title: Ionic products of bioactive glass dissolution increase proliferation of human osteoblasts and induce insulin-like growth factor II mRNA expression and protein synthesis.
abstract: Bioglass 45S5 is an osteoproductive material, which resorbs by releasing its constitutive ions into solution. Treatment with the ionic products of Bioglass 45S5 dissolution in DMEM for 4 days increased human osteoblast proliferation to 155% of control. Two days after treatment, differential gene expression was analyzed by cDNA microarrays. Expression of a potent osteoblast mitogenic growth factor, insulin-like growth factor II (IGF-II), was increased to 290%. Additionally, there was a 168% increase in the concentration of unbound IGF-II protein in the conditioned media of treated osteoblasts. Expression levels of IGFBP-3, an IGF-II carrier protein, metalloproteinase-2 and cathepsin-D were also increased to 200, 340, and 310% of control levels, respectively. Metalloproteinase-2 and cathepsin-D are proteases that cleave IGF-II from its carrier proteins, resulting in the release of the unbound biologically active IGF-II. We suggest that the stimulatory effect of the ionic products of Bioglass 45S5 dissolution on osteoblast proliferation may be mediated by IGF-II.
authors.affiliation: Department of Histochemistry, Imperial College School of Science, Technology and Medicine, London, W12 ONN, United Kingdom.
authors.forename: I D
authors.initials: ID
authors.lastname: Xynos
authors.forename: A J
authors.initials: AJ
authors.lastname: Edgar
authors.forename: L D
authors.initials: LD
authors.lastname: Buttery
authors.forename: L L
authors.initials: LL
authors.lastname: Hench
authors.forename: J M
authors.initials: JM
authors.lastname: Polak
mesh_terms: D018786:Bone Substitutes / Q000737:chemistry / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002516:Ceramics / Q000737:chemistry / Q000494:pharmacology*; D018076:DNA, Complementary / Q000032:analysis; D020869:Gene Expression Profiling; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C022107:Bioglass; D018786:Bone Substitutes; D018076:DNA, Complementary; D012333:RNA, Messenger; D007335:Insulin-Like Growth Factor II