Engineering 3D biomimetic osteogenesis imperfecta models to dissect mechanisms of N-cadherin mediated osteoblast-endothelial function

项目总结/摘要 成骨不全症是一种罕见的疾病，其特征是骨形成不足和不适当 导致骨骼脆弱。OI是由主要ECM中的功能丧失或显性阴性突变引起的 1型胶原（由COL 1A 1/COL 1A 2基因组成）。目前还没有治愈OI的方法， 目前治疗的长期益处在骨折复位和骨功能方面仍不清楚。 骨质疏松影响骨稳态，而骨稳态受各种细胞类型的功能及其空间排列的控制 通过与胶原蛋白支架的结合在三维（3D）中。具体地说， 内皮细胞、神经细胞、成骨细胞、破骨细胞、骨细胞和它们共享的胶原基质可以控制 它们的功能并显著影响骨稳态。(Aim 1）为了将每个单元贡献解耦到OI，我们 将开发一个强大的临床前筛选模型，基于器官芯片技术，概括 骨微血管系统与周围的细胞，如成骨细胞。该平台将用于药物 筛选和鉴定新的OI治疗剂，避免了费力和昂贵的体内试验的局限性， 和体外研究。(Aim 2）为了进一步扩大我们的研究，我们将使用这些3D疾病样器官芯片 系统剖析COL 1A 1的异质细胞机制，旨在确定OI的新基因靶点， 最后，制定新的预防战略。具体来说，我们的目标是了解一个追随者的作用， 骨微血管连接（AJs）分子，称为N-钙粘蛋白，通过解剖介导的机制， 成骨细胞-内皮细胞偶联考虑到多细胞复杂性在生物学中的重要性， 许多骨疾病，这些体外模型将解耦参与的重要机制， 多参数骨相关疾病，如骨质疏松症或骨癌。总的来说，这些新的体外 微生理系统可以被视为特定患者的受控物理表征，因此， 直接应用于临床，为疾病的治疗或预防提供信息。

Project Summary/Abstract Osteogenesis Imperfecta (OI) is a rare disease characterized by low and inappropriate bone formation resulting in bone fragility. OI is caused by loss-of-function or dominant-negative mutations in a major ECM component, named type 1 collagen (composed of COL1A1/COL1A2 genes). There is currently no cure for OI, and long-term benefits of current treatments remain unclear in terms of fracture reduction and bone functionality. OI affects bone homeostasis which is governed by the function of various cell types and their spatial arrangement in three-dimensions (3D) through association with collagen scaffolds. Specifically, signaling interactions among endothelial cells, nerve cells, osteoblasts, osteoclasts, osteocytes and their shared collagen matrix may control their function and dramatically impact bone homeostasis. (Aim 1) To decouple each cell contribution to OI, we will develop a robust preclinical screening model, based on the organ-on-a-chip technology, that recapitulates the bone microvasculature with the surrounding cells, such as osteoblasts. This platform will be used for drug screening and identification of new OI therapeutics, avoiding the limitations of laborious and expensive in vivo and in vitro studies. (Aim 2) To further expand our studies, we will use these 3D disease-like organ-on-a-chip systems to dissect the heterocellular mechanisms of COL1A1 aiming at identifying new gene targets for OI and ultimately, developing new strategies for prevention. Specifically, we aim to understand the role of an adheren junctions (AJs) molecule, named N-cadherin in bone microvasculature by dissecting the mechanisms mediating osteoblast-endothelial coupling. Given the recognized fundamental importance of multicellular complexity in numerous bone diseases, these in vitro models would decouple important mechanisms involved in multiparametric bone-related diseases such as osteoporosis or bone cancer. Overall, these new in vitro microphysiological systems can be regarded as controlled, physical representations of specific patients and therefore be applied directly in the clinic to inform strategies for treatment or prevention of disease.