Bisphenol A and other suspected estrogenic endocrine disruptors Andrea C. Gore Ph.D., University of Texas at Austin

1. Bisphenol A and other suspected estrogenic endocrine disruptors 1 Andrea C. Gore Ph.D., University of Texas at Austin

3. Industry (PCBs, dioxins)

4. Pesticides, fungicides (DDT, methoxychlor, vinclozolin)

5. Pharmaceuticals (DES, EE)

6. Phytoestrogens (soy, alfalfa)

8. 4 Estrogenic EDCs Mechanisms of action: Nuclear hormone receptors – ERa, ERb Membrane receptors – GPER (GPR30) Steroidogenic enzymes (p450 aromatase) Steroid metabolizing enzymes – steroid sulfatase Neurotransmitter receptors

9. EDCs –Brain & Behavior 5 Estrogenic EDCs Peripheral hormones, Reproductive function, Behaviors “Fetal/developmental basis of adult disease”

11. Used in high volume: >6 billion lbs annually.

12. Heat causes hydrolysis and leaching.H3C C3H HO OH Richter et al., Reprod. Toxicol. 24: 199-224 (2007)

14. Androgen receptor antagonist

15. Thyroid hormone receptor antagonist

16. AhR, RARa, RXRa are up-regulated by BPA

17. Enzyme activity

18. Epigenetic modifications (DNA methylation)ER agonist effects are best-studied.

20. LOAEL EPA reference dose = 50 mg/kg/day

22. Serum levels estimated from 0.2 to 20 ng/ml.

23. Amniotic fluid levels measured at 8.3 ng/ml.

24. Breast milk: mean 0.61 ng/ml.

25. Urine: Numerous studies show detectable BPA.

26. Assays include GC-MS, HPLC, ELISA, with sensitivity from 0.01 to 0.5 ng/ml.Vandenberg et al., Reprod. Toxicol. 24: 139-177 (2007)

28. Multiple mechanisms make prediction of outcomes difficult.

29. Likelihood of mixtures of EDC exposures.

31. Increased motor activity

32. Increased pain sensitivity

33. Impaired learning & memory

34. Decreased maternal behavior

35. Impairments in sexual behavior

36. Impaired neural plasticity – rodents & non-human primates

38. Prostate

39. Ovary (oocytes)/ Testes (sperm)

40. Uterus and vagina/ epididymis & seminal vesicles

41. Adipocytes

42. Thyroid

43. Anti-androgenNewbold, Reprod. Toxicol. 23: 290-296 (2007)

45. Persist & bioaccumulate

46. Adult exposure- contaminated food

47. Developmental exposure- placental and lactational transfer

48. Developmental PCB exposure- neurological/ reproductive deficits

50. E2 (50 µg)

51. A1221 (1 mg/kg)Birth E0 E16 E18 P0 ♂ ♂ ♀ ♀ P1 P60 Puberty Exposure during the critical period of brain sexual differentiation

52. 15 ERα Expression in the mPOA (P1) Female DMSO A1221 Male DMSO A1221 Sarah Dickerson, PhD dissertation (unpub.)

54. PCBs cause increased apoptosis in females – making them more “male-like.”Sarah Dickerson, PhD dissertation (unpub.)

56. E2 (50 µg)

57. A1221 (1 mg/kg)Birth E0 E16 E18 P0 ♂ ♂ ♀ ♀ P1 P60 Puberty Postnatal development, Reproductive cycles, Hypothalamic protein/gene expression, Behavior

58. Developmental effects Eye opening: Advanced in females (PCB). Pubertal timing: Advanced in females (EB, PCB), delayed in males (EB, PCB). Estrous cyclicity: Prolonged cycles in EB (46%), PCB (33%). 18

59. 19 Hypothalamic control of reproduction EDCs

61. PCBs cause ERa to decrease in the AVPV of females – making them more “male-like.”20 Sarah Dickerson, PhD dissertation (unpub.)

63. PCBs cause kisspeptin to decrease in the AVPV of females – making them more “male-like.”Sarah Dickerson, PhD dissertation (unpub.)

64. 22 GnRH-Fos co-expression (P60) in females The co-expression of Fos in GnRH neurons is significantly suppressed in PCB females. 2X 20X 40X 100X Sarah Dickerson, PhD dissertation (unpub.)

66. Reproductive success is enhanced when the female controls the pace of the mating.

67. A paced mating paradigm enables dissection of female-typical behaviors.RM Steinberg et al. (2007) Horm Behav 51: 364-372.

68. Summary Exposure to estrogenic EDCs during fetal development has long-term consequences on the molecular and cellular processes controlling reproduction. EDCs are associated with the masculinization of the hypothalamus of females. Puberty and reproductive physiology are perturbed, and reproductive behaviors are compromised. 24

69. Implications I propose that fetal exposures to EDCs reprogram the hypothalamus, and that this programming permanently compromises reproductive success. I also believe that these effects may be transmitted to future generations through molecular epigenetic changes. 25

70. 26 Acknowledgments Funding: NIH RC1 ES018139 NIH R21 ES12272 PhRMA UT-Austin Fellowships Sarah Dickerson Deena Walker