Reversal of Flow-Direction is A Critical Mechanical Stimulus for Full Activation of Endothelial Arteriogenesis Signaling Pathways

ABSTRACT: This study characterizes the response of primary human endothelial cells (human umbilical vein endothelial cells, HUVECs) to the relative shear stress changes that occur during the initiation of arteriogenesis at the entrance regions to a collateral artery network. HUVECs were preconditioned to a baseline level of unidirectional shear of 15 dynes/cm2 for 24 hours. After 24 hours preconditioning, HUVECs were subjected to an arteriogenic stimulus that mimics the shear stress changes observed in the opposing entrance regions into a collateral artery network. The arteriogenic stimulus consisted of a 100% step wise increase in shear stress magnitude to a unidirectional 30 dynes/cm2 in either the same or opposite direction of the preconditioned shear stress. This simulates either the feeding entrance to the collateral artery circuit or the region that drains into the vasculature downstream of an obstruction in a major artery, respectively. In vivo analysis of collateral growth in the mouse hindlimb showed enhanced outward remodeling in the re-entrant (direction reversing) region that reconnects to the downstream arterial tree, suggesting reversal of shear stress direction as a key enhancer of arteriogenesis. Transcriptional profiling using microarray techniques identified that the reversal of shear stress direction, but not an increase in shear stress alone, yielded a broad-based enhancement of the mechanotransduction pathways necessary for the induction of arteriogenesis. Human umbilical vein endothelial cells (HUVECs) were preconditioned to a unidirectional clockwise shear stress of 15 dynes/cm2 for 24 hours. An acute increase in shear stress magnitude to 30 dynes/cm2 in either a clockwise (non-reversed) or counter-clockwise (reversed) direction was applied for 6 hours. An additional preconditioned control culture was maintained under a unidirectional clockwise shear stress of 15 dynes/cm2 and harvested at the same time point, 6 hours post-conditioning. Each condition of reversed, non-reversed, and control was performed in tandem from the same starting cell culture as one replicate. The total experiment consisted of four replicates. Gene transcription was then assessed using microarray expression analysis.

ORGANISM(S): Homo sapiens

SUBMITTER: Stephen Turner 

PROVIDER: E-GEOD-46248 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress