PLC, PTH and NF-κB increased during orthodontic bone remodeling in chronic stress rats

Figures & data

Figure 1. CUMS rat model was successfully established. Tail suspension (A), Sucrose preference (B), and Forced swimming (C) in rats with or without exposure to CUMS. The sugar and water preference rate of rats in the stress group decreased significantly (p < 0.01), and the immobility time in the tail suspension experiment as well as the forced swimming experiment increased significantly. The concentration of ACTH (D,F) and CORT (E,G) in the serum of CUMS model rats increased significantly before and after the orthodontic application *p < 0.05, **p < 0.01, ***p < 0.001, compared with the control group.

CUMS rat model was successfully established. In rats receiving CUMS, tail suspension immobility time increased (A), sucrose preference rate decreased (B), and forced swimming immobility time increased (C). The serum concentrations of ACTH (D,F) and CORT (E,G) in CUMS model rats were different before and after orthodontic treatment.

Figure 2. Orthodontic tooth movement can alter the bone metabolism balance changes. (A) The tooth movement distance of rats in the stress group was markedly increased. The concentration of CTX (C) in the serum was increased but the concentration of PINP (B) was decreased. These results suggest that the osteoclast activity of rats in the stress group increased, but the osteogenic activity decreased. The balance of bone metabolism was disrupted. *p < 0.05, **p < 0.01, ***p < 0.001, compared with the control group.

(A) The tooth movement distance of rats in the stress group increased, and the serum concentration of (B) PINP decreased and (C) CTX increased.

Figure 3. HE staining showed that the alveolar bone fibers in the tooth movement area in the CUMS group were sparse and osteoclast lacuna was substantially increased.

HE staining section of the tooth movement area, it was found that compared with the control group, the density of bone trabecular bone in the orthodontic movement area of the rats in the chronic stress group was significantly reduced and the number of bone absorption lacunae was significantly increased.

Figure 4. TRAP staining revealed increased staining of osteoclasts in the alveolar bone in the tooth movement area in the CUMS group.

In TRAP stained sections, it was found that compared with the control group, the number of osteoclasts in jaw bone in the tooth movement area of rats in the chronic stress group was significantly increased.

Figure 5. Before exposure (A) and after exposure (B) to orthodontic stress, the PTH content in the CUMS group was found to be significantly increased. *p < 0.05, **p < 0.01, ***p < 0.001, compared with the control group.

Before (A) and after (B) orthodontic, the PTH content in the CUMS group increased significantly compared with Control group.

Figure 6. The AC content in the jaw bone tissue of the CUMS group did not change significantly, but the PLC content was significantly increased.

Western blot results indicated that, compared with the control group,Adenylate cyclase (AC) content in jaw tissue of CUMS group was not significantly affected, but phospholipase C(PLC) content was significantly increased.

Figure 7. The expression of NF-ĸB in the jaw bone of orthodontic tooth movement area was substntially increased in CUMS group.

Immunohistochemical results of bone tissues revealed that the expression of NF-κB in mandible in orthodontic movement area of rats in chronic stress group was substantially increased in CUMS group.