Sun Yulong, Berger Evelyn J, Zhao Chunfeng, Jay Gregory D, An Kai-Nan, Amadio Peter C
Orthopedic Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, Minnesota 55905, USA.
J Orthop Res. 2006 Sep;24(9):1861-8. doi: 10.1002/jor.20239.
Matrix composition and the biomechanical environment are intimately interdependent in most connective tissues. Lubricin has many distinct biological functions, including lubrication, antiadhesion, and cytoprotection in cartilage, tendons, and other tissues. This study investigated the distribution of lubricin in the canine flexor digitorum profundus (FDP) tendon by immunohistochemistry. Lubricin was found both on the tendon surface and at the interface of collagen fiber bundles within the tendon, where the cells are subjected to shear force in addition to tension and compression. The expression of lubricin in regions of the canine flexor tendon that differ in mechanical or nutritional environment was also investigated using RT-PCR. Six N-terminal splicing variants were identified from six distinct anatomical regions of flexor tendon. The variants with larger sizes were noted in regions subjected to significant shear and compressive forces. Lubricin is ubiquitous in the FDP tendon, with variations in distribution and splicing that appear to correspond to discrete anatomic locations that differ by mechanical or nutritional environment.
在大多数结缔组织中，基质组成和生物力学环境密切相关、相互依存。润滑素具有多种独特的生物学功能，包括在软骨、肌腱和其他组织中的润滑、抗粘连和细胞保护作用。本研究采用免疫组织化学方法，对犬趾深屈肌腱（FDP）中润滑素的分布进行了研究。结果发现，润滑素不仅存在于肌腱表面，也存在于肌腱内胶原纤维束的界面处，在这些部位，细胞除了承受拉力和压力外，还受到剪切力作用。本研究还采用逆转录聚合酶链反应（RT-PCR），对机械或营养环境不同的犬屈肌腱区域中润滑素的表达情况进行了研究。从屈肌腱的六个不同解剖区域中鉴定出六个N端剪接变体。在承受显著剪切力和压力的区域，发现了较大尺寸的变体。润滑素在FDP肌腱中普遍存在，其分布和剪接的变化似乎与因机械或营养环境不同而不同的离散解剖位置相对应。
