title: Polarization of plasma membrane microviscosity during endothelial cell migration.
abstract: Cell movement is characterized by anterior-posterior polarization of multiple cell structures. We show here that the plasma membrane is polarized in moving endothelial cells (EC); in particular, plasma membrane microviscosity (PMM) is increased at the cell leading edge. Our studies indicate that cholesterol has an important role in generation of this microviscosity gradient. In vitro studies using synthetic lipid vesicles show that membrane microviscosity has a substantial and biphasic influence on actin dynamics; a small amount of cholesterol increases actin-mediated vesicle deformation, whereas a large amount completely inhibits deformation. Experiments in migrating ECs confirm the important role of PMM on actin dynamics. Angiogenic growth factor-stimulated cells exhibit substantially increased membrane microviscosity at the cell front but, unexpectedly, show decreased rates of actin polymerization. Our results suggest that increased PMM in lamellipodia may permit more productive actin filament and meshwork formation, resulting in enhanced rates of cell movement.
authors.affiliation: Department of Cell Biology, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
authors.forename: Amit
authors.initials: A
authors.lastname: Vasanji
authors.forename: Prabar K
authors.initials: PK
authors.lastname: Ghosh
authors.forename: Linda M
authors.initials: LM
authors.lastname: Graham
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Eppell
authors.forename: Paul L
authors.initials: PL
authors.lastname: Fox
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D016764:Cell Polarity / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D016228:Endothelial Growth Factors / Q000378:metabolism / Q000494:pharmacology; D050356:Lipid Metabolism; D011108:Polymers / Q000378:metabolism; D011554:Pseudopodia / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D014783:Viscosity
chemical_list: D000199:Actins; D016228:Endothelial Growth Factors; D011108:Polymers; D002784:Cholesterol