title: Recombinant soluble receptor activator of nuclear factor-kappaB inhibits parathyroid hormone-induced osteoclastogenesis in vitro.
abstract: The recent identification of receptor activator of nuclear factor-kappaB ligand (RANKL)/RANK/osteoprotegerin (OPG) cytokine system has led to a new molecular perspective on osteoclast biology and bone homeostasis. Specifically, the interaction between RANKL and RANK is responsible for osteoclast differentiation. In the present study, we evaluated whether soluble RANK (sRANK) could act as an antagonist of RANKL and down-regulate osteoclastogenesis and bone resorption in vitro. The prokaryotic expression vector coding for sRANK was constructed. Then the construct was introduced into E. coli Origami B (DE3) competent cells and recombinant sRANK was successfully produced and purified through affinity chromatography. sRANK reduced osteoclast-like cell (OLC) formation and resorption pit formation induced by parathyroid hormone (PTH) in a dose-dependent manner. In addition, sRANK significantly inhibited PTH-induced mRNA expression of carbonic anhydrase II and tartrate-resistant acid phosphatase in murine bone marrow cells as confirmed by using semi-quantitative RT-PCR. The down-regulation was highly correlated with the effect of sRANK on OLC formation from marrow cells. These data demonstrate the anti-resorptive effects of sRANK in vitro and highlight the potential of sRANK as a novel therapeutic approach to bone disorders characterized by enhanced bone resorption.
authors: Institute of Endocrinology, Tianjin Medical University, Tianjin, China. bliwang72@yahoo.com.cn
authors: Bao-Li
authors: BL
authors: Wang
authors: Hui
authors: H
authors: Liang
authors: Fang
authors: F
authors: Zheng
authors: Xiao-Xia
authors: XX
authors: Li
authors: Yu-Bing
authors: YB
authors: Liu
authors: Chen-Lin
authors: CL
authors: Dai
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D001862:Bone Resorption / Q000517:prevention & control; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006801:Humans; D051379:Mice; D010010:Osteoclasts / Q000166:cytology*; D053244:Osteoprotegerin / Q000502:physiology; D010281:Parathyroid Hormone / Q000037:antagonists & inhibitors* / Q000502:physiology; D053245:RANK Ligand / Q000502:physiology; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*
chemical_list: D053244:Osteoprotegerin; D010281:Parathyroid Hormone; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D011994:Recombinant Proteins; C505686:TNFRSF11A protein, human