Lu C-C, Zhang T, Reisdorf R L, Amadio P C, An K-N, Moran S L, Gingery A, Zhao C
Biomechanics & Tendon and Soft Tissue Biology Laboratories, Division of Orthopedic Research, Mayo Clinic, Rochester, Minnesota, USA; Orthopaedic Department, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Kaohsiung Medical University, Kaohsiung, Taiwan.
Biomechanics & Tendon and Soft Tissue Biology Laboratories, Division of Orthopedic Research, Mayo Clinic, Rochester, Minnesota, USA.
Bone Joint Res. 2019 Jul 5;8(6):232-245. doi: 10.1302/2046-3758.86.BJR-2018-0239.R1. eCollection 2019 Jun.
Re-rupture is common after primary flexor tendon repair. Characterization of the biological changes in the ruptured tendon stumps would be helpful, not only to understand the biological responses to the failed tendon repair, but also to investigate if the tendon stumps could be used as a recycling biomaterial for tendon regeneration in the secondary grafting surgery.
A canine flexor tendon repair and failure model was used. Following six weeks of repair failure, the tendon stumps were analyzed and characterized as isolated tendon-derived stem cells (TDSCs).
Failed-repair stump tissue showed cellular accumulation of crumpled and disoriented collagen fibres. Compared with normal tendon, stump tissue had significantly higher gene expression of collagens I and III, matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and insulin-like growth factor (IGF). The stump TDSCs presented both mesenchymal stem and haematopoietic cell markers with significantly increased expression of CD34, CD44, and CD90 markers. Stump TDSCs exhibited similar migration but a lower proliferation rate, as well as similar osteogenic differentiation but a lower chondrogenic/adipogenic differentiation capability, compared with normal TDSCs. Stump TDSCs also showed increasing levels of SRY-box 2 (Sox2), octamer-binding transcription factor 4 (Oct4), tenomodulin (TNMD), and scleraxis (Scx) protein and gene expression.
We found that a failed repair stump had increased cellularity that preserved both mesenchymal and haematopoietic stem cell characteristics, with higher collagen synthesis, MMP, and growth factor gene expression. This study provides evidence that tendon stump tissue has regenerative potential.: C-C. Lu, T. Zhang, R. L. Reisdorf, P. C. Amadio, K-N. An, S. L. Moran, A. Gingery, C. Zhao. Biological analysis of flexor tendon repair-failure stump tissue: A potential recycling of tissue for tendon regeneration. 2019;8:232-245. DOI: 10.1302/2046-3758.86.BJR-2018-0239.R1.
在原发性屈肌腱修复后，再断裂很常见。对断裂肌腱残端的生物学变化进行特征描述将有所帮助，这不仅有助于理解对失败肌腱修复的生物学反应，还能研究肌腱残端是否可作为再生生物材料用于二期移植手术中的肌腱再生。
使用犬屈肌腱修复及失败模型。在修复失败六周后，对肌腱残端进行分析并将其鉴定为分离的肌腱源性干细胞（TDSCs）。
修复失败的残端组织显示出皱缩且排列紊乱的胶原纤维的细胞堆积。与正常肌腱相比，残端组织中I型和III型胶原、基质金属蛋白酶（MMPs）、血管内皮生长因子（VEGF）、血小板衍生生长因子（PDGF）和胰岛素样生长因子（IGF）的基因表达显著更高。残端TDSCs同时呈现间充质干细胞和造血细胞标志物，且CD34、CD44和CD90标志物的表达显著增加。与正常TDSCs相比，残端TDSCs表现出相似的迁移能力但增殖率较低，以及相似的成骨分化能力但软骨生成/脂肪生成分化能力较低。残端TDSCs还显示出SRY盒2（Sox2）、八聚体结合转录因子4（Oct4）、腱调蛋白（TNMD）和硬骨素（Scx）蛋白及基因表达水平升高。
我们发现，修复失败的残端细胞增多，保留了间充质和造血干细胞特征，胶原合成、MMP和生长因子基因表达更高。本研究提供了证据表明肌腱残端组织具有再生潜力。：C-C. 卢，T. 张，R. L. 赖斯多夫，P. C. 阿马迪奥，K-N. 安，S. L. 莫兰，A. 金杰里，C. 赵。屈肌腱修复失败残端组织的生物学分析：组织用于肌腱再生的潜在再利用。2019；8：232 - 245。DOI：10.1302/2046 - 3758.86.BJR - 2018 - 0239.R1。
