scholarly journals Deficiency of GD3 Synthase in Mice Resulting in the Attenuation of Bone Loss with Aging

2019 ◽  
Vol 20 (11) ◽  
pp. 2825 ◽  
Author(s):  
Shoyoku Yo ◽  
Kazunori Hamamura ◽  
Yoshitaka Mishima ◽  
Kosuke Hamajima ◽  
Hironori Mori ◽  
...  
Keyword(s):  
Bone Loss ◽  
Bone Metabolism ◽  
Three Dimensional ◽  
Bone Surface ◽  
Wild Type ◽  
Micro Computed Tomography ◽  
Receptor Activator ◽  
Gd3 Synthase ◽  
Genetic Deletion ◽  
Almost All

Gangliosides are widely expressed in almost all tissues and cells and are also considered to be essential in the development and maintenance of various organs and tissues. However, little is known about their roles in bone metabolism. In this study, we investigated the effects of genetic deletion of ganglioside D3 (GD3) synthase, which is responsible for the generation of all b-series gangliosides, on bone metabolism. Although b-series gangliosides were not expressed in osteoblasts, these gangliosides were expressed in pre-osteoclasts. However, the expression of these gangliosides was decreased after induction of osteoclastogenesis by receptor activator of nuclear factor kappa-B ligand (RANKL). Three-dimensional micro-computed tomography (3D-μCT) analysis revealed that femoral cancellous bone mass in GD3 synthase-knockout (GD3S KO) mice was higher than that in wild type (WT) mice at the age of 40 weeks, although there were no differences in that between GD3S KO and WT mice at 15 weeks old. Whereas bone formation parameters (osteoblast numbers/bone surface and osteoblast surface/bone surface) in GD3S KO mice did not differ from WT mice, bone resorption parameters (osteoclast numbers/bone surface and osteoclast surface/bone surface) in GD3S KO mice became significantly lower than those in WT mice at 40 weeks of age. Collectively, this study demonstrates that deletion of GD3 synthase attenuates bone loss that emerges with aging.

scholarly journals The Role of Alcohol, LPS Toxicity, and ALDH2 in Dental Bony Defects

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 651
Author(s):  
Hsiao-Cheng Tsai ◽  
Che-Hong Chen ◽  
Daria Mochly-Rosen ◽  
Yi-Chen Ethan Li ◽  
Min-Huey Chen
Keyword(s):  
Bone Loss ◽  
Bacterial Infection ◽  
Bone Regeneration ◽  
Alcohol Drinking ◽  
Bacterial Species ◽  
Dominant Negative ◽  
Enzyme Inactivation ◽  
Wild Type ◽  
Micro Computed Tomography ◽  
Dominant Negative Mutation

It is estimated that 560 million people carry an East Asian-specific ALDH2*2 dominant-negative mutation which leads to enzyme inactivation. This common ALDH2 polymorphism has a significant association with osteoporosis. We hypothesized that the ALDH2*2 mutation in conjunction with periodontal Porphyromonas gingivalis bacterial infection and alcohol drinking had an inhibitory effect on osteoblasts and bone regeneration. We examined the prospective association of ALDH2 activity with the proliferation and mineralization potential of human osteoblasts in vitro. The ALDH2 knockdown experiments showed that the ALDH2 knockdown osteoblasts lost their proliferation and mineralization capability. To mimic dental bacterial infection, we compared the dental bony defects in wild-type mice and ALDH2*2 knockin mice after injection with purified lipopolysaccharides (LPS), derived from P. gingivalis which is a bacterial species known to cause periodontitis. Micro-computed tomography (micro-CT) scan results indicated that bone regeneration was significantly affected in the ALDH2*2 knockin mice with about 20% more dental bony defects after LPS injection than the wild-type mice. Moreover, the ALDH2*2 knockin mutant mice had decreased osteoblast growth and more dental bone loss in the upper left jaw region after LPS injection. In conclusion, these results indicated that the ALDH2*2 mutation with alcohol drinking and chronic exposure to dental bacterial-derived toxin increased the risk of dental bone loss.

scholarly journals Functional Assessment of 12 Rare Allelic CYP2C9 Variants Identified in a Population of 4773 Japanese Individuals

2021 ◽  
Vol 11 (2) ◽  
pp. 94
Author(s):  
Masaki Kumondai ◽  
Akio Ito ◽  
Evelyn Marie Gutiérrez Rico ◽  
Eiji Hishinuma ◽  
Akiko Ueda ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Three Dimensional ◽  
Warfarin Dose ◽  
Catalytic Efficiency ◽  
Therapeutic Window ◽  
Wild Type ◽  
Drug Metabolizing Enzyme ◽  
Novel Variants ◽  
Metabolizing Enzyme ◽  
Almost All

Cytochrome P450 2C9 (CYP2C9) is an important drug-metabolizing enzyme that contributes to the metabolism of approximately 15% of clinically used drugs, including warfarin, which is known for its narrow therapeutic window. Interindividual differences in CYP2C9 enzymatic activity caused by CYP2C9 genetic polymorphisms lead to inconsistent treatment responses in patients. Thus, in this study, we characterized the functional differences in CYP2C9 wild-type (CYP2C9.1), CYP2C9.2, CYP2C9.3, and 12 rare novel variants identified in 4773 Japanese individuals. These CYP2C9 variants were heterologously expressed in 293FT cells, and the kinetic parameters (Km, kcat, Vmax, catalytic efficiency, and CLint) of (S)-warfarin 7-hydroxylation and tolbutamide 4-hydroxylation were estimated. From this analysis, almost all novel CYP2C9 variants showed significantly reduced or null enzymatic activity compared with that of the CYP2C9 wild-type. A strong correlation was found in catalytic efficiencies between (S)-warfarin 7-hydroxylation and tolbutamide 4-hydroxylation among all studied CYP2C9 variants. The causes of the observed perturbation in enzyme activity were evaluated by three-dimensional structural modeling. Our findings could clarify a part of discrepancies among genotype–phenotype associations based on the novel CYP2C9 rare allelic variants and could, therefore, improve personalized medicine, including the selection of the appropriate warfarin dose.

scholarly journals A Delphinidin-Enriched Maqui Berry Extract Improves Bone Metabolism and Protects against Bone Loss in Osteopenic Mouse Models

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 386 ◽  
Author(s):  
Masahiro Nagaoka ◽  
Toyonobu Maeda ◽  
Masahiro Chatani ◽  
Kazuaki Handa ◽  
Tomoyuki Yamakawa ◽  
...  
Keyword(s):  
Bone Loss ◽  
Bone Formation ◽  
Bone Metabolism ◽  
Mouse Models ◽  
Bone Morphogenetic Protein 2 ◽  
Bone Surface ◽  
Bone Formation Rate ◽  
Trabecular Thickness ◽  
Tissue Volume ◽  
Maqui Berry

In our previous investigation, delphinidin, one of the most abundant anthocyanins found in vegetables and berry fruits, had been shown to inhibit osteoclasts and prevent bone loss in mouse models of osteoporosis. In the present study, we investigated whether a delphinidin glycoside-enriched maqui berry extract (MBE, Delphinol®) exhibits beneficial effects on bone metabolism both in vitro and in vivo. MBE stimulated the osteoblastic differentiation of MC3T3-E1 cells, as indicated by enhanced mineralized nodule formation, and increased alkaline phosphatase activity, through the upregulation of bone morphogenetic protein 2 (Bmp2), runt-related transcription factor 2 (Runx2), Osterix (Osx), osteocalcin (Ocn), and matrix extracellular phosphoglycoprotein (Mepe) mRNA expression. Immunostaining and immunoprecipitation assays demonstrated that MBE suppressed NF-κB transnucleation through acting as a superoxide anion/peroxynitrite scavenger in MC3T3-E1 cells. Simultaneously, MBE inhibited both osteoclastogenesis in primary bone marrow macrophages and pit formation by maturated osteoclasts on dentine slices. Microcomputed tomography (micro-CT) and bone histomorphometry analyses of femurs demonstrated that the daily ingestion of MBE significantly increased BV/TV (ratio of bone volume to tissue volume), Tb.Th (trabecular thickness), Tb.N (trabecular number), N.Nd/N.Tm (node to terminus ratio), OV/TV (ratio of osteoid volume to tissue volume), BFR/TV (bone formation rate per tissue volume), and significantly decreased Tb.Sp (trabecular separation), ES/BS (ratio of eroded surface to bone surface) and N.Oc/BS (number of osteoclast per unit of bone surface), compared to vehicle controls in osteopenic mouse models. These findings suggest that MBE can be a promising natural agent for the prevention of bone loss in osteopenic conditions by not only inhibiting bone resorption, but also stimulating bone formation.

scholarly journals Klotho-deficient mice are resistant to bone loss induced by unloading due to sciatic neurectomy

2001 ◽  
Vol 168 (2) ◽  
pp. 347-351 ◽  
Author(s):  
T Yamashita ◽  
I Sekiya ◽  
N Kawaguchi ◽  
K Kashimada ◽  
A Nifuji ◽  
...  
Keyword(s):  
Bone Loss ◽  
Cortical Bone ◽  
Gene Product ◽  
Mutant Mice ◽  
Wild Type ◽  
Micro Computed Tomography ◽  
Klotho Gene ◽  
Sciatic Neurectomy ◽  
And Control ◽  
Deficient Mice

Unloading induces bone loss as seen in experimental animals as well as in space flight or in bed-ridden conditions; however, the mechanisms involved in this phenomenon are not fully understood. Klotho mutant mice exhibit osteopetrosis in the metaphyseal regions indicating that the klotho gene product is involved in the regulation of bone metabolism. To examine whether the klotho gene product is involved in the unloading-induced bone loss, the response of the osteopetrotic cancellous bones in these mice was investigated. Sciatic nerve resection was conducted using klotho mutant (kl/kl) and control heterozygous mice (+/kl) and its effect on bone was examined by micro-computed tomography (microCT). As reported previously for wild-type mice (+/+), about 30% bone loss was induced in heterozygous mice (+/kl) by unloading due to neurectomy within 30 days of the surgery. By contrast, kl/kl mice were resistant against bone loss induced by unloading after neurectomy. Unloading due to neurectomy also induced a small but significant bone loss in the cortical bone of the mid-shaft of the femur in the heterozygous mice; no reduction in the cortical bone was observed in kl/kl mice. These results indicate that klotho mutant mice are resistant against bone loss induced by unloading due to neurectomy in both cortical and trabecular bone and indicate that klotho is one of the molecules involved in the loss of bone by unloading.

scholarly journals Deletion of Gb3 Synthase in Mice Resulted in the Attenuation of Bone Formation via Decrease in Osteoblasts

2019 ◽  
Vol 20 (18) ◽  
pp. 4619 ◽  
Author(s):  
Kazunori Hamamura ◽  
Kosuke Hamajima ◽  
Shoyoku Yo ◽  
Yoshitaka Mishima ◽  
Koichi Furukawa ◽  
...  
Keyword(s):  
Bone Formation ◽  
Bone Mass ◽  
Bone Metabolism ◽  
Osteoclast Differentiation ◽  
Mrna Levels ◽  
Bone Surface ◽  
Micro Computed Tomography ◽  
Differentiation Markers ◽  
Double Labeling ◽  
Globo Series

Glycosphingolipids are known to play a role in developing and maintaining the integrity of various organs and tissues. Among glycosphingolipids, there are several reports on the involvement of gangliosides in bone metabolism. However, there have been no reports on the presence or absence of expression of globo-series glycosphingolipids in osteoblasts and osteoclasts, and the involvement of their glycosphingolipids in bone metabolism. In the present study, we investigated the presence or absence of globo-series glycosphingolipids such as Gb3 (globotriaosylceramide), Gb4 (globoside), and Gb5 (galactosyl globoside) in osteoblasts and osteoclasts, and the effects of genetic deletion of Gb3 synthase, which initiates the synthesis of globo-series glycosphingolipids on bone metabolism. Among Gb3, Gb4, and Gb5, only Gb4 was expressed in osteoblasts. However, these glycosphingolipids were not expressed in pre-osteoclasts and osteoclasts. Three-dimensional micro-computed tomography (3D-μCT) analysis revealed that femoral cancellous bone mass in Gb3 synthase-knockout (Gb3S KO) mice was lower than that in wild type (WT) mice. Calcein double labeling also revealed that bone formation in Gb3S KO mice was significantly lower than that in WT mice. Consistent with these results, the deficiency of Gb3 synthase in mice decreased the number of osteoblasts on the bone surface, and suppressed mRNA levels of osteogenic differentiation markers. On the other hand, osteoclast numbers on the bone surface and mRNA levels of osteoclast differentiation markers in Gb3S KO mice did not differ from WT mice. This study demonstrated that deletion of Gb3 synthase in mice decreases bone mass via attenuation of bone formation.

scholarly journals A Role for Site-Specific Phosphorylation of Mouse Progesterone Receptor at Serine 191 in Vivo

2014 ◽  
Vol 28 (12) ◽  
pp. 2025-2037 ◽  
Author(s):  
Sandra L. Grimm ◽  
Robert D. Ward ◽  
Alison E. Obr ◽  
Heather L. Franco ◽  
Rodrigo Fernandez-Valdivia ◽  
...  
Keyword(s):  
Mammary Epithelial Cells ◽  
Phosphorylation Site ◽  
Three Dimensional ◽  
Progesterone Receptors ◽  
Nuclear Factor Κb ◽  
Mammary Epithelial ◽  
Nuclear Factor ◽  
Wild Type ◽  
Receptor Activator

Progesterone receptors (PRs) are phosphorylated on multiple sites, and a variety of roles for phosphorylation have been suggested by cell-based studies. Previous studies using PR-null mice have shown that PR plays an important role in female fertility, regulation of uterine growth, the uterine decidualization response, and proliferation as well as ductal side-branching and alveologenesis in the mammary gland. To study the role of PR phosphorylation in vivo, a mouse was engineered with homozygous replacement of PR with a PR serine-to-alanine mutation at amino acid 191. No overt phenotypes were observed in the mammary glands or uteri of PR S191A treated with progesterone (P4). In contrast, although PR S191A mice were fertile, litters were 19% smaller than wild type and the estrous cycle was lengthened slightly. Moreover, P4-dependent gene regulation in primary mammary epithelial cells (MECs) was altered in a gene-selective manner. MECs derived from wild type and PR S191A mice were grown in a three-dimensional culture. Both formed acinar structures that were morphologically similar, and proliferation was stimulated equally by P4. However, P4 induction of receptor activator of nuclear factor-κB ligand and calcitonin was selectively reduced in S191A cultures. These differences were confirmed in freshly isolated MECs. Chromatin immunoprecipitation analysis showed that the binding of S191A PR to some of the receptor activator of nuclear factor-κB ligand enhancers and a calcitonin enhancer was substantially reduced. Thus, the elimination of a single phosphorylation site is sufficient to modulate PR activity in vivo. PR contains many phosphorylation sites, and the coordinate regulation of multiple sites is a potential mechanism for selective modulation of PR function.

scholarly journals Roles for B[a]P and FICZ in subchondral bone metabolism and experimental temporomandibular joint osteoarthritis via the AhR/Cyp1a1 signaling axis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuri Yoshikawa ◽  
Takashi Izawa ◽  
Yusaku Hamada ◽  
Hiroko Takenaga ◽  
Ziyi Wang ◽  
...  
Keyword(s):  
Bone Loss ◽  
Mouse Model ◽  
Bone Metabolism ◽  
Temporomandibular Joint ◽  
Subchondral Bone ◽  
Dependent Manner ◽  
Bone Homeostasis ◽  
Wild Type ◽  
Temporomandibular Joint Osteoarthritis ◽  
Signaling Axis

AbstractBone loss due to smoking represents a major risk factor for fractures and bone osteoporosis. Signaling through the aryl hydrocarbon receptor (AhR) and its ligands contributes to both bone homeostasis and inflammatory diseases. It remains unclear whether the same AhR signaling axis affects the temporomandibular joint (TMJ). The aim of this study was to investigate possible mechanisms which mediate bone loss in the TMJ due to smoking. In particular, whether benzo[a]pyrene (B[a]P), a carcinogen of tobacco smoke, induces expression of the AhR target gene, Cyp1a1, in mandibular condyles. Possible functions of an endogenous ligand of FICZ, were also investigated in a TMJ-osteoarthritis (OA) mouse model. B[a]P was administered orally to wild-type and AhR−/− mice and bone metabolism was subsequently examined. TMJ-OA was induced in wild-type mice with forceful opening of the mouth. Therapeutic functions of FICZ were detected with μCT and histology. Exposure to B[a]P accelerated bone loss in the mandibular subchondral bone. This bone loss manifested with osteoclastic bone resorption and upregulated expression of Cyp1a1 in an AhR-dependent manner. In a mouse model of TMJ-OA, FICZ exhibited a dose-dependent rescue of mandibular subchondral bone loss by repressing osteoclast activity. Meanwhile, in vitro, pre-treatment with FICZ reduced RANKL-mediated osteoclastogenesis. B[a]P regulates mandibular subchondral bone metabolism via the Cyp1a1. The AhR ligand, FICZ, can prevent TMJ-OA by regulating osteoclast differentiation.

Three-Dimensional Quantification of Alveolar Bone Loss inPorphyromonas gingivalis-Infected Mice Using Micro-Computed Tomography

2005 ◽  
Vol 76 (8) ◽  
pp. 1282-1286 ◽  
Author(s):  
Asaf Wilensky ◽  
Yankel Gabet ◽  
Hiromichi Yumoto ◽  
Yael Houri-Haddad ◽  
Lior Shapira
Keyword(s):  
Computed Tomography ◽  
Bone Loss ◽  
Alveolar Bone ◽  
Three Dimensional ◽  
Alveolar Bone Loss ◽  
Micro Computed Tomography

High-Resolution Three-Dimensional Micro-Computed Tomography Detects Bone Loss and Changes in Trabecular Architecture Early

2002 ◽  
Vol 37 (1) ◽  
pp. 40-46 ◽  
Author(s):  
ODILE BAROU ◽  
DAVID VALENTIN ◽  
LAURENCE VICO ◽  
CATHERINE TIRODE ◽  
ALAIN BARBIER ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Bone Loss ◽  
Three Dimensional ◽  
Trabecular Architecture ◽  
Micro Computed Tomography

scholarly journals The Fungal Metabolite (+)-Terrein Abrogates Ovariectomy-Induced Bone Loss and Receptor Activator of Nuclear Factor-κB Ligand–Induced Osteoclastogenesis by Suppressing Protein Kinase-C α/βII Phosphorylation

2021 ◽  
Vol 12 ◽  
Author(s):  
Kyosuke Sakaida ◽  
Kazuhiro Omori ◽  
Masaaki Nakayama ◽  
Hiroki Mandai ◽  
Saki Nakagawa ◽  
...  
Keyword(s):  
Bone Loss ◽  
Bone Mass ◽  
Bone Metabolism ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Common Disease ◽  
Mouse Bone Marrow ◽  
Nuclear Factor ◽  
Receptor Activator

Osteoporosis is a common disease characterized by a systemic impairment of bone mass and microarchitecture that results in fragility fractures. Severe bone loss due to osteoporosis triggers pathological fractures and consequently decreases the daily life activity and quality of life. Therefore, prevention of osteoporosis has become an important issue to be addressed. We have reported that the fungal secondary metabolite (+)-terrein (TER), a natural compound derived from Aspergillus terreus, has shown receptor activator of nuclear factor-κB ligand (RANKL)–induced osteoclast differentiation by suppressing nuclear factor of activated T-cell 1 (NFATc1) expression, a master regulator of osteoclastogenesis. TER has been shown to possess extensive biological and pharmacological benefits; however, its effects on bone metabolism remain unclear. In this study, we investigated the effects of TER on the femoral bone metabolism using a mouse-ovariectomized osteoporosis model (OVX mice) and then on RANKL signal transduction using mouse bone marrow macrophages (mBMMs). In vivo administration of TER significantly improved bone density, bone mass, and trabecular number in OVX mice (p < 0.01). In addition, TER suppressed TRAP and cathepsin-K expression in the tissue sections of OVX mice (p < 0.01). In an in vitro study, TER suppressed RANKL-induced phosphorylation of PKCα/βII, which is involved in the expression of NFATc1 (p < 0.05). The PKC inhibitor, GF109203X, also inhibited RANKL-induced osteoclastogenesis in mBMMs as well as TER. In addition, TER suppressed the expression of osteoclastogenesis-related genes, such as Ocstamp, Dcstamp, Calcr, Atp6v0d2, Oscar, and Itgb3 (p < 0.01). These results provide promising evidence for the potential therapeutic application of TER as a novel treatment compound against osteoporosis.

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