39 research outputs found

    Negative feedback loop of bone resorption by NFATc1-dependent induction of Cadm1.

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    Trimethylation of histone H3 lysine 4 and lysine 27 (H3K4me3 and H3K27me3) at gene promoter regions critically regulates gene expression. Key developmental genes tend to exhibit changes in histone modification patterns from the H3K4me3/H3K27me3 bivalent pattern to the H3K4me3 monovalent pattern. Using comprehensive chromatin immunoprecipitation followed by sequencing in bone marrow-derived macrophages (BMMs) and mature osteoclasts, we found that cell surface adhesion molecule 1 (Cadm1) is a direct target of nuclear factor of activated T cells 1 (NFATc1) and exhibits a bivalent histone pattern in BMMs and a monovalent pattern in osteoclasts. Cadm1 expression was upregulated in BMMs by receptor activator of nuclear factor kappa B ligand (RANKL), and blocked by a calcineurin/NFATc1 inhibitor, FK506. Cadm1-deficient mice exhibited significantly reduced bone mass compared with wild-type mice, which was due to the increased osteoclast differentiation, survival and bone-resorbing activity in Cadm1-deficient osteoclasts. These results suggest that Cadm1 is a direct target of NFATc1, which is induced by RANKL through epigenetic modification, and regulates osteoclastic bone resorption in a negative feedback manner

    Etiological factors in hallux valgus, a three-dimensional analysis of the first metatarsal

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    Abstract Background It has been reported that hallux valgus (HV) is associated with axial rotation of the first metatarsal (1MT). However, the association between HV and torsion of the 1MT head with respect to the base has not been previously investigated. The present study examined whether there was a significant difference in 1MT torsion between HV and control groups. Methods Three-dimensional (3D) computed tomography (CT) scans of 39 ft were obtained, and 3D surface models of the 1MT were generated to quantify the torsion of the head with respect to the base. The HV group consisted of 27 ft from 27 women (69.5 ± 7.5 years old). Only the feet of HV patients with an HV angle >20° on weight-bearing radiography were selected for analysis. The control group consisted of 12 ft from 12 women (67.7 ± 7.2 years old). In a virtual 3D space, two unit vectors, which describe the orientation of the 1MT head and base, were calculated. The angle formed by these two unit vectors representing 1MT torsion was compared between the control and hallux valgus groups. Results The mean (± standard deviation) of the torsional angle of the 1MT was 17.6 (± 7.7)° and 4.7 (± 4.0)° in the HV and control groups, respectively, and the difference was significant (p < 0.01). Conclusions This is the first study, to the best of our knowledge, to investigate 1MT torsion in HV patients using CT-based 3D analysis. The 1MT showed significant eversion in hallux valgus patients compared to control group patients

    A novel mouse model of soft-tissue infection using bioluminescence imaging allows noninvasive, real-time monitoring of bacterial growth.

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    Musculoskeletal infections, including surgical-site and implant-associated infections, often cause progressive inflammation and destroy areas of the soft tissue. Treating infections, especially those caused by multi-antibiotic resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) remains a challenge. Although there are a few animal models that enable the quantitative evaluation of infection in soft tissues, these models are not always reproducible or sustainable. Here, we successfully established a real-time, in vivo, quantitative mouse model of soft-tissue infection in the superficial gluteus muscle (SGM) using bioluminescence imaging. A bioluminescent strain of MRSA was inoculated into the SGM of BALB/c adult male mice, followed by sequential measurement of bacterial photon intensity and serological and histological analyses of the mice. The mean photon intensity in the mice peaked immediately after inoculation and remained stable until day 28. The serum levels of interleukin-6, interleukin-1 and C-reactive protein at 12 hours after inoculation were significantly higher than those prior to inoculation, and the C-reactive protein remained significantly elevated until day 21. Histological analyses showed marked neutrophil infiltration and abscesses containing necrotic and fibrous tissues in the SGM. With this SGM mouse model, we successfully visualized and quantified stable bacterial growth over an extended period of time with bioluminescence imaging, which allowed us to monitor the process of infection without euthanizing the experimental animals. This model is applicable to in vivo evaluations of the long-term efficacy of novel antibiotics or antibacterial implants

    Presynaptic selectivity of a ligand for serotonin 1A receptors revealed by in vivo PET assays of rat brain.

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    A novel investigational antidepressant with high affinity for the serotonin transporter and the serotonin 1A (5-HT(1A)) receptor, called Wf-516 (structural formula: (2S)-1-[4-(3,4-dichlorophenyl)piperidin-1-yl]-3-[2-(5-methyl-1,3,4-oxadiazol-2-yl)benzo[b]furan-4-yloxy]propan-2-ol monohydrochloride), has been found to exert a rapid therapeutic effect, although the mechanistic basis for this potential advantage remains undetermined. We comparatively investigated the pharmacokinetics and pharmacodynamics of Wf-516 and pindolol by positron emission tomographic (PET) and autoradiographic assays of rat brains in order to elucidate their molecular interactions with presynaptic and postsynaptic 5-HT(1A) receptors. In contrast to the full receptor occupancy by pindolol in PET measurements, the binding of Wf-516 to 5-HT(1A) receptors displayed limited capacity, with relatively high receptor occupancy being achieved in regions predominantly containing presynaptic receptors. This selectivity was further proven by PET scans of neurotoxicant-treated rats deficient in presynaptic 5-HT(1A) receptors. In addition, [(35)S]guanosine 5'-O-[γ-thio]triphosphate autoradiography indicated a partial agonistic ability of Wf-516 for 5-HT(1A) receptors. This finding has lent support to reports that diverse partial agonists for 5-HT(1A) receptors exert high sensitivity for presynaptic components. Thus, the present PET data suggest a relatively high capacity of presynaptic binding sites for partial agonists. Since our in vitro and ex vivo autoradiographies failed to illustrate these distinct features of Wf-516, in vivo PET imaging is considered to be, thus far, the sole method capable of pharmacokinetically demonstrating the unique actions of Wf-516 and similar new-generation antidepressants

    SIRT1 Regulates Thyroid-Stimulating Hormone Release by Enhancing PIP5Kγ[subscript gamma] Activity through Deacetylation of Specific Lysine Residues in Mammals

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    Background: SIRT1, a NAD-dependent deacetylase, has diverse roles in a variety of organs such as regulation of endocrine function and metabolism. However, it remains to be addressed how it regulates hormone release there. Methodology/Principal Findings: Here, we report that SIRT1 is abundantly expressed in pituitary thyrotropes and regulates thyroid hormone secretion. Manipulation of SIRT1 level revealed that SIRT1 positively regulated the exocytosis of TSH-containing granules. Using LC/MS-based interactomics, phosphatidylinositol-4-phosphate 5-kinase (PIP5K)γ[subscript gamma] was identified as a SIRT1 binding partner and deacetylation substrate. SIRT1 deacetylated two specific lysine residues (K265/K268) in PIP5Kγ[subscript gamma] and enhanced PIP5Kγ[subscript gamma] enzyme activity. SIRT1-mediated TSH secretion was abolished by PIP5Kγ[subscript gamma] knockdown. SIRT1 knockdown decreased the levels of deacetylated PIP5Kγ, PI(4,5)P[subscript 2], and reduced the secretion of TSH from pituitary cells. These results were also observed in SIRT1-knockout mice. Conclusions/Significance: Our findings indicated that the control of TSH release by the SIRT1-PIP5Kγ[subscript gamma] pathway is important for regulating the metabolism of the whole body.Mitsubishi Institute of Life SciencesJapan Society for the Promotion of Science. (WAKATE S grant

    Productivity and Water Source of Intercropped Wheat and Rice in a Direct-sown Sequential Cropping System: The Effects of No-tillage and Drought

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    In Japan, wheat-rice crop rotation with the practice of rice transplanting has been quite popular in the past. Mechanized direct-planted wheat-rice sequential cropping was developed at the Aichi Prefecture Agricultural Research Center by intercropping them for two months in spring. An objective of this study was to evaluate the introduction of continuous no-tillage to the cropping system with emphasis on water stress. The water source of intercropped wheat was also elucidated using deuterated heavy water to analyze water competition between crops. Continuous no-tillage of wheat-rice direct planting was performed for six seasons (three years) in an experimental small paddy field. No-tillage resulted in a doubled soil penetration resistance in the surface layer of soil, indicating the risk of suppressing root development. The higher yield of wheat in the dry plot suggested that excess-moisture stress occurs in the field. In the no-tillage plot, light transmission to intercropped rice seedlings increased significantly due to the reduced wheat biomass production. Wheat and rice yields were not statistically lowered by the no-tillage practice. This indicated that it is possible to introduce continuous no-tillage to the cropping system. The no-tillage significantly increased the deuterium concentrations in the xylem sap in wheat after the application of simulated rainfall with deuterated water. This indicated that the water uptake dependency of wheat shifted from stored soil water to recently applied water, which suggested the higher competition between the crops may occur under no-tillage conditions

    Relationships between dose or plasma concentration of test drugs and 5-HT<sub>1A</sub> receptor occupancies analyzed with [<sup>11</sup>C]WAY-100635-PET data.

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    <p>(A) Receptor occupancies in the hippocampus (closed circles) and raphe nucleus (open circles) plotted against oral dose of Wf-516. Regression curves were generated by the following equation: Occ  = Occ<sub>max</sub>×D/(D+ED<sub>50</sub>), where Occ, Occ<sub>max</sub>, D and ED<sub>50</sub> are 5-HT<sub>1A</sub> receptor occupancy, maximal occupancy, dose of Wf-516, and dose of Wf-516 required for 50% of maximal occupancy, respectively. Bars indicate S.E. (n = 4). (B) Receptor occupancies in the hippocampus (closed squares) and raphe nucleus (open squares) plotted against intraperitoneal dose of pindolol. Regression curves were generated by the following equation: Occ  = 100×D/(D+ED<sub>50</sub>). Bars indicate S.E. (n = 3). (C) Receptor occupancies in the hippocampus (closed squares) and raphe nucleus (open squares) plotted against plasma concentration of pindolol. Regression curves were generated by the following equation: Occ  = 100×C/(C+EC<sub>50</sub>), where C is plasma concentration of pindolol. Dashed and solid lines represent regressions in the hippocampus and raphe nucleus, respectively.</p

    The systemic overexpression of TACE causes no overt defects.

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    <p>(A) A schematic of the transgene construct. pA, polyadenylation signal sequence. (B) Gross morphology of the 8-week-old control (Ctrl) and <i>Tace</i>-Tg (Tg) mice. (C) Quantitative RT-PCR analysis of <i>Tace</i> expression in the liver, lung, skin, spleen, bone marrow cells (BM), and thymus from 8-week-old control (Ctrl) and <i>Tace</i>-Tg (Tg) mice. The expression level of <i>Tace</i> in each organ of the control mice is set to 1. Bars, S.D. *p<0.05. **p<0.005. (D) Western blot analysis using anti-HA, anti-TACE, and anti-β-Actin antibodies. (E) Hematoxylin and eosin-stained sections of the spleen, liver, and tibia from 8-week-old control, <i>Tace</i>-Tg, and <i>Tace</i>-tg/<i>Tace<sup>−/−</sup></i> (Tg/<i>Tace<sup>−/−</sup></i>) mice.</p
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