Alphavbeta3 integrin signaling pathway is involved in insulin-like growth factor I-stimulated human extravillous trophoblast cell migration.
IGF-I and -II provide paracrine and autocrine stimuli, respectively, for extravillous trophoblast (EVT) cell migration. This study examined the role of alpha(v)beta(3) integrin and its signaling pathway in IGF-I-stimulated migration. Migration assays were conducted using cultured EVT cells treated with or without IGF-I in the presence or absence of alphaIR3, Arg-Gly-Asp (RGD) hexapeptide, and antibody against alpha(v)beta(3) integrin. Morphological changes were studied using scanning electron microscopy. Colocalization of alpha(5)beta(1) alpha(v)beta(3) integrins, vinculin, focal adhesion kinase, and paxillin were determined by immuno-cytochemistry and immunoblotting. The results showed that IGF-I could stimulate EVT cell migration in a time- and dose-dependent manner and addition of alphaIR3, Arg-Gly-Asp hexapeptide, and antibody against alpha(v)beta(3) integrin attenuated the IGF-I migratory effect. Scanning electron microscopy images revealed that IGF-I promoted lamellipodia formation. Immunostaining and immunoblotting exhibited the colocalization of alpha(v)beta(3) integrin with phosphorylated focal adhesion kinase, paxillin, and vinculin at focal adhesions after IGF-I treatment. Immunoblotting demonstrated an increase in focal adhesion kinase and paxillin tyrosine phosphorylation followed by tyrosine phosphorylation of IGF-I receptor in a time- and dose-dependent manner. These findings indicated alpha(v)beta(3) integrin localization in the core of focal adhesions of EVT cells and that alpha(v)beta(3) integrin signaling pathways are activated in IGF-I-mediated migration of these cells.
Kabir-Salmani
Maryam
M
Department of Obstetrics and Gynecology, Kyorin University School of Medicine, Mitaka, Tokyo 181-8611, Japan.
Shiokawa
Shigetatsu
S
Akimoto
Yoshihiro
Y
Sakai
Keiji
K
Nagamatsu
Shinya
S
Sakai
Ken
K
Nakamura
Yukio
Y
Lotfi
Abbas
A
Kawakami
Hayato
H
Iwashita
Mitsutoshi
M
D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D003598:Cytoskeletal Proteins / Q000032:analysis; D005260:Female; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D007150:Immunohistochemistry; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D039302:Integrin alphaVbeta3 / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D019899:Paracrine Communication / Q000502:physiology; D051419:Paxillin; D010750:Phosphoproteins / Q000032:analysis; D011247:Pregnancy; D011505:Protein-Tyrosine Kinases / Q000032:analysis; D015398:Signal Transduction / Q000502:physiology*; D014327:Trophoblasts / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure
D003598:Cytoskeletal Proteins; D039302:Integrin alphaVbeta3; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D007334:Insulin-Like Growth Factor I; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human