Abstract
Osteoporosis is a major health issue, especially in older women. The absence of estrogen is the main cause of menopausal osteoporosis. Estrogen and androgen hormones play major roles during the growth and development of the skeletal system, including preservation of bone structure. Estrogen plays an important role in the balance between the bone formation of osteoblasts and osteoclasts, which are associated with bone resorption. Several pathways have been shown to regulate bone formation and degradation. Estrogen and Ephrin-Eph pathways are among the most important molecular mechanisms that regulate bone reconstruction. Many different genes are involved in these pathways, and in some cases, these pathways may work together for the bone reconstruction and resorption. In this review, we evaluate the relationship between estrogen, RANKL, and EphirinB2, and we highlight the direct relation between osteoporosis and estrogen hormone. The identification of direct or indirect pathways of bone formation and degradation in pre- and postmenopausal women could be an important tool for the development of therapeutic strategies in postmenopausal women.