Ovarian Folliculogenesis

Child Health And Human Development

Investigators

Linked publications & trials

Abstract

This project seeks to improve the clinical care available to patients with disorders of ovarian follicle function. In pursuing this goal, we expect to expand basic science understanding of the ovarian follicle in health and disease. We have focused on premature ovarian failure, a condition that prematurely terminates normal ovarian function and fertility in 1% of women. Our strategies to investigate the mechanisms of premature ovarian failure involve work in the basic science laboratory as well as in the clinic. [unreadable] [unreadable] One focus of our research is on autoimmune oophoritis, a specific form of premature ovarian failure that is associated with steroidogenic cell autoimmunity. A striking characteristic of autoimmune oophoritis is the well-established sparing of primordial follicles, despite the presence of intense lymphocytic infiltration in the theca of developing follicles. This distinctive pathophysiologic process that spares primordial follicles presents the theoretical possibility of developing an immunosuppressive treatment that could restore fertility. [unreadable] [unreadable] We have completed a controlled prospective evaluation to assess the association between serum adrenal cortex autoantibodies and histologically confirmed autoimmune lymphocytic oophoritis. We tested 266 women with 46, XX spontaneous premature ovarian failure for the presence of adrenal cortex antibodies as assessed by indirect immunofluoresence. We tested for the presence of autoimmune oophoritis in ovarian biopsy specimens from 10 women using immunohistochemical lymphocyte markers. We obtained a histological diagnosis of autoimmune oophoritis in 4 women who tested positive for adrenal cortex autoantibodies and excluded this diagnosis in ovarian biopsies from 6 women who tested negative for these autoantibodies (4/4 vs 0/6, p=0.005, Fisher's Exact Test). The availability of a validated serum marker with which to detect autoimmune lymphocytic oophoritis will spare women the need for ovarian biopsy and should facilitate clinical research toward developing a therapy that could restore fertility for these women.[unreadable] [unreadable] We are also investigating genetic mechanisms of spontaneous premature ovarian failure. Fragile X syndrome, an X-linked disorder, is the most common hereditary cause of mental retardation and developmental delay. In nearly all cases the disorder is caused by an expansion of CGG trinucleotide repeats in the 5? untranslated region of FMR1 (Fragile Site Mental Retardation 1 Gene). Interestingly, premutations in the FMR1 gene, located at Xq27.3, have been associated with the development of 46,XX spontaneous premature ovarian failure. We reported a case of a young woman with established spontaneous premature ovarian failure who conceived subsequent to the diagnosis and had a child who manifests mental retardation due to fragile X syndrome. The case illustrates the need to inform patients with premature ovarian failure regarding their increased risk of carrying a premutation in FMR1, their options for testing, and potential implications for family members with regard to diagnosis of menstrual irregularity, developmental delay, and neurological symptoms.[unreadable] [unreadable] Members of the TGF beta superfamily play a role in supporting normal ovarian function. The gene for bone morphogenic protein 15 (BMP15), one member of this family, is located at Xp11.2. We participated in an international collaboration to perform BMP15 genetic analysis in a large series of women with spontaneous premature ovarian failure. Investigation revealed two novel heterozygous missense alterations affecting the proregion of BMP15. These alterations were not present in any of the controls. Because BMP15 is within the Xp locus linked to premature ovarian failure the findings support the concept that BMP15 represents one of the genes whose haploinsufficiency significantly contributes to the primary ovarian insufficiency in Turner syndrome.[unreadable] [unreadable] The Deleted in AZoospermia-Like (DAZL), located at 3p24, is another candidate gene for premature ovarian failure. We participated in a large multicenter collaboration to determine if sequence variants in this gene may impact the development of spontaneous premature ovarian failure. We found that single nucleotide polymorphisms (SNPs) in the DAZL gene may act singly or jointly to affect reproductive characteristics of women. In addition sequencing of the entire coding region of DAZL identified four putative missense mutations. Further studies may shed light on the role of DAZL in the development of spontaneous premature ovarian failure.[unreadable] [unreadable] Mice with mutations in the c-kit tyrosine kinase receptor Kit (W) and the c-kit ligand Kitlg (Steel) have impaired development of primordial germ cells. During the current period we demonstrated that mutations in the coding regions of the KITLG gene appear not to be a common cause of this condition. [unreadable] [unreadable] In another line of clinical investigation we have been studying the normal age-related decline in ovarian function of women with regular menstrual cycles. Greater insight into the physiology of the normal ovarian aging process might provide a basis from which to more accurately assess ovarian endocrine function in an individual young woman. In a pilot study of the age-related decline in ovarian function we found that age correlated most strongly with FSH-stimulated inhibin B, followed by antral follicle count, basal FSH, basal Mullerian Inhibiting Substance (MIS), and basal inhibin B. Total antral follicle count correlated most strongly with basal MIS level. Further investigation is required to determine the cycle-to-cycle reproducibility of FSH-stimulated inhibin B levels and the ability of this test to detect asymptomatic ovarian endocrine insufficiency in young women.[unreadable] [unreadable] We also conduct clinical research to define more fully other needs of young women with spontaneous premature ovarian failure. We found that while on estradiol replacement 13% of women (95% confidence interval 7.9-20.3%) had serum free testosterone levels below the lower limit of normal ( less than 1.1 pg/mL). The clinical implications of this testosterone deficiency may be significant and these are currently under further investigation by our laboratory. [unreadable] [unreadable] We investigate women?s psychological response to the diagnosis of spontaneous premature ovarian failure. We found that over two-thirds of women with premature ovarian failure were unsatisfied with the manner in which they were informed of the diagnosis. Nearly 90% reported experiencing moderate to severe emotional distress at the time, the degree of which was positively correlated with the degree of dissatisfaction with the manner in which they had been informed of the diagnosis. The findings suggest that the manner in which patients are informed of this diagnosis can significantly impact their level of distress. Patients perceive a need for clinicians to spend more time with them and provide more information about premature ovarian failure. We also demonstrated a statistically significant positive correlation between Functional Well-Being and Spiritual Well-Being by employing an instrument specifically designed and validated to measure spirituality apart from religiosity. Our findings suggest a need for a controlled interventional clinical trial to test the hypothesis that strategies to assist women in finding meaning and purpose in the diagnosis of spontaneous premature ovarian failure would improve their functional well-being and quality of life. A group of women with the disorder who receive standard management would serve as controls.