title: Adipocytes enhance expression of osteoclast adhesion-related molecules through the CXCL12/CXCR4 signalling pathway.
abstract: OBJECTIVE
  The purpose of this study was to investigate effects of adipocytes on osteoclast adhesion-related molecules.
  
  
  METHODS
  ST2 cells, a cloned stromal cell line from mouse bone marrow, able to differentiate into adipocytes, were cultured in serum-free α-MEM which was then collected to be used as adipocyte-conditioned medium (ADIPO CM). RAW264.7 cells were cultured in ADIPO CM in the presence of RANKL, and bone marrow-derived macrophages were cultured in ADIPO CM in the presence of RANKL and macrophage-colony stimulating factor to induce osteoclast differentiation. TRAP staining, resorption pit assay, qRT-PCR and western blotting assays were performed.
  
  
  RESULTS
  ELISAs revealed that CXCL12 was abundant in ADIPO CM and CCK-8 assay revealed no proliferation of RAW264.7 cells after exogenous CXCL12 treatment. ADIPO CM enhanced osteoclast formation and resorption, both by RAW264.7 cells and BMMs. In addition, exogenous CXCL12 efficiently potentiated formation of TRAP-positive osteoclast and resorption by RAW264.7 cells. Western blotting and qRT-PCR suggested that ADIPO CM or combined treatment with exogenous CXCL12 caused significant increase in expression of NFAT2, src and osteoclast adhesion-related molecules, including β3 integrin, CD44 and osteopontin. However, these promotional effects were largely abrogated on treatment of AMD3100, a CXCR4 antagonist.
  
  
  CONCLUSIONS
  Adipocytes promoted osteoclast differentiation, function and expression of adhesion-related molecules through the CXCL12/CXCR4 signalling pathway.
authors.affiliation: School of Stomatology, Shanxi Medical University, Taiyuan, China.|Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Department of Bone Metabolism, School of Stomatology Shandong University, Jinan, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Luo
authors.affiliation: Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Department of Bone Metabolism, School of Stomatology Shandong University, Jinan, China.
authors.forename: Hongrui
authors.initials: H
authors.lastname: Liu
authors.affiliation: Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Department of Bone Metabolism, School of Stomatology Shandong University, Jinan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Feng
authors.affiliation: Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Department of Bone Metabolism, School of Stomatology Shandong University, Jinan, China.
authors.forename: Di
authors.initials: D
authors.lastname: Liu
authors.affiliation: Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Department of Bone Metabolism, School of Stomatology Shandong University, Jinan, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Du
authors.affiliation: Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Department of Bone Metabolism, School of Stomatology Shandong University, Jinan, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Sun
authors.affiliation: Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Department of Bone Metabolism, School of Stomatology Shandong University, Jinan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Department of Bone Metabolism, School of Stomatology Shandong University, Jinan, China.
authors.forename: Xiuchun
authors.initials: X
authors.lastname: Han
authors.affiliation: Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Department of Bone Metabolism, School of Stomatology Shandong University, Jinan, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Amizuka
authors.affiliation: School of Stomatology, Shanxi Medical University, Taiyuan, China.|Department of Hard Tissue Research, Graduate School of Oral Medicine, Matsumoto Dental University, Shiojiri, Japan.
authors.forename: Xianqi
authors.initials: X
authors.lastname: Li
authors.affiliation: Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Department of Bone Metabolism, School of Stomatology Shandong University, Jinan, China.
authors.forename: Minqi
authors.initials: M
authors.lastname: Li
mesh_terms: D017667:Adipocytes / Q000378:metabolism*; D000818:Animals; D001596:Benzylamines; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D054377:Chemokine CXCL12 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000080027:Cyclams; D006571:Heterocyclic Compounds / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010010:Osteoclasts / Q000166:cytology* / Q000378:metabolism*; D000067996:RAW 264.7 Cells; D019718:Receptors, CXCR4 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D001596:Benzylamines; C514936:CXCR4 protein, mouse; D015815:Cell Adhesion Molecules; D054377:Chemokine CXCL12; C515256:Cxcl12 protein, mouse; D000080027:Cyclams; D006571:Heterocyclic Compounds; D019718:Receptors, CXCR4; C088327:plerixafor
keywords: CXCL12/CXCR4; adhesion-related molecules; adipocyte; osteoclast