Education & Training
- 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
Research Interest Summary
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.
Valli H, Sukhwani M, Dovey SL, Peters KA, Donohue JN, Chu T, Marshall GR, Orwig KE. FACS and MACS sorting strategies to isolate and enrich human spermatogonial stem cells. Fertil Steril 2014; August 2014, Pages 566–580.e7.
Valli H, Phillips BT, Shetty G, Byrne JA, Clark AT, Meistrich ML, Orwig KE. Germline stem cells: toward the regeneration of spermatogenesis. Fertil Steril 2014; 101:3-13.
Durruthy Durruthy J, Ramathal C, Sukhwani M, Fang F, Cui J, Orwig KE, Reijo Pera RA. Gate of induced pluripotent stem cells following transplantation to murine seminiferous tubules. Hum Mol Gen 2014; 23: 3071-3084.
Ramathal C, Durruthy-Durruthy J, Sukhwani M, Arakaki JE, Turek PJ, Orwig KE, Reijo Pera RA. Fate of iPSCs derived from azoospermic and fertile men following xenotransplantation to murine seminiferous tubules. Cell Reports 2014; 7: 1284-1297.
Zhang Z, Zhang S, Huang X, Orwig KE, Sheng Y. Rapid assembly of customized TALENs into multiple delivery systems. PLoS ONE. 2013; 8:e80281.
Skaznik-Wikiel ME, McGuire MM, Sukhwani M, Donohue J, Chu T, Krivak TC, Rajkovic A, Orwig KE. Granulocyte colony-stimulating factor with or without stem cell factor extends time to premature ovarian insufficiency in female mice treated with alkylating chemotherapy. Fertil Steril 2013; 99:2045-2054.
Dovey SL, Valli H, Hermann BP, Sukhwani M, Donohue J, Castro CA, Chu T, Sanfilippo JS, Orwig KE. Eliminating malignant contamination from therapeutic human spermatogonial stem cells. Journal of Clinical Investigation 2013; 123:1833-1843.
Gassei K and Orwig KE. SALL4 expression in gonocytes and spermatogonial clones of postnatal mouse testes. PLoS ONE 2013; 8:e53976.
Hermann BP, Sukhwani M, Winkler F, Pascarella JN, Peters KA, Sheng Y, Valli H, Rodriguez M, Esselarab M, Dargo G, Peterson K, Masterson K, Ramsey C, Ward T, Lienesch M, Volk A, Cooper DK, Thomson AW, Kiss JE, Penedo MT, Schatten GP, Mitalipov S and Orwig KE. Spermatogonial stem cell transplantation into Rhesus testes regenerates spermatogenesis producing functional sperm. Cell Stem Cell 2012 (Featured article); 11:715-726. **Community Choice Highlight in Nature 491: 641, The Most Viewed Papers in Science.
Hermann BP, Sukhwani M, Simorangkir DR, Plant TM, Orwig KE. Molecular dissection of the male germ cell lineage identifies putative spermatogonial stem cells in rhesus macaques. Human Reproduction 2009; 24: 1704-1716.