title: Effects of geranylgeranoic acid in bone: induction of osteoblast differentiation and inhibition of osteoclast formation.
abstract: Retinoids are known to be of special importance for normal bone growth and development. Recently, we reported that retinoids not only induced osteoblast differentiation, but also inhibited osteoclast formation in vitro. In this study, we examined the osteogenic effects of geranylgeranoic acid (GGA), a chemically synthesized acyclic retinoid, in bone in vitro and in vivo. GGA not only suppressed proliferation of osteoblastic MC3T3-E1 cells, but also up-regulated differentiation markers of osteoblasts such as alkaline phosphatase (ALP) activity and expression of osteopontin (OP) messenger RNA (mRNA). In contrast, GGA inhibited osteoclast formation induced by 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] in cocultures of mouse bone marrow cells and primary osteoblasts. Treatment of stromal ST2 cells with GGA restored the 1alpha,25(OH)2D3- or prostaglandin E2 (PGE2)-induced suppression of osteoprotegerin (OPG) mRNA expression. GGA inhibited osteoclast formation induced by macrophage colony-stimulating factor (M-CSF) and soluble receptor activator of nuclear factor kappaB ligand (sRANKL) in the culture of bone marrow macrophages. Thus, it is likely that GGA inhibits osteoclast formation by affecting both osteoblasts and osteoclast progenitors in the coculture system. Furthermore, in vivo, GGA increased bone mineral density (BMD) of total as well as distal femur in a P6 strain of senescence-accelerated mice (SAMP6). These results indicate that GGA increases bone mass by maintaining a positive balance of bone turnover by inducing osteoblast differentiation and suppressing osteoclast formation.
authors.affiliation: Division of Food Science, National Institute of Health and Nutrition, Tokyo, Japan.
authors.forename: Xinxiang
authors.initials: X
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Shidoji
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Muto
authors.forename: Nobuko
authors.initials: N
authors.lastname: Ohishi
authors.forename: Kunio
authors.initials: K
authors.lastname: Yagi
authors.forename: Sachie
authors.initials: S
authors.lastname: Ikegami
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Shinki
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Udagawa
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Suda
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Ishimi
mesh_terms: D016475:3T3 Cells; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D015519:Bone Density / Q000187:drug effects; D001851:Bone Diseases, Metabolic / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D016723:Bone Remodeling / Q000187:drug effects / Q000502:physiology; D002117:Calcitriol / Q000494:pharmacology; D002352:Carrier Proteins / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D018920:Coculture Techniques; D004224:Diterpenes / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D008297:Male; D008562:Membrane Glycoproteins / Q000494:pharmacology; D051379:Mice; D008817:Mice, Mutant Strains; D009924:Organ Culture Techniques; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology; D053495:Osteopontin; D053245:RANK Ligand; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D053246:Receptor Activator of Nuclear Factor-kappa B; D012795:Sialoglycoproteins / Q000235:genetics
chemical_list: D002352:Carrier Proteins; D004224:Diterpenes; D008562:Membrane Glycoproteins; D053245:RANK Ligand; D012333:RNA, Messenger; D053246:Receptor Activator of Nuclear Factor-kappa B; D012795:Sialoglycoproteins; C506896:Spp1 protein, mouse; C505687:Tnfrsf11a protein, mouse; C505689:Tnfsf11 protein, mouse; D053495:Osteopontin; D016173:Macrophage Colony-Stimulating Factor; C040155:geranylgeranic acid; D000469:Alkaline Phosphatase; D002117:Calcitriol