Expression of receptors for insulin-like growth factor-I and transforming growth factor-beta in human follicles.
The in-vitro growth of immature oocytes in early follicles from cryopreserved human ovarian tissues is a new concept in in-vitro fertilization programmes for the treatment of infertile and cancer patients. To better understand the regulatory mechanism of follicular development, immunohistochemistry was used to study the expression of insulin-like growth factor (IGF) type I receptor (IGF-IR) and transforming growth factor-beta (TGFbeta) type I (TbetaR-I) and type II (TbetaR-II) receptors in fresh and frozen ovarian tissues from 14 women. Immunoreactivities for IGF-IR and TbetaR-I were present simultaneously in the oocytes of primordial, pre-antral and antral follicles. Staining for both IGF-IR and TbetaR-I was also observed in granulosa cells of primordial, pre-antral and antral follicles. IGF-IR and TbetaR-I also stained in thecal cells of pre-antral and antral follicles. Stromal cells in surrounding ovarian tissue expressed IGF-IR and TbetaR-I at various follicular stages. Unlike TbetaR-I, TbetaR-II was expressed only in the oocytes of primordial and primary follicles, and with weak staining intensity in thecal cells. No significant staining for TbetaR-II was found in oocytes and granulosa cells of antral follicles. There was no difference in staining patterns for IGF-IR, TbetaR-I and TbetaR-II between fresh and frozen ovarian tissues, indicating that cryopreservation might not significantly alter the immunoreactivities of these receptors in frozen ovarian tissue. The results suggest that IGF-I and TGFbeta may participate in the regulation of follicular growth by binding to their receptors through an autocrine or paracrine mechanism. IGF-I and TGFbeta may be useful in regulating the in-vitro or in-vivo maturation of oocytes not only in later follicles but also very early follicles, from cryopreserved ovarian tissues for clinical use in the future.
Qu
J
J
Laboratory of In Vitro Fertilization, Department of Gynecology, Hospital of Saint Luc, Catholic University of Louvain, Brussels, Belgium.
Godin
P A
PA
Nisolle
M
M
Donnez
J
J
D000328:Adult; D015925:Cryopreservation; D005260:Female; D005307:Fertilization in Vitro; D006107:Granulosa Cells / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D009865:Oocytes / Q000254:growth & development / Q000378:metabolism; D006080:Ovarian Follicle / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D017526:Receptor, IGF Type 1 / Q000378:metabolism*; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism*; D013799:Theca Cells / Q000378:metabolism
D018125:Receptors, Transforming Growth Factor beta; D017526:Receptor, IGF Type 1