Virk Mandeep S, Luo Wei, Sikes Katie J, Li Jun, Plaas Anna, Cole Brian J
Department of Orthopaedic Surgery, Division of Shoulder & Elbow, New York University Langone Orthopedic Hospital, 301 East 17th street, New York, 10003, NY, USA.
Dept of Internal Medicine, Rush University Medical Center, 1735 W Harrison St Jelke 1302, Chicago, 60612, IL, USA.
BMC Musculoskelet Disord. 2020 Mar 28;21(1):194. doi: 10.1186/s12891-020-03190-9.
Rotator cuff tendon tears are typically degenerative and usually affect the region of tendon insertion on bone. The remnant torn tendon is degenerative and may not be an ideal source for progenitor cells for cell-based therapies. Therefore, the aim of this study was to determine if musculotendinous junction (MTJ), which is adjacent to tendon would be a viable alternate source of progenitor stem cells. We also sought to study the gene expression profile MTJ progenitors and compare it with progenitors isolated from RC tendon, RC muscle and other existing tissue sources (bone marrow, adipose tissue, and Achilles tendon).
Rotator cuff tendon (RCT), muscle (RCM), and RCMTJ as well as Achilles tendon (AT) tissues were harvested from healthy male Lewis rats and progenitor cultures were established from these tissues and also from bone marrow and adipose tissue. Quantitative RT-PCR was performed on RNA extracts from intact tissues and progenitor cells using a custom array for the mesenchymal stem cell (MSC) differentiation marker genes. The gene expression profile of MSC differentiation markers within four tissues types, six progenitor cells, and between tissue and their corresponding progenitors were compared.
Progenitors cells can be isolated from rat rotator cuff musculotendinous tissue and their pattern of MSC gene expression was similar to the rotator cuff tendon progenitors for majority of the genes tested. However, there were significant differences between the MSC gene expression patterns of RCMTJ and RCM progenitors. Furthermore, there were differences in gene expression between the RCMTJ tissue and its progenitor cells with respect to MSC differentiation markers. The gene expression pattern of RCMTJ tissue was similar to RCM tissue with respect to markers of chondrogenesis, myogenesis, tenogenesis, and MSC specific markers.
We demonstrate that the musculotendinous junction contains distinct set of progenitor cells and their MSC gene expression pattern is similar to rotator cuff tendon progenitors. RCMTJ progenitors will be an attractive option for cell-based regenerative treatment of chronic rotator cuff tears.
肩袖肌腱撕裂通常是退行性的，且通常影响肌腱在骨上的附着区域。残留的撕裂肌腱是退行性的，可能不是基于细胞治疗的祖细胞的理想来源。因此，本研究的目的是确定与肌腱相邻的肌-腱交界区（MTJ）是否会是祖干细胞的可行替代来源。我们还试图研究MTJ祖细胞的基因表达谱，并将其与从肩袖肌腱、肩袖肌肉和其他现有组织来源（骨髓、脂肪组织和跟腱）分离的祖细胞进行比较。
从健康雄性Lewis大鼠获取肩袖肌腱（RCT）、肌肉（RCM）和RCMTJ以及跟腱（AT）组织，并从这些组织以及骨髓和脂肪组织建立祖细胞培养物。使用针对间充质干细胞（MSC）分化标记基因的定制阵列，对完整组织和祖细胞的RNA提取物进行定量逆转录聚合酶链反应（RT-PCR）。比较了四种组织类型、六种祖细胞以及组织与其相应祖细胞之间MSC分化标记的基因表达谱。
祖细胞可从大鼠肩袖肌-腱组织中分离出来，并且在大多数测试基因中，其MSC基因表达模式与肩袖肌腱祖细胞相似。然而，RCMTJ和RCM祖细胞的MSC基因表达模式存在显著差异。此外，就MSC分化标记而言，RCMTJ组织与其祖细胞之间存在基因表达差异。在软骨生成、肌生成、腱生成和MSC特异性标记方面，RCMTJ组织的基因表达模式与RCM组织相似。
我们证明肌-腱交界区含有独特的祖细胞群，其MSC基因表达模式与肩袖肌腱祖细胞相似。RCMTJ祖细胞将是慢性肩袖撕裂基于细胞的再生治疗的有吸引力的选择。
