EFFECTS OF ORAL ESTRADIOL THERAPY ON OSTEOCLASTOGENESIS

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 我们对雌激素调节骨细胞的机制的理解是不完整的。 这一过程很重要，因为绝经后妇女和可能性腺功能减退的男性的雌激素损失会导致骨量相对快速下降，并使易感个体易于发展为骨质疏松症。 这个翻译项目是康涅狄格大学健康中心（UCHC）的基础和临床科学家合作的结果，他们的工作重点是确定人类发展骨质疏松症的机制。 我们在这个试点项目中的具体目标是检查性类固醇充足和缺乏的老年男性和绝经后女性的骨髓中发生的细胞和分子变化的差异，以响应雌激素，因为小鼠的初步数据证明了这种激素的重要性。 在前期工作中，我们发现小鼠卵巢切除后，骨髓细胞分化为破骨细胞的能力迅速增加，破骨细胞是介导骨吸收的细胞。 这一发现表明，调节造血前体细胞分化成破骨细胞的能力，这一过程尚未得到充分的研究。 由于骨吸收率增加似乎是雌激素戒断对人体骨骼的最早已知影响，因此更好地了解这一过程可能会导致更有效的治疗男性和女性骨质疏松症的疗法。 具体目标1：通过评价雌激素（E2）治疗前后的骨髓穿刺液，检查这三组老年男性中每一组的破骨细胞生成潜力。 具体目标二：检查骨髓细胞中B淋巴细胞谱系发育和破骨细胞形成的参数，包括B淋巴细胞谱系发育的标志物，以及E2处理前后骨髓中早期和成熟B淋巴细胞的百分比。 这些研究还将评价经分级分离的（CD 19+和CD 19-）骨髓细胞在体外形成破骨细胞样细胞的能力，包括接受和不接受NF-κ B-配体受体激活剂（RANKL）和单核细胞集落刺激因子（M-CSF）处理。 具体目标3：检查已知影响破骨细胞形成的因子在骨髓中的表达，包括RANKL信使核糖核酸（RNA）、NF-κ B受体激活剂（RANK）、骨保护素（OPG）、M-CSF和M-CSF受体（c-Fms）。我们还将通过流式细胞术测量RANK和c-Fms的蛋白水平。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Our understanding of the mechanisms by which estrogens regulate bone cells are incomplete. This process is important because estrogen loss by women after menopause and probably in hypogonadal men produces a relatively rapid decrease in bone mass and predisposes susceptible individuals to the development of the disease osteoporosis. This translational project is the result of a collaboration between basic and clinical scientists at the University of Connecticut Health Center (UCHC) whose work focuses on the identification of the mechanisms by which human beings develop the disease osteoporosis. Our specific goal in this pilot project is to examine the differences in cellular and molecular changes that occur in the bone marrow of sex steroid-replete and deficient older men and postmenopausal women in response to estrogen, as preliminary data in mice demonstrates the importance of this hormone. In preliminary work we have found that ovariectomy in mice is rapidly followed by an increase in the ability of bone marrow cells to differentiate into osteoclasts, the cells that mediate bone resorption. This finding suggests that regulates the ability of hematopoietic precursor cells to differentiate into osteoclasts, a process that has not been adequately examined. Since increased rates of bone resorption appear to be the earliest known effects of estrogen withdrawal on the human skeleton, a better understanding of this process may lead to more effective therapies for the treatment of osteoporosis in both men and women. Specific Aim 1:Examine the osteoclastogenic potential of each of these three groups of older men by evaluation of bone marrow aspirates both before and after treatment with Estrogen (E2). Specific Aim 2: Examine parameters of B-lymphocyte lineage development and osteoclast formation in cells from bone marrow including markers of B-lymphocyte lineage development, and the percentage of early and mature B-lymphocytes in the bone marrow before and after E2 treatment. These studies will also evaluate the ability of fractionated (CD19+ and CD19-) bone marrow cells to form osteoclasts-like cells in vitro with and without treatment with receptor activator of NF-kappa B-ligand (RANKL) and monocyte- colony stimulating factor (M-CSF). Specific Aim 3: Examine the expression in the bone marrow of factors known to influence osteoclast formation including messenger ribonucleic acid (RNA) for RANKL, receptor activator of NF-kappa B (RANK), osteoprotegerin (OPG), M-CSF and the M-CSF receptor (c-Fms). We will also measure protein levels of RANK and c-Fms by flow cytometry.