Human Folliculogenesis Research Articles

Ca 2+]i responses during proliferation and differentiation of hepatocytes immortalized by transduction with a thermolabile mutant SV40 large T antigen : [formula omitted]. Department of Gastroenterology, Juntendo University School of Medicine, Tokyo, Japan; and ∗Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York

To determine if luteinizing human granulosa cells contain messenger ribonucleic acid (mRNAs) encoding insulin-like growth factor-binding protein (IGFBPs) and if cultured granulosa secrete IGFBPs into conditioned medium (CM).Northern analysis, using IGFBP-specific complementary deoxyribonucleic acid probes, was used to detect granulosa-derived IGFBP mRNAs. Western ligand blot analysis of CM was used to detect IGFBPs secreted by granulosa cultures with and without human chorionic gonadotropin (hCG).Granulosa cells were obtained from the In Vitro Fertilization (IVF) Program at Stanford University, a private teaching institution.Patients undergoing IVF for tubal disease.None.Transcripts of IGFBP mRNA and IGFBPs secreted into CM were detected by autoradiography of Northern and Western ligand blots, respectively.Transcripts of IGFBP-3, IGFBP-2, and IGFBP-1 mRNA were detected in human luteinizing granulosa. Cultured granulosa secreted IGFBPs with molecular weights corresponding to IGFBP-3, IGFBP-2, and IGFBP-1, and the latter two IGFBPs increased with 10 ng/mL hCG. A 24 kd IGFBP was noted, which may be newly characterized IGFBP-4.These data show that luteinizing human granulosa cells express mRNAs encoding three IGFBPs, secrete IGFBPs into culture medium, and that production of at least two of the IGFBPs is hCG-dependent, further supporting a role for the IGF system in human folliculogenesis.

Insulin-like growth factor binding protein-2, 28 kDa and 24 kDa insulin-like growth factor binding protein levels are decreased in fluid of dominant follicles, obtained from normal and polycystic ovaries.

In order to investigate potential changes in insulin-like growth factor binding proteins (IGFBPs) during human follicle maturation, we examined the IGFBP profiles in follicular fluid from follicles in different stages of maturation. Samples were obtained from ovaries of women with regular menstrual cycles and of subjects with cycle abnormalities and polycystic ovaries (diagnosed as polycystic ovary syndrome (PCOS)) and analyzed by Western ligand blotting. IGFBPs of 43 kDa, 37 kDa, 31 kDa, a doublet around 28 kDa and a minor band of 24 kDa were detected in follicle fluid of normal non-dominant (size < 10 mm) and atretic (androstenedione/estradiol ratio > 4) follicles of both regularly menstruating women and PCOS patients. The 43 and 37 kDa IGFBPs could be identified as IGFBP-3 and the 31 kDa IGFBP as IGFBP-2, whereas the 28 kDa IGFBP could not be identified as IGFBP-1, all by immunoblotting techniques. A dramatic decrease in IGFBP-2, the 28 kDa and 24 kDa IGFBPs was observed in follicular fluid of dominant follicles (size > 10 mm) of both regular menstruating individuals and one PCOS patient as compared with follicular fluid of normal non-dominant or atretic follicles. These observations indicate that the PCOS follicle may not be different from normal with respect to IGFBP profiles. Furthermore, these results suggest that at least one of these IGFBPs might be involved in human folliculogenesis.

Insulin-like growth factor-I (IGF-I) may not be essential for ovarian follicular development: evidence from IGF-I deficiency.

Insulin-like growth factor-I (IGF-I) stimulates growth and differentiation in follicular granulosa cells (GC). To examine whether this effect is prerequisite to human folliculogenesis, a patient with Laron-type dwarfism (IGF-I deficiency secondary to GH receptor abnormality) was examined while undergoing in vitro fertilization treatment. Despite low levels of IGF-I in serum and follicular fluid (less than 3 and less than 2 nmol/L) and very high levels of IGF-I-binding protein, the patient developed normal ovarian follicles. After the administration of GnRH analog (GnRHa) and human menopausal gonadotropin in a dose similar to that used in normovulatory women, estradiol (E2) levels reached above 5000 pmol/L on the day of hCG administration, and mature fertilizable oocytes were retrieved during ovum pickup. The patient's GC E2 production, tested in a primary culture, did not respond to IGF-I after 4 days of incubation, while control cultures showed a significant increase. Only after a priming period of 7 days did IGF-I have a significant effect on E2 production, as observed in the patient's GC culture. This delayed response suggests that the patient's GC were not exposed in vivo to IGF-I. Our data support the view that IGF-I is not required for normal follicular development, but is, rather, a nonessential modulator of FSH action.

Human granulosa contain messenger ribonucleic acids encoding insulin-like growth factor-binding proteins (IGFBPs) and secrete IGFBPs in culture

To determine if luteinizing human granulosa cells contain messenger ribonucleic acid (mRNAs) encoding insulin-like growth factor-binding protein (IGFBPs) and if cultured granulosa secrete IGFBPs into conditioned medium (CM). Northern analysis, using IGFBP-specific complementary deoxyribonucleic acid probes, was used to detect granulosa-derived IGFBP mRNAs. Western ligand blot analysis of CM was used to detect IGFBPs secreted by granulosa cultures with and without human chorionic gonadotropin (hCG). Granulosa cells were obtained from the In Vitro Fertilization (IVF) Program at Stanford University, a private teaching institution. Patients undergoing IVF for tubal disease. None. Transcripts of IGFBP mRNA and IGFBPs secreted into CM were detected by autoradiography of Northern and Western ligand blots, respectively. Transcripts of IGFBP-3, IGFBP-2, and IGFBP-1 mRNA were detected in human luteinizing granulosa. Cultured granulosa secreted IGFBPs with molecular weights corresponding to IGFBP-3, IGFBP-2, and IGFBP-1, and the latter two IGFBPs increased with 10 ng/mL hCG. A 24 kd IGFBP was noted, which may be newly characterized IGFBP-4. These data show that luteinizing human granulosa cells express mRNAs encoding three IGFBPs, secrete IGFBPs into culture medium, and that production of at least two of the IGFBPs is hCG-dependent, further supporting a role for the IGF system in human folliculogenesis.