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Home > Unit on Reproductive and Regenerative Medicine

Reproductive Stem Cell Biology

Erin Wolff, MD
  • Erin F. Wolff, MD, Head, Unit on Reproductive and Regenerative Medicine
  • Solji Park, DVM, PhD, Postdoctoral Fellow
  • Jaclyn Yu, BS, Postbaccalaureate Fellow

The long-term goal of our laboratory is to develop regenerative medicine approaches for reproductive disorders. We conduct basic stem-cell, translational non-human primate, and clinical research on reproductive conditions. Our projects are designed to complement basic stem-cell research with our ongoing cutting-edge assisted-reproductive medicine research. Using this integrated approach, we aim to pioneer the next breakthroughs in reproductive medicine.

The role of T-regulatory cells in the endometrium

While investigating hematopoietic stem cell transplantation in non-human primate (NHP) models, we became interested in the role of T-regulatory cells in stem-cell engraftment for both bone marrow transplants and endometrial engraftment. In parallel with ongoing T-regulatory cell experiments in the lab, we began considering the involvement of T-regulatory cells for both future reproductive tract stem cell transplant therapies (such as embryonic stem cell–derived therapies) and embryonic engraftment in the uterus in pregnancy. However, little was known about the role of T-regulatory cells in the endometrium. Maternal immune tolerance to fetal engraftment is critical for the establishment of pregnancy, but the mechanisms permitting such a semi-allograft are not completely understood. Given that T-regulatory (Treg) cells are known to promote tolerance to foreign antigens, we hypothesized that Treg cells could be one way the maternal immune system is able to permit implantation of the semi-allogeneic embryo. To study this, we utilized a conditional knockdown model of Treg cells, in which a transgenic mouse harbors a diphtheria toxin (DT) receptor–eGFP fusion protein under the control of the FoxP3 locus: the “DEpletion of REGulatory T cells” (DEREG) mouse model. In women, we are studying Treg cells in healthy volunteers, as well as in women with infertility, to determine whether abnormalities of Treg cell numbers or function could explain forms of infertility such as recurrent implantation failure and recurrent miscarriage.

Ovary-derived stem cells transplant in a Rhesus macaque model

In adult non-human primates (NHPs), we are testing the ability of ovary-derived stem cells (OSCs) to undergo meiosis and give rise to oocytes. To this end, we isolate OSCs, culture them in vitro, label them, and transplant them into the ovaries of a recipient NHP to test for meiotic potential. We are studying this in both a healthy autologous transplant model as well as in an ovarian injury model of NHPs that have been previously irradiated. In humans, we are studying OSCs in healthy women, as well as women with ovarian failure and insufficiency, to determine whether OSCs are involved in the infertility associated with these disorders. However, significant controversy exists regarding the stem-cell markers used to isolate OSCs. A separate aim of this project is to characterize OSC markers better.

Female germline differentiation of induced pluripotent stem cells (iPSCs) from Rhesus macaque

While male germ cell differentiation from embryonic stem cells (ESC) or induced pluripotent stem cells (iPSC) has been achieved for some time, female germline differentiation has typically been more difficult to accomplish. However, in 2012, viable oocyte differentiation from mouse iPSC was reported for the first time by Hayashi et al, and the oocytes could be fertilized normally and give rise to offspring. In ongoing work in our lab, we are utilizing an iPSC approach to generating oocytes in NHPs. The clinical significance of this approach is that it would allow women with premature ovarian insufficiency to have their own genetic offspring. As a first step toward human trials, we adapted the Hayashi mouse protocol to NHPs by testing several in vitro conditions. Our optimized protocol resulted in primordial germ cell like cell (PGCLC) differentiation. Future work will focus on differentiating the iPSC–derived PGCLCs into gametes by inducing meiosis and formation of oocytes.

Fertility preservation for women undergoing gonadotoxic therapies

For women undergoing gonadotoxic therapies, future fertility is often one of the greatest concerns. At the NIH, investigators have made remarkable strides in treated benign and malignant conditions such as sickle cell disease and cancer. Unfortunately, while these breakthroughs cure young women of their disease, patients are often rendered infertile. Historically, the most effective form of fertility preservation was to freeze fertilized embryos prior to gonadotoxic treatment, using routine assisted reproductive technologies such as IVF. However, this is prohibited at the NIH because embryos would be created under research protocols. Historically, only fertilized embryos could be frozen and thawed successfully, but oocytes (the largest cell in the human body) were too sensitive to the cytoplasmic ice crystal formation that occurs with traditional freezing methods. Newer methods of oocyte freezing (i.e., vitrification) were developed that dramatically improved the success of oocyte freezing. The approaches are now considered to have similar success rates as routine IVF. Given these advances, we are now able to offer fertility preservation to patients at the NIH by freezing oocytes. Cryo-preserved oocytes are given to patients, and they are stored at private storage facilities until the patients have completed treatments and are ready to start a family. We are studying patients with rare conditions (e.g., sickle cell disease) undergoing the fertility preservation cycles to develop the safest and most effective IVF protocols suited their underlying disease.

Additional Funding

  • American Society of Reproductive Medicine KY Cha Award in Stem Cell Technology
  • Cooperative Research and Development Agreement (CRADA): OvaScience


  1. Wolff EF, Mutlu L, Elsworth JD, Redmond E, Taylor HS. Endometrial stem cell transplantation in MPTP- exposed primates: an alternative cell source for treatment of Parkinson’s disease. J Cell Mol Med 2014;E-pub ahead of print.
  2. Wolff EF, Uchida N, Donahue RE, Metzger ME, Libfraind LL, Hill MJ, Tisdale JT. Peripheral blood stem cell transplants do not result in endometrial stromal engraftment. Fertil Steril 2013;99:526-532.
  3. Wolff EF, Gao XB, Yao KV, Du H, Andrews ZB, Elsworth JD, Taylor HS. Endometrial stem cell transplantation restores dopamine production in a Parkinson’s disease model. J Cell Mol Med 2011;15(4):747-755.
  4. Santamaria X, Massasa E, Feng Y, Wolff EF, Taylor HS. Derivation of insulin producing cells from human endometrial stromal stem cells and use in the treatment of murine diabetes. Mol Ther 2011;19(11):2065-2071.
  5. Hill MJ, Cooper JC, Levy G, Alford C, Richter KS, DeCherney AH, Katz C, Levens ED, Wolff EF. Ovarian reserve and subsequent ART outcomes following methotrexate therapy for ectopic pregnancy and pregnancy of unknown location. Fertil Steril 2014;101(2):413-419.


  • Cynthia Dunbar, MD, Hematology Branch, NHLBI, Bethesda, MD
  • Sunni Mumford, PhD, Division of Epidemiology, Statistics & Prevention Research, NICHD, Rockville, MD
  • Bo R. Rueda, PhD, Massachusetts General Hospital, Boston, MA
  • Hugh S. Taylor, MD, Yale School of Medicine, New Haven, CT
  • John Tisdale, MD, Molecular and Clinical Hematology Branch, NHLBI, Bethesda, MD
  • Neal Young, MD, Hematology Branch, NHLBI, Bethesda, MD


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