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Identifier

000348013

Title

Μελέτη της έκφρασης, της ρύθμισης και του βιολογικού ρόλου των μορίων συνάφειας σε κοκκιώδη κύτταρα της ανθρώπινης ωοθήκης

Author

Ρολάκη, Αλεξάνδρα

Thesis advisor

Μακρυγιαννάκης, Αντώνιος

Reviewer

Γραβάνης, Αχιλλέας
Τσατσάνης, Χρήστος
Μαργιωρής, Ανδρέας
Στουρνάρας, Χρήστος
Λιαπάκης, Γιώργος
Παπακωνσταντή, Λίτσα

Abstract

The formation of the corpus luteum (CL) is critical for the establishment of a successful pregnancy. Following ovulation, under the influence of luteogenic hormones, the CL develops from the remnants of the ovulated ovarian follicle. This process involves intense reorganization of constituent cells, phenomena that includes varying cell-matrix interactions. These events, however, are poorly characterized. Adhesion molecules, especially integrins, have crucial role in the physiological functions of many different systems. Many studies, in the past, have established for several cell types that the binding of cell surface integrins to their ligands in the extracellular matrix facilitates cell proliferation, migration and survival. Integrins have also been found to participate in many important functions of the reproductive system, such as fertilization, interactions between the preimplantation embryo and endometriun as well as trophoblast outgrowth during implantation. Moreover, it has been demonstrated that activity of integrins was regulated by human chorionic gonadotropin (hCG) and vascular endothelial growth factor (VEGF). In order to understand the role and potential regulation of cell-matrix interactions in the formation of the CL, we investigated the expression of the matrix protein fibronectin (FN) and selected FN-binding integrin receptors on luteinized granulosa cells (GCs). We further examined the possible regulation of that expression by the luteogenic hormone, hCG and the involvement of mitogenic VEGF. Lastly, we investigated the role of the aforementioned integrins in promoting the adhesion, migration and survival of GCs. The present data reported that FN is detected around GCs with luteinization, while several FN-binding integrins, along with the VEGF receptor (Flt-1), appeared on the surface of these cells during the early luteal phase. Expression of these proteins declined in the late luteal phase with regression of the CL. In vitro, GCs released FN and stimulation of these cells with hCG, increased the surface expression of α5β1 and αvβ3 integrins, as well as the amount of FN associated with the cell surface. These effects were reproduced by stimulation with VEGF and hCG-stimulated up-regulation of FN, α5β1 and αvβ3 on the surface of GCs was inhibited by anti-VEGF antibody. In addition, there has been shown that expression of α5β1 and αvβ3 integrins mediates adhesion to FN, an ability that promotes cell movement and prevents apoptosis. In conclusion, the present study reports new data on the role of integrins in migration, adhesion and apoptosis of human GCs, and the regulation of these processes by the hCG and VEGF, and thus indicate the potential contribution of these molecules in formation and maintenance of the CL.

Physical description

xvi, 135 σ. : πιν. ; 30 εκ.

Language

Greek

Subject

Cell Adhesion Molecules

Corpus Luteum

Reproduction

Αναπαραγωγή

Ωχρό σωμάτιο

Issue date

2007-12-14