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

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 alpha-subunit of IGF-I receptor (alphaIR3). 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 alphaIR3. 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 alphaIR3 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.

Early treatment of the pregnant guinea pig with IGFs promotes placental transport and nutrient partitioning near term

“…This normal physiological process permits uninterrupted high-conductance flow of blood from the mother that constitutes 30 -40% of the total maternal cardiac output (57). In culture, IGF-I stimulates trophoblast migration and invasion (52) through elevated matrix metalloproteinase-9 activity (40), activation of integrins (46,47), and altered cytoskeletal organization (45). It also inhibits vasoconstrictors, such as thromboxane B 2 and prostaglandin F 2␣ , in human term placental explants (69).…”

Real-time QCM-D monitoring of cellular responses to different cytomorphic agents

“…They respond in very specific ways to different types of perturbations, allowing them to be used as biointerfaces for the detection of molecules interfering with a cell's activity. Cells respond to stressful agents by complex pathways that often lead to cytoskeletal changes to the cells, that can be detected using different techniques, such as microscopy or flow cytometry (Basu et al, 1999;Hosoya et al, 1993;Kabir-Salmani et al, 2002;Rotsch and Radmacher, 2000;Walter et al, 1998;Yamaguchi et al, 1993). Although these measurement techniques are generally sensitive and useful, their implementation requires that the cells be lysed or fixed, hence rendering these techniques unsuitable for real-time in situ characterization of cell health.…”

The polymorphism of rs6505162 in the MIR423 coding region and recurrent pregnancy loss

“…Igf1 has been shown to play a critical role in placental function, which stimulates extravillous trophoblast (EVT) cell migration and invasion and thereby influences placental development and fetal growth. Insufficient invasion of EVT cells into the endometrium leads to pregnancy-related complications, including pregnancy loss (Kabir-Salmani et al 2002, Mayama et al 2013. Grb10 encodes a signaling adapter protein, is expressed predominantly from the maternally inherited allele, and acts to restrict fetal and placental growth (Charalambous et al 2010).Grb10 expression in term placenta is significantly negatively correlated with head circumference (Moore et al 2015).…”