BACKGROUND Exposure of pregnant mice to inorganic arsenic induces a spectrum of tumors, including hepatocellular carcinoma (HCC), in their adult offspring similar to that induced by exposing adult mice to estrogenic compounds. To investigate whether arsenic exposure in utero causes altered estrogen signaling, we examined expression of estrogen receptor-alpha (ER-alpha), cyclin D1 (an estrogen-r...

Lipopolysaccharide (LPS), a highly conserved component of the outer membrane of gram-negative bacteria, stimulates macrophages to release various cytokine and eicosanoid mediators of the immune response. The mechanism by which LPS stimulates these cells is poorly characterized. One of the most rapid LPS-stimulated events is the phosphorylation and activation of the p42 and p44 isoforms of mitog...

The estrogen receptor (ER) mediates estrogenic activity in a variety of organs, including those in the reproductive, cardiovascular, immune, and central nervous systems. Experimental studies have demonstrated that 17beta-estradiol (E2) protects the heart from ischemia-reperfusion injury. Two estrogen receptors, ER alpha and ER beta, mediate the actions of estrogen; however, it is not certain wh...

The effects of estrogen are mediated through two functionally distinct receptors, estrogen receptor alpha (ER- alpha ), and estrogen receptor beta (ER- beta ), both of which are expressed in the cardiovascular system. The etiology of cardiovascular disease is believed to result in part from the loss of endogenous estrogen, indicating that estrogen and its receptors may play important roles in t...

BACKGROUND Variations in maternal care are associated with neonatal stress, hormonal disturbances and reproductive injuries during adulthood. However, the effects of these variations on sex hormones and steroid receptors during ovary development remain undetermined. This study aimed to investigate whether variations in maternal care are able to influence the hormonal profile, follicular dynamic...

Estrogenic activity in environmental samples could be mediated through a wide variety of compounds and by various mechanisms. High-affinity compounds for estrogen receptors (ERs), such as natural or synthetic estrogens, as well as low-affinity compounds such as alkylphenols, phthalates, and polychlorinated biphenyls are present in water and sediment samples. Furthermore, compounds such as polyc...

It was recently demonstrated that antiestrogens prevented prostate cancer (PRCA) in men. The source of estradiol (E2) that contributes to carcinogenesis, as well as the selected estrogen receptor (ER) signaling pathway, is unknown. To evaluate estrogen's effects in carcinogenesis, we developed a new model of PRCA utilizing testosterone and E2 to stimulate PRCA. To determine whether local in sit...

Women are at greater risk of tearing their knee anterior cruciate ligament (ACL) than men participating in similar athletic activities. There is currently no conclusive explanation for this disparity; however, as ACL injuries in women have been linked with estrogen fluctuations during the menstrual cycle, one hypothesis is that estrogen has a direct detrimental effect on knee ligament mechanica...

Epidermal growth factor reproduces many of the effects of estrogen on the murine female reproductive tract and may partially mediate estrogen-induced growth and differentiation. The mechanism by which the actions of estrogens and epidermal growth factor (EGF) converge is unknown. The studies described herein were performed to investigate the possibility that some of the actions of EGF may be me...

There is significant clinical interest in the factors that influence the development of tamoxifen resistance in estrogen receptor-alpha (ER-alpha)-positive breast cancers. Recent studies suggest that in ER-positive breast tumor cells, elevated protein levels, and in particular, nuclear localization of p21-activated kinase 1 (PAK1), is associated with the progressive limitation of tamoxifen sens...