Improvement of Animal Models for TMJ Stem Cell-Based Regeneration

项目总结 TMJ骨关节炎(OA)是一个主要的临床问题，但目前还没有促进TMJ的治疗方法。 再生。在治疗上利用驻留干细胞代表了一种基于干细胞的组织策略 再生。我们发现TMJ纤维软骨干细胞(FCSCs)定位于TMJ髁状突内。 表面区。移植的FCSCs植入，自组织和再生软骨，脂肪和血管 骨头。FCSCs是异质性的，但对研究FCSCs调控信号至关重要的标记尚不清楚。我们 发现Prg4、Lgr5和Prg4 Lgr5细胞代表了啮齿动物和猪的FCSC群体。我们发现 Wnt/β连环蛋白信号转导通路通过诱导增殖和抑制FCSc的生长而对其命运的决定起关键作用 FCSCs的分化。然而，过度激活的Wnt/β连接素与TMJOA有关。我们开发了两个 在小鼠和猪的TMJ病模型上发现TMJOA与β连环蛋白和TMJO的增加有关 细胞凋亡介导的FCSC耗竭。这些数据表明，抑制Wnt/β连环蛋白可能是一种 治疗再生策略治疗TMJ骨关节炎。事实上，我们展示了治疗应用 经典的Wnt抑制剂在兔TMJ损伤模型中修复TMJ。基于我们已发表的工作和 初步数据，我们假设Prg4、Lgr5和Prg4Lgr5是FCSCs和Wnt/β连环蛋白抑制因子 FCSCs再生TMJ。我们将使用三个具体目标来验证我们的假设：1)定义FCSC群体 对TMJ的发育和稳态至关重要；2)确定Wnt/β连环蛋白信号在调节中的作用 FCSC的命运；3)靶向驻留FCSCs在猪TMJ损伤模型中再生软骨。使用鼠标 遗传学方面，我们将描述胚胎干细胞的特征，并阐明Wnt/β连环蛋白信号在调控胚胎干细胞命运中的作用。 我们将优化一种新的、具有临床意义的大型动物模型，并测试Wnt在FCSCs中的抑制作用 治疗TMJ骨关节炎。综上所述，这些新颖的研究将有助于发展一种 TMJ再生的外科微创干细胞疗法。

PROJECT SUMMARY TMJ osteoarthritis (OA) poses a major clinical problem, but there are no therapies that promote TMJ regeneration. Therapeutically exploiting resident stem cells represents a stem cell-based strategy for tissue regeneration. We have identified TMJ fibrocartilage stem cells (FCSCs) localized within the TMJ condyle superficial zone. Transplanted FCSCs engraft, self-organize and regenerate cartilage, fat and vascularized bone. FCSCs are heterogeneous, yet markers critical for studying signals regulating FCSCs are unknown. We found that Prg4+, Lgr5+ and Prg4+Lgr5+ cells represent FCSC populations in rodents and pigs. We discovered that Wnt/βCatenin signaling is critical for FCSC fate specification by inducing proliferation and inhibiting differentiation of FCSCs. However, over-active Wnt/βCatenin is associated with TMJ OA. We developed two TMJ disease models in mice and pigs and discovered that TMJ OA is correlated with increased βCatenin and apoptosis mediated FCSC depletion. These data suggest inhibition of Wnt/βCatenin may serve as a therapeutic regenerative strategy for the treatment of TMJ OA. In fact, we show that therapeutic application of a canonical Wnt inhibitor repairs TMJ in a rabbit TMJ injury model. Based on our published work and preliminary data, we hypothesize that Prg4+, Lgr5+ and Prg4+Lgr5+ are FCSCs and Wnt/βCatenin inhibition in FCSCs regenerates TMJ. We will test our hypothesis using three specific aims: 1) Define FCSC populations critical for TMJ development and homeostasis; 2) Determine the role of Wnt/βCatenin signaling in regulating FCSC fate; 3) Target resident FCSCs to regenerate cartilage in a porcine TMJ injury model. Using mouse genetics, we will characterize FCSCs and delineate the role of Wnt/βCatenin signaling in regulating FCSC fate. We will optimize a new, clinically relevant large animal model and test Wnt inhibition in FCSCs as a potential therapy for TMJ OA. Taken together, these novel studies will contribute towards the development of a non- surgical, minimally invasive stem cell-based therapy for TMJ regeneration.