| Co-Investigator(Kenkyū-buntansha) |
KUJI Naoaki Keio University School of Medicine, Dept of OB/GYN, 医学部, 助手 (80169987)
MIYAZAKI Toyohiko Keio University School of Medicine, Dept of OB/GYN, 医学部, 講師 (20174162)
SUEOKA Kou Keio University School of Medicine, Dept of OB/GYN, 医学部, 講師 (90162833)
|
|---|
| Research Abstract |
In human embryo implantation, a large number of trophoblasts infiltrate through the decidua and extend as far as the superficial layer of the myometrium. We have demonstrated that human endometrial and decidual cells express components of receptors for ECM proteins, the βィイD21ィエD2 integrin family, on their surfaces and that the expression is a dynamic process related to the menstrual cycle. In addition, the expression of βィイD21ィエD2 integrins in human endometrium increases at the time of implantation and remains high in the decidua during early pregnancy. We developed assays for the attachment of mouse embryos and for trophoblastic spreading on cultured human decidual cells. The addition of antibodies directed against βィイD21ィエD2 and α integrin subunits to cultured decidual cells did not affect the rates of hatching or attachment of the blastocysts, whereas the outgrowth of embryos on the decidual cells was inhibited by their antibodies in a dose-dependent manner. Thus, βィイD21ィエD2 integr
… More
in in human endometrium and decidua may be important in mediating the organization of extracellular matrix proteins derived from embryos during the early stage of implantation.
In the next experiment, the expression and function of focal adhesion kinase (FAK) in human decidual cells were investigated. This kinase is localized to focal adhesions in fibroblasts, and is phosphorylated on tyrosine in normal and src-transformed fibroblasts. Immunofluorescent staining revealed that the cultured decidual cells expressed high levels of FAK at the cell periphery. FAK co-localized with integrins in cellular focal adhesions. Treatment of decidual cells with herbimycin A, a tyrosine kinase inhibitor, did not affect the rate of hatching or attachment of blastocysts. However, the outgrowth of embryos on the decidual cells was inhibited by the addition of herbimycin A in a dose-dependent manner, implying that blastocyst attachment and outgrowth are mediated by different mechanisms. Thus, tyrosine phosphorylation of FAK on decidual cells may be important in development and differentiation following attachment.
The final experiment was undertaken to study the role of the RGD cross-linking region of integrin βィイD21ィエD2 subunit in embryo implantation. A peptide corresponding to integrin βィイD21ィエD2 [140-164] (DDL; DYPIDLYYLMDLSYSMKDDLENVKS) inhibited decidual cell attachment to FN-coated dishes in a dose-dependent manner. A variant integrin peptide in which Asp 157 and Asp 158 were replaced by Ala (AAL; DYPIDLYYLMDLSYSMKAALENVKS) did not affect decidual cell attachment to FN. Inhibition by DDL peptide was reversed by prior treatment with an RGD-containing peptide but not by prior treatment with an RGE-containing peptide. Treatment of decidual cells with synthetic peptides did not affect the rates of hatching and attachment of blastocysts. The outgrowth of embryos on decidual cells was inhibited by DDL peptide in a dose-dependent manner, but not by AAL peptide. These findings suggest that integrin βィイD21ィエD2 [140-164] on decidual cells may be important in embryonic development and differentiation following attachment. Less
|
