ABSTRACT
Objective Take frizzled class receptor 4(FZD4) as an example for exploring whether the transmembrane receptor protein is a suitable marker for wound age estimation. Methods A total of 78 Sprague-Dawley rats were divided randomly into the control group and the contusion groups of 4h, 8h, 12h, 16h, 20h, 24h, 28h, 32h, 36h, 40h, 44h, and 48h after injury (n=6). Using a drop-ball technique, a contusion was produced in the right lamb of rats. The samples were dissected from injury zones. Then the expression of FZD4 was detected using immunofluorescence, real-time PCR and western blot, respectively. Results FZD4 was located on the membrane of skeletal muscle cells. Compared to the control group, FZD4 mRNA showed a signiifcant increase (over 2-fold) in 8h, 12h, 36h, and 40h after injury by Real-time PCR (P<0.05), and FZD4 protein showed a statistical up-regulation (less than 2-fold) in 8h, 36h, 40h, 44h, and 48h post contusion by western blotting (P<0.05). Conclusion The expression of FZD4 mRNA and protein are both time-dependent during contused skeletal muscle repair. To some degree, FZD4 mRNA was more suitable than corresponding protein for determining wound age.