关节镜下不同塑形状态前交叉韧带移植物Mohawk转录因子及胶原表达差异的研究

Differences in expression of Mohawk transcription factors and collagen in anterior cruciate ligament grafts between two remodeling outcomes under arthroscopy

目的评估自体膪绳肌腱移植重建前交叉韧带（ACL）术后移植物稳定塑形阶段，关节镜下不同塑形状态的移植物在Mohawk（MKX）转录因子及Ⅰ型、Ⅲ型胶原表达方面的差异。方法2017年3月至12月期间选择应用自体膪绳肌腱移植单束重建ACL、因移除胫骨端内固定物返深圳大学第一附属医院（术后48—131个月，平均83．1个月）行二次关节镜探查的17例患者为研究对象。根据关节镜下移植物血管及滑膜覆盖、张力、容量，将移植物评估为塑形良好（塑形良好组，11例）、塑形一般（塑形一般组，6例）2个等级，取移植物体部中央表面标本；另取8例同时期、年龄〈60岁行全膝关节置换术的患者正常ACL标本作为对照组，分别行MKX转录因子及Ⅰ型、Ⅲ型胶原免疫组织化学及实时荧光定量聚合酶链式反应（qRT-PCR）检查。结果对照组及塑形良好组标本胶原纤维含量丰富，纤维排列有序，MKX阳性细胞比率高。塑形一般组标本胶原含量明显降低，纤维排列较紊乱，MKX阳性细胞比率少，免疫组织化学评分低于对照组及塑形良好组标本，差异均有统计学意义（P〈0．05）。实时荧光定量聚合酶链式反应结果显示：塑形一般组MKX基因（O．44±0．30）、COL1A1基因（0．52±0．27）、COL3A1基因（0．60±0．22）表达量低于对照组（1．00±0．00、1．00±0．00、1．00±0．00）及塑形良好组（0．97±0．67、0．99±0．38、1．00±0．35），差异均有统计学意义（P〈0．05）。结论自体胭绳肌腱移植重建ACL，移植物塑形稳定后，关节镜下评估为塑形良好的移植物较塑形一般的移植物MKX转录因子及Ⅰ型、Ⅲ型胶原表达更接近于正常ACL。

Objective To investigate the differences in expression of Mohawk （MKX） transcription factors and collagen of types Ⅰ and Ⅲ in anterior cruciate ligament （ACL） grafts between 2 remodeling out- comes under arthroscopy. Methods Enrolled for this study were 17 patients who had undergone arthroscopic single-bundle ACL reconstruction with autogenous hamstring tendons and secondary arthroscopic ex ploration 48 to 131 months （average, 83.1 months） after removal of tibial internal fixator at Department of Sports Medicine, The First Affiliated Hospital to Shenzhen University from March 2017 to December 2017. They were divided into a good remodeling group （11 cases） and a fair remodeling group （6 cases） according to the graft quality under arthroscopy （synovial and vascular coverage, and apparent tension, thickness and retear of the grafts） . During the secondary arthroseopic procedures, biopsy of the central ACL grafts was performed. Moreover, normal ACL tissues were harvested from 8 contemporary controls of 〈 60 years old who underwent total knee replacement. Immunohistochemical assay and quantificatioual real-time polymerase chain reaction were conducted to detect the expression of transcription factors and collagen of types Ⅰ and Ⅲ in all the samples. Results In the samples from good remodeling and control groups, there were abundant well-arranged collagen fibers of types Ⅰ and Ⅲ and MKX-positive ceils; in the fair remolding group, the collagen fibers of types Ⅰ and Ⅲ and MKX-positive cells were much decreased in number and the fibers were not well arranged. The former 2 groups scored in immunohistochemical assay significantly higher than the latter one （ P 〈 0.05） . qRT-PCR showed that the expression levels of MKX gene （0.44 ±0.30）, COL1AI gene （0.52 ±0.27） and COL3A1 gene （0. 60 ± 0. 22） in the fair remolding group were significantly lower than in the control group （1.00 ±0. 00, 1.00 ±0. 00 and 1.00 ±0.00） and than in the good remolding group （0.97 ±0.67, 0. 99 ± 0.38 and 1.00 ± 0. 35） （ P 〈 0. 05） . Conclusion Good remodeling ACL grafts with histological maturation under arthroscopy are more similar to normal ACL than fair remodeling ACL grafts in expression of MKX transcription factors and collagen of types Ⅰ and Ⅲ.