人RANKL胞外结构域原核表达载体的构建及表达条件优化

细胞核因子κB受体活化因子配体(Receptor activator of the NF-κB ligand,RANKL)是TNF超家族的重要成员之一,属于Ⅱ型跨膜蛋白,通过与其受体核因子κB受体活化因子(RANK)构建的信号通路参与乳腺癌的发生、肿瘤骨转移、骨质疏松、关节炎等病理过程。人RANKL胞外结构域基因片段与原核表达载体pET-21b融合并转化至表达菌Rosetta,并对其表达条件进行了优化。通过对诱导时机,诱导温度,异丙基-β-D-硫代吡喃半乳糖苷(IPTG)浓度,诱导时间及甘油浓度的条件优化表明,当IPTG的浓度为0.2 mmol/mL,20℃振荡诱导培养6 h时,甘油浓度为4%时,可在上清中获得高效表达的pET-21bRANKL融合蛋白,为该蛋白的进一步纯化及结构与功能研究打下了良好的基础。     

不同角度机械力作用后种植体周沟液中RANKL/OPG比值的改变

研究狗颌骨种植体受到0°和30°角100 Ncm机械力作用后,种植周沟液(PISF)中RANKL/OPG比值的改变.应用ELISA方法检测狗PISF中RANKL和OPG浓度,计算RANKL/OPG比值.100 Ncm 30°角连续机械力刺激后RANKL/OPG比值较100 Ncm 0°角及非机械刺激组明显增高,具有统计学意义.说明100 Ncm 30°角机械力作用后,PISF中破骨作用占主导地位.     

RANKL,RANK, osteoprotegerin: key partners of osteoimmunology and vascular diseases

1997 saw the identification of a novel set of proteins within the tumor necrosis factor (TNF)/TNF receptor families that are required for the control of bone remodeling. Therefore, these receptors, receptor activator of nuclear factor kappa B (RANK), osteoprotegerin (OPG) and their ligand RANK ligand (RANKL) became the critical molecular triad controlling osteoclastogenesis and pathophysiologic bone remodeling. However, the establishment of the corresponding knock-out and transgenic mice revealed unexpected results, most particularly, the involvement of these factors in the vascular system and immunity. Thus, the OPG/RANK/RANKL molecular triad appears to be associated with vascular calcifications and plays a pivotal function in the development of the immune system through dendritic cells. OPG/RANK/RANKL thus constitute a molecular bridge spanning bone metabolism, vascular biology and immunity. This review summarizes recent knowledge of OPG/RANK/RANKL interactions and activities as well as the current evidence for their participation in osteoimmunology and vascular diseases. In fine, the targeting of the OPG/RANK/RANKL axis as novel therapeutic approaches will be discussed. Received 27 February 2007; accepted 4 April 2007     

Etiologic factors in Paget’s disease of bone

Paget’s disease of bone is a chronic focal skeletal disorder characterized by increased bone resorption by the osteoclasts. Paramyxoviral gene products have been detected in pagetic osteoclasts. Paget’s disease is an autosomal dominant trait with genetic heterogeneity. Several mutations in the ubiquitin-associated (UBA) domain of sequestosome 1 (SQSTM1/p62) have been identified in patients with Paget’s disease. Similarly, mutations in the valosin-containing protein (VCP) gene have been shown to cause inclusion body myopathy associated with Paget’s disease of bone and frontotemporal dementia. In addition, gene polymorphisms and enhanced levels of cytokine/growth factors associated with Paget’s disease have been identified. However, the etiologic factors in Paget’s disease remain elusive. A cause and effect relationship for the paramyxoviral infection and SQSTM1/ p62 gene mutations responsible for pagetic osteoclast development and disease severity are unclear. This article will highlight the etiologic factors involved in the pathogenesis of Paget’s disease. Received 6 October 2005; received after revision 2 November 2005; accepted 24 November 2005