REPRODUCTIVE ENDOCRINOLOGY AND INFERTILITY
, Head, Unit on Reproductive Endocrinology and Infertility
Alicia Armstrong, MD, Associate Fellowship Program Director, Reproductive Endocrinology and Infertility
Pamela Stratton, MD, Head, Gynecology Consult Service
DeWolf Payson, MD, Guest Researcher
Michael Wittenberger, MD, Guest Researcher
John Norian, MD, Research Fellow
Ninet Sinaii, MPH, PhD, Research Fellow
Takahisa Shibata, MD, PhD, Visiting Fellow
Hyacinth Browne, MD, Clinical Fellow
Eve Feinberg, MD, Clinical Fellow
Barbara Stegmann, MD, Clinical Fellow
Chantal Mayers, BS, Predoctoral Fellow
Uterine leiomyomata
Uterine leiomyomata, commonly called fibroids, are one of the most common and prevalent diseases of the female reproductive tract. Fibroids disproportionately affect African American women and increase the likelihood of adverse pregnancy outcomes, such as preterm delivery, miscarriage, and cesarean section; they also cause excessive menstrual bleeding and pelvic pain.
Factors that promote leiomyoma growth and development remain poorly understood. To gain insight into strategies for medical therapy, we used a gene-profiling approach to examine genes that might lead to leiomyoma development. Our approach revealed a striking similarity between leiomyomata and disorders of altered wound healing. Based on the similarity of uterine fibroids with tissue undergoing wound healing, we focused on the composition of the extracellular matrix (ECM) in uterine fibroids. In collaboration with William Catherino and Phyllis Leppert, we showed that leiomyoma cells secrete relatively high levels of the large proteoglycan versican. Versican is differentially spliced, with the V0 and V1 variants more highly expressed in leiomyomata than in matched myometrial samples. Versican has glycosaminoglycan side chains, suggesting that increased secretion of versican is partly responsible for the elevated glycosaminoglycan content in leiomyomata. Our observation is relevant to leiomyoma formation because increased levels of glycosaminoglycan may contribute to the stiffness of leiomyomata. Alteration in the mechanical property of the tissue may promote the growth of leiomyomata, a possibility we plan to assess in the coming year.
Some leiomyomata are associated with rare genetic syndromes, such as hereditary leiomyomatosis and renal cell cancer (HLRCC). To learn whether the cellular events associated with HLRCC leiomyoma resemble “common” or nonsyndromic leiomyomata, we used gene-profiling experiments to compare the two types of leiomyoma. We found that, while both types exhibited low levels of fumarate hydratase, expression of glycolysis enzymes was significantly higher in the HLRCC-syndromic leiomyoma than in the common leiomyoma. We confirmed overexpression of the genes with real-time reverse-transcriptase PCR. Interestingly, overexpression of the glycolysis enzymes in one HLRCC specimen was consistent throughout the glycolysis pathway, with the exception of phosphoglycerate kinase. We interpret the findings to suggest that the glycolysis pathway is upregulated in HLRCC leiomyoma, whereas the Krebs cycle function was diminished in response to low levels of fumarate hydratase. In short, the results indicate that, while leiomyomata associated with rare syndromes may physically resemble common nonsyndromic leiomyomata, the two tumor types evidence marked differences. In the coming year, we will examine whether the altered ECM produced by uterine fibroids may contribute to the growth of fibroids.
Catherino WH, Leppert PC, Segars JH. The promise and perils of microarray analysis. Am J Obstet Gynecol 2006;195:389-93.
Catherino WH, Mayers CM, Mantzouris T, Armstrong AY, Linehan WM, Segars JH. Compensatory alterations in energy homeostasis characterized in uterine tumors from hereditary leiomyomatosis and renal cell cancer. Fertil Steril 2007;88(4 Suppl):1039-48.
Dixon D, Parrott EC, Segars JH, Olden K, Pinn VW. The second National Institutes of Health international congress on advances in uterine leiomyoma research: conference summary and future recommendations. Fertil Steril 2006;86:800-6.
Leppert PC, Catherino WH, Segars JH. A new hypothesis about the origin of uterine fibroids based on gene expression profiling with microarrays. Am J Obstet Gynecol 2006;195:415-20.
Payson M, Leppert P, Segars J. Epidemiology of myomas. Obstet Gynecol Clin North Am 2006;33:1-11.
Role of BRX (also known as AKAP13) in cardiac development
Our interest in the molecular mechanism of estrogen action in reproductive tissues led us to clone a large modular protein called Brx—for breast receptor auxiliary factor (the gene is now known as AKAP13)—from a breast cancer expression library. Our earlier research revealed that Brx augmented ligand-dependent activation of estrogen receptors alpha and beta and was capable of interacting with the receptors in vivo. Last year, in collaboration with George Chrousos and Tomoshige Kino, we reported that Brx was capable of influencing in vivo activation of the glucocorticoid receptor (GR), as mice haplo-insufficient for the AKAP13 gene exhibited an impaired response to dexamethasone.
In collaboration with Heiner Westphal, we have continued to examine the AKAP13-homozygmous null mice (knockout). Unexpectedly, mice with mutations in both alleles of the AKAP13 gene died in utero by embryonic day 10.5 to 11.0. During the past year, studies confirmed our initial findings and revealed that the mice died from a failure of heart development. It was known that AKAPs were involved in heart function, but a specific requirement for AKAP13 in heart development had not been reported. Experiments this past year therefore focused on the genes affected by loss of AKAP13 during development. We found that several critical genes involved in heart formation, such as MEF2C, were altered in the AKAP13 null mice. In addition, we examined expression of the AKAP13 protein in adult and normal developing heart tissues and found strong expression of a transcript encoding a 210kDa protein variant of AKAP13.
Also in the past year, in collaboration with John Wu, we examined the central nervous system (CNS) for expression of AKAP13, given that AKAP13-null mice exhibited altered CNS development. We tested whether AKAP13 contributed to estrogen action in CNS tissues. The studies revealed an interesting pattern of expression in the brain and pituitary of the mouse. In the coming year, we plan to focus on the effects of AKAP13 on cardiac development in order to characterize more fully the defect in cardiac development.
Eddington DO, Baldwin EL, Segars JH, Wu TJ. Estrogen effects on the expression of Brx in the brain and pituitary of the mouse. Brain Res Bull 2006;69:447-51.
Kino T, Souvatzoglou E, Charmandari E, Ichijo T, Driggers P, Mayers C, Alatsatianos A, Manoli I, Westphal H, Chrousos GP, Segars JH. Rho family guanine nucleotide exchange factor Brx couples extracellular signals to the glucocorticoid signaling system. J Biol Chem 2006;281:9118-26.
Endometriosis and chronic pelvic pain
Endometriosis adversely affects the reproductive lives of up to 10 percent of women (Stratton, Fertil Steril 2006;86:1302; Gustofson RL et al., Fertil Steril 2006;86:298). In the past year, Pamela Stratton completed the analysis of a randomized, prospective, placebo-controlled trial of raloxifene (180 mg daily) for biopsy-proven endometriosis. The study was one of the largest randomized studies of medical therapy for endometriosis. Unexpectedly, the results indicated that women treated with the selective estrogen-receptor modulator raloxifene experienced return of pain sooner than women treated with placebo. The results suggested that, contrary to expectations, interference with estrogen action increased the pain threshold.
Diagnosis of endometriosis represents a problem for patients and providers in that surgery is required for accurate diagnosis; nevertheless, one persistent issue concerns the appearance of endometriosis lesions at surgery. In the past year, Stratton and Barbara Stegmann correlated biopsy results with lesion appearance in order to determine the characteristics of lesions most likely to represent endometriosis. The results showed that, in contrast to prevailing opinion, no single color had a high association with endometriosis and that surgeons operating on women with endometriosis should biopsy any suspicious lesion. Specifically, subtle lesions were nearly as likely to contain endometriosis as were black or mixed-color lesions. Overall, the lesions most likely to contain pathologically confirmed disease were greater than 10 mm in diameter and 5 mm in depth. However, experienced surgeons were able to identify lesions correctly only 64 percent of the time. This study suggests that biopsy, not visual inspection, should remain the gold standard for disease diagnosis. In the coming year, we will continue examining the relationship between disease severity and patient characteristics in endometriosis by analyzing questionnaires from 1,000 women in the Oxford Endometriosis Gene (OXEGENE) Study.
Premkumar A, Venzon DJ, Avila N, Johnson DV, Remaley AT, Forman MR, Eng-Wong J, Zujewski J, Stratton P. Gynecologic and hormonal effects of raloxifene in premenopausal women. Fertil Steril 2007;88:1637-44.
Sinaii N, Cleary SD, Younes N, Ballweg ML, Stratton P. Treatment utilization for endometriosis symptoms: a cross-sectional survey study of lifetime experience. Fertil Steril 2007;87:1277-86.
Sinaii N, Plumb K, Cotton L, Lambert A, Kennedy S, Zondervan K, Stratton P. Differences in characteristics among 1,000 women with endometriosis based on extent of disease. Fertil Steril 2007 [E-pub ahead of print].
Stegmann BJ, Sinaii N, Liu S, Segars J, Merino M, Nieman LK, Stratton P. Using location, color, size, and depth to characterize and identify endometriosis lesions in a cohort of 133 women. Fertil Steril 2007 [E-pub ahead of print].
Stratton P, Sinaii N, Segars J, Koziol D, Wesley R, Zimmer C, Winkel C, Neiman L. Return of chronic pelvic pain after raloxifene treatment: a randomized controlled trial. Obstet Gynecol 2008, in press.
Assessment and preservation of ovarian function in women and girls undergoing cancer treatment
In the past year, Alicia Armstrong began an initiative to study treatment regimens designed to minimize the effect of cancer treatments on the later reproductive function of women. Thanks in large part to today’s more successful cancer treatments, many girls and women are cancer survivors but find that their reproductive function is irreparably damaged by their treatment. The objective of the initiative is to evaluate and devise strategies to enable women who are cancer survivors to maximize ovarian and reproductive function. One possible strategy is the use of hormonal therapy to reduce blood supply to the ovary before initiation of chemotherapy. In the coming year, we plan to begin large multicenter trials of gonadotropin-releasing hormone antagonists in young women before cancer treatment.
Armstrong AY, Calis KA, Nelson LM. Do survivors of childhood cancer have increased incidence of primary ovarian insufficiency? Nat Clin Pract Endocrinol Metab 2007;3:326-7.
Infertility and reproductive health disparities
In the past two decades, many couples who experienced infertility have used Assisted Reproductive Technologies (ART) to achieve pregnancy. We have long been interested in the factors that affect the success of ART. In some cases, delayed child bearing and reduced numbers of oocytes (diminished ovarian reserve) may adversely influence the likelihood of a couple’s success when pursuing assisted reproduction. In the past year, we examined—in 1,238 first-time ART cycles—how a woman’s age and serum basal follicle-stimulating hormone value influenced both success with ART and the cost of a live birth. Given that many couples consider cost when planning to pursue assisted reproduction, we focused on cost for a live birth. We found that the cost per delivery was relatively similar until the expected delivery rates fell below 5 percent; below a 5 percent expected delivery, the cost rose sharply. The results suggest that, in instances where success is unlikely, patients and providers would be wise to pursue other strategies for parenthood. In the coming year, we plan to test algorithms that will enable providers and patients to assess the likelihood of success with assisted reproduction.
Reproductive health disparities exist for many women. In an effort to devise strategies to optimize reproductive outcomes across racial and ethnic groups, we have been interested in examining the causes and consequences of these disparities. One such disparity relates to outcomes of infertility treatments. Recently, we found that the different incidence of leiomyoma in African American women explained, at least in part, a reduction in the rate of successful pregnancy outcomes with assisted reproduction. In the past year, we evaluated ART utilization and outcomes among Hispanic couples. The study suggested that, contrary to claims of some that economic barriers account for lower rates of utilization, other factors were responsible. In the coming year, we plan to initiate a multicenter trial to assess disparities in and utilization of infertility services.
Armstrong A, Maddox Y. Health disparities and women’s reproductive health. Ethn Dis 2007;17(S2):4-7.
Feinberg EC, Larsen FW, Catherino WH, Zhang J, Armstrong AY. Comparison of assisted reproductive technology utilization and outcomes between Caucasian and African American patients in an equal-access-to-care setting. Fertil Steril 2006;85:888-94.
Feinberg EC, Larsen FW, Wah RM, Alvero RJ, Armstrong AY. Economics may not explain Hispanic underutilization of assisted reproductive technology services. Fertil Steril 2007;88:1439-41.
Henne MB, Stegmann BJ, Neithardt AB, Catherino WH, Armstrong AY, Kao TC, Segars JH. The combined effect of age and basal follicle-stimulating hormone on the cost of a live birth at assisted reproductive technology. Fertil Steril 2007 [E-pub ahead of print].
Wittenberger MD, Catherino WH, Armstrong AY. Role of embryo transfer in fellowship training. Fertil Steril 2007;88:1014-5.
1 Jennifer Wadell, BS, former Predoctoral Fellow
COLLABORATORS
William H. Catherino, MD, PhD, Uniformed Services University of the Health Sciences, Bethesda, MD
Faye Chen, PhD, Cartilage Biology and Orthopaedics Branch, NIAMS, Bethesda, MD
Greg Christman, MD, University of Michigan, Ann Arbor, Michigan
George Chrousos, MD, University of Athens, Athens, Greece
Alan DeCherney, MD, Program in Reproductive and Adult Endocrinology, NICHD, Bethesda, MD
Paul Driggers, PhD, Uniformed Services University of the Health Sciences, Bethesda, MD
Tomoshige Kino, PhD, Program in Reproductive and Adult Endocrinology, NICHD, Bethesda, MD
Phyllis Leppert, MD, PhD, Duke University Medical Center, Durham, NC
Lynnette Nieman, MD, Program in Reproductive and Adult Endocrinology, NICHD, Bethesda, MD
Steven Z. Pavletic, MD, Experimental Transplantation and Immunology Branch, NCL, Bethesda, MD
Rocky Tuan, PhD, Cartilage Biology and Orthopaedics Branch, NIAMS, Bethesda, MD
Heiner Westphal, MD, Program in Genomics of Differentiation, NICHD, Bethesda, MD
T. John Wu, PhD, Uniformed Services University of the Health Sciences, Bethesda, MD
For further information, contact segarsj@mail.nih.gov.
