Smooth muscle cell migration stimulated by interleukin 6 is associated with cytoskeletal reorganization.
BACKGROUND
Interleukin 6 (IL-6) is elevated in the arterial wall in atherosclerosis and restenosis after angioplasty. An important contributor to these pathologies is migration of vascular smooth muscle cells (VSMC), which is often associated with cytoskeletal reorganization initiated by growth factors and chemokines. We recently reported that IL-6 stimulated migration of VSMC. Here, we examined the cytoskeleton of VSMC and cytoskeletal associated proteins to determine potential mechanisms associated with IL-6 induced migration.


METHODS
Studies were performed in VSMC cultured from rat aortas.


RESULTS
IL-6 significantly stimulated VSMC migration. IL-6 induced actin polymerization, and tyrosine phosphorylation of focal adhesion-associated cytoskeletal proteins including focal adhesion kinase (FAK) and paxillin. Cytochalasin D, an inhibitor of actin polymerization, blocked phosphorylation of FAK and paxillin as well as cell motility induced by the cytokine.


CONCLUSIONS
Collectively, these data demonstrate for the first time that IL-6 stimulates VSMC motility which correlated with induction of actin cytoskeletal reorganization and tyrosine phosphorylation of FAK and paxillin.
Wang
Zhongbiao
Z
Division of Basic Medical Science and Department of Anesthesiology, Mercer Universtiy School of Medicine and Medical Center of Central Georgia, Macon, 31207, USA. wang_z@mercer.edu
Newman
Walter H
WH
D000199:Actins / Q000737:chemistry; D000818:Animals; D001013:Aorta, Thoracic; D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D015638:Cytochalasin D / Q000494:pharmacology; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000187:drug effects / Q000648:ultrastructure*; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D015850:Interleukin-6 / Q000494:pharmacology*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000737:chemistry / Q000648:ultrastructure*; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011108:Polymers / Q000737:chemistry; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D000199:Actins; D003598:Cytoskeletal Proteins; D015850:Interleukin-6; D051419:Paxillin; D010750:Phosphoproteins; D011108:Polymers; C496063:Pxn protein, rat; D019000:Phosphotyrosine; D015638:Cytochalasin D; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496052:Ptk2 protein, rat