PLASMA MEMBRANE CALCIUM PUMP IN OSTEOBLASTS

这项赠款的总体目标是分离和表征 质膜钙泵（Ca 2+泵，Ca 2+泵-Ca 2 +-Mg-ATPase） 从人类成骨细胞样细胞，并检查其生理学在这些 细胞 我们推测，质膜钙泵在细胞凋亡中起着至关重要的作用。 控制人成骨细胞内的细胞内钙。几 研究人员已经表明，细胞内Ca 2+浓度是重要的， 来决定成骨细胞的功能状态。所以一间 对这种泵的结构和生理学的理解是 重要性 我们的具体目标是：1.分离和表征质膜Ca 2+泵从人成骨细胞样细胞。这些实验将包括 离体质膜Ca ~（2+）转运的证明 2+_Mg2+ -ATP酶的重建研究。 2.分离人成骨细胞质膜钙泵的cDNA克隆. 3.测定细胞膜Ca 2+泵的活性是否 通过将人成骨细胞样细胞暴露于激素剂， 作为甲状旁腺激素类似物，1，25-二羟基维生素[1，25（OH）2 D3]和 其他维生素D代谢物。短期和长期的实验将 被执行。将使用以下方法定量Ca 2+泵mRNA的变化： 北方印迹分析。如果注意到变化， 将被执行。 4.使用一系列的表达系统来评估可能的生理 成骨样细胞系中质膜钙泵的作用 了解成骨细胞的生理学和生物化学， 对我们理解重要的骨骼疾病至关重要。一个这样 对公众健康具有重要意义的疾病是骨质疏松症。 绝经前和老年骨质疏松症至少占100亿美元， 每年的医疗费用。从许多人的研究中可以清楚地看出， 实验室，包括我们自己的实验室， 钙摄入中的因素在这种疾病的发生中是重要的。 我们的研究将大大增加对成骨细胞生物学的理解 这反过来又可以用来设计合理的治疗原则， 骨质疏松症的治疗

The overall objective of this grant is to isolate and characterize the plasma membrane calcium pump (Ca2+ -pump, Ca2+ -Pumping-Ca2+-Mg-ATPase) from human osteoblast-like cells and to examine its physiology in these cells. We hypothesize that the plasma membrane Ca2+-pump plays a vital role in the control of intracellular calcium within human osteoblasts. Several investigators have shown that intracellular Ca2+ concentration is important in determining the functional state of the osteoblast. Therefore, an understanding of the structure and physiology of this pump is of importance. Our specific aims are to: 1.Isolate and characterize the plasma membrane Ca 2+- pump from human osteoblast-like cells. These experiments will include the demonstration of Ca 2+ transport by the isolated plasma membrane Ca 2+_Mg2+ -ATPase in reconstitution studies. 2.Isolate cDNA clones for the human osteoblast plasma membrane Ca 2+- pump. 3.Determine whether the activity of the plasma membrane Ca 2+- pump is altered by exposure of human osteoblast-like cells to hormonal agents such as parathyroid hormone analogs, 1,25-dihydroxyvitamin [1,25(OH)2 D3] and other vitamin D metabolites. Both short-term and long-term experiments will be performed. Changes in Ca 2+- pump mRNA will be quantitated using Northern blot analysis. If changes are noted, nuclear run-off experiments will be performed. 4. Use a series of expression systems to assess the possible physiological role of the plasma membrane Ca 2+- pump in osteoblast-like cell lines. An understanding of the physiology and biochemistry of the osteoblast is central to our understanding of important diseases of bone. One such disease, of significant public health importance, is osteoporosis. Premenopausal and senile osteoporosis account for at least $10 billion of health care expenditures per year. It is clear from the studies of many laboratories, including our own, that abnormalities in various hormonal factors nd in calcium intake are important in the genesis of this disease. Our studies will add greatly to the understanding of osteoblast biology which in turn can be utilized to devise rational therapeutic principles for the treatment of osteoporosis.