This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kabir-Salmani, M. Articles by Iwashita, M. Search for Related Content PubMed PubMed Citation Articles by Kabir-Salmani, M. Articles by Iwashita, M.

Characterization of Morphological and Cytoskeletal Changes in Trophoblast Cells Induced by Insulin-Like Growth Factor-I

Departments of Obstetrics and Gynecology (M.K.-S., S.S., K.J.S., K.S., Y.N., M.I.), Anatomy (Y.A.), Biochemistry (S.N.), and Pharmacology (H.H.-N.), Kyorin University School of Medicine, Mitaka, Tokyo 181-8611, Japan; and Cell Research Center, Shahid Beheshti Medical University (A.S.), Tehran 19835-177, Iran

Address all correspondence and requests for reprints to: M. Iwashita, M.D., Ph.D., Department of Obstetrics and Gynecology, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611, Japan. E-mail: iwashita{at}enjoy.ne.jp.

Abstract

IGF-I and IGF-II were appeared to play major roles in the adhesive and migratory events that are considered to be crucial in the implantation process. The purpose of this study was to determine the effects of IGF-I on trophoblast adhesion to extracellular matrix. Trophoblast cells obtained from early gestation at artificial abortion were incubated with the indicated doses of IGF-I at the indicated times. Trophoblast cells were treated with IGF-I in the presence or absence of RGD peptide and an antibody against -subunit of IGF-I receptor (IR3). Morphometric and morphological changes were studied using light and electron microscopy. Furthermore, vinculin, actin stress fibers, phosphorylated focal adhesion kinase (FAK), phosphotyrosine, and paxillin were immunolocalized in trophoblast cells after IGF-I treatment in the presence or absence of IR3. Immunoprecipitation and anti-phosphotyrosine immunoblotting were carried out to detect the phosphorylated FAK and phosphorylated paxillin contents of the IGF-I-treated and untreated trophoblast cells. The results showed that IGF-I promoted trophoblast adhesion to fibronectin substrate in a time- and dose-dependent manner, and addition of RGD peptide and IR3 monoclonal antibody abolished the effects of IGF-I in these cells. Morphological studies exhibited an increase in the lamellipodia formation upon IGF-I treatment, and confocal images of immunofluorescent staining revealed localization of phosphorylated FAK, paxillin, and vinculin at focal adhesions as well as redistribution of actin microfilaments and formation of actin stress fibers inside the cell. Western blotting, using antiphosphotyrosine demonstrated proteins with molecular masses of 125 kDa (FAK) and 68 kDa (paxillin) present in the IGF-I-treated cells, which were lacking in the control groups. In conclusion, these findings suggest that IGF-I can stimulate lamellipodia formation and promote adhesion of trophoblast cells to extracellular matrix by activating their adhesion molecules that must be activated within the implantation window.

This article has been cited by other articles:

				A. N. Sferruzzi-Perri, J. A. Owens, P. Standen, R. L. Taylor, G. K. Heinemann, J. S. Robinson, and C. T. Roberts Early treatment of the pregnant guinea pig with IGFs promotes placental transport and nutrient partitioning near term Am J Physiol Endocrinol Metab, March 1, 2007; 292(3): E668 - E676. [Abstract] [Full Text] [PDF]

				M. Kabir-Salmani, S. Shiokawa, Y. Akimoto, K. Sakai, K. Sakai, and M. Iwashita Tissue Transglutaminase at Embryo-Maternal Interface J. Clin. Endocrinol. Metab., August 1, 2005; 90(8): 4694 - 4702. [Abstract] [Full Text] [PDF]

				M. Kabir-Salmani, S. Shiokawa, Y. Akimoto, K. Sakai, and M. Iwashita The role of {alpha}5{beta}1-integrin in the IGF-I-induced migration of extravillous trophoblast cells during the process of implantation Mol. Hum. Reprod., February 1, 2004; 10(2): 91 - 97. [Abstract] [Full Text] [PDF]

				M. Kabir-Salmani, S. Shiokawa, Y. Akimoto, K. Sakai, S. Nagamatsu, K. Sakai, Y. Nakamura, A. Lotfi, H. Kawakami, and M. Iwashita {alpha}v{beta}3 Integrin Signaling Pathway Is Involved in Insulin-Like Growth Factor I-Stimulated Human Extravillous Trophoblast Cell Migration Endocrinology, April 1, 2003; 144(4): 1620 - 1630. [Abstract] [Full Text] [PDF]