Novel bone specific pharmacological treatment for osteogenesis imperfecta

项目摘要 目前还没有治愈骨生成性骨质疏松症（OI或脆骨病），这是最常见的遗传性 影响1：15，000出生的骨骼疾病。OI最明显的临床特征是骨脆性和骨骼 畸形OI主要由I型胶原蛋白缺陷引起，导致胶原蛋白分子折叠不正确， 破坏原纤维排列和结构，并为骨中的矿化提供异常模板。为此 因此，OI传统上被认为是一种骨细胞外基质疾病，目前对OI的治疗 依赖于使用药理学药物，主要是双膦酸盐，一类抑制骨吸收的药物 并用于骨质疏松症的治疗。尽管初步取得了成功，但这些药物的实际疗效 降低骨折风险的治疗是有争议的，长期使用 这种药物在发育骨关节炎儿童的骨骼。最近的研究表明，细胞成分， OI疾病：OI骨的成骨细胞中的内质网（ER）应激。我们最近还发现， 使用4-苯基丁酸酯（4PBA）对ER应激的药理作用能够减少OI表型 严重性，增加骨形成和减少骨骼畸形。这种药物治疗需要两个 改进：1）增加其稳定性和2）使其能够有效地到达骨骼。此外，未知 是治疗对骨质量和力学的影响。 所提出的实验的基本原理是合成4PBA衍生物，N-苄基甘氨酸（N-BG）， 更稳定，并确定其对OI ER细胞应力和OI骨材料性质的影响。在第二 在实验中，我们将测试载体（（GfO）8）将N-BG递送至骨细胞的功效以及对OI骨的影响 质量.我们将使用来自OI的Brt 1小鼠模型的原代分离的成骨细胞用于ER和成骨细胞的体外测试。 用N-BG的凋亡应激。隐性（p3 h1-/-）和显性（奇瓦瓦州）型OI的斑马鱼模型，以及 健康的斑马鱼将注射安慰剂或N-BG药物或（GfO）8-N-BG药物+载体。形态 和组织孔隙度的ψ dal椎骨将分析在处理的斑马鱼和c 吸毒成瘾 将检查治疗对胶原纤维组织、骨组织组成和机械性能的影响 使用一系列高分辨率实验。 从本研究中获得的知识将为疗效提供信息 新的4PBA衍生物疗法和使用载体治疗骨脆性的OI。这项工作还将 提供了第一个标准化的管道，以评估药物对斑马鱼骨骼疾病模型的影响。

Project Summary There is no cure for osteogenesis imperfecta (OI or brittle bone disease), the most common of the heritable disorders of bone affecting 1:15,000 births. The most evident clinical hallmarks of OI is bone fragility and skeletal deformities. OI is caused primarily by defects in collagen type I, leading to collagen molecules folding improperly, disrupting fibril alignment and structure, and providing an abnormal template for mineralization in bone. For this reason, OI has been traditionally considered a bone extracellular matrix disorder, and current treatments for OI rely on the use of pharmacological drugs, mainly bisphosphonates, a class of drugs that inhibit bone resorption and is used in the management of osteoporosis. Despite the initial success, the actual efficacy of these treatments to reduce the fracture risk are controversial and additional risks may arise from the long-term use of this drug in developing bones of children with OI. Recent research has demonstrated a cellular component to the OI disease: the endoplasmic reticulum (ER) stress in the osteoblasts of OI bone. We also recently found that pharmacological action toward ER stress using the 4-phenyl butyrate (4PBA) is able to reduce the OI phenotype severity, increasing bone formation and reducing skeletal deformities. This drug treatment needs two improvements: 1) increase its stability and 2) make it able to effectively reach the bone. Furthermore, unknown is the effect of the treatment on bone quality and mechanics. The rationale of the proposed experiments is to synthesize a 4PBA derivative, the N-benzyl glycine (N-BG), that is more stable and to determine its effect on OI ER cells stress and on OI bone material properties. In a second experiment, we will test the efficacy of a carrier ((GfO)8) to deliver N-BG to bone cells and the effect on OI bone quality. We will use primary isolated osteoblasts from Brtl mouse model of OI for the in vitro testing of ER and apoptotic stress with N-BG. Zebrafish models of recessive (p3h1-/-) and dominant (Chihuahua) type of OI, and healthy zebrafishes will be injected with either placebo or N-BG drug or (GfO)8-N-BG drug+carrier. Morphology and tissue porosity of precaudal vertebrae will be analyzed in the treated zebrafishes and the c hanges with drug therapy to the collagen fiber organization, bone tissue composition and mechanical properties will be examined using an array of high resolution experiments. The knowledge gained from this study will inform on the efficacy of new 4PBA derivatives therapies and on the use of carriers to treat bone fragility in OI. This work will also provide the first and standardized pipeline to evaluate drug effect on Zebrafish skeletal disease models.