Fig. 1

Supraspinatus tendon in a model of a RTC tear. a Top panel . Normal anatomy of the rat RTC (used as control) is shown, with the supraspinatus muscle (SS) and infraspinatus muscle (IS), including attachment of their tendons to the greater tubercle of the humerus (yellow circle). RTC tear was surgically induced by tenotomizing the supraspinatus and infraspinatus tendons. Bottom panel . After 2 days (2D), the RTC tear results in retraction of the tendons. Fifteen days after RTC tear (15D), the space between the muscle tendon and insertion site is filled by a fibrous-connective tissue (arrow) that reattaches the supraspinatus to the humeral head (inset). b As expected, supraspinatus muscle mass was slightly altered after tenotomy and significantly reduced by day 15. c Western blot analysis was used to detect ubiquitinated proteins in total protein extracts of supraspinatus muscles. Equal amounts of protein were loaded and confirmed with Ponceau and probed with anti-ubiquitin antibody. Total protein ubiquitination was upregulated at 2 and 15 days after tenotomy in supraspinatus muscle compared to control (CTRL). All data are presented as mean ± SD, p < 0.05. *, indicates statistical significance compared to control