NGF调节骨关节炎血管形成机制及在骨-软骨损伤重建钙化层的基础研究

Bone - cartilage repair has been a clinical problem. In view of the potential effects of the nerve growth factor (NGF) in regulating blood vessel formation in osteoarthritis and the importance of calcification layer in maintaining bone and cartilage respective stable microenvironment, the project explore the regulation mechanism of NGF on VEGF expression in cartilage of OA patients, to silence NGF receptor on chondrocytes to inhibit VEGF expression and vascularization. To obtain the low expression of the TrkA chondrocytes by gene silencing method and combined imitation extracellular matrix nanofiber scaffolds with micro and nano structures, evaluate the matrix stimulation - response with biomimetic extracellular. With detailed observation on the surface of the scaffold which was given artificial nano-structure, chemical composition and specific biological signal to active proliferation and oriented differentiation ability of deep zone chondrocytes (DZC). We assess the efficiency and effectiveness of the biomimetic scaffold which carrier of DZC on regeneration of calcified cartilage and the correlative discipline and mechanism as well as the extent and level of repairment by using a porcine femoral condyle osteochondral defect model. The series of studies of the project will establish the technical and theoretical basis by optimizing design of the tissue-engineered artificial calcified cartilage and display a new technical solutions and treatment strategies both in structure and functional repair of osteochondral defect.

骨-软骨联合损伤的修复一直是临床治疗的难题。鉴于神经生长因子(NGF)在骨关节炎中调节血管形成的潜在效应和钙化层在维持骨、软骨各自稳定微环境促进软骨-骨愈合的重要性，本项目从探讨OA病人中NGF对软骨细胞VEGF表达调节的机制和通路出发，明确软骨细胞的NGF受体沉默对VEGF表达和抑制血管化的内在关系；利用我们自主设计和构建的具有钙化层微纳结构的仿细胞外基质纳米纤维支架，评估基因沉默法获得的TrkA低表达软骨细胞对该仿生型细胞基质的刺激-响应关系，系统分析评估该类支架材料表面人工赋予的微纳结构和化学组成所示特异性生物信号对人深层软骨细胞(DZC)的活性、增殖能力，并通过动物骨-软骨联合损伤模型，评估载DZC细胞的仿生支架对钙化层再生效率和效果的相关规律和机制，以及软骨-骨联合损伤修复的水平。本项目的研究将为组织工程化人工钙化层奠定技术与理论基础，并为软骨-骨联合损再生修复建立全新的治疗策略

骨-软骨联合损伤的修复一直是临床治疗的难题。鉴于神经生长因子(NGF)在骨关节炎中调节血管形成的潜在效应和钙化层在维持骨、软骨各自稳定微环境促进软骨-骨愈合的重要性，本项目从探讨OA病人中NGF对软骨细胞FGF2表达调节的机制和通路出发，明确软骨细胞的NGF受体沉默对FGF2表达和抑制血管化的内在关系；利用我们自主设计和构建的具有钙化层微纳结构的仿细胞外基质掺镁硅酸钙组织工程支架，系统分析评估该类支架材料表面人工赋予的微纳结构和化学组成所示特异性生物信号对人深层软骨细胞(DZC)的活性、增殖能力与钙化层再生潜能。本研究发现NGF在软骨细胞中通过PI3K/akt与ERK/MAPK通路促进FGF2表达，并促进内皮细胞迁移与小管形成，从而发挥血管形成作用。同时掺镁硅酸钙-胶原复合支架对深层软骨细胞相容性好，支持基质分泌，促进矿化能力，具有钙化层再生潜能。本项目的研究将为组织工程化人工钙化层奠定技术与理论基础，并为软骨-骨联合损再生修复建立全新的治疗策略。