Preconditioning of mesenchymal stem cells with mechanobiological load and hypoxia for joint regeneration in moderate osteoarthritis

机械生物学负荷和缺氧预处理间充质干细胞用于中度骨关节炎的关节再生

• 批准号: 289280976
• 负责人: Professor Dr. Peter Angele
• 金额: --
• 依托单位: Klinik und Poliklinik für Unfallchirurgie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/289280976?language=en
• 关键词: Preconditioning; mesenchymal; stem; cells; mechanobiological

The presence of osteoarthritic changes in a joint is a contraindication for current tissue engineering approaches, which are designed for regeneration of localized traumatic osteochondral lesions. Our long-term goal is the restoration of degenerative osteochondral lesions and beyond that, the treatment of chondral and osteochondral defects in an OA environment. To be successful we need to understand the constructive and destructive interactions between chondrogenesis, mechanical stress, oxygen tension and inflammation. We propose that mesenchymal stem cells can be preconditioned with mechanobiological load and/or hypoxia prior to implantation in order to achieve a stable chondrogenic phenotype. This preconditioning could allow regeneration of osteochondral defects even in an OA environment. Mechanical load in physiological range is an important factor for maintenance of the healthy status of joint cartilage. On the other hand, overloading is believed to increase the risk of osteoarthritis. Therefore we will apply hydrostatic pressure in different mechanobiological loading regimes to MSCs undergoing chondrogenesis in an in vitro 3D-aggregate culture system. We will identify loading conditions that show the strongest chondrogenic (increased anabolism and decreased catabolism) difference between loaded and unloaded conditions. We plan to achieve this under physiological conditions, but also in OA conditions, which will be mimicked by addition of IL-1ß to the culture medium.Hypoxic culture conditions have also been shown to have beneficial preconditioning for chondrogenic cells. We propose that hypoxia will promote differentiation and suppress markers of hypertrophy in both healthy and osteoarthritic culture conditions. We will apply hypoxia to MSCs undergoing in vitro chondrogenesis and analyse for anabolic and catabolic effects. We will focus on the suppression of hypertrophy in order to achieve a stable chondrogenic phenotype. We plan to identify key signaling pathways involved in the preconditioning process. In particular, we will analyse the PI3K/Akt-dependent pathway, because this cascade is involved in the modulation of chondrogenesis through mechanotransduction and also hypoxia. Finally we want to examine the effect of MSC-sponge constructs, preconditionend with mechanobiological load and/or hypoxia, to repair posttraumatic osteochondral defects in an animal model in a healthy and an early osteoarthritic condition.

关节中骨关节炎变化的存在是当前组织工程方法的禁忌症，该方法被设计用于局部创伤性骨软骨损伤的再生。我们的长期目标是恢复退行性骨软骨病变，除此之外，还治疗OA环境中的软骨和骨软骨缺损。为了取得成功，我们需要了解软骨形成、机械应力、氧张力和炎症之间的建设性和破坏性相互作用。我们建议间充质干细胞可以在植入前用机械生物学负荷和/或缺氧进行预处理，以实现稳定的软骨形成表型。这种预处理可以允许骨软骨缺损的再生，即使在OA环境中。生理范围内的机械负荷是维持关节软骨健康状态的重要因素。另一方面，超载被认为会增加骨关节炎的风险。因此，我们将在不同的机械生物学加载制度的静水压力，骨髓间充质干细胞进行软骨形成在体外三维聚集体培养系统。我们将确定负载条件下，显示最强的软骨形成（增加的关节炎和减少的关节炎）之间的负载和卸载条件的差异。我们计划在生理条件下实现这一点，但也在OA条件下，这将通过向培养基中加入IL-1 β来模拟。我们认为，缺氧将促进分化和抑制肥大的标志物在健康和骨关节炎的文化条件。我们将缺氧应用于骨髓间充质干细胞进行体外软骨形成和分析合成代谢和分解代谢的影响。我们将集中在抑制肥大，以实现稳定的软骨形成表型。我们计划确定参与预处理过程的关键信号通路。特别是，我们将分析PI 3 K/Akt依赖性通路，因为该级联通过机械转导和缺氧参与软骨形成的调节。最后，我们希望在健康和早期骨关节炎的动物模型中，检查MSC-海绵结构在机械生物学负荷和/或缺氧预处理下修复创伤后骨软骨缺损的效果。