MOLECULAR MECHANISMS OF OSTEOCLASTIC BONE RESORPTION

描述（改编自研究者摘要）： 拟议的研究是确定OC-116 kDa的作用， 新描述的分子，在破骨细胞的功能，并应用这些知识， 控制溶骨性疾病。 拟议的研究涉及一个 深入分析OC-116 kDa的表达、调控和功能 在骨细胞骨吸收中。 拟议研究的假设是 OC-116 kDa选择性地在破骨细胞中表达;它构成了 破骨细胞质子泵的一个组成部分，它在 功能作用的酸化subosteocellular陷窝。 在Aim中 1，使用RT-PCR在体内测定OC-116 kDa的表达， RNA酶保护，原位杂交和免疫化学，在细胞 和超微结构水平。 在目标2中，OC-116 kDa作为部分 的破骨细胞质子泵将确定共沉淀 OC-116 kDa与已知的泵亚基，并在功能上通过反义 体外抑制。 在目标3中，OC-116 kDa的功能将是 使用内源基因的靶向破坏建立。 的影响 胚胎期破骨细胞表型和功能的无效突变， 将测定新生和成年小鼠。 在目标4中， 破骨细胞中OC-116 kDa的骨吸收刺激剂和抑制剂 将被评估。 此外，对细胞特异性免疫抑制机制的研究， OC-116 kDa的调节将使用启动子-报告基因启动 转基因动物 在目标5中，OC-116 kDa的特异性抑制剂将是 并测定其对骨吸收的影响。 凭借其 选择性表达，OC-116 kDa可用作特异性靶点， 再吸收的治疗性抑制剂。

DESCRIPTION (Adapted from the investigator's Abstract): The overall goal of the proposed studies is to determine the role of OC-116 kDa, a newly-described molecule, in osteoclast function and to apply this knowledge to the control of osteolytic diseases. The proposed studies involve an in-depth analysis of the expression, regulation, and function of OC-116 kDa in osteoclastic bone resorption. The hypothesis of the proposed studies is that OC-116 kDa is expressed selectively in osteoclasts; that it constitutes an integral part of the osteoclast proton pump; and that it plays a key functional role in the acidification of the subosteoclastic lacuna. In Aim 1, the expression of OC-116 kDa will be determined in vivo, using RT-PCR, RNase protection, in situ hybridization and immunochemistry, at the cellular and ultrastructural levels. In Aim 2, the association of OC-116 kDa as part of the osteoclast proton pump will be determined by coprecipitation of OC-116 kDa with known subunits of the pump, and functionally by antisense inhibition in vitro. In Aim 3, the function of OC-116 kDa will be established using targeted disruption of the endogenous gene. The effect of the null mutation on phenotype and osteoclast function in embryonic, neonatal and adult mice will be determined. In Aim 4, the regulation of OC-116 kDa in osteoclasts by stimulators and inhibitors of bone resorption will be assessed. In addition, studies of the mechanisms of cell-specific regulation of OC-116 kDa will be initiated using promoter-reporter transgenic animals. In Aim 5, specific inhibitors of OC-116 kDa will be sought and their effect on bone resorption determined. By virtue of its selective expression, OC-116 kDa may be useful as a target of specific therapeutic inhibitors of resorption.