Effect of osthole on tricalcium phosphate particles-induced calvarial oste-olysis in a mouse model / 中国病理生理杂志

ABSTRACT

AIM: To observe the effect of osthole on tricalcium phosphate (TCP) particles-induced calvarial osteolysis in vivo.METHODS:Male ICR mice were randomly divided into sham group , TCP group and osthole group .A mouse calvarial model of osteolysis was established by TCP particles .On the second postoperative day , osthole (20 mg/kg) was locally injected into the calvarium under the periosteum 3 times a week.Two weeks after osthole treatment , blood and calvaria were collected to determine the level of bone turnover markers such as alkaline phosphatase ( ALP) , osteocalcin and tartrate-resistant acid phosphatase ( TRACP) .The periosteum was performed to examine the release of tumor necrosis factor-α(TNF-α), interleukin-6 (IL-6) and IL-1βby ELISA.The calvaria was obtained for histological and molecular analyses.RESULTS:Data from HE and TRACP staining revealed that osthole prevented TCP particles-induced obvious increase in osteoclastogenesis and resorption area in the metaphysis of mouse calvaria .Osthole treatment increased ALP ac-tivity and osteocalcin level , and dncreased the activity of TRACP in the mouse serum compared with TCP group .Further-more, TCP particles-induced the releases of TNF-α, IL-6 and IL-1βwere significantly suppressed by osthole treatment .In addition, Western blot demonstrated that endoplasmic reticulum ( ER) stress markers such as glucose-regulated protein 78 (GRP78) and CAAT/enhancer binding protein homologous protein (CHOP) were significantly up-regulated in TCP parti-cles-implanted calvarial mice , indicating that TCP particles triggered an ER stress response in the mouse calvarial osteolysis model , which obviously attenuated by osthole .CONCLUSION:Osthole inhibits TCP particles-induced calvarial osteolysis in mice, which is mediated by inhibition of ER stress signaling pathway .