Best5: a novel interferon-inducible gene expressed during bone formation.
Regulation of bone formation is important in the pathogenesis of many conditions such as osteoporosis, fracture healing, and loosening of orthopedic implants. We have recently identified a novel rat cDNA (best5) by differential display PCR that is regulated during osteoblast differentiation and bone formation in vitro and in vivo. Expression of best5 mRNA is induced in cultures of osteoblasts by both interferon-alpha (IFN-alpha) or IFN-gamma. Whereas IFN-alpha induced a rapid, transient induction of best5 expression peaking at 4-6 h poststimulation, IFN-gamma elicited a more prolonged induction of best5 expression, which remained elevated 48 h poststimulation. A polyclonal antibody generated to a peptide derived from the best5 coding region recognized a 27 kDa protein on Western blot analysis of osteoblast lysates. We localized BEST5 protein in osteoblast progenitor cells and mature osteoblasts in sections of rat tibiae and in sections of bones loaded in vivo to induce adaptive bone formation. Best5 may therefore be a fundamental intermediate in the response of osteoblasts to stimuli that modulate proliferation/differentiation, such as interferons or mechanical loading. These findings highlight the close interactions between the immune system and bone cells and may open new therapeutic avenues in modulating bone mass.
Grewal
T S
TS
Department of Biology, The University of York, Heslington, York YO10 5YW, United Kingdom. tsg@york.ac.uk
Genever
P G
PG
Brabbs
A C
AC
Birch
M
M
Skerry
T M
TM
D000595:Amino Acid Sequence; D000818:Animals; D001846:Bone Development; D001854:Bone Marrow Cells / Q000166:cytology; D001859:Bone Neoplasms; D001842:Bone and Bones / Q000166:cytology; D003001:Cloning, Molecular; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology*; D007371:Interferon-gamma / Q000494:pharmacology*; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D007506:Iron-Sulfur Proteins; D008969:Molecular Sequence Data; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012516:Osteosarcoma; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics* / Q000494:pharmacology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D000090123:Viperin Protein
D007370:Interferon Type I; D007371:Interferon-gamma; D007375:Interleukin-1; D015850:Interleukin-6; D007506:Iron-Sulfur Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C406152:Rsad2 protein, rat; D000090123:Viperin Protein