Abstract 15940: Laminar Shear Stress Induces a Vangl2 Vimentin Association in HUVEC
Introduction: Vascular endothelial cells (ECs) are strongly influenced by flow. Disturbed flow patterns trigger vascular pathology including atherosclerosis, neointimal hyperplasia, and faulty tone control. While directed, laminar flow leads to polarized EC morphology and health. Flow-dependent regulation of ECs occurs via a complex integration of the underlying matrix, cytoskeleton, and molecular signaling complexes. While much is known concerning the players of this complex dynamic, less is known about how these responses are integrated, particularly in directed, laminar flow.
Hypothesis: We have evidence that human ECs express Vangl2, a transmembrane protein that establishes polarity in epithelial cells. Given its function as a cell signaling organizer, we hypothesized that Vangl2 mediates EC responses to polarizing, unidirectional laminar fluid flow.
Methods: HUVEC on fibronectin-coated coverslips were exposed to ~20 dynes/cm2 for 0, 2 and 48 Hr with a parallel-plate flow chamber. IHC, Co-IP and western blot approaches in combination with MS-MS proteomics, characterized the distribution and association of Vangl2 and Vimentin.
Results: Laminar flow induced a change in the subcellular distribution of unphosphorylated and phosphorylated forms of Vangl2. A proteomic screen of immunoprecipitated Vangl2 from static cultures identified cytoskeleton vimentin as a predominant co-precipitant, which was confirmed with subsequent Western blotting and immunostaining experiments. Vangl2 colocalized with vimentin in HUVECs in a time-dependent manner following exposure to laminar flow. Vangl2 and vimentin relocated to a polarized perinuclear location after 2 Hr of flow.
Conclusions: We report that the highly conserved, transmembrane protein, Vangl2 is expressed in ECs and that it differentially partitions in ECs following laminar flow. This partitioning strongly correlates with colocalization of Vangl2 with the vimentin-based cytoskeleton. Given the highly conserved role of Vangl2 organizing signaling complexes in other cell types, our findings suggest a role for Vangl2 in organizing signaling associated with flow-dependent EC polarization.
Author Disclosures: L. Curtis-Whitchurch: None. D. Wilkey: None. M. Merchant: None. J. Hoying: None.
- © 2016 by American Heart Association, Inc.