Publications

Characterization of the ovarian and reproductive abnormalities in prepubertal and adult estrogen non-responsive estrogen receptor alpha knock-in (ENERKI) mice.

Characterization of the ovarian and reproductive abnormalities in prepubertal and adult estrogen non-responsive estrogen receptor alpha knock-in (ENERKI) mice.

Steroids. 2009 Nov;74(12):913-9

Authors: Sinkevicius KW, Woloszyn K, Laine M, Jackson KS, Greene GL, Woodruff TK, Burdette JE

Abstract

Estrogen non-responsive estrogen receptor alpha (ERalpha) knock-in (ENERKI) mice have a mutation (glycine 525 to leucine, G525L) in the ligand-binding domain of ERalpha. The mutant ERalpha protein has a significantly lower affinity and response to endogenous estrogens, while not altering growth factor activated ligand-independent pathways. ENERKI females demonstrated signs of early follicle development as determined by a significant increase in antral follicle formation by 20 days of age. Adult ENERKI females were infertile, had hemorrhagic ovarian follicular cysts, and failed to develop corpora lutea in response to a superovulation regimen. These results illustrate the importance of ERalpha ligand-induced signaling for ovarian development and for estrogen feedback on the hypothalamus and pituitary. Although ERalpha ligand-induced signaling by endogenous estrogens is lost in ENERKI females, the ERalpha selective agonist propyl pyrazole triol (PPT), a synthetic nonsteroidal compound, is still able to activate G525L ERalphain vivo to increase uterine weight. To test whether PPT could restore ligand-dependent receptor activation, ENERKI females were treated with PPT and evaluated for spontaneous ovulation, ovarian hemorrhagic cysts, and LH serum levels. Daily PPT treatments beginning on day 4 of life prevented formation of ovarian hemorrhagic cysts in adult ENERKI animals. In accordance with this result, preputial gland weight and LH levels were also lowered in these animals, indicating PPT treatments most likely led to restoration of ERalpha negative feedback of the hypothalamic-pituitary axis.

PMID: 19631674 [PubMed - indexed for MEDLINE]

Interpenetrating fibrin-alginate matrices for in vitro ovarian follicle development.

Interpenetrating fibrin-alginate matrices for in vitro ovarian follicle development.

Biomaterials. 2009 Oct;30(29):5476-85

Authors: Shikanov A, Xu M, Woodruff TK, Shea LD

Abstract

In this report, we investigate the fibrin-alginate interpenetrating network (FA-IPN) to provide dynamic cell-responsive mechanical properties, which we apply to the in vitro growth of ovarian follicles. The mechanical properties and polymerization rate of the gels were investigated by rheology, and the fiber structure was imaged by electron microscopy. Using a mouse model, two-layered secondary follicles were encapsulated in FA-IPNs, and growth, morphology, hormone production, fibrin degradation rate and the numbers of competent eggs were assessed. The initial mechanics of the FA-IPN are determined by the composite material, and subsequent degradation of fibrin by the encapsulated cells would produce a material with mechanical properties due to the alginate alone. The rate of meiotically competent oocytes produced by culture in FA-IPN was 82%, which was significantly greater than in alginate alone. This increase in oocyte quality is an important step in identifying 3D culture systems that can provide a fundamental tool to investigate follicle maturation, and may be applied to promote the growth of human follicles, which can be used to provide reproductive options for women facing a cancer diagnosis.

PMID: 19616843 [PubMed - indexed for MEDLINE]

In vitro grown human ovarian follicles from cancer patients support oocyte growth.

In vitro grown human ovarian follicles from cancer patients support oocyte growth.

Hum Reprod. 2009 Oct;24(10):2531-40

Authors: Xu M, Barrett SL, West-Farrell E, Kondapalli LA, Kiesewetter SE, Shea LD, Woodruff TK

Abstract

BACKGROUND: Young female adult and adolescent cancer patients facing life-preserving but fertility-threatening chemo- or radiation-therapy are increasingly seeking options to protect their reproductive potential. Ovarian tissue cryopreservation with transplantation is a promising technique to safeguard fertility in cancer patients. However, this method may risk re-introduction of the original cancer to the survivor of the disease. Thus, developing a method for in vitro growth of immature follicles may provide a method for fertility restoration in the future.

METHODS: Human secondary follicles were isolated from ovarian tissues obtained from cancer patients and grown in vitro within a bio-engineered culture system for 30 days.

RESULTS: Human ovarian follicles became steroidogenically active, and developed from the early secondary to antral stage in vitro. The follicles contained healthy, growing oocytes that were connected by transzonal projections between the somatic cells and oocyte.

CONCLUSIONS: Our data support the notion that human follicle development can be achieved in vitro in a bio-engineered culture system. More studies are required to investigate whether the fully sized oocytes obtained from in vitro grown follicle are competent to resume meiosis and be fertilized.

PMID: 19597190 [PubMed - indexed for MEDLINE]

Roles for transforming growth factor beta superfamily proteins in early folliculogenesis.

Roles for transforming growth factor beta superfamily proteins in early folliculogenesis.

Semin Reprod Med. 2009 Jan;27(1):14-23

Authors: Trombly DJ, Woodruff TK, Mayo KE

Abstract

Primordial follicle formation and the subsequent transition of follicles to the primary and secondary stages encompass the early events during folliculogenesis in mammals. These processes establish the ovarian follicle pool and prime follicles for entry into subsequent growth phases during the reproductive cycle. Perturbations during follicle formation can affect the size of the primordial follicle pool significantly, and alterations in follicle transition can cause follicles to arrest at immature stages or result in premature depletion of the follicle reserve. Determining the molecular events that regulate primordial follicle formation and early follicle growth may lead to the development of new fertility treatments. Over the last decade, many of the growth factors and signaling proteins that mediate the early stages of folliculogenesis have been identified using mouse genetic models, in vivo injection studies, and ex vivo organ culture approaches. These studies reveal important roles for the transforming growth factor beta (TGF-beta) superfamily of proteins in the ovary. This article reviews these roles for TGF-beta family proteins and focuses in particular on work from our laboratories on the functions of activin in early folliculogenesis.

PMID: 19197801 [PubMed - indexed for MEDLINE]

The emergence of a new interdiscipline: oncofertility.

The emergence of a new interdiscipline: oncofertility.

Cancer Treat Res. 2007;138:3-11

Authors: Woodruff TK

PMID: 18080653 [PubMed - indexed for MEDLINE]

Postnatal regulation of germ cells by activin: the establishment of the initial follicle pool.

Postnatal regulation of germ cells by activin: the establishment of the initial follicle pool.

Dev Biol. 2006 Oct 1;298(1):132-48

Authors: Bristol-Gould SK, Kreeger PK, Selkirk CG, Kilen SM, Cook RW, Kipp JL, Shea LD, Mayo KE, Woodruff TK

Abstract

Mammalian females enter puberty with follicular reserves that exceed the number needed for ovulation during a single lifetime. Follicular depletion occurs throughout reproductive life and ends in menopause, or reproductive senescence, when the follicle pool is exhausted. The mechanisms regulating the production of a species-specific initial follicle pool are not well understood. However, the establishment of a follicular reserve is critical to defining the length of reproductive cyclicity. Here we show that activin A (rh-ActA), a known regulator of follicle formation and growth in vitro, increased the number of postnatal mouse primordial follicles by 30% when administered to neonatal animals during the time of germline cyst breakdown and follicle assembly. This expansion in the initial follicle pool was characterized by a significant increase in both germ cell and granulosa cell proliferation. However, the excess follicles formed shortly after birth did not persist into puberty and both adult rh-ActA- and vehicle-treated animals demonstrated normal fertility. A follicle atresia kinetic constant (k(A)) was modeled for the two groups of animals, and consistent with the empirical data, the k(A) for rh-ActA-treated was twice that of vehicle-treated animals. Kinetic constants for follicle formation, follicle loss and follicle expansion from birth to postnatal day 19 were also derived for vehicle and rh-ActA treatment conditions. Importantly, introduction of exogenous rh-ActA revealed an intrinsic ovarian quorum sensing mechanism that controls the number of follicles available at puberty. We propose that there is an optimal number of oocytes present at puberty, and when the follicle number is exceeded, it occurs at the expense of oocyte quality. The proposed mechanism provides a means by which the ovary eliminates excess follicles containing oocytes of poor quality prior to puberty, thus maintaining fertility in the face of abnormal hormonal stimuli in the prepubertal period.

PMID: 16930587 [PubMed - indexed for MEDLINE]

To beta or not to beta: estrogen receptors and ovarian function.

To beta or not to beta: estrogen receptors and ovarian function.

Endocrinology. 2005 Aug;146(8):3244-6

Authors: Woodruff TK, Mayo KE

PMID: 16009972 [PubMed - indexed for MEDLINE]

Normal reproductive function in InhBP/p120-deficient mice.

Normal reproductive function in InhBP/p120-deficient mice.

Mol Cell Biol. 2003 Jul;23(14):4882-91

Authors: Bernard DJ, Burns KH, Haupt B, Matzuk MM, Woodruff TK

The inhibins are gonadal transforming growth factor beta superfamily protein hormones that suppress pituitary follicle-stimulating hormone (FSH) synthesis. Recently, betaglycan and inhibin binding protein (InhBP/p120, also known as the product of immunoglobulin superfamily gene 1 [IGSF1]) were identified as candidate inhibin coreceptors, shedding light on the molecular basis of how inhibins may affect target cells. Activins, which are structurally related to the inhibins, act within the pituitary to stimulate FSH production. Betaglycan increases the affinity of inhibins for the activin type IIA (ACVR2) receptor, thereby blocking activin binding and signaling through this receptor. InhBP/p120 may not directly bind inhibins but may interact with the activin type IB receptor, ALK4, and participate in inhibin B's antagonism of activin signaling. To better understand the in vivo functions of InhBP/p120, we characterized the InhBP/p120 mRNAs and gene in mice and generated InhBP/p120 mutant mice by gene targeting in embryonic stem cells. InhBP/p120 mutant male and female mice were viable and fertile. Moreover, they showed no alterations in FSH synthesis or secretion or in ovarian or testicular function. These data contribute to a growing body of evidence indicating that InhBP/p120 does not play an essential role in inhibin biology.

PMID: 12832474 [PubMed - indexed for MEDLINE]

Inhibin binding protein in rats: alternative transcripts and regulation in the pituitary across the estrous cycle.

Inhibin binding protein in rats: alternative transcripts and regulation in the pituitary across the estrous cycle.

Mol Endocrinol. 2001 Apr;15(4):654-67

Authors: Bernard DJ, Woodruff TK

Inhibin binding protein (InhBP) and the transforming growth factor-beta (TGF beta) type III receptor, beta glycan, have been identified as putative inhibin coreceptors. Here we cloned the InhBP cDNA in rats and predict that it encodes a large membrane-spanning protein that is part of the Ig superfamily, as has been described for humans. Two abundant InhBP transcripts (4.4 and 1.8 kb) were detected in the adult rat pituitary. The larger transcript encodes the full-length protein while the 1.8-kb transcript (InhBP-short or InhBP-S) corresponds to a splice variant of the receptor. This truncated isoform contains only the N-terminal signal peptide and first two (of 12) Ig-like domains observed in the full-length InhBP (InhBP-long or InhBP-L). InhBP-S does not contain a transmembrane domain and is predicted to be a soluble protein. Beta glycan was also detected in the pituitary; however, it was most abundant within the intermediate lobe. Although we also observed beta glycan immunopositive cells in the anterior pituitary, they rarely colocalized with FSH beta-producing cells. We next examined physiological regulation of the coreceptors across the rat estrous cycle. Like circulating inhibin A and inhibin B levels, pituitary InhBP-L and InhBP-S mRNA levels were dynamically regulated across the cycle and were negatively correlated with serum FSH levels. Expression of both forms of InhBP was also positively correlated with serum inhibin B, but not inhibin A, levels. These data are particularly interesting in light of our in vitro observations that InhBP may function as an inhibin B-specific coreceptor. Pituitary beta glycan mRNA levels did not fluctuate across the cycle nor did they correlate with serum FSH. These observations, coupled with its pattern of expression within the pituitary, indicate that beta glycan likely functions as more than merely an inhibin coreceptor within the pituitary. A direct role for InhBP or beta glycan in regulation of pituitary FSH by inhibin in vivo has yet to be determined, but the demonstration of dynamic regulation of pituitary InhBP and its negative relation to serum FSH across the estrous cycle is an important step in this direction.

PMID: 11266515 [PubMed - indexed for MEDLINE]

Secondary follicle growth and oocyte maturation by culture in alginate hydrogel following cryopreservation of the ovary or individual follicles.

Secondary follicle growth and oocyte maturation by culture in alginate hydrogel following cryopreservation of the ovary or individual follicles.

Biotechnol Bioeng. 2009 Jun 1;103(2):378-86

Authors: Xu M, Banc A, Woodruff TK, Shea LD

Abstract

An option for fertility preservation for women facing a cancer diagnosis involves the cryopreservation of ovarian tissue for later re-transplantation or in vitro culture, with in vitro culture preferred to avoid reintroduction of the cancer. Small, immature follicles survive the freeze-thaw process, and can be matured through in follicle maturation (IFM) that involves an initial growth of the follicle and subsequent maturation of the oocyte. The ovarian tissue can be cryopreserved in two forms: (i) cortical strips consisting of follicles and surrounding stroma (Cryo-Ov) or (ii) individually isolated follicles (Cryo-In). The aim of this study was to assess the follicle growth and oocyte maturation for follicles that were cryopreserved either as strips or individually using a slow-freezing cryopreservation method. The two follicle groups, together with non-cryopreserved control follicles, were grown in an alginate-based three-dimensional culture system for 12 days. The overall survival, size increase and antrum formation rates were comparable among the three groups. At day 12 of culture, Androstenedione levels were decreased in the Cryo-Ov group relative to the other two, and the ratio of progesterone to estradiol was increased in the two cryopreserved groups relative to the control. Both Gja1 (known as connexin 43) and Gja4 (known as connexin 37) mRNA expression were decreased at day 6 in the cryopreserved groups relative to controls, and by day 12, Gja1 was similar for all three groups. Moreover, Cryo-In resulted in lower GVBD rate indicating some impaired oocyte development. Overall, the present study demonstrated that mouse preantral follicles, either within ovarian tissues or individually isolated, could be successfully cryopreserved by the slow-freezing method, as evidenced by post-thaw follicle development and steroidgenesis, oocyte maturation and molecular markers for oocyte and/or granulosa cells connection.

PMID: 19191350 [PubMed - indexed for MEDLINE]