We investigated the expression of N-cadherin and alpha N-catenin, which is a key protein to regulate adhesive function of N-cadherin, in skeletal muscle during the degeneration/regeneration processes using rat sciatic nerve and gastrocnemius muscle model. The right sciatic nerve was exposed at the mid-thigh region, and the nerve was transected with small scissors. After then, nerve was sutured using 10-0 monofilament perineurial nylon sutures. At various periods up to 24 weeks after the operation, the middle portion of gastrocnemius muscle of treated hindlimbs was removed. Four rats were used at each time point in the both groups. N-cadherin and alpha N-catenin expressions were detected by Western blot analysis and immunofluorescent staining with anti N-cadherin and alpha N-catenin antibody. The level of N-cadherin expression have already increased in the 1st postoperative week(2.27 +/- 0.16 fold). After then, the level decreased gradually, and in the 9th postoperative week, returned to almost the same as the control level. The level of alpha N-catenin was almost the same with the control(1.0) within the 2nd postoperative week. After 4th postoperative week, the level elevated gradually with a peak in the 6th postoperative week(1.61 +/- 0.11fold). After then, the level decreased and returned to almost the control after the 16th postoperative week. In both N-cadherin and alpha N-catenin, immunofluorescent staining was observed around the muscular membrane in all specimens including the control, and their time course of the degree of staining were highly consistent with the results of Western blot analysis. The different kinetics between N-cadherin and alpha N-catenin expression and localization of both proteins may suggest that N-cadherin and alpha N-catenin plays different roles in the muscle cell, not in the satellite and inflammatory cells during degeneration/regeneration process after nerve injury. Especially, it may be considered that N-cadherin does not play a role as an adhesion molecule in early period after regeneration process.

View Synopsis (.doc format, 369.0 kb)