Zelieann R Craig
Assistant Dean, Research
Associate Professor, Animal and Comparative Biomedical Sciences
Associate Professor, BIO5 Institute
Member of the Graduate Faculty
Department Affiliations
(520) 621-8082
Work Summary
We investigate how the chemicals in our daily lives interact with the female reproductive system and influence fertility. We hope that our discoveries will help reduce the incidence of infertility and improve women's health.
Research Interest
Nearly 50 million couples experience some form of infertility worldwide. Several factors increase a woman’s risk for infertility including aging, stress, and exposure to chemicals. A group of chemicals collectively known as phthalates have been classified as endocrine disruptors based on their ability to interact with the reproductive system. Phthalates have been detected in human urine, animal tissues, and feed. Despite these observations, how phthalates interact with the female reproductive system and what this means for overall fertility is currently unknown. Dr. Craig's work focuses on understanding how phthalates affect the function of the ovary, the major reproductive organ in females. Thus, work in her laboratory is focused on using animal models to help us understand the mechanisms by which phthalates exert their effects on the ovary, determine whether phthalates cause female infertility, and examine whether the effects of phthalates on female reproduction can be prevented or reversed. Using this knowledge she hopes to inspire and guide future work aimed at reducing, preventing, and/or reversing chemical-related infertility in humans and animals. Keywords: Infertility, Toxicology, Endocrine Disruptors, Phthalates, Reproduction

Publications

Craig, Z. R., Davis, J. R., Marion, S. L., Barton, J. K., & Hoyer, P. B. (2010). 7,12-Dimethylbenz[A]Anthracene Induces Sertoli-Leydig-Cell Tumors in the Follicle-Depleted Ovaries of Mice Treated with 4-Vinylcyclohexene Diepoxide. COMPARATIVE MEDICINE, 60(1), 10-17.
BIO5 Collaborators
Jennifer Kehlet Barton, Zelieann R Craig
Rivera, Z., Christian, P. J., Marion, S. L., Brooks, H. L., & Hoyer, P. B. (2009). Steroidogenic capacity of residual ovarian tissue in 4-vinylcyclohexene diepoxide-treated mice. Biology of reproduction, 80(2), 328-36.
BIO5 Collaborators
Heddwen L Brooks, Zelieann R Craig

Menopause is an important public health issue because of its association with a number of disorders. Androgens produced by residual ovarian tissue after menopause could impact the development of these disorders. It has been unclear, however, whether the postmenopausal ovary retains steroidogenic capacity. Thus, an ovary-intact mouse model for menopause that uses the occupational chemical 4-vinylcyclohexene diepoxide (VCD) was used to characterize the expression of steroidogenic genes in residual ovarian tissue of follicle-depleted mice. Female B6C3F1 mice (age, 28 days) were dosed daily for 20 days with either vehicle or VCD (160 mg kg(-1) day(-1)) to induce ovarian failure. Ovaries were collected on Day 181 and analyzed for mRNA and protein. Acyclic aged mice were used as controls for natural ovarian senescence. Relative to cycling controls, expression of mRNA encoding steroidogenic acute regulatory protein (Star); cholesterol side-chain cleavage (Cyp11a1); 3beta-hydroxysteroid dehydrogenase (Hsd3b); 17alpha-hydroxylase (Cyp17a1); scavenger receptor class B, type 1 (Scarb1); low-density lipoprotein receptor (Ldlr); and luteinizing hormone receptor (Lhcgr) was enriched in VCD-treated ovaries. In acyclic aged ovaries, mRNA expression for only Cyp17a1 and Lhcgr was greater than that in controls. Compared to cycling controls, ovaries from VCD-treated and aged mice had similar levels of HSD3B, CYP17A1, and LHCGR protein. The pattern of protein immunofluorescence staining for HSD3B in follicle-depleted (VCD-treated) ovaries was homogeneous, whereas that for CYP17A1 was only seen in residual interstitial cells. Circulating levels of FSH and LH were increased, and androstenedione levels were detectable following follicle depletion in VCD-treated mice. These findings support the idea that residual ovarian tissue in VCD-treated mice retains androgenic capacity.

Barton, J. K., Connolly, D. C., Craig, Z. R., Chambers, S. K., Hutchens, G. V., Dominguez Cooks, J. P., Koevary, J. W., Howard, C. C., Rice, P. F., & Hoyer, P. (2018). Comparison of Markers of Reproductive Function in Female C57Bl/6 versus TgMISIIR-TAg Transgenic Mice: Effect of VCD exposure on Ovarian Failure.. Comparative Medicine.
BIO5 Collaborators
Jennifer Kehlet Barton, Zelieann R Craig
Karman, B. N., Basavarajappa, M. S., Craig, Z. R., & Flaws, J. A. (2012). 2,3,7,8-Tetrachlorodibenzo-p-dioxin activates the aryl hydrocarbon receptor and alters sex steroid hormone secretion without affecting growth of mouse antral follicles in vitro. Toxicology and applied pharmacology, 261(1), 88-96.

The persistent environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an ovarian toxicant. These studies were designed to characterize the actions of TCDD on steroidogenesis and growth of intact mouse antral follicles in vitro. Specifically, these studies tested the hypothesis that TCDD exposure leads to decreased sex hormone production/secretion by antral follicles as well as decreased growth of antral follicles in vitro. Since TCDD acts through binding to the aryl hydrocarbon receptor (AHR), and the AHR has been identified as an important factor in ovarian function, we also conducted experiments to confirm the presence and activation of the AHR in our tissue culture system. To do so, we exposed mouse antral follicles for 96 h to a series of TCDD doses previously shown to have effects on ovarian tissues and cells in culture, which also encompass environmentally relevant and pharmacological exposures (0.1-100 nM), to determine a dose response for TCDD in our culture system for growth, hormone production, and expression of the Ahr and Cyp1b1. The results indicate that TCDD decreases progesterone, androstenedione, testosterone, and estradiol levels in a non-monotonic dose response manner without altering growth of antral follicles. The addition of pregnenolone substrate (10 μM) restores hormone levels to control levels. Additionally, Cyp1b1 levels were increased by 3-4 fold regardless of the dose of TCDD exposure, evidence of AHR activation. Overall, these data indicate that TCDD may act prior to pregnenolone formation and through AHR transcriptional control of Cyp1b1, leading to decreased hormone levels without affecting growth of antral follicles.

Craig, Z. R., Leslie, T. C., Hatfield, K. P., Gupta, R. K., & Flaws, J. A. (2010). Mono-hydroxy methoxychlor alters levels of key sex steroids and steroidogenic enzymes in cultured mouse antral follicles. Toxicology and applied pharmacology, 249(2), 107-13.

Methoxychlor (MXC) is an organochlorine pesticide that reduces fertility in female rodents by decreasing antral follicle numbers and increasing follicular death. MXC is metabolized in the body to mono-hydroxy MXC (mono-OH). Little is known about the effects of mono-OH on the ovary. Thus, this work tested the hypothesis that mono-OH exposure decreases production of 17β-estradiol (E₂) by cultured mouse antral follicles. Antral follicles were isolated from CD-1 mice (age 35-39 days) and exposed to dimethylsulfoxide (DMSO), or mono-OH (0.1-10 μg/mL) for 96 h. Media and follicles were collected for analysis of sex steroid levels and mRNA expression, respectively. Mono-OH treatment (10 μg/mL) decreased E(2) (DMSO: 3009.72±744.99 ng/mL; mono-OH 0.1 μg/mL: 1679.66±461.99 ng/mL; 1 μg/mL: 1752.72±532.41 ng/mL; 10 μg/mL: 45.89±33.83 ng/mL), testosterone (DMSO: 15.43±2.86 ng/mL; mono-OH 0.1μg/mL: 17.17±4.71 ng/mL; 1 μg/mL: 13.64±3.53 ng/mL; 10 μg/mL: 1.29±0.23 ng/mL), androstenedione (DMSO: 1.92±0.34 ng/mL; mono-OH 0.1 μg/mL: 1.49±0.43ng/mL; 1 μg/mL: 0.64±0.31 ng/mL; 10 μg/mL: 0.12±0.06 ng/mL) and progesterone (DMSO: 24.11±4.21 ng/mL; mono-OH 0.1μg/mL: 26.77±4.41 ng/mL; 1 μg/mL: 20.90±3.75 ng/mL; 10 μg/mL: 9.44±2.97 ng/mL) levels. Mono-OH did not alter expression of Star, Hsd3b1, Hsd17b1 and Cyp1b1, but it did reduce levels of Cyp11a1, Cyp17a1 and Cyp19a1 mRNA. Collectively, these data suggest that mono-OH significantly decreases levels of key sex steroid hormones and the expression of enzymes required for steroidogenesis.