Combined Effect of Noggin Suppression and Nell-1 on Bone Regeneration

Noggin 抑制和 Nell-1 对骨再生的联合作用

• 批准号: 8306999
• 负责人: Min Lee
• 金额: $ 34.65万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-25 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8306999
• 关键词: Adverse effects; Autologous; BMP2 gene; Biological; Biological Models; Biomimetics; Bone Morphogenetic Proteins; Bone Regeneration; Bone Transplantation; Calvaria; Cells; Clinical; Complement; Cyst; Defect; Development; Dose; Down-Regulation; Elements; Employment; Environment; Epidermal Growth Factor; Exhibits; Feedback; Fracture; Goals; Gold; Growth Factor; Healed; In Vitro; Marrow; Mechanics; Mediating; Mesenchymal Stem Cells; Methods; Modality; Modeling; Morbidity - disease rate; Natural regeneration; Osteoblasts; Osteogenesis; Pathway interactions; Physiological; Proteins; RNA Interference; Research; Signal Transduction; Site; Small Interfering RNA; Spinal Fusion; Stem cells; System; Testing; Therapeutic; Tibial Fractures; Tissues; Transplanted tissue; Vesicle; Viral; base; bone; healing; in vivo; inhibitor/antagonist; long bone; maxillofacial; non-viral gene delivery; novel; osteoblast differentiation; osteogenic; osteoinductive factor; osteoprogenitor cell; polyarginine; protein expression; relating to nervous system; repaired; scaffold; uptake

DESCRIPTION (provided by applicant): The current "gold standard" for bone graft material is autologous bone graft, but autologous grafts are limited by availability and donor site morbidity. Various osteoinductive growth factor-based therapies have been developed in an attempt to find an effective and safer method of bone regeneration. Among the various osteoinductive factors available, bone morphogenetic proteins (BMPs) are believed to be the most potent osteoinductive factors and have been extensively studied for the treatment of many bone fractures and bone defects. However, BMPs are highly pleiotropic molecules and their supra-physiological dose requirement leads to adverse side effects such as cyst formation, and inefficient bone formation. Thus, there is a need to develop alternative osteoinductive growth factor strategies that can effectively complement BMP activity to maximize biological efficiency while minimizing the BMP dose. One alternative approach is to deliver no BMP at all, while enhancing the ability of the progenitor cells that participate in regeneration to respond to endogenous BMPs. This can be accomplished by delivering inhibitors of BMP antagonists such as Noggin, thereby enhancing endogenous BMP activities. Noggin is a direct target of BMP pathways in osteoprogenitors, and it is thus highly likely that supraphysiological BMP doses are required clinically in large part due to Noggin induction. Thus, we propose an approach for enhancing BMP signaling through down-regulation of Noggin. The potency of endogenous BMPs can be enhanced by delivering osteoinductive signals that are more specific and less pleiotropic than BMPs, such as Nell-1 [Nel-like molecule-1; Nel (a protein strongly expressed in neural tissue encoding epidermal growth factor like domain)]. In previous studies, Nell-1 has been shown to accelerate osteogenic differentiation in vitro and calvarial bone formation in vivo. Moreover, Nell-1 is a secreted protein that can be delivered extracellularly, and most importantly Nell-1 promotes synergistic effects with BMP2 on bone regeneration. By suppressing Noggin locally, we seek to enhance endogenous BMP signaling which in turn, should synergistically stimulate osteoblast differentiation induced by Nell-1, thereby leading to maximum bone formation without the concerns surrounding BMP mediated adverse effects. The specific hypothesis of this proposal is that controlled delivery of Nell-1 combined with the employment of Noggin suppression can enhance repair of segmental femoral defects. Two specific aims are proposed to investigate this hypothesis. Aim 1: To enhance bone regeneration via Noggin suppression + Nell-1. In this specific aim, we will evaluate synergistic effects of Nell-1 combined with Noggin-suppressed MSC on osteogenic capacity and bone regeneration. Aim 2: To enhance bone regeneration via controlled delivery of Noggin-siRNA + Nell-1. In this aim, we will develop non-viral gene delivery/scaffolding systems that release Nell-1 and Noggin-siRNA and will test whether they can effectively regenerate bone in a segmental femoral defect model.

描述（由申请人提供）：目前骨移植材料的“黄金标准”是自体骨移植，但自体移植受到可用性和供体部位发病率的限制。人们已经开发了各种基于骨诱导生长因子的疗法，试图找到一种有效且更安全的骨再生方法。在各种可用的骨诱导因子中，骨形态发生蛋白（BMP）被认为是最有效的骨诱导因子，并已被广泛研究用于治疗许多骨折和骨缺损。然而，BMP 是高度多效性的分子，其超生理剂量需求会导致不良副作用，例如囊肿形成和骨形成效率低下。因此，需要开发替代的骨诱导生长因子策略，能够有效补充 BMP 活性，以最大限度地提高生物效率，同时最大限度地减少 BMP 剂量。 一种替代方法是根本不递送 BMP，同时增强参与再生的祖细胞对内源性 BMP 做出反应的能力。这可以通过递送 BMP 拮抗剂（例如 Noggin）的抑制剂来实现，从而增强内源性 BMP 活性。 Noggin 是骨祖细胞中 BMP 途径的直接靶标，因此临床上很可能需要超生理学的 BMP 剂量，这在很大程度上是由于 Noggin 的诱导。因此，我们提出了一种通过下调 Noggin 来增强 BMP 信号传导的方法。内源性 BMP 的效力可以通过传递比 BMP 更具特异性且多效性较差的骨诱导信号来增强，例如 Nell-1 [Nel-like molecular-1; Nel-like molecular-1; Nel（一种在编码表皮生长因子样结构域的神经组织中强烈表达的蛋白质）]。在之前的研究中，Nell-1已被证明可以加速体外成骨分化和体内颅骨形成。此外，Nell-1是一种可以在细胞外递送的分泌蛋白，最重要的是Nell-1可以促进与BMP2对骨再生的协同作用。通过局部抑制 Noggin，我们寻求增强内源性 BMP 信号传导，从而协同刺激 Nell-1 诱导的成骨细胞分化，从而导致最大限度的骨形成，而无需担心 BMP 介导的副作用。该提案的具体假设是 Nell-1 的控制递送结合 Noggin 抑制的使用可以增强节段性股骨缺损的修复。提出了两个具体目标来研究这一假设。目标 1：通过 Noggin 抑制 + Nell-1 增强骨再生。在这个具体目标中，我们将评估 Nell-1 与 Noggin 抑制的 MSC 联合对成骨能力和骨再生的协同作用。目标 2：通过 Noggin-siRNA + Nell-1 的受控递送来增强骨再生。为此，我们将开发释放 Nell-1 和 Noggin-siRNA 的非病毒基因传递/支架系统，并测试它们是否能够在节段性股骨缺损模型中有效地再生骨。