Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2008-1-21
pubmed:abstractText
We recently demonstrated that migrating human leukocytes respond to normal physiologic fluid stresses (approximately 1 dyn/cm(2)) by active control of local cytoplasmic extensions (pseudopods). To better understand the governing mechanisms of this response, we determined the fluid stress distributions on individual migrating leukocytes whose shapes were reconstructed with serial confocal microscopy. The flow over adherent leukocytes was computed by solution of the Stokes equation for plasma motion over the cell membrane. The fluid stresses are highest at the top of the cell and lowest in the substrate contact region. Pseudopods experience enhanced shear stresses but at lower values than at the top. Interestingly, leukocytes retract pseudopods in all regions and not only at sites with maximum fluid stresses. Therefore we hypothesized that sub-micron membrane folds (microvilli) serve to locally enhance the fluid stress on the cell. Using a separate model, we found that tips of microvilli experience greatly increased levels of stresses while the troughs between microvilli are shielded from fluid shear. This evidence suggests that the highly irregular shape of active leukocytes leads to fluid stresses that may stimulate local mechanosensory responses at many sites on the plasma membrane, even if they are located close to the cell-substrate contact region.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1521-6047
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
298-307
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Fluid stresses on the membrane of migrating leukocytes.
pubmed:affiliation
Department of Bioengineering, The Whitaker Institute of Biomedical Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0412, USA. sususan@alumni.ucsd.edu
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural