alpha-Smooth muscle actin and TGF-beta receptor I expression in the healing rabbit medial collateral and anterior cruciate ligaments

作者：Menetrey Jacques^*; Laumonier Thomas; Garavaglia Guido; Hoffmeyer Pierre; Fritschy Daniel; Gabbiani Giulio; Bochaton Piallat Marie Luce

来源：Injury-International Journal of the Care of the Injured, 2011, 42(8): 735-741.

DOI：10.1016/j.injury.2010.07.246

• Ligament injury
• Ligament healing
• Myofibroblasts
• Rabbit

The aim of our study was to advance the knowledge about the biological differences in the healing of the anterior cruciate ligament (ACL) versus the medial collateral ligament (MCL). We quantified alpha-smooth muscle actin (alpha-SMA) expression and TGF-beta receptor I (TGF-beta RI) expression in experimentally injured rabbit ligaments (from day 3 to 12 weeks post-injury). Myofibroblasts (alpha-SMA positive cells) were identified as early as the third day post-injury in MCL and their density increased steadily up to day 21. Myofibroblasts were also detected in injured ACL but their density remained very low at all time points. The percentage of positive TGF-beta RI area significantly increased in both injured ligaments compared to controls, with a peak expression at day 21; however, it remained constantly lower in ACL compared to MCL. A significant correlation was found between the percentage of TGF-beta RI positive cells and the percentage of alpha-SMA expression only in injured MCL. These results provide evidence that myofibroblasts are important players in MCL remodelling after injury. The combined presence of myofibroblasts and TGF-beta RI in the first 3 weeks post-MCL injury may partially explain the difference in the MCL and ACL healing process.

• 出版日期2011-8