[The influence of combined use of rhPDGF-BB and rhTGF-β1 on protein expression of FAK in osteoclast during orthodontic tooth movement in rats].

Purpose: To explore the combined effects of recombinant human platelet-derived growth factor-BB(rhPDGF-BB)and recombinant human transforming growth factor-β1 (rhTGF-β1) on protein expression of FAK in osteolasts of the pressure side of orthodontic tooth in rats.

Methods: One hundred and sixty male Sprague-Dawley rats were randomly divided into 2 groups: experimental group(A) and control group(B). Each group was subdivided equally into 5 subgroups. Orthodontic tooth movement model was established. The experimental group received injection of 0.1 mL solution, containing 10 ng rhPDGF-BB and 5 ng rhTGF-β1 every other day from day 1. Rats in each subgroup were sacrificed at each of five time points(1, 4, 7, 10 and 14 days) after appliance placement. The distances of the teeth movement were measured using stereomicroscope, and the changes of the amount of osteoclasts were detected by using tartrate resistant acid phosphatase histochemistry (TRAP). The protein expressions of FAK were assayed by immunohistochemical technique. SPSS17.0 software package was used for statistics analysis.

Results: Teeth in group A moved more rapidly than group B, and there were significant differences between 2 groups (P<0.05) except subgroup A1 and B1(P>0.05). The number of osteoclasts in group A was significantly higher than in group B. Except at 14 days, significant differences existed in between other time points (P<0.05). The protein expression of FAK in group A was significantly higher than in group B at any time points.

Conclusions: The combined effects of rhPDGF-BB and rhTGF-β1 up-regulate the protein expression of FAK within osteoclast in the pressure side, further promoted osteoclast differentiation, proliferation and bone resorption, thus accelerate the rate of orthodontic tooth movement.