In mammals, retinoic acid (RA) is absolutely essential for the progression of undifferentiated A spermatogonia into differentiating Al spermatogonia (the A to Al transition). The action of RA and the appearance of differentiating spermatogonia represents the commitment of the germ cell to enter meiosis. The rate-limiting step in RA synthesis is the oxidation of retinaldehyde to RA by retinaldehyde dehydrogenases (RALDHs). In the previous grant period, we demonstrated that the bisdichloroacetyldiamines (BDADs) function as male contraceptives via inhibiting the RALDHs [4, 5]. Treatment of male mice with one particular BDAD, WIN 18,446, effectively mimics testicular vitamin A deficiency and blocks spermatogonial differentiation and the production of STRAS, the classic marker of RA activity in the testis. This block is rescued by RA but not by ROL proving that the biologically important action is the inhibition of RALDHs. The cellular sources of RA and the localization of the biologically important RALDHs in the adult testis are unknown. Our hypothesis is that RALDH enzymes are a critical component in the control of RA levels in the testis and therefore, may represent excellent targets for male contraceptive agents. This proposal will investigate the expression and function of RALDHs present in the different cell types in the testis during germ cell development in mice and humans. Specfic aim 1 will investigate the expression and activity ofthe RALDHs in both the murine and human testis as well as define the transcrtipome response of the human testis to RA. Specfic Aim 2 will utilize a novel method, developed during the last grant period, for synchronizing spermatogenesis to assess retinoid levels and RALDH activites across the cycle of the seminiferous epithelium as well as the transcriptome in response to RA at the A to Al transisiton. Specfic aim 3 will elucidate which RALDH enzymes are essential for spermatogenesis via mouse knockout models. Collectively, these data will significantly enhance our understanding of how vitamin A metabolism is regulated in the testis and determine whether perturbing RALDH activity is a viable approach to male contraception.

Public Health Relevance

The ideal male contraceptive agent would allow reversible control of sperm formation or function with no permanent changes to the testis or no side effects elsewhere in the body. The proteins responsibe for vitamin A metabolism have been proposed as potential male contraceptive targets. This proposal will investigate the expression and function of one group of vitamin A metabolizing proteinsi the RALDHs, and aid in determining whether their inhibition is a viable approach to male contraception.

National Institute of Health (NIH)
Specialized Center--Cooperative Agreements (U54)
Project #
Application #
Study Section
Special Emphasis Panel (ZHD1)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Washington
United States
Zip Code
Cooper, Lori A; Page, Stephanie T (2014) Androgens and prostate disease. Asian J Androl 16:248-55
Surampudi, P; Page, S T; Swerdloff, R S et al. (2014) Single, escalating dose pharmacokinetics, safety and food effects of a new oral androgen dimethandrolone undecanoate in man: a prototype oral male hormonal contraceptive. Andrology 2:579-87
Chao, Jing; Page, Stephanie T; Anderson, Richard A (2014) Male contraception. Best Pract Res Clin Obstet Gynaecol 28:845-57
Amory, John K; Hong, SungWoo; Yu, Xiaozhong et al. (2014) Melphalan, alone or conjugated to an FSH-? peptide, kills murine testicular cells in vitro and transiently suppresses murine spermatogenesis in vivo. Theriogenology 82:152-9
Chakraborty, Papia; Buaas, F William; Sharma, Manju et al. (2014) LIN28A marks the spermatogonial progenitor population and regulates its cyclic expansion. Stem Cells 32:860-73
Amory, John K; Arnold, Samuel; Lardone, MarĂ­a C et al. (2014) Levels of the retinoic acid synthesizing enzyme aldehyde dehydrogenase-1A2 are lower in testicular tissue from men with infertility. Fertil Steril 101:960-6
Paik, Jisun; Haenisch, Michael; Muller, Charles H et al. (2014) Inhibition of retinoic acid biosynthesis by the bisdichloroacetyldiamine WIN 18,446 markedly suppresses spermatogenesis and alters retinoid metabolism in mice. J Biol Chem 289:15104-17
Roth, Mara Y; Shih, Grace; Ilani, Niloufar et al. (2014) Acceptability of a transdermal gel-based male hormonal contraceptive in a randomized controlled trial. Contraception 90:407-12
Anawalt, Bradley D (2013) Approach to male infertility and induction of spermatogenesis. J Clin Endocrinol Metab 98:3532-42
Roth, M Y; Nya-Ngatchou, J J S; Lin, K et al. (2013) Androgen synthesis in the gonadotropin-suppressed human testes can be markedly suppressed by ketoconazole. J Clin Endocrinol Metab 98:1198-206

Showing the most recent 10 out of 73 publications