Estrogen in the Mechanism of Bone Metabolism

绝经后骨质疏松症主要由雌激素水平下降引起。骨量减少被认为是由绝经后骨质疏松症的高代谢转换引起的。然而，我们使用动物模型和培养系统的研究结果表明，绝经后骨质疏松症的骨量减少是由造血微环境中造血功能的改变引起的骨代谢变化引起的。雌激素水平的降低会增加骨髓中未成熟b细胞的数量，这些细胞粘附在基质细胞上，刺激白细胞介素-6的产生，白细胞介素-6是一种促进骨吸收的细胞因子。这一系列事件刺激骨吸收级联反应，导致骨的高代谢转换和随之而来的骨量损失。雌激素缺乏会导致骨吸收速度超过骨形成速度，从而导致骨量减少。然而，雌激素缺乏导致骨量减少的原因不同，雌激素通过增加骨吸收来减少骨量。了解这一机制可以在临床实践中导致疾病特异性治疗。当骨质疏松症的减少主要是由雌激素水平下降引起的，纠正和抑制增加的骨吸收是首选的治疗方法。

Postmenopausal osteoporosis is caused mainly by decreased levels of estrogen. Decreased bone mass is thought to result from high metabolic turnover in the postmenopausal osteoporosis. However, the results of our studies using animal models and culture systemic suggest that in postmenopausal osteoporosis decreased bone mass in caused by changes in bone metabolism, triggered by altered hematopoiesis in the hematopoictic microenvironment. Decreases levels of estrogen increase the number of immature B-cells in marrow, which adhere to stromal cells and stimulate production of interleukin-6, a cytokine that promotes bone resorption.This series of events stimulates the bone resorption cascade, resulting in high metabolic turnover of bone and consequent loss of bone mass.Estrogen deficiency can thus lead to a situation where the rate of resorption surpasses that bone formation, resulting in decreased bone mass. However, the causes underlying the decrease in bone mass differ for estrogen deficiency, its reduces bone mass by increasing bone resorption. An understanding of this mechanism can lead to disease-specific therapy in clinical practice. When reduction in bone mass osteoporois is caused mainly by decreased levels of estrogen, correction and inhibition of increased bone resorption is the therapy of choice.