Chang Yuhan, Hu Chih-Chien, Wu Ying-Yu, Ueng Steve W N, Chang Chih-Hsiang, Chen Mei-Feng
Bone and Joint Research Center, Chang Gung Memorial Hospital, No. 5, Fuxing Street, Guishan Dist., Taoyuan 33305, Taiwan.
Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan.
Int J Mol Sci. 2021 Jan 25;22(3):1169. doi: 10.3390/ijms22031169.
Bacterial infection in orthopedic surgery is challenging because cell wall components released after bactericidal treatment can alter osteoblast and osteoclast activity and impair fracture stability. However, the precise effects and mechanisms whereby cell wall components impair bone healing are unclear. In this study, we characterized the effects of lipopolysaccharide (LPS) on bone healing and osteoclast and osteoblast activity in vitro and in vivo and evaluated the effects of ibudilast, an antagonist of toll-like receptor 4 (TLR4), on LPS-induced changes. In particular, micro-computed tomography was used to reconstruct femoral morphology and analyze callus bone content in a femoral defect mouse model. In the sham-treated group, significant bone bridge and cancellous bone formation were observed after surgery, however, LPS treatment delayed bone bridge and cancellous bone formation. LPS inhibited osteogenic factor-induced MC3T3-E1 cell differentiation, alkaline phosphatase (ALP) levels, calcium deposition, and osteopontin secretion and increased the activity of osteoclast-associated molecules, including cathepsin K and tartrate-resistant acid phosphatase in vitro. Finally, ibudilast blocked the LPS-induced inhibition of osteoblast activation and activation of osteoclast in vitro and attenuated LPS-induced delayed callus bone formation in vivo. Our results provide a basis for the development of a novel strategy for the treatment of bone infection.
骨科手术中的细菌感染具有挑战性，因为杀菌处理后释放的细胞壁成分会改变成骨细胞和破骨细胞的活性，并损害骨折稳定性。然而，细胞壁成分损害骨愈合的具体作用和机制尚不清楚。在本研究中，我们在体外和体内表征了脂多糖（LPS）对骨愈合以及破骨细胞和成骨细胞活性的影响，并评估了Toll样受体4（TLR4）拮抗剂异丁司特对LPS诱导变化的影响。具体而言，使用微型计算机断层扫描来重建股骨形态，并分析股骨缺损小鼠模型中的骨痂骨含量。在假手术治疗组中，术后观察到明显的骨桥和松质骨形成，然而，LPS治疗延迟了骨桥和松质骨形成。在体外，LPS抑制成骨因子诱导的MC3T3-E1细胞分化、碱性磷酸酶（ALP）水平、钙沉积和骨桥蛋白分泌，并增加破骨细胞相关分子的活性，包括组织蛋白酶K和抗酒石酸酸性磷酸酶。最后，异丁司特在体外阻断了LPS诱导的成骨细胞活化抑制和破骨细胞活化，并在体内减弱了LPS诱导的骨痂骨形成延迟。我们的结果为开发一种治疗骨感染的新策略提供了依据。
