title: Spontaneous and induced osteoclastogenic behaviour of human peripheral blood mononuclear cells and their CD14(+) and CD14(-) cell fractions.
abstract: OBJECTIVE
  Osteoclasts are descended from the CD14(+) monocyte/macrophage lineage, but influence of other haematopoietic cells on osteoclastic commitment of their precursors has remained poorly understood. In this study, osteoclastogenic behaviour of peripheral blood mononuclear cells (PBMC) and their CD14(+) and CD14(-) subpopulations has been accessed, in the absence or presence of M-CSF and RANKL.
  
  
  METHODS
  Cell cultures were characterized for presence of actin rings and vitronectin and calcitonin receptors, TRAP activity and calcium phosphate resorbing activity, expression of osteoclast-related genes and secretion of M-CSF and RANKL.
  
  
  RESULTS
  In the absence of growth factors, PBMC and CD14(+) cultures had some degree of cell survival, and some spontaneous osteoclastogenesis was observed, only on cultures of the former. Supplementation with M-CSF and RANKL significantly increased osteoclastogenic behaviour of cell cultures, particularly CD14(+) cell cultures. Nevertheless, PBMC derived a higher degree of osteoclastogenesis, either as absolute values or after normalization by protein content. It was observed that unlike CD14(+) cells, PBMC were able to express M-CSF and RANKL, which increased following growth factor treatment. Also, expression of TNF-α, GM-CSF, IL-1β, IL-6 and IL-17 was higher in PBMC cultures. Finally, CD14(-) cultures exhibited limited cell survival and did not reveal any osteoclast features.
  
  
  CONCLUSIONS
  Results show that although osteoclastic precursors reside in the CD14(+) cell subpopulation, other populations (such as CD14(-) cells) derived from PBMC, have the ability to modulate osteoclastogenesis positively.
authors.affiliation: Laboratório de Farmacologia e Biocompatibilidade Celular, Faculdade de Medicina Dentária, Universidade do Porto, Porto, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Costa-Rodrigues
authors.forename: A
authors.initials: A
authors.lastname: Fernandes
authors.forename: M H
authors.initials: MH
authors.lastname: Fernandes
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D001483:Base Sequence; D002130:Calcium Phosphates / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D017931:DNA Primers / Q000235:genetics; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000166:cytology* / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D018950:Lipopolysaccharide Receptors / Q000378:metabolism*; D016173:Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D018613:Microscopy, Confocal; D010010:Osteoclasts / Q000166:cytology* / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D053245:RANK Ligand / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D000071681:Tartrate-Resistant Acid Phosphatase
chemical_list: D002130:Calcium Phosphates; D017931:DNA Primers; D007527:Isoenzymes; D018950:Lipopolysaccharide Receptors; D053245:RANK Ligand; D011994:Recombinant Proteins; C505688:TNFSF11 protein, human; D016173:Macrophage Colony-Stimulating Factor; C020243:calcium phosphate; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase