title: Use of an Osteoblast Overload Damage Model to Probe the Effect of Icariin on the Proliferation, Differentiation and Mineralization of MC3T3-E1 Cells through the Wnt/β-Catenin Signalling Pathway.
abstract: OBJECTIVE
  Mechanical loading plays an important role in the regulation of bone mass. However, bone cells are not always under physiological stress. In some cases, bone tissue is subjected to an overloaded mechanical environment. For example, a person who is weight training and a stevedore often experience bone pain, inflammation and other bone fatigue damage symptoms. Icariin is the major ingredient of Herba epimedii, which has been widely used for the treatment of bone injury in traditional Chinese medicine, but its mechanism remains unknown. The aim of this study was to probe the effect of icariin on the proliferation and differentiation of osteoblasts exposed to overload and to determine whether the Wnt/β-catenin signalling pathway is involved in the drug response in osteoblasts.
  
  
  METHODS
  Mouse MC3T3-E1 cells were exposed to mechanical tensile strain using a four- point bending device to create an overload damage model. An MTT assay was performed to determine the effects of icariin on MC3T3-E1 cell proliferation. The mRNA and protein levels of ALP, COL-I, OCN, RUNX2 and β-catenin were assessed using RT-PCR and immunoblotting. The protein levels of β-catenin in the MC3T3-E1 cells were also determined using fluorescence microscopy. The mineralization of osteoblasts was assessed using Alizarin Red S staining.
  
  
  RESULTS
  We found that icariin enhanced the proliferation of osteoblasts exposed to overload and promoted MC3T3-E1 cell differentiation and mineralization. Furthermore, the gene and protein expression levels of β-catenin and RUNX2 all increased with icariin treatment compared with those in the damage group.
  
  
  CONCLUSIONS
  Our study suggested that icariin promotes proliferation and differentiation in osteoblasts exposed to overload. The effect of icariin on osteoblastic differentiation acted by activating the RUNX2 promoter and the Wnt/β- catenin pathway.
authors.affiliation: Tianjin Medical University General Hospital, Tianjin, China.|Institute of Medical Equipment, Academy of Military Medical Science, Tianjin, China.
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Xiangya School of Medicine, Central South University, Changsha, China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Huang
authors.affiliation: Institute of Medical Equipment, Academy of Military Medical Science, Tianjin, China.|First Hospital of Jilin University, Changchun, China.
authors.forename: Baohui
authors.initials: B
authors.lastname: Hao
authors.affiliation: Institute of Medical Equipment, Academy of Military Medical Science, Tianjin, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.affiliation: Tianjin Medical University General Hospital, Tianjin, China.
authors.forename: Shuanglong
authors.initials: S
authors.lastname: Zhu
authors.affiliation: Institute of Medical Equipment, Academy of Military Medical Science, Tianjin, China.
authors.forename: Qiangsong
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Institute of Medical Equipment, Academy of Military Medical Science, Tianjin, China.
authors.forename: Ruixin
authors.initials: R
authors.lastname: Li
authors.affiliation: Tianjin Medical University General Hospital, Tianjin, China.
authors.forename: Yunqiang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Institute of Medical Equipment, Academy of Military Medical Science, Tianjin, China.
authors.forename: Xizheng
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D050659:Core Binding Factor Alpha 1 Subunit / Q000096:biosynthesis; D005419:Flavonoids / Q000494:pharmacology*; D051379:Mice; D008954:Models, Biological; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D060449:Wnt Signaling Pathway / Q000187:drug effects*; D051176:beta Catenin / Q000096:biosynthesis
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D005419:Flavonoids; C493716:Runx2 protein, mouse; D051176:beta Catenin; C056599:icariin
keywords: Icariin; MC3T3-E1; Overload; Wnt/β-catenin