Tribbles homolog 3 and BMP-2 induced bone formation

Tribbles 同源物 3 和 BMP-2 诱导骨形成

• 批准号: 10165689
• 负责人: Min Lee
• 金额: $ 37.05万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-06-08 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10165689
• 关键词: Adverse effects; BMP2 gene; Binding; Bone Morphogenetic Proteins; Bone Regeneration; Cell Differentiation process; Clinical; Complement; Cyst; DNA; Data; Defect; Development; Dose; Employment; Feedback; GTP-Binding Protein alpha Subunits, Gs; Gene Transfer; Genes; Genetic Transcription; Goals; Health; Histologic; Homologous Gene; In Vitro; Liposomes; Mandible; Mechanics; Mediating; Mesenchymal; Mesenchymal Differentiation; Mesenchymal Stem Cells; Modality; Modeling; Molecular Target; Osteoblasts; Osteogenesis; PPAR gamma; Pathway interactions; Phospholipids; Play; Proteins; Proteolysis; Public Health; RNA Interference; Rattus; Research; Role; Safety; Signal Transduction; Small Interfering RNA; Structure; System; Testing; Therapeutic; Transfection; Treatment Efficacy; Ubiquitin; Viral Insertional Mutageneses; adverse outcome; base; bone; bone morphogenetic protein receptors; clinical application; clinical efficacy; clinical translation; improved; in vitro activity; knock-down; lipid biosynthesis; microCT; milligram; nanocarrier; nanocomplexes; novel; osteogenic; osteogenin; osteoinductive factor; overexpression; particle; response; skeletal; small molecule; therapeutic gene

Abstract Although bone morphogenetic protein-2 (BMP-2) is believed to be the most potent osteoinductive factor available for bone regeneration, its clinical application requires supraphysiological BMP doses that increase inappropriate adipogenesis and cyst-like bone formation. Therefore, recent promising alternative strategies are toward promoting pro-osteogenic activity of BMPs while simultaneously suppressing their adverse effects. Recent studies suggest important roles of tribbles homologs proteins in development and cellular differentiation. In response to BMP stimulation, in particular, tribbles homolog 3 (Trb3) is dissociated from BMP receptor and degrades Smad ubiquitin regulatory factor 1 (Smurf1), a negative regulator of BMP receptor-regulated Smads. Moreover, Trb3 has been shown to bind and suppress peroxisome proliferator-activated receptor-γ (PPARγ), a master regulator of adipogenesis. Thus, Trb3 may be a promising molecular target to enhance BMP-2 induced osteogenesis and reduce adverse adipogenesis. Upon BMP stimulation, however, BMP efficacy is greatly reduced due to the enhanced expression of natural BMP antagonists to auto-regulate endogenous BMP-2 levels. Thus, the potency of Trb3 in BMP treatments can be enhanced by inhibiting expression of BMP antagonists such as noggin. The objective of this study is to investigate whether overexpression of Trb3 and simultaneous abrogation of BMP antagonism can enhance BMP-induced osteogenesis and bone formation quality while lowering exogenous BMP requirement. The specific hypothesis is that the augmentation of Trb3 expression combined with the employment of noggin suppression can enhance bone formation by activation of Smad pathway and suppression of PPARγ, tested in the following aims. In Aim 1, we will evaluate whether Trb3 overexpression can synergistically enhance bone formation with BMP-2 in a rat critical size mandibular defect (MD). We will also apply high dose BMP-2 to induce adverse cyst-like bone formation in the MD model and test whether Trb3 overexpression can reduce the BMP-2 induced adverse outcomes and improve bone formation quality. In addition, we will determine whether the positive Trb3 effects are dependent on Smurf1 and PPARγ activities in vitro. Next in Aim 2, we will stimulate endogenous BMP signaling by downregulating noggin using an RNAi strategy and evaluate the synergistic effect of noggin suppression on Trb3-induced bone formation in the MD model. We will subsequently determine whether Trb3 expression + noggin suppression can lower total BMP-2 dose requirements or even eliminate use of exogenous BMP-2 without compromising osteogenic efficacy. Finally in Aim 3, we will further elaborate our complementary bone formation strategy (Trb3 expression + noggin suppression) toward clinical translations via use of appropriate carriers that deliver these therapeutic genes in much safer and efficient manners based on our novel non-phospholipid liposomal systems. Successful completion of these studies will identify a new strategy to improve clinical efficacy and safety of current BMP therapeutics by regulating expression of Trb3 and noggin for enhanced bone repair.

抽象的 虽然骨形态发生蛋白-2（BMP-2）被认为是最有效的骨诱导因子 可用于骨骼再生，其临床应用需要上造典礼的BMP剂量增加 不适当的脂肪形成和囊肿样骨形成。因此，最近的承诺替代策略是 促进BMP的促核活性，同时抑制其不良反应。 最近的研究表明，Trabbles同源物蛋白在发育和细胞分化中的重要作用。 尤其是针对BMP刺激，Trabbles同源物3（TRB3）与BMP受体分离和 Smad泛素调节因子1（SMURF1）降解，BMP受体调节的SMAD的负调节剂。 此外，TRB3已被证明可以结合和抑制过氧化物组增殖物激活的受体-γ（PPARγ），A 脂肪形成的主要调节剂。那就是TRB3可能是增强BMP-2诱导的分子靶标 成骨并减少脂肪形成。但是，在BMP刺激后，BMP效率很高 由于天然BMP拮抗剂的表达增强而减少了自动调节内源性BMP-2 水平。这是通过抑制BMP的表达来增强TRB3在BMP处理中的效力 敌手，例如诺格金。这项研究的目的是研究TRB3和 BMP拮抗作用的同时促成可以增强BMP诱导的成骨和骨形成 质量同时降低外源性BMP要求。具体假设是TRB3的增强 表达结合使用Noggin抑制可以通过激活来增强骨形成 Smad途径和PPARγ的抑制作用，在以下目的中进行了测试。在AIM 1中，我们将评估是否 TRB3过表达可以协同增强大鼠临界大小下颌的BMP-2的骨形成 缺陷（MD）。我们还将在MD模型中施加高剂量BMP-2以诱导不良囊肿样骨形成 并测试TRB3过表达是否可以减少BMP-2引起的不良结果并改善骨骼 编队质量。此外，我们将确定阳性trb3效应是否取决于smurf1和 体外PPARγ活性。接下来在AIM 2中，我们将通过下调Noggin刺激内源性BMP信号传导 使用RNAi策略并评估Noggin抑制对TRB3诱导的骨的协同作用 MD模型中的形成。随后，我们将确定TRB3表达 + Noggin抑制是否 可以降低总BMP-2剂量要求，甚至可以消除不妥协的外源BMP-2的使用 成骨效率。最后，在AIM 3中，我们将进一步阐述我们完整的骨形成策略 （TRB3表达 + Noggin抑制）通过使用适当的载体来临床翻译 这些治疗基因基于我们的新型非磷脂脂质体，以更安全，更有效的方式 系统。这些研究的成功完成将确定提高临床效率和 通过控制TRB3和Noggin的表达来增强骨修复的表达，目前BMP治疗的安全性。