Objective To investigate the effect of trichostatin A (TSA) on titanium implant (TI) osseointegration in ovariectomized rats. Methods 3-Month-old female Sprague-Dawley rats (n=30) were randomly divided into Sham group (n=5) and OVX group (n=25). After 3 months of normal feeding, 5 rats in each group were randomly selected and were sacrificed. The distal femurs were harvested for evaluation with high-resolution micro-CT. HE staining was used to verify the establishment of osteoporosis model. TI was inserted bilaterally in the femoral metaphyseal region of remaining rats in OVX group. All the TI implanted rats were randomly divided into 2 groups: Control group (n=10) and TSA group (n=10). The rats in TSA group were intraperitoneally injected trichostatin A for 4 weeks. The rats in Control group were intraperitoneally injected the same amount of normal saline. All the rats were sacrificed after the drug treatment and the distal femurs were harvested for evaluation with high-resolution micro-CT, HE staining, and Masson staining. The serum of the rats was examined using ELISA. Results Compared with those in Sham group, micro-CT results showed that bone mineral density (BMD), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and connective density (Conn.D) in OVX group decreased (P<0.05), and trabecular separation (Tb.Sp) and structure model index (SMI) increased (P<0.05) in OVX group. HE staining results showed that Tb.N in OVX group significantly decreased. Compared with those in the Control group, BMD, BV/TV, Tb.Th, and Tb.N increased in TSA group (P<0.05), and Tb.Sp and SMI decreased (P<0.05). HE staining and Masson staining results showed that Tb.N and new bone increased in TSA group. ELISA results showed that bone morphogenesis-related proteins bone morphogenetic protein-2 (BMP2) and serum osteocalcin (OCN) increased in TSA group. Conclusion TSA improves TI implant osseointegration by promoting bone trabecular formation in OVX rats by up-regulating the key proteins of bone formation OCN and BMP2. |