A NOVEL STRATEGY FOR OSTEOPOROSIS GENE THERAPY

骨质疏松症基因治疗的新策略

• 批准号: 6254690
• 负责人: Joanne T Douglas
• 金额: $ 7.18万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6254690
• 关键词: biotechnology; bone metabolism; gene targeting; gene therapy; hormone regulation /control mechanism; human subject; human tissue; immunogenetics; osteoblasts; osteocalcin; osteoclasts; osteoporosis; parathyroid hormones; technology /technique development; transfection /expression vector

DESCRIPTION (Taken from the application): Osteoporosis is a group of diseases of diverse etiology in which the rate of bone resorption by osteoclasts exceeds that of bone formation by osteoblasts, resulting in a reduction in the mass of bone per unit volume. Patients with end-stage, 1ow-turnover osteoporosis do not respond to existing therapies. Osteoblasts in end-stage osteoporosis can be activated by parathyroid hormone (PTH); however, this also invokes an increase in osteoclastic activity that limits the effectiveness of this approach. In this project, we propose to develop a gene therapy method to allow PTH activation of osteoblasts that will have reduced ability to produce RANKL, a key regulator of osteoclastogenesis. We hypothesize that this could be accomplished by employing an intracellular single-chain antibody (sFv) to achieve osteoblast-specific downregulation of RANKL. This approach mandates the use of a gene delivery vehicle, or vector, which can target expression of the sFv specifically to osteoblasts. Capitalizing on the ability of recombinant adenoviral (Ad) vectors to accomplish efficient gene transfer, we hypothesize that Ad-mediated gene delivery can be targeted specifically to osteoblasts. The first Specific Aim is to develop an Ad vector targeted to osteoblasts at the transductional and transcriptional levels. Transductional targeting will be achieved using a bispecific antibody with specificities for the adenovirus fiber protein and an osteoblastrelated marker protein, while transcriptional targeting will be achieved by placing the transgene under the control of the osteoblast-specific osteocalcin promoter. The second Specific Aim is to derive an intracellular sFv to selectively downregulate the expression of RANKL. In the third Specific Aim, we will employ the targeted Ad vector to direct the intracellular expression of this sFv specifically within osteoblasts and will determine whether the downregulation of RANKL results in a reduction in osteoclast recruitment in vitro. The realization of these Specific Aims would establish the feasibility of this approach as a rational strategy for gene therapy in patients with end-stage, low-turnover osteoporosis.

描述（摘自申请书）：骨质疏松症是一组疾病 具有多种病因，其中破骨细胞的骨吸收率超过 成骨细胞形成骨的过程，导致骨量减少 单位体积的骨。终末期 1 低周转骨质疏松症患者不 对现有疗法有反应。终末期骨质疏松症中的成骨细胞可以 由甲状旁腺激素（PTH）激活；然而，这也导致增加 破骨细胞活性限制了这种方法的有效性。在 这个项目，我们建议开发一种基因治疗方法，让PTH 成骨细胞的激活会降低产生 RANKL 的能力，RANKL 是一种 破骨细胞生成的关键调节因子。我们假设这可能是 通过使用细胞内单链抗体（sFv）来完成 实现成骨细胞特异性下调 RANKL。这种方法要求 使用基因递送载体或载体，其可以靶向表达 sFv 特异针对成骨细胞。充分利用重组能力 我们假设腺病毒（Ad）载体可以实现有效的基因转移 Ad介导的基因传递可以特异性地靶向成骨细胞。这 第一个具体目标是开发一种针对成骨细胞的 Ad 载体 转导和转录水平。转导靶向将是 使用具有腺病毒特异性的双特异性抗体实现 纤维蛋白和成骨细胞相关标记蛋白，而转录 通过将转基因置于 成骨细胞特异性骨钙素促进剂。第二个具体目标是得出 细胞内 sFv 选择性下调 RANKL 的表达。在 第三个具体目标，我们将采用有针对性的广告向量来指导 该 sFv 在成骨细胞内特异性表达，并且将 确定 RANKL 的下调是否会导致 破骨细胞体外募集。这些具体目标的实现将 确定该方法作为基因合理策略的可行性 治疗终末期低周转骨质疏松症患者。