Wei Bing, Li Zhuang, Lin Yucheng, Hu Xinyue, Xu Li, Wang Shanzheng, Ji Mingliang, Lu Jun
School of Medicine, Southeast University, Nanjing, Jiangsu Province, China.
Department of Orthopaedic Surgery/Joint and Sports Medicine Center, Zhongda Hospital, Southeast University, Nanjing, Jiangsu Province, China.
Biotechnol J. 2023 May;18(5):e2200470. doi: 10.1002/biot.202200470. Epub 2023 Feb 1.
Bone morphogenetic protein-2 (BMP-2) and transforming growth factor-β1 (TGF-β1) reportedly induce the osteogenic and tenogenic differentiation of anterior cruciate ligament (ACL)-derived stem cells (LDSCs), respectively. However, few studies have investigated the effect of BMP-2/TGF-β1 on the differentiation of LDSC. We developed a BMP-2/TGF-β1 gene insertion into an LDSC cell sheet that promotes tendon-bone healing in a mouse ACL reconstruction (ACLR) model. CD34 LDSCs were isolated from human ACL stump tissues, virally transduced to express BMP-2 or TGF-β1, and then embedded within cell sheets. All mice underwent ACLR using an autograft wrapped with a cell sheet and were randomly divided into three groups: BMP-2-, TGF-β1-, and BMP-2/TGF-β1-transduced. At 4 and 8 weeks, tendon-bone healing was evaluated by micro-CT, biomechanical test, and histological analysis. BMP-2 and TGF-β1 promoted the osteogenic and tenogenic differentiation of LDSC in vitro. BMP-2/TGF-β1-transduced LDSC sheet application contributed to early improvement in mean failure load and graft stiffness, accelerated maturation of the tendon-bone junction, and inhibited bone tunnel widening. Furthermore, reduced M1 macrophage infiltration and a higher M2 macrophage percentage were observed in the BMP-2/TGF-β1-transduced LDSC group. This work demonstrated that BMP-2 and TGF-β1 promoted CD34 LDSCs osteogenic and tenogenic differentiation in vitro and in vivo, which accelerated the tendon-bone healing after ACLR using autografts wrapped with cell sheets in a mouse model.
据报道，骨形态发生蛋白2（BMP-2）和转化生长因子-β1（TGF-β1）分别诱导前交叉韧带（ACL）来源的干细胞（LDSCs）向成骨和成腱分化。然而，很少有研究调查BMP-2/TGF-β1对LDSC分化的影响。我们开发了一种将BMP-2/TGF-β1基因插入LDSC细胞片的方法，该方法可促进小鼠ACL重建（ACLR）模型中的腱骨愈合。从人ACL残端组织中分离出CD34 LDSCs，通过病毒转导使其表达BMP-2或TGF-β1，然后包埋在细胞片中。所有小鼠均使用包裹有细胞片的自体移植物进行ACLR，并随机分为三组：转导BMP-2、转导TGF-β1和转导BMP-2/TGF-β1组。在第4周和第8周，通过微型计算机断层扫描（micro-CT）、生物力学测试和组织学分析评估腱骨愈合情况。BMP-2和TGF-β1在体外促进了LDSC的成骨和成腱分化。应用转导BMP-2/TGF-β1的LDSC细胞片有助于早期提高平均破坏载荷和移植物刚度，加速腱骨结合处的成熟，并抑制骨隧道增宽。此外，在转导BMP-2/TGF-β1的LDSC组中观察到M1巨噬细胞浸润减少，M2巨噬细胞百分比更高。这项研究表明，BMP-2和TGF-β1在体外和体内均促进了CD34 LDSCs的成骨和成腱分化，这加速了在小鼠模型中使用包裹有细胞片的自体移植物进行ACLR后的腱骨愈合。
