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121.
Pleiotropic roles of polyglycerolphosphate synthase of lipoteichoic acid in growth of Staphylococcus aureus cells 总被引:1,自引:0,他引:1
Lipoteichoic acid (LTA) is one of two anionic polymers on the surface of the gram-positive bacterium Staphylococcus aureus. LTA is critical for the bacterium-host cell interaction and has recently been shown to be required for cell growth and division. To determine additional biological roles of LTA, we found it necessary to identify permissive conditions for the growth of an LTA-deficient mutant. We found that an LTA-deficient S. aureus ΔltaS mutant could grow at 30°C but not at 37°C. Even at the permissive temperature, ΔltaS mutant cells had aberrant cell division and separation, decreased autolysis, and reduced levels of peptidoglycan hydrolases. Upshift of ΔltaS mutant cells to a nonpermissive temperature caused an inability to exclude Sytox green dye. A high-osmolarity growth medium remarkably rescued the colony-forming ability of the ΔltaS mutant at 37°C, indicating that LTA synthesis is required for growth under low-osmolarity conditions. In addition, the ΔltaS mutation was found to be synthetically lethal with the ΔtagO mutation, which disrupts the synthesis of the other anionic polymer, wall teichoic acid (WTA), at 30°C, suggesting that LTA and WTA compensate for one another in an essential function. 相似文献
122.
Koichiro Yamada Tomonori Tsukahara Kazuhisa Yoshino Katsuhiko Kojima Hideyuki Agawa Yuki Yamashita Yuji Amano Mariko Hatta Yasunori Matsuzaki Naoki Kurotori Keiko Wakui Yoshimitsu Fukushima Ryosuke Osada Tanri Shiozawa Kazuo Sakashita Kenichi Koike Satoru Kumaki Nobuyuki Tanaka Toshikazu Takeshita 《Retrovirology》2009,6(1):1-9
123.
Kazuhisa Nozawa Maki Fujishiro Mikiko Kawasaki Hiroshi Kaneko Kazuhisa Iwabuchi Mitsuaki Yanagida Fujihiko Suzuki Keiji Miyazawa Yoshinari Takasaki Hideoki Ogawa Kenji Takamori Iwao Sekigawa 《Arthritis research & therapy》2009,11(6):R174
Introduction
A protein analysis using a mass spectrometry indicated that there are serum proteins showing significant quantitative changes after the administration of infliximab. Among them, connective tissue growth factor (CTGF) seems to be related to the pathogenesis of rheumatoid arthritis (RA). Therefore, this study was conducted to investigate how CTGF is associated with the disease progression of RA.Methods
Serum samples were collected from RA patients in active or inactive disease stages, and before or after treatments with infliximab. CTGF production was evaluated by ELISA, RT-PCR, indirect immunofluorescence microscopy, and immunoblotting. Osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase (TRAP) staining, a bone resorption assay and osteoclasts specific catalytic enzymes productions.Results
The serum concentrations of CTGF in RA were greater than in normal healthy controls and disease controls. Interestingly, those were significantly higher in active RA patients compared to inactive RA patients. Furthermore, the CTGF levels significantly were decreased by infliximab concomitant with the disease amelioration. In addition, tumour necrosis factor (TNF)α can induce the CTGF production from synovial fibroblasts even though TNFα can oppositely inhibit the production of CTGF from chondrocytes. CTGF promoted the induction of the quantitative and qualitative activities of osteoclasts in combination with M-CSF and receptor activator of NF-κB ligand (RANKL). In addition, we newly found integrin αVβ3 on the osteoclasts as a CTGF receptor.Conclusions
These results indicate that aberrant CTGF production induced by TNFα plays a central role for the abnormal osteoclastic activation in RA patients. Restoration of aberrant CTGF production may contribute to the inhibition of articular destruction in infliximab treatment. 相似文献124.
An ice-ridge line more than 2,000 m long was discovered in a closed, deep lake—Lake Kuttara, Hokkaido, Japan—in the ice-covered
season of 1995. To clarify when and how the ice-ridge line built up, meteorology and ice and water temperatures were monitored,
and the density, thermal conductivity, and thickness of the covered ice were measured from January through March 1995. The
covered ice on 4 and 5 March 1995, which corresponded to the period with the thickest lake ice, consisted of snow ice 0.05-
to 0.07-m thick and candle ice 0.18- to 0.21-m thick. Numerical simulations for the ice thickness and temperature were carried
out using a one-dimensional, unsteady, three-layer model. The simulated results, which were reasonable to the observations,
indicate that due to the ice contraction and expansion, the ice-ridge line started to construct on 2 February and was completed
the next day. 相似文献
125.
126.
Homma D Sumi-Ichinose C Tokuoka H Ikemoto K Nomura T Kondo K Katoh S Ichinose H 《The Journal of biological chemistry》2011,286(2):1445-1452
Postnatal development of dopaminergic system is closely related to the development of psychomotor function. Tyrosine hydroxylase (TH) is the rate-limiting enzyme in the biosynthesis of dopamine and requires tetrahydrobiopterin (BH4) as a cofactor. To clarify the effect of partial BH4 deficiency on postnatal development of the dopaminergic system, we examined two lines of mutant mice lacking a BH4-biosynthesizing enzyme, including sepiapterin reductase knock-out (Spr(-/-)) mice and genetically rescued 6-pyruvoyltetrahydropterin synthase knock-out (DPS-Pts(-/-)) mice. We found that biopterin contents in the brains of these knock-out mice were moderately decreased from postnatal day 0 (P0) and remained constant up to P21. In contrast, the effects of BH4 deficiency on dopamine and TH protein levels were more manifested during the postnatal development. Both of dopamine and TH protein levels were greatly increased from P0 to P21 in wild-type mice but not in those mutant mice. Serotonin levels in those mutant mice were also severely suppressed after P7. Moreover, striatal TH immunoreactivity in Spr(-/-) mice showed a drop in the late developmental stage, when those mice exhibited hind-limb clasping behavior, a type of motor dysfunction. Our results demonstrate a critical role of biopterin in the augmentation of TH protein in the postnatal period. The developmental manifestation of psychomotor symptoms in BH4 deficiency might be attributable at least partially to high dependence of dopaminergic development on BH4 availability. 相似文献
127.
Takatsu H Baba K Shima T Umino H Kato U Umeda M Nakayama K Shin HW 《The Journal of biological chemistry》2011,286(44):38159-38167
Type IV P-type ATPases (P4-ATPases) are putative phospholipid flippases that translocate phospholipids from the exoplasmic (lumenal) to the cytoplasmic leaflet of lipid bilayers and are believed to function in complex with CDC50 proteins. In Saccharomyces cerevisiae, five P4-ATPases are localized to specific cellular compartments and are required for vesicle-mediated protein transport from these compartments, suggesting a role for phospholipid translocation in vesicular transport. The human genome encodes 14 P4-ATPases and three CDC50 proteins. However, the subcellular localization of human P4-ATPases and their interactions with CDC50 proteins are poorly understood. Here, we show that class 5 (ATP10A, ATP10B, and ATP10D) and class 6 (ATP11A, ATP11B, and ATP11C) P4-ATPases require CDC50 proteins, primarily CDC50A, for their exit from the endoplasmic reticulum (ER) and final subcellular localization. In contrast, class 2 P4-ATPases (ATP9A and ATP9B) are able to exit the ER in the absence of exogenous CDC50 expression: ATP9B, but not ATP11B, was able to exit the ER despite depletion of CDC50 proteins by RNAi. Although ATP9A and ATP9B show a high overall sequence similarity, ATP9A localizes to endosomes and the trans-Golgi network (TGN), whereas ATP9B localizes exclusively to the TGN. A chimeric ATP9 protein in which the N-terminal cytoplasmic region of ATP9A was replaced with the corresponding region of ATP9B was localized exclusively to the Golgi. These results indicate that ATP9B is able to exit the ER and localize to the TGN independently of CDC50 proteins and that this protein contains a Golgi localization signal in its N-terminal cytoplasmic region. 相似文献
128.
Adipocyte/macrophage fatty acid binding proteins control integrated metabolic responses in obesity and diabetes 总被引:8,自引:0,他引:8
Maeda K Cao H Kono K Gorgun CZ Furuhashi M Uysal KT Cao Q Atsumi G Malone H Krishnan B Minokoshi Y Kahn BB Parker RA Hotamisligil GS 《Cell metabolism》2005,1(2):107-119
Fatty acid binding proteins (FABPs) are cytosolic fatty acid chaperones whose biological role and mechanisms of action are not well understood. Here, we developed mice with targeted mutations in two related adipocyte FABPs, aP2 and mal1, to resolve their role in systemic lipid, glucose, and energy metabolism. Mice lacking aP2 and mal1 exhibited a striking phenotype with strong protection from diet-induced obesity, insulin resistance, type 2 diabetes, and fatty liver disease. These mice have altered cellular and systemic lipid transport and composition, leading to enhanced insulin receptor signaling, enhanced muscle AMP-activated kinase (AMP-K) activity, and dramatically reduced liver stearoyl-CoA desaturase-1 (SCD-1) activity underlying their phenotype. Taken together with the previously reported strong protection against atherosclerosis, these results demonstrate that adipocyte/macrophage FABPs have a robust impact on multiple components of metabolic syndrome, integrating metabolic and inflammatory responses in mice and constituting a powerful target for the treatment of these diseases. 相似文献
129.
Akemi Shimada Satoshi Wada Kouji Inoue Hisashi Ideno Taichi Kamiunten Koichiro Komatsu Akira Kudo Yoshiki Nakamura Tetsuji Sato Kazuhisa Nakashima Akira Nifuji 《Histochemistry and cell biology》2014,142(2):205-215
Development of regenerative therapies for damaged tendons remains a great challenge, largely because of lack of information regarding the mechanisms responsible for differentiation of tenocytes. Mouse tenocytes have not been fully characterized owing to the absence of efficient and reproducible methods for their in vitro expansion without losing phenotypic features. The objective of the study was to establish an improved and reliable method for stable primary culture of mouse tenocytes by using collagen gel. Achilles and tail tendon tissues were harvested and embedded in collagen gel. After 10 days of continuous culture, the gel was digested and cells were passaged on tissue culture-treated plastic dishes. Mouse tenocytes cultured in collagen gel exhibited significantly shorter doubling time and higher numbers of proliferation when maintained on the plastic dishes compared with those cultured without using gel. Transmission electron microscopic analyses showed that cultured tenocytes retained some morphological features of tenocytes in tendon tissues, such as cell–cell junctional complex formation, well-developed rough endoplasmic reticulum, and mitochondria in their cytoplasm. mRNA expression of tenocyte markers (tenomodulin, type I collagen, periostin, and scleraxis) was higher in cells cultured in collagen gel than in those cultured in the absence of gel. Our results show that tenocytes cultured using the collagen gel method express typical lineage markers and exhibit improved growth characteristics, thus providing a stable platform for studying molecular mechanisms that control their differentiation. 相似文献
130.
Katsutoshi Ando Fumiyuki Takahashi Motoyasu Kato Norihiro Kaneko Tokuhide Doi Yuichiro Ohe Fumiaki Koizumi Kazuto Nishio Kazuhisa Takahashi 《PloS one》2014,9(7)