Enhancement of intraarticular tissue repairs by injecting a large number of synovial stem cells into the knee joint

我们研究了滑膜干细胞在膝关节中的作用和作用。(1)从大鼠的骨髓、滑膜、骨膜、脂肪、肌肉中分离出间充质干细胞，并比较它们的产量、扩增能力和多潜能。滑膜干细胞具有最大的增殖和软骨形成潜能。(2)检测脂肪滑膜干细胞、纤维滑膜干细胞和皮下脂肪干细胞的特性，以确定它们的相似性。脂肪滑膜干细胞更接近于纤维滑膜来源的细胞，而不是皮下脂肪干细胞。(3)将未分化的滑膜干细胞移植到成年兔全层关节软骨缺损处，并对其细胞事件进行了研究。移植的滑膜干细胞根据微环境在一段时间内发生改变。(4)我们检测了滑液来源的MSCs的行为和特性。滑液-MSCs与滑膜-MSCs相似，在前交叉韧带损伤和手术后数量增加，但其性质没有明显变化。(5)滑液-MSCs是否扩张滑膜MSCs。自体滑液通过促进细胞迁移，在骨性关节炎患者滑膜组织培养中促进间充质干细胞的扩增。(6)探讨滑膜间充质干细胞移植对大鼠肌腱-骨愈合的影响及其机制。滑膜间充质干细胞植入骨隧道促进了肌腱-骨愈合的早期重建，这些结果表明关节内注射滑膜间充质干细胞可以提高关节的自然愈合能力。关节内注射滑膜干细胞很有吸引力，因为它不需要侵入性程序或人工支架。

We investigated the role and effect of synovial stem cells in the knee joint.(1) We isolated rat mesenchymal stem cells (MSCs) from bone marrow, synovium, periosteum, adipose, muscle and compared their properties for yield, expansion, and multipotentiality. Synovial stem cells had the greatest potential for both proliferation and chondrogenesis.(2) We examined the features of adipose synovium-stem cells, fibrous synovium-stem cells, and subcutaneous fat-stem cells to determine their similarities. Adipose synovium-stem cells were more similar to fibrous synovium-derived cells than to subcutaneous fat-stem cells.(3) We transplanted undifferentiated synovial stem cells into a full-thickness articular cartilage defect of adult rabbits and defined the cellular events. Transplanted synovial stem cells were altered over a time course according to the microenvironments.(4) We examined the behavior and properties of MSCs derived from synovial fluid. Synovial fluid-MSCs were similar to synovium-MSCs, and increased in number after anterior cruciate ligament injury and surgery without marked alteration of the properties.(5) We investigated whether synovial fluid expanded synovial MSCs. Autologous synovial fluid enhanced expansion of MSCs in tissue culture of synovium from osteoarthritis patients by promoting cell migration.(6) We investigated the effect and mechanism of the implantation of the synovial MSCs on tendon-bone healing in rats. Implantation of synovial MSCs into bone tunnel accelerated early remodeling of tendon-bone healing.These results demonstrate that intraarticular injection of synovial MSCs can boost natural healing ability in the joint. Intraarticular injection of synovial stem cells is attractive because it requires no invasive procedure or artificial scaffold.