Mouse GDF9 decreases KITL gene expression in human granulosa cells.

Kit ligand (KITL) is an important granulosa cell-derived growth factor in ovarian folliculogenesis, but its expression and function in human granulosa cells are currently poorly understood. Based on studies performed in animal models, it was hypothesised that KITL gene expression in human granulosa cells is regulated by androgens and/or growth differentiation factor 9 (GDF9). We utilised two models of human granulosa cells, the KGN granulosa tumour cell line and cumulus granulosa cells obtained from preovulatory follicles of women undergoing assisted reproduction. Cells were treated with combinations of 5α-dihydrotestosterone (DHT), recombinant mouse GDF9, and the ALK4/5/7 inhibitor SB431542. KITL mRNA levels were measured by quantitative real-time PCR. No change in KITL mRNA expression was observed after DHT treatment under any experimental conditions, but GDF9 treatment resulted in a significant decrease in KITL mRNA levels in both KGN and cumulus cells. The effect of GDF9 was abolished by the addition of SB431542. These results indicate that KITL is not directly regulated by androgen signalling in human granulosa cells. Moreover, this study provides the first evidence that GDF9 negatively regulates KITL gene expression in human granulosa cells providing new information on the regulation of these important growth factors in the human ovary.

Factors predicting the outcome of intracytoplasmic sperm injection for infertility.

BACKGROUND: Male factor abnormality is the cause of infertility in about 20%-40% of infertile couples. Assisted reproduction with intracytoplasmic sperm injection is the only treatment option for severe forms of andrological infertility. METHODS: We retrospectively analysed patients who had had intracytoplasmic sperm injection for male factor infertility. The clinical and laboratory factors that influenced the pregnancy rate were also analysed. RESULTS: One hundred and seventy-five cycles in 164 couples were analysed. The fertilization, cleavage and pregnancy rates were similar in the groups that had had intracytoplasmic sperm injection with epididymal, testicular or ejaculate sperm. Univariate analysis of the clinical variables showed progressive reduction in pregnancy rate with increase in the woman partner's age and body mass index, and presence of pelvic disease, but these were not statistically significant. The age of the woman was the most significant factor affecting the pregnancy rate after adjusting for body mass index and pelvic disease in the multivariate analysis (OR 0.26, 95% CI: 0.08-0.84, p=0.03). The oocyte number, embryo transfer number and transfer day had no significant influence on the outcome. CONCLUSION: The woman partner's age influences the success of assisted reproduction with intracytoplasmic sperm injection in male factor infertility. Thus, the chances of success are better if the couple seeks treatment at an early age.