings have potential clinical implications, as VEGF-D was found in fibroblast nuclei in idiopathic pulmonary fibrosis, a disease characterized by fibroblast proliferation. These findings are consistent with actions of full-length VEGF-D in cellular homeostasis in health and disease, independent of its receptors.
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