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. We have particular interest in autoimmunity as a cause of ovarian failure. Our strategies to investigate the mechanisms of premature ovarian failure involve work in the basic science laboratory as well as in the clinic. For most young women with premature ovarian failure the most troubling part of the diagnosis is the associated infertility, and this is a major focus of our work. In our clinical investigation we have focused 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. 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). Women with histologically confirmed autoimmune oophoritis had a greater total ovarian volume as assessed by transvaginal sonography. They were also more likely to have subclinical adrenal insufficiency and clinical signs of androgen deficiency. Overall, 10/266 women tested positive for adrenal cortex autoantibodies (3.8%, 95% confidence interval: 1.8 to 6.5%). 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. 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. We completed a pilot study of the age-related decline in ovarian function. We studied 42 regularly menstruating normal women aged 18 to 50 years. All women had regular ovulatory menstrual cycles and a prior pregnancy. We administered a single 300 IU dose of human recombinant FSH on day 3 of the menstrual cycle. Main outcome measures were antral follicle count by transvaginal ultrasound, and basal and FSH-stimulated serum markers. 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. We have also been investigating other medical conditions that may be associated with 46,XX spontaneous premature ovarian failure. Our research has demonstrated a clear association between ocular surface disease and premature ovarian failure that has not been reported before. Keratoconjunctivitis sicca is defined as at least one symptom of dry eye occurring often or present all of the time. Compared with age-matched control women, we found that young women with 46,XX spontaneous POF have an increased prevalence and severity of both signs and symptoms of ocular surface disease. Given that not all patients had dry eye, it is possible that the dry eye phenotype may signal a particular mechanism of premature ovarian failure, such as autoimmunity. It is also possible that endocrine factors, such as the androgen deficiency associated with premature ovarian failure, might explain the association. Additional studies are planned to further characterize this pathology and determine its etiology. Learning the diagnosis of premature ovarian failure can be emotionally traumatic and difficult for women. We have completed a study designed to collect quantitative data about women?s emotional responses to learning the diagnosis of premature ovarian failure and to identify the supports that women with this condition use for coping. We conducted structured telephone interviews with 100 women who had been previously diagnosed with 46,XX spontaneous premature ovarian failure. The structured interviews used a script that was developed based on our findings in two focus group meetings. We found that overall, 71% of women (95% confidence interval 61-80) were unsatisfied with the manner in which they were informed by their clinician and 89% of them (95% confidence interval 81-94) reported experiencing moderate to severe emotional distress at the time. The degree of emotional distress was positively correlated with the degree of dissatisfaction with the manner in which they had been informed of the diagnosis. Thorough and accurate medical information on premature ovarian failure, support of others, and spirituality were perceived as helpful in coping. The findings suggest that the manner in which patients are informed of this diagnosis can significantly impact their level of distress. Patients with premature ovarian failure perceive a need for clinicians to spend more time with them and to provide more information about the condition. In a mouse model we found that autoantibodies from mice with experimental autoimmune oophoritis bind to Mater, a novel 125 kd protein that is specific to the oocyte cytoplasm. Mater is a novel oocyte-specific maternal effect gene whose product we previously demonstrated is essential for embryonic development beyond the two-cell stage. We have demonstrated in mice that the expression pattern of Mater and its protein is consistent with its role as a maternal effect gene, and we also demonstrated by immunogold electron microscopy that Mater protein is localized in the nucleolus and mitochondria. Recently we defined the human homologue of mouse Mater, a maternal effect gene critical to female fertility.