DeepCAGE transcriptomics identify HOXD10 as transcription factor regulating lymphatic endothelial responses to VEGF-C

Abstract

Lymphangiogenesis plays a crucial role during development, in cancer metastasis and in inflammation. Activation of VEGFR-3 by VEGF-C is one of the main drivers of lymphangiogenesis, but the transcriptional events downstream of VEGFR-3 activation are largely unknown. Recently, we identified a wave of immediate early transcription factors (TF) upregulated in human lymphatic endothelial cells (LEC) within the first 30 to 80 min after VEGFR-3 activation. Expression of these TFs must be regulated by additional, pre-existing TFs, which are rapidly activated by VEGFR-3 signaling. Using TF activity analysis, we identified the homeobox TF HOXD10 to be specifically activated at early time points after VEGFR-3 stimulation, and to regulate expression of immediate early TFs, including NR4A1. Gain- and loss of function studies revealed that HOXD10 is involved in LEC migration and formation of cord-like structures. Furthermore, HOXD10 regulates expression of VE-cadherin, claudin-5 and e-NOS, and promotes lymphatic endothelial permeability. Taken together, these results reveal an important and unanticipated role of HOXD10 in the regulation of VEGFR-3 signaling in lymphatic endothelial cells and in the control of lymphangiogenesis and permeability.