TGFß signaling positively regulates lymphatic endothelial cell sprouting in vitro

Monday, September 22, 2014 — Poster Session I
12:00 p.m. – 2:00 p.m.	FAES Academic Center	NHLBI	DEVBIO-7

Authors

• B.T. Shepherd
• J.M. James
• Y.S. Mukouyama

Abstract

During lymphatic development, a subset of venous endothelial cells differentiate into lymphatic endothelial cells (LECs) and sprout from the cardinal and intersomitic veins to form lymphatic network. Molecular signals regulating initial lymphatic network patterning and migration are unclear. We previously showed that Transforming Growth Factor ß (TGFß) signaling, a critical molecular pathway required for cardiovascular development, is also required for lymphatic network patterning. Genetic disruption of the TGFß pathway in embryonic mouse skin reduced LEC sprouting and lymphatic network branching complexity in vivo; however, the precise mechanism of TGFß action during developmental lymphangiogenesis remains to be elucidated. Therefore, we generated an in vitro assay to measure the direct effects of TGFßs on LEC sprouting. Using human dermal lymphatic microvascular endothelial cell (HMVEC-dLy) or FACS-isolated primary mouse LECs cultured in 3-D type I Collagen gels, we found that addition of TGFßs significantly enhanced LEC sprouting compared to non-treated controls. Live imaging of LEC sprouting in culture provided further insights into the behavior of individual LECs and lymphatic sprouts in cultures exposed to TGFß treatment. Combined, our results suggest that TGFß positively regulates LEC sprouting and targeted migration.

back to top