Ionic products of bioactive glass dissolution increase proliferation of human osteoblasts and induce insulin-like growth factor II mRNA expression and protein synthesis.
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.
Xynos
I D
ID
Department of Histochemistry, Imperial College School of Science, Technology and Medicine, London, W12 ONN, United Kingdom.
Edgar
A J
AJ
Buttery
L D
LD
Hench
L L
LL
Polak
J M
JM
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
C022107:Bioglass; D018786:Bone Substitutes; D018076:DNA, Complementary; D012333:RNA, Messenger; D007335:Insulin-Like Growth Factor II