[Show abstract][Hide abstract] ABSTRACT: Soy isoflavones, genistein, daidzein and its metabolite equol, as well as β-carotene have been reported to be effective for maintaining bone health. However, it remains to be elucidated whether combining soy isoflavones with β-carotene is beneficial to bone formation. This study investigated the combined effect of soy isoflavones and β-carotene on the differentiation of MC3T3-E1 preosteoblastic cells. Daidzein and genistein alone did not affect cell growth but increased alkaline phosphatase (ALP) activity. Beta-carotene alone inhibited cell growth and markedly enhanced ALP activity. Soy isoflavones combined with β-carotene resulted in higher ALP activity than treatment with isoflavones or β-carotene alone. We observed significant main effects of β-carotene on the enhanced expression of Runx2, ALP, and ostepontin mRNA, whereas there was a significant main effect of soy isoflavones on the expression of osterix mRNA. To investigate how β-carotene affected osteoblast differentiation, MC3T3-E1 cells were treated with retinoic acid receptor (RAR) pan-antagonist combined with β-carotene. Osteopontin and ALP mRNA expression levels, which were increased following treatment with β-carotene, were significantly suppressed by the RAR pan-antagonist. This suggests treatment with β-carotene enhanced early osteoblastic differentiation, at least in part via RAR signaling. These results indicate that a combination of isoflavones and β-carotene may be useful for maintaining a positive balance of bone turnover by inducing osteoblast differentiation.
Preview · Article · Oct 2015 · International Journal of Environmental Research and Public Health
[Show abstract][Hide abstract] ABSTRACT: The stromal cells associated with tumors such as melanoma are significant determinants of tumor growth and metastasis. Using
membrane-bound prostaglandin E synthase 1 (mPges1−/−) mice, we show that prostaglandin E2 (PGE2) production by host tissues is critical for B16 melanoma growth, angiogenesis, and metastasis to both bone and soft tissues.
Concomitant studies in vitro showed that PGE2 production by fibroblasts is regulated by direct interaction with B16 cells. Autocrine activity of PGE2 further regulates the production of angiogenic factors by fibroblasts, which are key to the vascularization of both primary
and metastatic tumor growth. Similarly, cell-cell interactions between B16 cells and host osteoblasts modulate mPGES-1 activity
and PGE2 production by the osteoblasts. PGE2, in turn, acts to stimulate receptor activator of NF-κB ligand expression, leading to osteoclast differentiation and bone
erosion. Using eicosanoid receptor antagonists, we show that PGE2 acts on osteoblasts and fibroblasts in the tumor microenvironment through the EP4 receptor. Metastatic tumor growth and vascularization
in soft tissues was abrogated by an EP4 receptor antagonist. EP4-null Ptger4−/− mice do not support B16 melanoma growth. In vitro, an EP4 receptor antagonist modulated PGE2 effects on fibroblast production of angiogenic factors. Our data show that B16 melanoma cells directly influence host stromal
cells to generate PGE2 signals governing neoangiogenesis and metastatic growth in bone via osteoclast erosive activity as well as angiogenesis in
soft tissue tumors.
No preview · Article · Oct 2015 · Journal of Biological Chemistry
[Show abstract][Hide abstract] ABSTRACT: Epigallocatechin gallate (EGCG), a major polyphenol in green tea, possesses antioxidant properties and regulates various cell functions. Here, we examined the function of EGCG in inflammatory bone resorption. In calvarial organ cultures, lipopolysaccharide (LPS)-induced bone resorption was clearly suppressed by EGCG. In osteoblasts, EGCG suppressed the LPS-induced expression of COX-2 and mPGES-1 mRNAs, as well as prostaglandin E2 production, and also suppressed RANKL expression, which is essential for osteoclast differentiation. LPS-induced bone resorption of mandibular alveolar bones was attenuated by EGCG in vitro, and the loss of mouse alveolar bone mass was inhibited by the catechin in vivo.
[Show abstract][Hide abstract] ABSTRACT: We examined the effects of heptamethoxyflavone (HMF), a citrus flavonoid on inflammatory bone resorption. HMF suppressed the osteoclast formation and PGE2 production induced by IL-1. In mouse calvarial organ cultures, HMF attenuated the bone resorption elicited by LPS. HMF suppressed bone resorption in the mandibular alveolar bone. HMF may protect against inflammatory bone loss such as periodontal disease.
No preview · Article · Aug 2014 · Bioscience Biotechnology and Biochemistry
[Show abstract][Hide abstract] ABSTRACT: S-equol is a natural metabolite of the soy isoflavone, daidzein, produced by intestinal bacteria. S-equol has been shown to have greater estrogenic activity than other soy isoflavones and prevent bone loss in post-menopausal women. Estrogen regulates both bone remodeling and hemopoiesis in the bone marrow, these processes that communicate closely with each other. In this study, we investigated the effect of S-equol on bone mass and gene expression of bone marrow cells in ovariectomized (OVX) mice. Female ddY strain mice, aged 12 weeks, were either sham operated or OVX. The OVX mice were randomly divided into two groups: (1) OVX control and (2) OVX fed a 0.06% (w/w) S-equol supplemented diet. After 2 weeks, the trabecular bone volume of the femoral distal metaphysis was markedly reduced in OVX mice. However, treatment with equol was observed to ameliorate this. Expression of inflammatory-, osteoclastogenesis- and adipogenesis-related genes was increased in OVX mice compared with sham mice, and equol was observed to suppress their expression. The present study demonstrates that equol might ameliorate bone loss caused by estrogen deficiency through regulating hemopoiesis and production of inflammatory cytokines in bone marrow cells.
Full-text · Article · Jul 2013 · Journal of Clinical Biochemistry and Nutrition
[Show abstract][Hide abstract] ABSTRACT: We examined the effects of β-cryptoxanthin, a typical carotenoid, on inflammatory periodontitis. β-Cryptoxanthin suppressed lipopolysaccharide (LPS)-induced osteoclast formation in co-cultures of bone marrow cells and osteoblasts. In a mouse model of periodontitis, it suppressed bone resorption in the mandibular alveolar bone in vitro and restored alveolar bone loss induced by LPS in vivo. β-Cryptoxanthin might protect against periodontal disease.
No preview · Article · Apr 2013 · Bioscience Biotechnology and Biochemistry
[Show abstract][Hide abstract] ABSTRACT: We investigated the effects of equol on adipogenesis by measuring lipid accumulation and analyzing the change in adipocyte-related gene expression in MC3T3-L1 cells. Treatment with 10 µM equol tended to increase adipocyte-related gene expression, whereas 100 µM equol reduced lipid accumulation and suppressed the expression of these genes and proteins. Our results suggest that equol regulated adipogenesis in a bi-phasic fashion.
No preview · Article · Jan 2013 · Bioscience Biotechnology and Biochemistry
[Show abstract][Hide abstract] ABSTRACT: Bombyx mori silk fibroin (SF) shows remarkably earlier calcification than bovine serum albumin, indicating advantage of the SF scaffold for bone regeneration. We provide evidence for the first time, that SF not only activate early differentiation markers of osteoblasts, but also activate expression of the late differentiation markers.
No preview · Article · Dec 2012 · Journal of Bioscience and Bioengineering
[Show abstract][Hide abstract] ABSTRACT: TLR2 forms heterodimers with TLR1 and TLR6, and regulates host defense mechanisms against pathogens. We examined the role of TLR2 heterodimer signaling in osteoclast formation and inflammatory periodontitis. In co-cultures of mouse bone marrow cells and osteoblasts, a TLR2/6 ligand (diacylated lipopeptide designed from Gram-positive bacteria) markedly induced osteoclast formation. A TLR2/1 ligand (triacylated lipopeptide designed from Gram-negative bacteria) also induced osteoclast formation. The osteoclast formation induced by TLR2/6 and TLR2/1 ligands was completely suppressed by indomethacin. Osteoblasts expressed TLR1, 2, 4, and 6 mRNAs, and both TLR2/6 and TLR2/1 ligands induced the expression of COX-2, mPGES-1, and RANKL mRNA, as well as PGE production in osteoblasts. Both TLR2/6 and TLR2/1 ligands induced the resorption of mandibular alveolar bone in organ cultures, and elicited inflammatory periodontitis in vivo. Therefore, TLR2 heterodimer signaling may play a key role in PGE-mediated inflammatory bone loss in periodontal disease.
No preview · Article · Oct 2012 · Biochemical and Biophysical Research Communications
[Show abstract][Hide abstract] ABSTRACT: Binding of a series of novel 1α,25-dihydroxyvitamin D(3) (1,25-VD(3)) derivatives, having a nitrogen-linked substituent at the 2α- or 2β-position of the A-ring (2-N-substituted compounds), with the vitamin D receptor (VDR) was investigated by means of computational docking studies. Selected compounds were synthesized by coupling A-ring synthons and/or with CD-ring-bearing bromomethylene under Trost's conditions. The 2α- and 2β-stereoisomers of the A-ring synthons were synthesized from l-serine () as a single chiral source by installing vinyl and propargyl groups at opposite ends of the molecule. The activity of the obtained compounds was evaluated by means of a luciferase-based VDR transcriptional activity assay in NIH3T3 cells. Relatively small substituents incorporating a hydrogen-bonding donor, i.e., NHAc and NHMs, were effective for eliciting VDR transcriptional activity, and 2β-NHMs-1,25-VD(3) () showed the highest activity, being more potent than 1,25-VD(3). Derivatives with bulky substituents were inactive. These new insights into the structure-activity relationships of 1,25-VD(3) derivatives may be helpful in separating the various biological activities of 1,25-VD(3) and in generating novel therapeutic drug candidates.
No preview · Article · Aug 2012 · Organic & Biomolecular Chemistry
[Show abstract][Hide abstract] ABSTRACT: Proteinases play a pivotal role in wound healing by regulating cell-matrix interactions and availability of bioactive molecules. The role of matrix metalloproteinase-13 (MMP-13) in granulation tissue growth was studied in subcutaneously implanted viscose cellulose sponge in MMP-13 knockout (Mmp13(-/-)) and wild type (WT) mice. The tissue samples were harvested at time points day 7, 14 and 21 and subjected to histological analysis and gene expression profiling. Granulation tissue growth was significantly reduced (42%) at day 21 in Mmp13(-/-) mice. Granulation tissue in Mmp13(-/-) mice showed delayed organization of myofibroblasts, increased microvascular density at day 14, and virtual absence of large vessels at day 21. Gene expression profiling identified differentially expressed genes in Mmp13(-/-) mouse granulation tissue involved in biological functions including inflammatory response, angiogenesis, cellular movement, cellular growth and proliferation and proteolysis. Among genes linked to angiogenesis, Adamts4 and Npy were significantly upregulated in early granulation tissue in Mmp13(-/-) mice, and a set of genes involved in leukocyte motility including Il6 were systematically downregulated at day 14. The expression of Pdgfd was downregulated in Mmp13(-/-) granulation tissue in all time points. The expression of matrix metalloproteinases Mmp2, Mmp3, Mmp9 was also significantly downregulated in granulation tissue of Mmp13(-/-) mice compared to WT mice. Mmp13(-/-) mouse skin fibroblasts displayed altered cell morphology and impaired ability to contract collagen gel and decreased production of MMP-2. These results provide evidence for an important role for MMP-13 in wound healing by coordinating cellular activities important in the growth and maturation of granulation tissue, including myofibroblast function, inflammation, angiogenesis, and proteolysis.
[Show abstract][Hide abstract] ABSTRACT: Nobiletin, a polymethoxy flavonoid (PMF), inhibits systemic bone resorption and maintains bone mass in estrogen-deficient ovariectomized mice. This study examined the anti-inflammatory effects of PMFs, nobiletin, and tangeretin on lipopolysaccharide (LPS)-induced bone resorption. Nobiletin and tangeretin suppressed LPS-induced osteoclast formation and bone resorption and suppressed the receptor activator of NFκB ligand-induced osteoclastogenesis in RAW264.7 macrophages. Nobiletin clearly restored the alveolar bone mass in a mouse experimental model for periodontitis by inhibiting LPS-induced bone resorption. PMFs may therefore provide a new therapeutic approach for periodontal bone loss.
No preview · Article · Jul 2012 · Journal of Pharmacological Sciences
[Show abstract][Hide abstract] ABSTRACT: We have invented a mouse model of periodontitis associated with alveolar bone loss induced by lipopolysaccharide. Ovariectomized (OVX) animals are widely used as a model for osteoporosis due to estrogen deficiency. To define the relationship between periodontitis and osteoporosis, we examined the influence of estrogen deficiency on the mouse alveolar bone mass. In OVX mice, bone loss was detected not only in the femur, but also in the alveolar bone, indicating that estrogen deficiency could induce resorption in alveolar bone. In experiments using a combination of osteoporosis and periodontitis models, OVX significantly enhanced the alveolar bone loss in the model of periodontitis. Therefore, postmenopausal osteoporosis may enhance the risk of periodontitis associated with inflammatory alveolar bone resorption.
No preview · Article · Apr 2012 · Experimental Animals
[Show abstract][Hide abstract] ABSTRACT: Capsaicin, a transient receptor potential vanilloid type 1 (TRPV1) ligand, regulates nerve-related pain-sensitive signals, inflammation, and cancer growth. Capsaicin suppresses interleukin-1-induced osteoclast differentiation, but its roles in bone tissues and bone diseases are not known. This study examined the effects of capsaicin on inflammatory bone resorption and prostaglandin E (PGE) production induced by lipopolysaccharide (LPS) in vitro and on bone mass in LPS-treated mice in vivo. Capsaicin suppressed osteoclast formation, bone resorption, and PGE production induced by LPS in vitro. Capsaicin suppressed the expression of cyclooxygenase-2 (COX-2) and membrane-bound PGE synthase-1 (mPGES-1) mRNAs and PGE production induced by LPS in osteoblasts. Capsaicin may suppress PGE production by inhibiting the expression of COX-2 and mPGES-1 in osteoblasts and LPS-induced bone resorption by TRPV1 signals because osteoblasts express TRPV1. LPS treatment markedly induced bone loss in the femur in mice, and capsaicin significantly restored the inflammatory bone loss induced by LPS in mice. TRPV1 ligands like capsaicin may therefore be potentially useful as clinical drugs targeting bone diseases associated with inflammatory bone resorption.
[Show abstract][Hide abstract] ABSTRACT: Ovariectomized (OVX) animal is a typical experimental model for investigation of postmenopausal osteoporosis due to estrogen deficiency in women. Recently, both OVX mouse and OVX rat are commonly used for the evaluation of bone tissues in the animal model. OVX mouse is appropriate for the study of pathogenesis of postmenopausal osteoporosis, since various gene knockout mice are available for the experiments. OVX rat model is widely used for the evaluation and development of new drug compounds for postmenopausal osteoporosis treatments. On the other hand, orchidectomized (ORX) animal model is excellent in the study of osteoporosis due to androgen deficiency in men. Both OVX and ORX animal exhibits marked bone loss with increased bone resorption. We focused on the feature and evaluation technique for bone tissues in OVX and ORX animals.
No preview · Article · Feb 2011 · Clinical calcium
[Show abstract][Hide abstract] ABSTRACT: Nobiletin, a polymethoxy flavonoid, prevents cancer and inflammation, but the roles of nobiletin in bone are unclear. We examined the effects of nobiletin on bone resorption in vitro and on bone mass in ovariectomized (OVX) mice in vivo. In vitro, nobiletin suppressed osteoclast formation and bone resorption induced by interleukin (IL)-1. Nobiletin suppressed the expression of cyclooxygenase-2, NFκB-dependent transcription, and prostaglandin E (PGE) production induced by IL-1 in osteoblasts. OVX mice showed severe bone loss in the femur by increased bone resorption due to estrogen deficiency, and nobiletin significantly restored the bone mass. Nobiletin could be beneficial to bone health in postmenopausal women.
No preview · Article · Jan 2011 · Journal of Pharmacological Sciences
[Show abstract][Hide abstract] ABSTRACT: Tissue engineering for skin regeneration is closely related to advances in carrier materials for fibrob-last. To investigate the optimal fibroblast scaffold, we developed a silk protein containing multiple (Ala-Gly-Ala-Gly-Ser-Gly) n sequences, and used it for in vitro evaluations of cell shape, adhesion and matrix production. NIH-3T3 fibroblasts were cultured on silk scaffold and on control culture plates. At 2 hr, fibroblasts cultured on silk scaffold showed round-rose shape, but cells spread on control plates. The numbers of adhesive fibroblasts were the same in both scaffolds, indicating that silk scaffold affects cell shape but not adhesive efficiency. To examine the ef-fects of silk scaffold on cytoskeletal changes of fibrob-lasts, cells were applied to actin staining. Fibroblasts cultured for 2 hr on silk scaffold showed dense actin fibers which formed ring-like structures, while actin stress fibers were formed in cells cultured on control plates. In a long-term culture of 14 days, piled ma-trices produced by fibroblasts have been shown dis-tinctly in cells cultured on silk scaffold compared with cells cultured on control plates. The expression of fi-bronectin mRNA was elevated in fibroblasts cultured on silk scaffold compared with control, but the ex-pression of collagens, type I and type III, mRNAs was similar in fibroblasts cultured on both scaffold. These results indicate that silk scaffold influences cell shape and actin fiber, and enhances matrix production with increased fibronectin. Therefore, silk protein may be an useful scaffold for regenerative therapy in various skin wounds.
Preview · Article · Dec 2010 · Journal of health science