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111.
Flesh‐eating Streptococcus pyogenes triggers the expression of receptor activator of nuclear factor‐κB ligand 下载免费PDF全文
Hidenori Matsui Yuriko Nakatani Haruno Yoshida Asako Takizawa Osamu Takeuchi Anders Øverby Takashi Takahashi Somay Y. Murayama Koichi Matsuo 《Cellular microbiology》2016,18(10):1390-1404
Human CD46 is a receptor for the M protein of group A streptococcus (GAS). The emm1 GAS strain GAS472 was isolated from a patient suffering from streptococcal toxic shock‐like syndrome. Human CD46‐expressing transgenic (Tg) mice developed necrotizing fasciitis associated with osteoclast‐mediated progressive and severe bone destruction in the hind paws 3 days after subcutaneous infection with 5 × 105 colony‐forming units of GAS472. GAS472 infection induced expression of the receptor activator of nuclear factor‐κB ligand (RANKL) while concomitantly reducing osteoprotegerin expression in the hind limb bones of CD46 Tg mice. Micro‐computed tomography analysis of the bones suggested that GAS472 infection induced local bone erosion and systemic bone loss in CD46 Tg mice. Because treatment with monoclonal antibodies (mAbs) against mouse CD4+ and CD8+ T lymphocytes did not inhibit osteoclastogenesis, T lymphocyte‐derived RANKL was not considered a major contributor to massive bone loss during GAS472 infection. However, immunohistochemical analysis of the hind limb bones showed that GAS472 infection stimulated RANKL production in various bone marrow cells, including fibroblast‐like cells. Treatment with a mAb against mouse RANKL significantly inhibited osteoclast formation and bone resorption. These data suggest that increased expression of RANKL in heterogeneous bone marrow cells provoked bone destruction during GAS infection. 相似文献
112.
Emerging solar cells, namely, organic solar cells and perovskite solar cells, are the thin‐film photovoltaics that have light to electricity conversion efficiencies close to that of silicon solar cells while possessing advantages in having additional functionalities, facile‐processability, and low fabrication cost. To maximize these advantages, the electrode components must be replaced by materials that are more flexible and cost‐effective. Researchers around the globe have been looking for the new electrodes that meet these requirements. Among many candidates, single‐walled carbon nanotubes have demonstrated their feasibility as the new alternative to conventional electrodes, such as indium tin oxide and metals. This review discusses various growth methods of single‐walled carbon nanotubes and their electrode applications in thin‐film photovoltaics. 相似文献
113.
Small-angle X-ray scattering experiments were carried out to investigate the structural changes of cardiac thin filaments induced by the cardiomyopathy-causing E244D mutation in troponin T (TnT). We examined native thin filaments (NTF) from a bovine heart, reconstituted thin filaments containing human cardiac wild-type Tn (WTF), and filaments containing the E244D mutant of Tn (DTF), in the absence and presence of Ca2+. Analysis by model calculation showed that upon Ca2+-activation, tropomyosin (Tm) and Tn in the WTF and NTF moved together in a direction to expose myosin-binding sites on actin. On the other hand, Tm and Tn of the DTF moved in the opposite directions to each other upon Ca2+-activation. These movements caused Tm to expose more myosin-binding sites on actin than the WTF, suggesting that the affinity of myosin for actin is higher for the DTF. Thus, the mutation-induced structural changes in thin filaments would increase the number of myosin molecules bound to actin compared with the WTF, resulting in the force enhancement observed for the E244D mutation. 相似文献
114.
Yu Kitadate David J. Jörg Moe Tokue Ayumi Maruyama Rie Ichikawa Soken Tsuchiya Eri Segi-Nishida Toshinori Nakagawa Aya Uchida Chiharu Kimura-Yoshida Seiya Mizuno Fumihiro Sugiyama Takuya Azami Masatsugu Ema Chiyo Noda Satoru Kobayashi Isao Matsuo Yoshiakira Kanai Shosei Yoshida 《Cell Stem Cell》2019,24(1):79-92.e6
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Yukinori Yamada Tomoharu Yokooji Naoki Ninomiya Takanori Taogoshi Eishin Morita Hiroaki Matsuo 《Biochemistry and Biophysics Reports》2019
We previously developed Hokushin wheat line as a hypoallergenic wheat lacking ω5-gliadin (1BS-18), a major allergen for wheat-dependent exercise-induced anaphylaxis. However, the allergenicity of 1BS-18 has not been understood completely. In this study, we evaluated the allergenicity of 1BS-18 such as anaphylactic elicitation ability and sensitization ability using rats sensitized with ω5-gliadin or glutens prepared from Hokushin (Hokushin gluten) or 1BS-18 (1BS-18 gluten). Rats were sensitized by intraperitoneal administration of ω5-gliadin, Hokushin gluten or 1BS-18 gluten. Immunoglobulin E-mediated systemic anaphylaxis was evaluated by measuring changes in rectal temperature for 30 min after intravenous challenge with ω5-gliadin or the test glutens in unsensitized rats or rats sensitized with ω5-gliadin or the test glutens. In ω5-gliadin-sensitized rats, intravenous challenge with ω5-gliadin or Hokushin gluten significantly decreased the rectal temperature at 30 min after challenge while challenge with 1BS-18 gluten did not reduce the rectal temperature. Furthermore, intravenous challenge with ω5-gliadin significantly decreased the rectal temperature in rats sensitized with Hokushin gluten or 1BS-18 gluten. However, the reduced degree observed in 1BS-18 gluten-sensitized rats was smaller than that in Hokushin gluten-sensitized rats. In conclusion, 1BS-18 elicited no allergic reaction in ω5-gliadin-sensitized rats and had less sensitization ability for ω5-gliadin than that of Hokushin wheat. 相似文献
117.
Freeze-dried platelets promote hepatocyte proliferation in mice 总被引:1,自引:0,他引:1
Hoshi R Murata S Matsuo R Myronovych A Hashimoto I Ikeda H Ohkohchi N 《Cryobiology》2007,55(3):255-260
In recent years, platelets are reported to promote liver, as well as bone regeneration and dermal wound healing. Platelets are required not only for thrombocytopenia treating but also for regenerative therapy. Platelets cannot be stored beyond three days, therefore, shortage of fresh platelets sometimes occurs. To preserve platelets for a long duration without degrading growth factors, a freeze-dried technique is required. We report here that platelets can be preserved by freeze-drying, using a programmed freezing method to avoid intracellular ice crystal formation. Freeze-dried platelets kept their morphological countenance and response with the agonist of thrombin was well maintained. Freeze-dried platelets stored adenine nucleotides, PDGF, and IGF-1 the same as those of fresh platelets. Freeze dried platelets also preserved their proliferative effect on hepatocytes identical to that of fresh platelets. These results of our study suggest that freeze dried platelets will obviate the storage problem of fresh platelets. 相似文献
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Murayama K Shirouzu M Kawasaki Y Kato-Murayama M Hanawa-Suetsugu K Sakamoto A Katsura Y Suenaga A Toyama M Terada T Taiji M Akiyama T Yokoyama S 《The Journal of biological chemistry》2007,282(7):4238-4242
The Rac-specific guanine nucleotide exchange factor (GEF) Asef is activated by binding to the tumor suppressor adenomatous polyposis coli mutant, which is found in sporadic and familial colorectal tumors. This activated Asef is involved in the migration of colorectal tumor cells. The GEFs for Rho family GTPases contain the Dbl homology (DH) domain and the pleckstrin homology (PH) domain. When Asef is in the resting state, the GEF activity of the DH-PH module is intramolecularly inhibited by an unidentified mechanism. Asef has a Src homology 3 (SH3) domain in addition to the DH-PH module. In the present study, the three-dimensional structure of Asef was solved in its autoinhibited state. The crystal structure revealed that the SH3 domain binds intramolecularly to the DH domain, thus blocking the Rac-binding site. Furthermore, the RT-loop and the C-terminal region of the SH3 domain interact with the DH domain in a manner completely different from those for the canonical binding to a polyproline-peptide motif. These results demonstrate that the blocking of the Rac-binding site by the SH3 domain is essential for Asef autoinhibition. This may be a common mechanism in other proteins that possess an SH3 domain adjacent to a DH-PH module. 相似文献
120.
Okura T Nakata Y Ohkawara K Numao S Katayama Y Matsuo T Tanaka K 《Obesity (Silver Spring, Md.)》2007,15(10):2478-2484
Objective: The objective was to test effects of aerobic exercise training on metabolic syndrome (MetSyn) improvement in response to weight reduction. Research Methods and Procedures: A total of 459 overweight and obese women (age, 49 ± 9 years; BMI, 28 ± 3 kg/m2) were recruited for a baseline examination to test the relationship between cardiorespiratory fitness and metabolic syndrome prevalence; among these, 67 subjects with MetSyn were treated with 14‐week weight‐loss programs, which included low‐calorie diet and aerobic exercise. The MetSyn was defined according to the Examination Committee of Criteria for “Metabolic Syndrome” in Japan. Maximal oxygen uptake (V?o 2max) during a maximal cycling test was measured as an index of cardiorespiratory fitness at baseline and after the intervention. Results: In the baseline examination, age‐ and BMI‐adjusted odds ratios for MetSyn prevalence in the low, middle, and upper thirds of V?o 2max were 1.0 (referent), 0.50 (95% confidence interval, 0.26 to 0.95), and 0.39 (95% confidence interval, 0.14 to 0.96), respectively (linear trend, p = 0.02). The adjusted odds ratios for MetSyn improvement in the two interventions with diet alone and diet plus exercise were 1.0 and 3.68 (95% confidence interval, 1.02 to 17.6; p = 0.04), respectively. Discussion: These results suggest that adding aerobic exercise training to a dietary weight‐reduction program further improves MetSyn (adjusted odds ratio, 3.68) in obese women, compared with diet alone. Further studies on an association between V?o 2max change and MetSyn improvement are needed. 相似文献