Differential regulation of phosphoinositide metabolism by alphaVbeta3 and alphaVbeta5 integrins upon smooth muscle cell migration.
Smooth muscle cell migration is a key step of atherosclerosis and angiogenesis. We demonstrate that alpha(V)beta(3) and alpha(V)beta(5) integrins synergistically regulate smooth muscle cell migration onto vitronectin. Using an original haptotactic cell migration assay, we measured a strong stimulation of phosphoinositide metabolism in migrating vascular smooth muscle cells. Phosphatidic acid production and phosphoinositide 3-kinase IA activation were triggered only upon alpha(V)beta(3) engagement. Blockade of alpha(V)beta(3) engagement or phospholipase C activity resulted in a strong inhibition of smooth muscle cell spreading on vitronectin. By contrast, blockade of alpha(V)beta(5) reinforced elongation and polarization of cell shape. Moreover, Pyk2-associated tyrosine kinase and phosphoinositide 4-kinase activities measured in Pyk2 immunoprecipitates were stimulated upon cell migration. Blockade of either alpha(V)beta(3) or alpha(V)beta(5) function, as well as inhibition of phospholipase C activity, decreased both Pyk2-associated activities. We demonstrated that the Pyk2-associated phosphoinositide 4-kinase corresponded to the beta isoform. Our data point to the metabolism of phosphoinositides as a regulatory pathway for the differential roles played by alpha(V)beta(3) and alpha(V)beta(5) upon cell migration and identify the Pyk2-associated phosphoinositide 4-kinase beta as a common target for both integrins.
Paulhe
F
F
Institut Fédératif de Recherche Claude de Préval, INSERM, Unité 326, Hôpital Purpan, F31059 Toulouse cedex, France.
Racaud-Sultan
C
C
Ragab
A
A
Albiges-Rizo
C
C
Chap
H
H
Iberg
N
N
Morand
O
O
Perret
B
B
D019870:1-Phosphatidylinositol 4-Kinase / Q000502:physiology; D000818:Animals; D002465:Cell Movement; D002478:Cells, Cultured; D051418:Focal Adhesion Kinase 2; D016023:Integrins / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D010716:Phosphatidylinositols / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000502:physiology; D019030:Receptors, Vitronectin / Q000502:physiology*; D013552:Swine; D019096:Vitronectin / Q000502:physiology; D018909:src Homology Domains
D016023:Integrins; D010716:Phosphatidylinositols; D019030:Receptors, Vitronectin; D019096:Vitronectin; C064660:integrin alphaVbeta5; D019869:Phosphatidylinositol 3-Kinases; D019870:1-Phosphatidylinositol 4-Kinase; D011505:Protein-Tyrosine Kinases; D051418:Focal Adhesion Kinase 2