乙酰肝素酶在股骨头坏死骨组织及外周血中的表达及意义

背景：大量研究表明低分子肝素可预防和治疗早期股骨头坏死，但其作用机制尚未阐明。肝素在体内与乙酰肝素酶呈动态平衡状态，可抑制其表达水平。目的：观察乙酰肝素酶及组织因子途径抑制剂在股骨头坏死患者的股骨头坏死骨内及外周血液中蛋白表达的变化，探讨乙酰肝素酶在股骨头坏死中的病理生理作用及意义。方法：选取特发性股骨头坏死患者36例为实验组，按照国际骨循环研究会（ARCO）分期Ⅰ-Ⅳ期分为4组，每组9例；选取新鲜股骨颈骨折行髋关节置换患者9例做对照组；治疗前抽取患者外周静脉血，测定血浆乙酰肝素酶及组织因子途径抑制物含量；治疗中取ARCO Ⅱ-Ⅳ组股骨头内坏死骨组织，行Western Blot蛋白定量，行病理学苏木精-伊红染色观察。结果与结论：股骨头坏死患者血浆中的乙酰肝素酶、组织因子途径抑制物表达含量较对照组增加，随在病程进展而呈弧形改变，其中 ARCO Ⅲ期含量最高，Ⅳ期含量稍显下降，组间差异有显著性。坏死股骨头局部的乙酰肝素酶、组织因子途径抑制物蛋白表达较对照组增强，在ARCO Ⅲ期含量最高，Ⅱ、Ⅳ期中蛋白表达无明显差异。结果表明乙酰肝素酶及组织因子途径抑制剂在股骨头坏死患者中随着坏死程度的发展表达逐渐增高，在股骨头坏死中发挥重要作用。

Heparanase expression in necrotic bone and peripheral blood after osteonecrosis of the femoral head

BACKGROUND：Accumulating evidence shows that, low molecular heparin can prevent and treat early osteonecrosis of femoral head, but the mechanism remains unclear. The heparin exhibits a dynamic balance with heparanase in vivo, and inhibits heparanase expression. OBJECTIVE：To observe the changes of heparanase and tissue factor pathway inhibitor expression level in plasma and femoral head of patients with idiopathic osteonecrosis of femoral head, and investigate the pathophysiological role of heparanase in the progression of idiopathic osteonecrosis of femoral head. METHODS：A total of 36 patients with idiopathic osteonecrosis of femoral head were randomly divided into four groups according to ARCO I-IV period, with nine patients in each group. Patients with fresh femoral neck fracture for hip arthroplasty were included in the control group. Heparanase and tissue factor pathway inhibitor levels in preoperative venous plasma were measured by ELISA, and in subchondral necrosis bone of ARCO II-IV groups were observed for western blot analysis and hematoxylin-eosin staining. RESULTS AND CONCLUSION：In plasma, heparanase and tissue factor pathway inhibitor levels were significantly increased along with the development of idiopathic osteonecrosis of femoral head compared with control group, the highest levels were found in ARCO III period, and then slightly decreased in ARCO IV period, showing significant differences. The protein levels of heparanase and tissue factor pathway inhibitor in necrosis bone were increased significantly compared with control group, the highest levels occurred in ARCO III period, no obvious difference was found between ARCO II and IV periods. Heparanase and tissue factor pathway inhibitor levels are gradual y increased along with the development of the necrosis, and heparanase plays an important role in idiopathic osteonecrosis of femoral head.