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101.
Hanada S Harada M Abe M Akiba J Sakata M Kwan R Taniguchi E Kawaguchi T Koga H Nagata E Ueno T Sata M 《The journal of histochemistry and cytochemistry》2012,60(6):475-483
Mallory-Denk bodies (MDBs) are hepatocyte cytoplasmic inclusions found in several liver diseases and consist primarily of the cytoskeletal proteins, keratins 8 and 18 (K8/K18). Recent evidence indicates that the extent of stress-induced protein misfolding, a K8>K18 overexpression state, and transglutaminase-2 activation promote MDB formation. In addition, the genetic background and gender play an important role in mouse MDB formation, but the effect of aging on this process is unknown. Given that oxidative stress increases with aging, the authors hypothesized that aging predisposes to MDB formation. They used an established mouse MDB model-namely, feeding non-transgenic male FVB/N mice (1, 3, and 8 months old) with 3,5 diethoxycarbonyl-1,4-dihydrocollidine for 2 months. MDB formation was assessed using immunofluorescence staining and biochemically by demonstrating keratin and ubiquitin-containing crosslinks generated by transglutaminase-2. Immunofluorescence staining showed that old mice had a significant increase in MDB formation compared with young mice. MDB formation paralleled the generation of high molecular weight ubiquitinated keratin-containing complexes and induction of p62. Old mouse livers had increased oxidative stress. In addition, 20S proteasome activity and autophagy were decreased, and endoplasmic reticulum stress was increased in older livers. Therefore, aging predisposes to experimental MDB formation, possibly by decreased activity of protein degradation machinery. 相似文献
102.
Sakaguchi K Matsuda T Kobayashi T Ohara J Hamaguchi R Abe E Nagano N Hayashi M Ueda M Honda D Okita Y Taoka Y Sugimoto S Okino N Ito M 《Applied and environmental microbiology》2012,78(9):3193-3202
A versatile transformation system for thraustochytrids, a promising producer for polyunsaturated fatty acids and fatty acid-derived fuels, was established. G418, hygromycin B, blasticidin, and zeocin inhibited the growth of thraustochytrids, indicating that multiple selectable marker genes could be used in the transformation system. A neomycin resistance gene (neo(r)), driven with an ubiquitin or an EF-1α promoter-terminator from Thraustochytrium aureum ATCC 34304, was introduced into representatives of two thraustochytrid genera, Aurantiochytrium and Thraustochytrium. The neo(r) marker was integrated into the chromosomal DNA by random recombination and then functionally translated into neo(r) mRNA. Additionally, we confirmed that another two genera, Parietichytrium and Schizochytrium, could be transformed by the same method. By this method, the enhanced green fluorescent protein was functionally expressed in thraustochytrids. Meanwhile, T. aureum ATCC 34304 could be transformed by two 18S ribosomal DNA-targeting vectors, designed to cause single- or double-crossover homologous recombination. Finally, the fatty acid Δ5 desaturase gene was disrupted by double-crossover homologous recombination in T. aureum ATCC 34304, resulting in an increase of dihomo-γ-linolenic acid (C(20:3n-6)) and eicosatetraenoic acid (C(20:4n-3)), substrates for Δ5 desaturase, and a decrease of arachidonic acid (C(20:4n-6)) and eicosapentaenoic acid (C(20:5n-3)), products for the enzyme. These results clearly indicate that a versatile transformation system which could be applicable to both multiple transgene expression and gene targeting was established for thraustochytrids. 相似文献
103.
Ishii S Kishi M Yamagami K Okada S Abe K Misaka T 《Bioscience, biotechnology, and biochemistry》2012,76(3):523-529
Acetic acid induces unique physiological responses in mammalian cells. Our previous study found that fura-2-loaded human embryonic kidney (HEK) 293T cells showed a robust intracellular fluorescence response immediately after stimulation with acetic acid, and no such response in the case of citric acid. In the present study, we aimed to identify the unique characteristics of acetic acid responsible for this phenomenon. We found that one such feature is its hydrophobicity. We also discovered that acetic acid induces cell responses by intracellular acidification. Of the components of acetic acid in solution (protons, acetate ions, and undissociated acetic acid), undissociated acetic acid might be the functional unit that penetrates the lipid bilayer of cell membranes to acidify the intracellular environment, thereby inducing cell responses. The method used in this study might be convenient in evaluating the intracellular acidification of cultured cells by acids in the external environment. 相似文献
104.
Hara K Inada Y Ono T Kuroda K Yasuda-Kamatani Y Ishiguro M Tanaka T Misaka T Abe K Ueda M 《Bioscience, biotechnology, and biochemistry》2012,76(3):512-516
Despite many recent studies of G-protein-coupled receptor (GPCR) structures, it is not yet well understood how these receptors activate G proteins. The GPCR assay using baker's yeast, Saccharomyces cerevisiae, is an effective experimental model for the characterization of GPCR-Gα interactions. Here, using the yeast endogenous Gα protein (Gpa1p) as template, we constructed various chimeric Gα proteins with a region that is considered to be necessary for interaction with mammalian receptors. The signaling assay using the yeast pheromone receptor revealed that the chimeric Gα protein harboring 37 gustducin-specific amino acid residues at its C-terminus (GPA1/gust37) maintained functionality in yeast. In contrast, GPA1/gust44, a variant routinely used in mammalian experimental systems, was not functional. 相似文献
105.
K Sasaki M Hayashi T Narita M Motoyama M Oe K Ojima I Nakajima S Muroya K Chikuni K Aikawa Y Ide N Nakanishi N Suzuki S Shioya A Takenaka 《Bioscience, biotechnology, and biochemistry》2012,76(8):1596-1599
This study examined the accumulation and tissue distribution of radioactive cesium nuclides in Japanese Black beef heifers raised on roughage contaminated with radioactive fallout due to the accident at the Fukushima Daiichi Nuclear Power Station on March 2011. Radiocesium feeding increased both (134)Cs and (137)Cs levels in all tissues tested. The kidney had the highest level and subcutaneous adipose had the lowest of radioactive cesium in the tissues. Different radioactive cesium levels were not found among parts of the muscles. These results indicate that radiocesium accumulated highly in the kidney and homogenously in the skeletal muscles in the heifers. 相似文献
106.
Y Inoue H Itoh M Aoki S Ogawa T Yamane T Baba N Tachibana M Kohno Y Oishi K Kobayashi-Hattori 《Bioscience, biotechnology, and biochemistry》2012,76(8):1549-1551
Two weeks of feeding soy peptides containing 2% collagen peptides increased the levels of type I and III tropocollagen and their mRNAs. In contrast, the diet did not increase the mRNA levels of rat hyaluronan synthases, serine palmitoyltransferase (the rate-limiting enzyme of ceramide synthesis), and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (the key enzyme of cholesterol synthesis). These results suggest that feeding of soy peptides with collagen peptides specifically enhanced the tropocollagen level in the skin. 相似文献
107.
Watanabe T Kurata I Umezawa Y Takahashi Y Akamatsu Y 《Bioorganic & medicinal chemistry letters》2012,22(1):231-234
Five human 2,3-oxidosqualnene cyclase (OSC) inhibitors were discovered using the combination of a virtual screening based on a docking study and an isotope-free assay system. All of these inhibitors were revealed to have activities comparable or superior to that of LDAO, a known OSC inhibitor. The computational study of the newly identified inhibitors suggested that CH/π interactions with F444 and W581 contribute to the binding, and these interactions are candidates for additional structural filters in the next generation of virtual screening. 相似文献
108.
109.
In response to contamination from the recent Fukushima nuclear accident, we conducted radionuclide analysis on bamboos sampled from six sites within a 25 to 980 km radius of the Fukushima Daiichi nuclear power plant. Maximum activity concentrations of radiocesium (134)Cs and (137)Cs in samples from Fukushima city, 65 km away from the Fukushima Daiichi plant, were in excess of 71 and 79 kBq/kg, dry weight (DW), respectively. In Kashiwa city, 195 km away from the Fukushima Daiichi, the sample concentrations were in excess of 3.4 and 4.3 kBq/kg DW, respectively. In Toyohashi city, 440 km away from the Fukushima Daiichi, the concentrations were below the measurable limits of up to 4.5 Bq/kg DW. In the radiocesium contaminated samples, the radiocesium activity was higher in mature and fallen leaves than in young leaves, branches and culms. 相似文献
110.
Iwai S Kikuchi T Kasahara N Teratani T Yokoo T Sakonju I Okano S Kobayashi E 《PloS one》2012,7(3):e33157