Reciprocal VEGFC/VEGFR3-CDH5 regulation of lymphatic and sinusoidal vascular growth

Project Summary Sinusoidal and lymphatic vessel regeneration are predicted to improve treatment of hematopoietic diseases and lymphedema, but are presently limited by an incomplete understanding of the molecular and genetic pathways that control growth of these specialized vascular beds. Prior studies by us and others have demonstrated that VEGFC is required for fetal liver hematopoiesis, but a clear mechanism for this requirement has not been identified. Our preliminary studies demonstrate that loss of VEGFC/VEGFR3 function or gain of CDH5 function confers identical defects in sinusoidal and lymphatic vascular growth. Further, our genetic studies demonstrate that partial loss of CDH5 rescues both the anemia and edema conferred by the loss sinusoidal and lymphatic vascular growth, respectively, in VEGFR3-deficient animals. We hypothesize that a reciprocal VEGFC/VEGFR3-CDH5 regulatory loop controls sinusoidal and lymphatic vascular growth. This proposal will test this hypothesis in vivo and in vitro, investigate the molecular mechanism of this co-regulatory axis, and determine whether manipulation of CDH5 can be used to stimulate sinusoidal and lymphatic regeneration in mature animals. These studies are predicted to provide fundamental new insights into sinusoidal and lymphatic vessel growth that may be leveraged to treat patients with hematopoietic and lymphatic vascular diseases.