Possible Rotation Projects:
- Genetic regulation of stem cells and spermatogenesis using gene editing technologies (CRISPR/Cas9, TALEN, miRNA, etc.), stem cell transplantation and transgenic/knockout animal models.
- Development stem cell technologies for treatment of male infertility
- Examine the effects of cancer treatments (chemotherapy and radiation) on testicular and ovarian function. Develop strategies to preserve and restore the fertility of cancer survivors.
Training Technologies Used:
- Gene editing technologies (CRISPR/Cas9, TALEN, miRNA); transgenic/knockout animal models; stem cell culture; stem cell transplantation; immunohistochemistry
- Ph.D. in Biochemistry & Biophysics from Oregon State University, 1994
- Ph.D. in Animal Sciences from Oregon State University, 1994
- B.A. in Chemistry from Whitworth College, 1990
- B.S. in Biology from Whitworth College, 1990
Sheng Y, Yap YT, Li W, Dhikhirullahi O, Niu C, Rabbani M, Krawetz SA, Hammoud SS, Orwig KE, Zhang Z. Normal embryo development needs MEIG1-mediated sperm formation. FASEB J 2025. doi: 10.1096/fj.202500109R. [PUBMED]
Harancher MR, Sukhwani M, Castro CA, Hsieh MH, Orwig KE. Generation of two isogenic sickle cell disease induced pluripotent stem cell lines from testicular fibroblasts. Stem Cell Res. 2023 Dec:73:103257. doi: 10.1016/j.scr.2023.103257. [PUBMED]
Younis N, Caldeira-Brant AL, Chu T, Abdalla S, Orwig KE. Human immature testicular tissue organ culture: a step towards fertility preservation and restoration. Front Endocrinol (Lausanne). 2023 Aug 28:14:1242263. doi: 10.3389/fendo.2023.1242263. [PUBMED]
Tran KTD, Valli-Pulaski H, Colvin A, Orwig KE. Male fertility preservation and restoration strategies for patients undergoing gonadotoxic therapies. Biol Reprod 2022;107(2):382-405. doi: 10.1093/biolre/ioac072. [PUBMED]
Shami AN, Zheng X, Munyoki SK, Ma Q, Manske GL, Green GD, Sukhwani M, Orwig KE, Li JL*, Hammoud SS. Single-cell RNA sequencing of human, macaque, and mouse testes uncovers conserved and divergent features of mammalian spermatogenesis. Dev Cell 2020, 54(4):529-547.e12. doi: 10.1016/j.devcel.2020.05.010. [PUBMED]
Valli-Pulaski H, Peters KA, Gassei K, Steimer SR, Sukhwani M, Hermann BP, Dwomor L, David S, Fayomi AP, Munyoki SK, Chu T, Chaudhry R, Cannon GM, Fox PJ, Jaffe TM, Sanfilippo JS, Menke MN, Lunenfeld E, Abofoul-Azab M, Sender LS, Messina J, Klimpel LM, Gosiengfiao Y, Rowell EE, Hsieh MH, Granberg CF, Reddy PP, Sandlow JI, Huleihel M, Orwig KE. Testicular tissue cryopreservation: 8 years of experience from a coordinated network of academic centers. Hum Reprod. 2019; May 21; doi: 10.1093/humrep/dez043. [PUBMED]
Fayomi A, Peters K, Sukhwani M, Valli-Pulaski H, Shetty G, Meistrich M, Houser L, Robertson N, Roberts V, Ramsey C, Hanna C, Hennebold J, Dobrinski I, Orwig KE. Autologous Grafting of Cryopreserved Prepubertal Rhesus Testis Produces Sperm and Offspring. Science. 2019; March 22; 363(6433): 1314-1319. doi: 10.1126/science.aav2914. [PUBMED], [PDF]
Research in the Orwig laboratory focuses on
1) stem cells; 2) germ lineage development in the ovaries and the testes that give rise to eggs and sperm, which are essential for reproductive success; and 3) fertility & infertility. The laboratory is committed to translating lab bench discoveries to the clinic to improve the diagnosis, prevention and treatment of infertility.
Stem cells and spermatogenic lineage development. The Orwig lab uses gene editing technologies (CRISPR/Cas9; TALEN; miRNA and others), stem cell culture, stem cell transplantation and transgenic and knockout animal models to unravel the molecular mechanisms that regulate spermatogonial stem cells and spermatogenic lineage development. We also use microarray RNA sequencing technologies to identify genes expressed by stem and progenitor spermatogonia. We use the information to
- Gain basic insights about the molecular regulation of stem cell self-renewal and differentiation
- Identify molecules that can be used to isolate and enrich spermatogonial stem cells
- Identify factors that may facilitate the maintenance and expansion of stem cells in culture.
Stem cell transplantation and regenerative medicine. The Orwig lab has extensive expertise with stem cell transplantation. The spermatogonial stem cell transplantation technique is used as a routine bioassay to test the spermatogenic potential of any experimental cell population. The technique may also have application for treating male infertility. The laboratory has optimized the methodology for transplanting stem cells into the testes of infertile primates. The transplanted cells regenerated spermatogenesis and produced functional sperm. This is a valuable model for testing the safety and feasibility of stem cell technologies before they are translated to the clinic. Dr. Orwig is the founding director of the Fertility Preservation Program in Pittsburgh (http://www.mwrif.org/220), a multidisciplinary effort to educate patients and physicians about the reproductive side effects of cancer treatments and about options for preserving and restoring fertility. The Fertility Preservation Program in Pittsburgh, along with several other centers around the world, is actively cryopreserving testicular tissues (containing stem cells) for patients in anticipation that stem cell technologies for treating infertility will be available in the future.
Determine the effects of cancer treatments and disease on ovarian and testicular function. Chemotherapy and radiation treatments for cancer or other conditions can cause permanent infertility and this can have a devastating impact on the relationships and emotional well-being of survivors. The mechanisms that lead to infertility in males and females are probably different because the cellular mechanisms that lead to sperm production in males and egg production in females are different. We are actively characterizing the effects of chemotherapy on ovarian and testicular function so that we can logically develop methods to protect, preserve or restore fertility. While stem cell therapies may be an option to preserve and restore male fertility (see above), these options may not be available to females because oogenesis is not a stem cell-based system. It is generally understood that females are born with all of the eggs they will ever have and this number decreases throughout life until menopause occurs. Chemotherapy can reduce the number of follicles (eggs) in the ovaries and lead to premature ovarian insufficiency (POI). Therefore, we are actively screening drugs or molecules that can protect the ovaries and eggs from the toxic effects of chemotherapy.
