Estrogen disruptors and neuroimmune signaling in obesity: focus on bisphenol A

Investigations of the obesity epidemic implicate environmental toxins that affect hormone systems, including the estrogen disruptor bisphenol acetate (BPA). This review concentrates on effects of BPA exposure on central nervous system areas involved in the control of feeding and body weight, drawing parallels between central nervous system effects of estrogens and of BPA. Conflicting findings abound because of methodological differences in species and sex, as well as BPA dose, timing of exposure, and specific model systems used. Nonetheless, common factors include the hypothalamic feeding-inhibitory peptide, pro-opiomelanocortin, and neuroimmune signaling in the hypothalamus, which may involve neuronal and non-neuronal cells. Receptor and intracellular mechanisms remain elusive but likely involve nuclear factor-kappa B signaling via interactions between nuclear estrogen receptors and peroxisome proliferator–activated receptor gamma.