Nathan Sniadecki,
Ph.D.
Department of Mechanical Engineering
E-mail: nsniadec@uw...
TITLE:
"Endothelial Mechanobiology: Pulling
Together Tightly under Shear Flow"
ABSTRACT:
Endothelial cells line the inner surface of blood vessels and form a
tightly-knit monolayer
that acts as a barrier to keep blood and its constituents from leaking
into the vessel wall.
Shear stress from blood flow can stimulate mechanotransduction in
endothelial cells, which in
turn changes their biomechanics and barrier function. In my talk, I
will present my lab?s
recent work on endothelial mechanobiology using a novel shear flow
chamber with microposts.
Endothelial cells were cultured on arrays of microposts and subjected
to laminar or disturbed
flow. We found that laminar flow increased cytoskeletal tension and
adherens junction size in
the cells, while disturbed flow caused lower cytoskeletal tension and
reduced adherens junction
size. Decreasing cytoskeletal tension with Y-27632 reduced the size of
their adherens
junctions, while increasing tension through Calyculin-A increased their
size. Furthermore, we
developed a novel method to measure intercellular forces between
endothelial cells and found
that intercellular forces were significantly higher for laminar flow
than for static or
disturbed conditions. The size of adherens junctions and tight
junctions in the endothelial
cells matched closely with the changes in their intercellular forces
for laminar flow. Our
results indicate that shear flow influences intercellular tension in
endothelial monolayer,
which subsequently affects the assembly of their cell-cell junctions.
These findings provide
deeper insight into the mechanobiology of endothelial cells and the
role of shear stress in
atherosclerosis and vascular surgery.