Human brain microvascular endothelial cells resist elongation due to shear stress

Microvasc Res. 2015 May:99:8-18. doi: 10.1016/j.mvr.2015.02.008. Epub 2015 Feb 26.

Abstract

Endothelial cells in straight sections of vessels are known to elongate and align in the direction of flow. This phenotype has been replicated in confluent monolayers of bovine aortic endothelial cells and human umbilical vein endothelial cells (HUVECs) in cell culture under physiological shear stress. Here we report on the morphological response of human brain microvascular endothelial cells (HBMECs) in confluent monolayers in response to shear stress. Using a microfluidic platform we image confluent monolayers of HBMECs and HUVECs under shear stresses up to 16 dyne cm(-2). From live-cell imaging we quantitatively analyze the cell morphology and cell speed as a function of time. We show that HBMECs do not undergo a classical transition from cobblestone to spindle-like morphology in response to shear stress. We further show that under shear stress, actin fibers are randomly oriented in the cells indicating that there is no cytoskeletal remodeling. These results suggest that HBMECs are programmed to resist elongation and alignment under shear stress, a phenotype that may be associated with the unique properties of the blood-brain barrier.

Keywords: Alignment; Cell morphology; Elongation; Human brain microvascular endothelial cells; Shear stress.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Actins / metabolism
  • Blood Flow Velocity
  • Blood-Brain Barrier
  • Brain / blood supply*
  • Brain / cytology
  • Cell Line
  • Cell Proliferation
  • Cytoskeleton / metabolism
  • Endothelial Cells / cytology*
  • Human Umbilical Vein Endothelial Cells / cytology
  • Humans
  • Lab-On-A-Chip Devices
  • Microcirculation*
  • Microscopy, Fluorescence
  • Phenotype
  • Shear Strength
  • Stress, Mechanical
  • Zonula Occludens-1 Protein / metabolism
  • beta Catenin / metabolism

Substances

  • Actins
  • TJP1 protein, human
  • Zonula Occludens-1 Protein
  • beta Catenin