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951.
Takashi Koyama Mayumi Makita Nobuyuki Shibata Yoshio Okawa 《Carbohydrate research》2009,344(16):2195-2200
In this study, we investigated the structural changes in the cell wall mannan of Candida albicans serotype A strain cells cultured under various stress conditions, that is, oxidative stress of 3.5 mM H2O2, osmotic stress of 1.5 M NaCl, and heat stress at 37 °C, compared with the normal condition of 30 °C in yeast extract-added Sabouraud liquid medium (YSLM). Based on the 1H nuclear magnetic resonance (NMR) and fluorophore-assisted carbohydrate electrophoresis (FACE) analyses of the mannans, we showed that the proportion of the terminal β-1,2-linked mannose side chain unit in the mannan increased in the cell proliferation process under both the normal condition and the oxidative stress condition. The osmotic stress induced a slight decrease in the proportion of the β-1,2-linked mannose unit in the acid-labile fraction. The heat stress induced a significant decrease in the proportions of the β-1,2-linked mannose unit in both the acid-labile and acid-stable fractions. Based on these results, we propose that C. albicans significantly changes the mannan structures under various stress conditions and that sufficient attention to the cultural conditions is needed to perform an accurate diagnosis of candidiasis. 相似文献
952.
Norio Ishii Takeshi Matsumura Hiroyuki Kinoshita Hiroyuki Motoshima Kanou Kojima Atsuyuki Tsutsumi Shuji Kawasaki Miyuki Yano Takafumi Senokuchi Tomoichiro Asano Takeshi Nishikawa Eiichi Araki 《The Journal of biological chemistry》2009,284(50):34561-34569
Macrophage-derived foam cells play important roles in the progression of atherosclerosis. We reported previously that ERK1/2-dependent granulocyte/macrophage colony-stimulating factor (GM-CSF) expression, leading to p38 MAPK/ Akt signaling, is important for oxidized low density lipoprotein (Ox-LDL)-induced macrophage proliferation. Here, we investigated whether activation of AMP-activated protein kinase (AMPK) could suppress macrophage proliferation. Ox-LDL-induced proliferation of mouse peritoneal macrophages was assessed by [3H]thymidine incorporation and cell counting assays. The proliferation was significantly inhibited by the AMPK activator 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) and restored by dominant-negative AMPKα1, suggesting that AMPK activation suppressed macrophage proliferation. AICAR partially suppressed Ox-LDL-induced ERK1/2 phosphorylation and GM-CSF expression, suggesting that another mechanism is also involved in the AICAR-mediated suppression of macrophage proliferation. AICAR suppressed GM-CSF-induced macrophage proliferation without suppressing p38 MAPK/Akt signaling. GM-CSF suppressed p53 phosphorylation and expression and induced Rb phosphorylation. Overexpression of p53 or p27kip suppressed GM-CSF-induced macrophage proliferation. AICAR induced cell cycle arrest, increased p53 phosphorylation and expression, and suppressed GM-CSF-induced Rb phosphorylation via AMPK activation. Moreover, AICAR induced p21cip and p27kip expression via AMPK activation, and small interfering RNA (siRNA) of p21cip and p27kip restored AICAR-mediated suppression of macrophage proliferation. In conclusion, AMPK activation suppressed Ox-LDL-induced macrophage proliferation by suppressing GM-CSF expression and inducing cell cycle arrest. These effects of AMPK activation may represent therapeutic targets for atherosclerosis. 相似文献
953.
Masayuki Takada Yoshio Mishima Shosuke Natsume 《Landscape and Ecological Engineering》2009,5(1):45-58
By examining the area of the Sarobetsu Mire in northern Japan using ALOS/PALSAR data, we have clarified the backscattering
behavior and characteristics of the L-band microwaves when used in the study of peatlands. We classified the vegetation into
six categories and noted the differences in scattering intensity and incident-angle dependencies among these. The scattering
intensity for HH and HV polarizations was greatest with sasa (dwarf bamboo) and reeds, and least with sphagnum. The incident-angle
dependency with the HH polarization was higher for sasa and reed than for other vegetation types. Analysis of the polarization
revealed that such differences among vegetation classes were reflected most clearly in the volume scattering characteristic.
Applying simple and multiple regression analysis for the environmental factors of soil, hydrology, vegetation, and roughness
against the backscatter coefficient, we also found stronger interrelations with soil factors such as bulk density, nitrogen
and carbon content, and C/N ratio, and against the backscatter coefficient, than with either the roughness or vegetation.
Based on such results, we clarified the unique scattering characteristics of peatlands in which scattering from the surface
soil is more marked than that from other elements. We consequently estimated the spatial distribution of surface soil characteristics
in peatland using the combined data available from L-band satellite SAR, aircraft laser (airborne LiDAR), and optical sensors. 相似文献
954.
Takashi Hirasawa Kazuyuki Yamada Keisuke Nagahisa Thai Nho Dinh Chikara Furusawa Yoshio Katakura Suteaki Shioya Hiroshi Shimizu 《Process Biochemistry》2009,44(6):647-653
The difference in responses to osmotic stress between the laboratory and sake-brewing strains of Saccharomyces cerevisiae at the translational level was compared by two-dimensional polyacrylamide gel electrophoresis. Proteins, whose production was significantly changed by the osmotic stress, were identified by peptide mass fingerprinting. In the laboratory strain, translation of Hor2p, the protein responsible for glycerol biosynthesis, and Ald6p, related to acetate biosynthesis, was induced under high osmotic pressure conditions. In addition, production of proteins related to translation and stress response was also changed under this condition. On the other hand, in the sake-brewing strain, translation of Hor2p, Hsp26p, and some stress-related proteins was upregulated. The change in the production of enzymes related to glycolysis and ethanol formation was small; however, the production of enzymes related to glycerol formation increased in both strains. These results suggest that enhancement of glycerol formation due to enhancement of the translation of proteins, such as Hor2p, is required for growth of S. cerevisiae under high osmotic pressure condition. This is the first report on the analysis of responses of a sake-brewing strain to high osmotic pressure stress based on proteomics. 相似文献
955.
Ana Paula Ribeiro Paiotti Sender Jankiel Miszputen Celina Tizuko Fujiyama Oshima Henrique de Oliveira Costa Daniel Araki Ribeiro Marcello Franco 《Journal of molecular histology》2009,40(4):317-324
Inflammatory bowel disease (IBD) is a common chronic gastrointestinal disorder characterized by alternating periods of remission
and active intestinal inflammation. Some studies suggest that antiinflammatory drugs are a promising alternative for treatment
of the disease. Thus, this study aimed to evaluate the effect of lumiracoxib, a selective-cyclooxygenase-2 (COX-2) inhibitor,
on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced experimental colitis. Wistar rats (n = 25) were randomized into four groups, as follows: Group (1) Sham group: sham induced-colitis rats; Group (2) TNBS group:
nontreated induced-colitis rats; Group (3) Lumiracoxib control group; and Group (4) Lumiracoxib-treated induced-colitis rats.
Our results showed that rats from groups 2 and 4 presented similar histopathological damage and macroscopic injury in the
distal colon as depicted by significant statistically differences (P < 0.01; P < 0.05) compared to the other two groups. Weak expression of COX-2 mRNA was detected in normal colon cells, while higher
levels of COX-2 mRNA were detected in group 2 and group 4. Therapy with lumiracoxib reduced COX-2 expression by 20–30%, but
it was still higher and statistically significant compared to data obtained from the lumiracoxib control group. Treatment
with the selective COX-2 inhibitor lumiracoxib did not reduce inflammation-associated colonic injury in TNBS-induced experimental
colitis. Thus, the use of COX-2 inhibitors for treating IBD should be considered with caution and warrants further experimental
investigation to elucidate their applicability. 相似文献
956.
Yoshio Nagai Shin Yonemitsu Derek M. Erion Takanori Iwasaki Romana Stark Dirk Weismann Jianying Dong Dongyan Zhang Michael J. Jurczak Michael G. Löffler James Cresswell Xing Xian Yu Susan F. Murray Sanjay Bhanot Brett P. Monia Jonathan S. Bogan Varman Samuel Gerald I. Shulman 《Cell metabolism》2009,9(3):252-264
957.
Eliana Maria Minicucci Glenda Nicioli da Silva Daniel Araki Ribeiro Daisy Maria Favero Salvadori 《Journal of molecular histology》2009,40(1):71-76
The medium-term tongue carcinogenesis assay is a useful model for studying oral squamous cell carcinomas phase by phase. The
present study aimed to investigate mutations in exon 2 of gene p16CDKN2A during rat tongue carcinogenesis induced by 4-nitroquinoline
1-oxide (4NQO) using direct DNA-sequencing method. A total of 30 male Wistar rats were treated with 4-nitroquinoline 1-oxide
(4NQO) in drinking water for 4, 12, and 20 weeks at 50 ppm dose. Ten animals were used as negative control. No histopathological
changes in tongue epithelia were observed among controls or in the group treated for 4 weeks with 4NQO. Following 12-week
treatment, hyperplasia and epithelial dysplasia were found in mild and moderate forms. At 20 weeks, the tongue presented moderate
and/or severe oral dysplasia and squamous cell carcinoma, with squamous cell carcinoma in the majority of animals. No mutations
were found in any experimental period evaluated that corresponded to normal oral mucosa, hyperplasia, dysplasia and squamous
cell carcinomas. Taken together, our results suggest that p16CDKN2A mutations in exon 2 are not involved in the multistep
tongue carcinogenesis of Wistar rats induced by 4NQO. 相似文献
958.
Wenfeng Lin Jingkai Sun Takuya Sadahira Naijin Xu Koichiro Wada Chunxiao Liu Motoo Araki Abai Xu Masami Watanabe Yasutomo Nasu Peng Huang 《International journal of biological sciences》2021,17(12):3255
Repeated cycles of first-line chemotherapy drugs such as doxorubicin (DOX) and cisplatin (CIS) trigger frequent chemoresistance in recurrent urothelial bladder cancer (UBC). Nitroxoline (NTX), an antibiotic to treat urinary tract infections, has been recently repurposed for cancer treatment. Here we aimed to investigate whether NTX suppresses drug-resistant UBC and its molecular mechanism. The drug-resistant cell lines T24/DOX and T24/CIS were established by continual exposure of parental cell line T24 to DOX and CIS, respectively. T24/DOX and T24/CIS cells were resistant to DOX and CIS, respectively, but they were sensitive to NTX time- and dose-dependently. Overexpressions of STAT3 and P-glycoprotein (P-gp) were identified in T24/DOX and T24/CIS, which could be reversed by NTX. Western blot revealed that NTX downregulated p-STAT3, c-Myc, Cyclin D1, CDK4, CDK6, Bcl-xL, Mcl-1, and Survivin, which were further confirmed by Stattic, a selective STAT3 inhibitor. In vivo, NTX exhibited the significant anti-tumor effect in T24/DOX and T24/CIS tumor-bearing mice. These results suggested that NTX-induced P-gp reversal, G0/G1 arrest, and apoptosis in drug-resistant UBC were mediated by inhibition of STAT3 signaling. Our findings repurpose NTX as a novel STAT3 inhibitor to induce P-gp reversal, G0/G1 arrest, and apoptosis in drug-resistant UBC. 相似文献
959.
Kawachi S Hara Y Arao T Suzuki Y Tamura K 《Bioscience, biotechnology, and biochemistry》2010,74(10):1991-1996
The inhibitory action of compressed hydrocarbon gases on the growth of the yeast Saccharomyces cerevisiae was investigated quantitatively by microcalorimetry. Both the 50% inhibitory pressure (IP(50)) and the minimum inhibitory pressure (MIP), which are regarded as indices of the toxicity of hydrocarbon gases, were determined from growth thermograms. Based on these values, the inhibitory potency of the hydrocarbon gases increased in the order methane < ethane < propane < i-butane < n-butane. The toxicity of these hydrocarbon gases correlated to their hydrophobicity, suggesting that hydrocarbon gases interact with some hydrophobic regions of the cell membrane. In support of this, we found that UV absorbing materials at 260 nm were released from yeast cells exposed to compressed hydrocarbon gases. Additionally, scanning electron microscopy indicated that morphological changes occurred in these cells. 相似文献
960.
Nobue Kitanaka Junichi Kitanaka Tomohiro Tatsuta Koh-ichi Tanaka Kaname Watabe Nobuyoshi Nishiyama Yoshio Morita Motohiko Takemura 《Neurochemical research》2010,35(5):749-760
A variety of drug treatment regimens have been proposed to model the dysphoric state observed during methamphetamine (METH)
withdrawal in rats, but little has been established in experiments using mice. In male ICR mice, a fixed-dose injection regimen
of METH (1.0 or 2.5 mg/kg, i.p., twice daily for 10 consecutive days) induced a significant decrease in the time spent in
open arms in an elevated plus maze after 5 days of drug abstinence. Under an escalating-dose injection regimen (0.2–2.0 mg/kg,
i.p., 3 times daily for 4 days, total: 15 mg/kg/animal) or continuous subcutaneous administration with osmotic mini-pumps
(15 or 76 mg/kg of METH for 2 weeks), no significant behavioral change was observed after 5 days of drug abstinence, compared
with control animals. Reduced gains in body weight were observed during repeated treatment with METH in the fixed-dose injection
and mini-pump treatment regimens, but not the escalating-dose injection regimen. HPLC analysis revealed significant decreases
in the level of cerebral 3-methoxy-4-hydroxyphenylglycol, a norepinephrine metabolite, and norepinephrine turnover, which
may be attributed to the expression of anxiety-related behavior in the elevated plus maze. These observations suggest that
the mice treated with a fixed-dose of METH may model the anxiety-related behavior observed in the dysphoric state induced
by METH withdrawal in humans. 相似文献