Schnurri-3 Inhibitors: specific inducers of adult bone formation

Schnurri-3 抑制剂：成人骨形成的特异性诱导剂

基本信息

批准号：
8259713
负责人：
LAURIE Hollis GLIMCHER
金额：
$ 4.04万
依托单位：
HARVARD SCHOOL OF PUBLIC HEALTH
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-04-21 至 2013-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8259713
关键词：
3&apos Untranslated Regions Address Adult Adverse effects Affect Age Aging Alkaline Phosphatase Biological Biological Assay Biological Preservation Bone Resorption Cell Line Cells Characteristics Chemicals Deposition Disease Disease Progression Dose Drug Delivery Systems Environment Equilibrium Family Fireflies Firefly Luciferases Fracture Gene Expression Generations Genes Goals Health Hematopoiesis Human In Vitro Incidence Individual Inhibitory Concentration 50 Institutes Large T Antigen Libraries Luc Gene Maintenance Malignant Neoplasms Mediating Mesenchymal Stem Cells Messenger RNA Morbidity - disease rate Morphogenesis Morphology Mus Organ Osteoblasts Osteoclasts Osteogenesis Osteoporosis Pharmaceutical Preparations Phenotype Physiological Population Prevention Process Property Proteins Refractory Renilla Luciferases Reporter Series Simian virus 40 Skeletal system Skeleton Source Specificity Technology Testing Therapeutic Transcript United States Untranslated Regions Zinc Fingers base bone bone loss bone mass cost cytotoxic design high throughput screening in vivo inhibitor/antagonist interest member mineralization mortality novel null mutation osteoblast differentiation osteogenic postnatal prevent promoter public health relevance response skeletal skeletal disorder small hairpin RNA small molecule therapeutic target

项目摘要

DESCRIPTION (provided by applicant): In a normal physiological state the skeletal system provides mobility, protection for vital organs and serves as an essential environment in which hematopoiesis can occur [1]. To achieve these functions, the skeleton exists in a dynamic equilibrium characterized by continuous osteoclast-mediated resorption of bone and osteoblast- mediated bone deposition [2]. Maintenance of this homeostatic remodeling is disrupted during aging leading to debilitating bone loss referred to as osteoporosis that affects over 10 million individuals in the United States [3]. As an individual ages, the progression of this disease results in an increased incidence of fracture that results in serious health consequences [4]. Since few therapeutic options are available for the prevention or treatment of osteoporosis, our goal is to develop novel mechanism-based treatments that increase anabolic bone formation and prevent bone loss. We have recently identified Schnurri-3 (Shn3), a member of the Schnurri family of large zinc-finger proteins, as an essential regulator of adult bone formation [5]. Our generation and subsequent analysis of mice bearing a null mutation in Shn3 (Shn3-/- mice) revealed a profound high-bone mass phenotype that arises through augmented osteoblast activity and is characterized by greatly increased rates of bone formation. The osteosclerotic phenotype observed in Shn3-/- mice does not affect skeletal morphology since its onset is postnatal. However, the loss of Shn3 renders these mice refractory to the age-associated loss in bone that occurs in control mice. The characteristics of Shn3-/- bone: increased bone anabolic activity, preservation of normal morphogenesis, mineralization and biophysical properties suggest that this protein is an ideal therapeutic target for the treatment of certain skeletal disorders. Unfortunately, structural analysis of Shn3 has revealed a dearth of functional domains within this protein that are suitable for drug targeting. We have, however, demonstrated that shRNA targeting of the 3'UTR of Shn3 reduces protein levels and augments osteoblast function in vitro. Furthermore, we have determined that post-transcriptional blockade of Shn3 results in increased bone mass in vivo. Therefore, we have designed a series of cell-based assays that will allow for the identification of chemical probes that selectively reduce Shn3 protein levels through a post- transcriptional mechanism targeting the 3'UTR of this gene. The identification of compounds that decrease Shn3 levels would provide a valuable therapeutic approach to prevent the destructive bone loss associated with osteoporosis. PUBLIC HEALTH RELEVANCE: Osteoporosis is a debilitating disease of the skeletal system that currently affects over 10 million individuals in the United States. Disease progression results in an increased incidence of fracture that results in serious health consequences and will present an expanding source of morbidity and mortality in an aging global population. While a few classes of medications are available to either prevent bone loss or increase bone formation in the setting of osteoporosis or cancer, current therapeutics are far from ideal due to toxic side effects, intolerance, or prohibitive cost. The ultimate goal of this proposal is to develop mechanism-based treatments to prevent bone loss and to increase anabolic bone formation. 2

描述（由申请人提供）：在正常的生理状态下，骨骼系统为重要器官提供活动性和保护，并作为造血发生的重要环境[1]。为了实现这些功能，骨骼处于动态平衡状态，其特征是连续破骨细胞介导的骨吸收和成骨细胞介导的骨沉积[2]。这种稳态重塑的维持在衰老过程中被破坏，导致骨质流失（称为骨质疏松症），在美国影响着超过 1000 万人 [3]。随着个体年龄的增长，这种疾病的进展会导致骨折发生率增加，从而导致严重的健康后果[4]。由于预防或治疗骨质疏松症的治疗选择很少，我们的目标是开发基于机制的新型治疗方法，以增加合成代谢骨形成并防止骨质流失。我们最近发现 Schnurri-3 (Shn3)，大锌指蛋白 Schnurri 家族的成员，是成人骨形成的重要调节因子 [5]。我们对携带Shn3无效突变的小鼠（Shn3-/-小鼠）的产生和随后的分析揭示了通过增强的成骨细胞活性而产生的深刻的高骨量表型，其特征是骨形成率大大增加。在 Shn3-/- 小鼠中观察到的骨硬化表型不会影响骨骼形态，因为它是在出生后发病的。然而，Shn3 的缺失使得这些小鼠难以抵抗对照小鼠中发生的与年龄相关的骨质流失。 Shn3-/-骨的特征：骨合成代谢活性增加、正常形态发生、矿化和生物物理特性的保存表明该蛋白是治疗某些骨骼疾病的理想治疗靶点。不幸的是，Shn3 的结构分析表明该蛋白内缺乏适合药物靶向的功能域。然而，我们已经证明，shRNA 靶向 Shn3 的 3'UTR 可降低体外蛋白质水平并增强成骨细胞功能。此外，我们已经确定Shn3的转录后阻断会导致体内骨量增加。因此，我们设计了一系列基于细胞的检测方法，能够识别化学探针，通过针对该基因 3'UTR 的转录后机制选择性降低 Shn3 蛋白水平。降低Shn3水平的化合物的鉴定将为预防与骨质疏松症相关的破坏性骨质流失提供有价值的治疗方法。公共卫生相关性：骨质疏松症是一种使骨骼系统衰弱的疾病，目前影响美国超过 1000 万人。疾病进展导致骨折发生率增加，从而导致严重的健康后果，并将在全球人口老龄化中带来不断扩大的发病率和死亡率来源。虽然有几类药物可以在骨质疏松症或癌症的情况下预防骨质流失或增加骨形成，但由于毒副作用、不耐受或成本过高，目前的治疗方法远非理想。该提案的最终目标是开发基于机制的治疗方法，以防止骨质流失并增加合成代谢骨形成。 2