McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA 19104; Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA 19104.
J Biomech Eng. 2025 Jan 1;147(1). doi: 10.1115/1.4066570.
Collagen XI is ubiquitous in tissues such as joint cartilage, cancellous bone, muscles, and tendons and is an important contributor during a crucial part in fibrillogenesis. The COL11A1 gene encodes one of three alpha chains of collagen XI. The present study elucidates the role of collagen XI in the establishment of mechanical properties of tendons and ligaments. We investigated the mechanical response of three tendons and one ligament tissues from wild type and a targeted mouse model null for collagen XI: Achilles tendon (ACH), the flexor digitorum longus tendon (FDL), the supraspinatus tendon (SST), and the anterior cruciate ligament (ACL). Area was substantially lower in Col11a1ΔTen/ΔTen ACH, FDL, and SST. Maximum load and maximum stress were significantly lower in Col11a1ΔTen/ΔTen ACH and FDL. Stiffness was lower in Col11a1ΔTen/ΔTen ACH, FDL, and SST. Modulus was reduced in Col11a1ΔTen/ΔTen FDL and SST (both insertion site and midsubstance). Collagen fiber distributions were more aligned under load in both wild type group and Col11a1ΔTen/ΔTen groups. Results also revealed that the effect of collagen XI knockout on collagen fiber realignment is tendon-dependent and location-dependent (insertion versus midsubstance). In summary, this study clearly shows that the regulatory role of collagen XI on tendon and ligament is tissue specific and that joint hypermobility in type II Stickler's Syndrome may in part be due to suboptimal mechanical response of the soft tissues surrounding joints.
胶原 XI 普遍存在于关节软骨、松质骨、肌肉和肌腱等组织中，是原纤维生成过程中的一个重要贡献者。COL11A1 基因编码胶原 XI 的三个α链之一。本研究阐明了胶原 XI 在肌腱和韧带机械性能建立中的作用。我们研究了三种肌腱和一种韧带组织的力学响应，这些组织来自野生型和靶向胶原 XI 缺失的小鼠模型：跟腱（ACH）、指深屈肌腱（FDL）、冈上肌腱（SST）和前交叉韧带（ACL）。Col11a1ΔTen/ΔTen ACH、FDL 和 SST 的面积明显较低。Col11a1ΔTen/ΔTen ACH 和 FDL 的最大载荷和最大应力显著降低。Col11a1ΔTen/ΔTen ACH、FDL 和 SST 的刚度降低。Col11a1ΔTen/ΔTen FDL 和 SST 的模量降低（均为插入部位和中间部位）。在两种野生型和 Col11a1ΔTen/ΔTen 组中，在载荷下胶原纤维的分布更趋于一致。结果还表明，胶原 XI 缺失对胶原纤维重新排列的影响是肌腱依赖性和位置依赖性的（插入部位与中间部位）。总之，本研究清楚地表明，胶原 XI 对肌腱和韧带的调节作用具有组织特异性，II 型斯提克勒综合征的关节过度活动可能部分是由于关节周围软组织的机械反应不佳。
