Migration of vascular smooth muscle cells by phospholipase A2 via specific binding sites.
Pancreatic-type group I phospholipase A2 (PLA2-I), EC 3.1.1.4, long thought to act as a digestive enzyme, has a specific binding site in several types of tissues and cells and these sites promote PLA2-I-stimulated DNA synthesis. In this study we report a PLA2-I action on the migration of rat embryonic thoracic aorta smooth muscle cells (A7r5). A7r5 cells had a single class of PLA2-I binding site with an equilibrium binding constant (Kd) value of 1.7 nM and a maximum binding capacity (Bmax) of 40,000 sites/cell. The migration activity of PLA2-I for A7r5 cells was examined using modified Boyden chambers. PLA2-I stimulated the migration dose-dependently, and the ED50 value was about 1 nM, which was almost the same as the Kd value for PLA2-I binding. Checkerboard analysis showed that the response of A7r5 cells to PLA2-I was chemokinetic, but not chemotactic. These findings reveal a new aspect of PLA2-I in the modulation of vascular function.
Kanemasa
T
T
Shionogi Research Laboratories, Shionogi & Co., Osaka, Japan.
Hanasaki
K
K
Arita
H
H
D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D000818:Animals; D001013:Aorta, Thoracic / Q000196:embryology; D001665:Binding Sites; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects*; D002630:Chemotactic Factors / Q000494:pharmacology; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D007457:Iodine Radioisotopes; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000201:enzymology / Q000502:physiology*; D010741:Phospholipases A / Q000378:metabolism / Q000502:physiology*; D054467:Phospholipases A2; D051381:Rats
D002630:Chemotactic Factors; D006893:Hydroxyeicosatetraenoic Acids; D007375:Interleukin-1; D007457:Iodine Radioisotopes; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D010741:Phospholipases A; D054467:Phospholipases A2