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101.
102.
Yamada T Konno N Matsuda K Uchiyama M 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2007,177(5):503-508
In our previous study, it was suggested that ANP and cGMP may increase Na+ absorption in the urinary bladder of the Japanese tree frog, Hyla japonica. Thus, Na+ transport activated by ANP was investigated electrophysiologically by using a cell-attached patch-clamp technique in freshly
isolated cells from the urinary bladder. A predominant channel expressed was a low conductance Na+ channel in the epithelial cells. The channel exhibited conductance for inward currents of 4.9 ± 0.2 pS, long open and closed
times (c.a. 190 ms), and positive reversal potential. The channel activity was decreased under the pipette solution including
10−6 M amiloride. These characteristics were similar to those of amiloride-sensitive Na+ channels (ENaC). Addition of 10−9 M ANP activated and significantly increased the ENaC activity from 0.58 ± 0.09 to 1.47 ± 0.34. On the other hand, mean amplitudes
and conductance of single channel did not change significantly after the addition of ANP. Addition of 10−5 M 8-Br-cGMP also activated the ENaC and significantly increased the channel activity from 0.56 ± 0.10 to 2.00 ± 0.33. The
addition of ANP failed to activate the ENaC in the presence of 10−6 M amiloride. These results suggested that ANP and cGMP activate Na+ transport via ENaC in the epithelial cells of frog urinary bladder. 相似文献
103.
Musch MW Arvans DL Walsh-Reitz MM Uchiyama K Fukuda M Chang EB 《American journal of physiology. Gastrointestinal and liver physiology》2007,292(6):G1549-G1558
Apical membrane sodium hydrogen exchanger 3 (NHE3), a major pathway for non-nutrient-dependent intestinal Na(+) absorption, is tightly regulated by second messenger systems that affect its functional activity and membrane trafficking. However, the events and components involved in NHE3 regulation are only partially understood. We report that the adaptor protein synaptotagmin I (Syt I) plays a pivotal role in cAMP- and Ca(2+)-induced cargo recognition of NHE3 and initiation of its endocytosis. Both mouse small intestine (jejunum) and Caco-2BBe Syt I coimmunoprecipitated with NHE3, particularly following increases in cellular cAMP or Ca(2+). Following short interfering RNA (siRNA) suppression of Syt I expression, cAMP- and Ca(2+)-induced inhibition of NHE3 activity were still observed but NHE3 endocytosis was blocked, as assessed by (22)Na influx and apical membrane biotin labeling, respectively. Similar effects on NHE3 inhibition and endocytosis were observed by siRNA suppression of either the mu-subunit of the adaptor protein 2 (AP2) complex or the heavy chain of clathrin. Coimmunoprecipitation analyses of NHE3 with these adaptor proteins revealed that cAMP- and Ca(2+)-induced NHE3-Syt I interaction preceded and was required for recruitment of AP2 and the clathrin complex. Confocal microscopy confirmed both the time sequence and protein associations of these events. We conclude that Syt I plays a pivotal role in mediating cAMP- and Ca(2+)-induced endocytosis of NHE3 (but not in inhibition of activity) through cargo recognition of NHE3 and subsequent recruitment of AP2-clathrin assembly required for membrane endocytosis. 相似文献
104.
Berhanu A Huang J Watkins SC Okada H Storkus WJ 《Journal of immunology (Baltimore, Md. : 1950)》2007,178(6):3400-3408
Regulatory T cells can suppress activated CD4+ and CD8+ T effector cells and may serve as an impediment to spontaneous or therapeutic type 1 antitumor immunity. In a previous study, we observed minimal therapeutic impact, but significantly enhanced T cell cross-priming and lesional infiltration of tumor-reactive CD8+ T cells into established CMS4 sarcomas after combined treatment of BALB/c mice with rFLt3 ligand (rFL) and recombinant GM-CSF (rGM-CSF). In this study, we show that this cytokine regimen also results in the profound enhancement of CD4+ tumor-infiltrating lymphocytes (TIL) expressing FoxP3, IL-10, and TGF-beta mRNA, with 50 or 90% of CD4+ TIL coexpressing the CD25 and glucocorticoid-induced TNFR family related molecules, respectively. Intracellular staining for Foxp3 protein revealed that combined treatment with rFL plus rGM-CSF results in a significant increase in CD4+Foxp3+ T cells in the spleen of both control and tumor-bearing mice, and that nearly half of CD4+ TIL expressed this marker. In addition, CD4+ TIL cells were of an activated/memory (ICOS(high)CD62L(low)CD45RB(low)) phenotype and were capable of suppressing allospecific T cell proliferation and IFN-gamma production from (in vivo cross-primed) anti-CMS4 CD8+ T cells in vitro, via a mechanism at least partially dependent on IL-10 and TGF-beta. Importantly, in vivo depletion of CD4+ T cells resulted in the ability of previously ineffective, rFL plus rGM-CSF therapy-induced CD8+ T cells to now mediate tumor regression. 相似文献
105.
The growth response of Chlorella sorokiniana to certain irradiance, DO, and temperature demonstrated the possible causes of low productivity with this strain in outdoor
cultures. The growth (biomass productivity) and chlorophyll fluorescence (Fv/Fm) were substantially reduced when the dissolved oxygen (above 200 % of air saturation) and temperature were elevated. 相似文献
106.
In this study, in addition to the karyotype analysis, the chromosomal distributions of 5 S and 18 S rDNAs, and the Arabidopsis-type (T3AG3) telomeric sequences were detected by means of fluorescence in situ hybridization (FISH) to promote the information of chromosomal organization and evolution in the cultivated lettuce and its wild relatives, L. sativa, L. serriola, L. saligna and L. virosa. The karyotype analysis revealed the dissimilarity between L. virosa and the remaining species. In all four Lactuca species studied, one 5 S rDNA and two 18 S rDNA loci were detected. The simultaneous FISH of 5 S and 18 S rDNAs revealed that both rDNA loci of L. sativa, L. serriola and L. saligna were identical, however, that of L. virosa was different from the other species. These analyses indicate the closer relationships between L. sativa/L. serriola and L. saligna rather than L. virosa. Arabidopsis-type telomeric sequences were detected at both ends of their chromatids of all chromosomes not in the other regions. This observation suggests the lack of telomere-mediated chromosomal rearrangements among the Lactuca chromosomes. 相似文献
107.
Sakaki J Kishida M Konishi K Gunji H Toyao A Matsumoto Y Kanazawa T Uchiyama H Fukaya H Mitani H Arai Y Kimura M 《Bioorganic & medicinal chemistry letters》2007,17(17):4804-4807
A series of diazepinylbenzoic acid derivatives were synthesized and tested in the inhibition assay of the transactivation of RXR. Oral treatment of cyano derivatives (16f) was found to show anti-diabetic and anti-obesity effects in KK-A(y) mice. 相似文献
108.
Sakaki J Konishi K Kishida M Gunji H Kanazawa T Uchiyama H Fukaya H Mitani H Kimura M 《Bioorganic & medicinal chemistry letters》2007,17(17):4808-4811
Synthesis and structure-activity relationship of RXR antagonists employing a diazepinylbenzoic acid scaffold are described. Of those antagonists, sulfonamide derivatives (6v and 6w) reveal a high antagonistic activity and good pharmacokinetic properties. 相似文献
109.
Hattori J Okumura N Yamazaki Y Uchiyama M Hamaguchi M Nishiyama Y Kaneda T 《Microbiology and immunology》2007,51(2):193-200
Several reports have documented a better prognosis for HIV‐1‐infected patients co‐infected with GBV‐C, while other reports have contradicted such findings with the result that this issue remains controversial. We attempted to clarify the complicated status of the effect of GBV‐C co‐infection on HIV‐1‐infected patients. GBV‐C RNA was detected in 37 samples in 182 HIV‐1‐infected patients (20.3%) using RT/nested PCR. Of these, 3 were determined to be GBV‐C genotype 1, 12 were genotype 2, and the remaining 22 were genotype 3. The GBV‐C viral load quantified by real‐time PCR ranged from 7.8 × 103 to 3.3 × 106 copies/ml. Weakly negative correlation was observed between GBV‐C viral load and HIV‐1 viral load in 19 HAART‐naïve patients, indicating that a higher GBV‐C viral load is associated with a greater suppression of HIV‐1 replication. A previously published in vitro study suggested that GBV‐C infection would induce up‐regulation of RANTES, leading to suppression of HIV‐1 replication. However, in our present study, the blood RANTES level was significantly lower in the GBV‐C co‐infected group than in the uninfected group (190–9,959 vs. 264–31,038 pg/ml, P=0.004). Our results suggested that a suppression of HIV‐1 replication by GBV‐C co‐infection is not mediated by up‐regulated RANTES, and thus call for another as yet unknown factor. 相似文献
110.