GATA2 controls lymphatic endothelial cell junctional integrity and lymphovenous valve morphogenesis through

Mutations in the transcription factor GATA2 cause lymphedema. GATA2 is necessary for the development of lymphatic valves and lymphovenous valves, and for the patterning of lymphatic vessels. Here, we report that GATA2 is not necessary for valvular endothelial cell (VEC) differentiation. Instead, GATA2 is required for VEC maintenance and morphogenesis. GATA2 is also necessary for the expression of the cell junction molecules VE-cadherin and claudin 5 in lymphatic vessels. We identified miR-126 as a target of GATA2, and miR-126-/- embryos recapitulate the phenotypes of mice lacking GATA2. Primary human lymphatic endothelial cells (HLECs) lacking GATA2 (HLECΔGATA2) have altered expression of claudin 5 and VE-cadherin, and blocking miR-126 activity in HLECs phenocopies these changes in expression. Importantly, overexpression of miR-126 in HLECΔGATA2 significantly rescues the cell junction defects. Thus, our work defines a new mechanism of GATA2 activity and uncovers miR-126 as a novel regulator of mammalian lymphatic vascular development.USA NIH National Heart Lung & Blood Institute (NHLBI) [R01HL131652, R01HL133216]; National Institute of General Medical Sciences COBRE [P20 GM103441]; Oklahoma Center for Adult Stem Cell Research [4340]; American Heart Association [16PRE31190025, 19POST34380819]Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu