Vascular smooth muscle cell spreading onto fibrinogen is regulated by calpains and phospholipase C.
Fibrinogen deposition and smooth muscle cell migration are important causes of atherosclerosis and angiogenesis. Involvement of calpains in vascular smooth muscle cell adhesion onto fibrinogen was investigated. Using calpain inhibitors, we showed that activation of calpains was required for smooth muscle cell spreading. An increase of (32)P-labeled phosphatidic acid and phosphatidylinositol-3,4-bisphosphate, respective products of phospholipase C and phosphoinositide 3-kinase activities, was measured in adherent cells. Addition of the calpain inhibitor calpeptin strongly decreased phosphatidic acid and phosphatidylinositol-3,4-bisphosphate. However, smooth muscle cell spreading was prevented by the phospholipase C inhibitor U-73122, but poorly modified by phosphoinositide 3-kinase inhibitors wortmannin and LY-294002. Moreover, PLC was found to act upstream of the PI 3-kinase IA isoform. Thus, our data provide the first evidence that calpains are required for smooth muscle cell spreading. Further, phospholipase C activation is pointed as a key step of cell-spreading regulation by calpains.
Paulhe
F
F
Institut Fédératif de Recherche Claude de Préval, INSERM, Unité 326, Hôpital Purpan, Toulouse cedex, F31059, France.
Bogyo
A
A
Chap
H
H
Perret
B
B
Racaud-Sultan
C
C
D000199:Actins / Q000378:metabolism; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D002154:Calpain / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D002867:Chromones / Q000494:pharmacology; D004151:Dipeptides / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004963:Estrenes / Q000494:pharmacology; D005109:Extracellular Matrix / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism*; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000737:chemistry / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011485:Protein Binding; D021122:Protein Subunits; D011760:Pyrrolidinones / Q000494:pharmacology; D013552:Swine; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000077191:Wortmannin
D000199:Actins; D000730:Androstadienes; D002154:Calpain; D002867:Chromones; D004151:Dipeptides; D004963:Estrenes; D005340:Fibrinogen; D007527:Isoenzymes; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D010716:Phosphatidylinositols; D000081082:Phosphoinositide-3 Kinase Inhibitors; D021122:Protein Subunits; D011760:Pyrrolidinones; D010738:Type C Phospholipases; D000077191:Wortmannin; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; C071482:calpeptin; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one