title: RhoA is required for monocyte tail retraction during transendothelial migration.
abstract: Transendothelial migration of monocytes is the process by which monocytes leave the circulatory system and extravasate through the endothelial lining of the blood vessel wall and enter the underlying tissue. Transmigration requires coordination of alterations in cell shape and adhesive properties that are mediated by cytoskeletal dynamics. We have analyzed the function of RhoA in the cytoskeletal reorganizations that occur during transmigration. By loading monocytes with C3, an inhibitor of RhoA, we found that RhoA was required for transendothelial migration. We then examined individual steps of transmigration to explore the requirement for RhoA in extravasation. Our studies showed that RhoA was not required for monocyte attachment to the endothelium nor subsequent spreading of the monocyte on the endothelial surface. Time-lapse video microscopy analysis revealed that C3-loaded monocytes also had significant forward crawling movement on the endothelial monolayer and were able to invade between neighboring endothelial cells. However, RhoA was required to retract the tail of the migrating monocyte and complete diapedesis. We also demonstrate that p160ROCK, a serine/threonine kinase effector of RhoA, is both necessary and sufficient for RhoA-mediated tail retraction. Finally, we find that p160ROCK signaling negatively regulates integrin adhesions and that inhibition of RhoA results in an accumulation of beta2 integrin in the unretracted tails.
authors.affiliation: Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. becky_worthylake@med.unc.edu
authors.forename: R A
authors.initials: RA
authors.lastname: Worthylake
authors.forename: S
authors.initials: S
authors.lastname: Lemoine
authors.forename: J M
authors.initials: JM
authors.lastname: Watson
authors.forename: K
authors.initials: K
authors.lastname: Burridge
mesh_terms: D000577:Amides / Q000494:pharmacology; D018821:CD18 Antigens / Q000378:metabolism; D002448:Cell Adhesion; D002465:Cell Movement; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000378:metabolism; D018920:Coculture Techniques; D003599:Cytoskeleton / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D018274:Electroporation; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008856:Microscopy, Fluorescence; D018715:Microscopy, Video; D008870:Microtubules / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013997:Time Factors; D014471:Umbilical Veins / Q000166:cytology; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein / Q000378:metabolism* / Q000502:physiology*
chemical_list: D000577:Amides; D018821:CD18 Antigens; D018932:Chemokine CCL2; D004791:Enzyme Inhibitors; D007375:Interleukin-1; D047908:Intracellular Signaling Peptides and Proteins; D011725:Pyridines; D011993:Recombinant Fusion Proteins; C108830:Y 27632; D005982:Glutathione Transferase; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D009218:Myosins; D020742:rhoA GTP-Binding Protein