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991.
Fujimoto T Tomitaka Y Abe H Tsuda S Futai K Mizukubo T 《Journal of plant physiology》2011,168(10):1084-1097
We investigated what gene(s) in the plant roots have the positive role against repressing root-knot nematode (RKN) infection. We investigated the interaction between RKN infection and gene expression in the plant roots induced by methyl jasmonate (MeJA). We focused on the induced resistance response and the duration after foliar treatment with MeJA of 0.1, 0.5, 1.0, and 5.0mM at 1, 24, 48, and 72h prior to the inoculation of RKN. As a result, the foliar treatment with MeJA at 0.5mM or higher concentrations significantly reduced the infection of RKN in plants and the effect lasted for about 1 week. The repressing effect on RKN population declined to the lowest level in two weeks after MeJA treatment. The expression of proteinase inhibitors (PIs) and multicystatin (MC) were induced while the repressing effect on RKN was valid and a negative correlation was found between the expression of PIs or MC and RKN infection. In addition, when tomato plants no longer expressing MC and PIs were treated again with MeJA, the repressing effect revived. These phenomena appeared to be regardless of the existence of Mi-genes or isolate of RKN. Our results indicate that the expression level of MC and PIs may be effective as marker genes for estimating the induced resistance response against RKN infection. 相似文献
992.
Ikeda T Sun L Tsuruoka N Ishigaki Y Yoshitomi Y Yoshitake Y Yonekura H 《The Biochemical journal》2011,436(2):399-407
sFlt-1 (soluble Flt-1) potently inhibits angiogenesis by binding extracellularly to VEGF (vascular endothelial growth factor). In the present paper, we report that hypoxia down-regulates sFlt-1 expression in HMVECs (human microvascular endothelial cells), a constituent of microvessels where angiogenesis occurs. Hypoxia (5-1% O?) increased VEGF expression in HMVECs. In contrast, the levels of sFlt-1 mRNA and protein in HMVECs decreased significantly as the O? concentration fell, whereas mFlt-1 (membrane-bound Flt-1) mRNA and protein remained unchanged. This suggested that hypoxia selectively regulates alternative 3'-end processing of sFlt-1 pre-mRNA. We have also demonstrated that sFlt-1 overexpression in lentiviral-construct-infected HMVECs counteracted VEGF-induced endothelial cell growth. We next identified cis-elements involved in sFlt-1 mRNA processing in HMVECs using a human Flt-1 minigene and found that two non-contiguous AUUAAA sequences function as the poly(A) signal. Furthermore, we identified a cis-element in intron 13 that regulates sFlt-1 mRNA processing. Mutagenesis of the U-rich region in intron 13 caused a significant decrease in the soluble-form/membrane-form RNA ratio in the minigene-transfected HMVECs. These results suggest that decreased sFlt-1 expression due to hypoxia contributes to hypoxia-induced angiogenesis and reveals a novel mechanism regulating angiogenesis by alternative mRNA 3'-end processing. 相似文献
993.
Matsumoto T Tostes RC Webb RC 《American journal of physiology. Heart and circulatory physiology》2011,301(2):H409-H417
Uridine adenosine tetraphosphate (Up(4)A) was reported as a novel endothelium-derived contracting factor. Up(4)A contains both purine and pyrimidine moieties, which activate purinergic (P2)X and P2Y receptors. However, alterations in the vasoconstrictor responses to Up(4)A in hypertensive states remain unclear. The present study examined the effects of Up(4)A on contraction of isolated renal arteries (RA) and pulmonary arteries (PA) from DOCA-salt rats using isometric tension recording. RA from DOCA-salt rats exhibited increased contraction to Up(4)A versus arteries from control uninephrectomized rats in the absence and presence of N(G)-nitro-l-arginine (nitric oxide synthase inhibitor). On the other hand, the Up(4)A-induced contraction in PA was similar between the two groups. Up(4)A-induced contraction was inhibited by suramin (nonselective P2 antagonist) but not by diinosine pentaphosphate pentasodium salt hydrate (Ip(5)I; P2X(1) antagonist) in RA from both groups. Furthermore, 2-thiouridine 5'-triphosphate tetrasodium salt (2-ThioUTP; P2Y(2) agonist)-, uridine-5'-(γ-thio)-triphosphate trisodium salt (UTPγS; P2Y(2)/P2Y(4) agonist)-, and 5-iodouridine-5'-O-diphosphate trisodium salt (MRS 2693; P2Y(6) agonist)-induced contractions were all increased in RA from DOCA-salt rats. Protein expression of P2Y(2)-, P2Y(4)-, and P2Y(6) receptors in RA was similar between the two groups. In DOCA-salt RA, the enhanced Up(4)A-induced contraction was reduced by PD98059, an ERK pathway inhibitor, and Up(4)A-stimulated ERK activation was increased. These data are the first to indicate that Up(4)A-induced contraction is enhanced in RA from DOCA-salt rats. Enhanced P2Y receptor signaling and activation of the ERK pathway together represent a likely mechanism mediating the enhanced Up(4)A-induced contraction. Up(4)A might be of relevance in the pathophysiology of vascular tone regulation and renal dysfunction in arterial hypertension. 相似文献
994.
Shimazu T Otani H Yoshioka K Fujita M Okazaki T Iwasaka T 《American journal of physiology. Heart and circulatory physiology》2011,301(5):H2061-H2072
Uncoupling of nitric oxide synthase (NOS) has been implicated in left ventricular (LV) remodeling and dysfunction after myocardial infarction (MI). We hypothesized that inducible NOS (iNOS) plays a crucial role in LV remodeling after MI, depending on its coupling status. MI was created in wild-type, iNOS-knockout (iNOS(-/-)), endothelial NOS-knockout (eNOS(-/-)), and neuronal NOS-knockout (nNOS(-/-)) mice. iNOS and nNOS expressions were increased after MI associated with an increase in nitrotyrosine formation. The area of myocardial fibrosis and LV end-diastolic volume and ejection fraction were more deteriorated in eNOS(-/-) mice compared with other genotypes of mice 4 wk after MI. The expression of GTP cyclohydrolase was reduced, and tetrahydrobiopterin (BH(4)) was depleted in the heart after MI. Oral administration of sepiapterin after MI increased dihydrobiopterin (BH(2)), BH(4), and BH(4)-to-BH(2) ratio in the infarcted but not sham-operated heart. The increase in BH(4)-to-BH(2) ratio was associated with inhibition of nitrotyrosine formation and an increase in nitrite plus nitrate. However, this inhibition of NOS uncoupling was blunted in iNOS(-/-) mice. Sepiapterin increased capillary density and prevented LV remodeling and dysfunction after MI in wild-type, eNOS(-/-), and nNOS(-/-) but not iNOS(-/-) mice. N(ω)-nitro-L-arginine methyl ester abrogated sepiapterin-induced increase in nitrite plus nitrate and angiogenesis and blocked the beneficial effects of sepiapterin on LV remodeling and function. These results suggest that sepiapterin enhances angiogenesis and functional recovery after MI by activating the salvage pathway for BH(4) synthesis and increasing bioavailable nitric oxide predominantly derived from iNOS. 相似文献
995.
The centrosome is essential for the formation of the cilia and has been implicated in cell polarization and signaling during early embryonic development. A number of Wnt pathway components were found to localize at the centrosome, but how this localization relates to their signaling functions is unclear. In this study, we assessed a role for Diversin, a putative Wnt pathway mediator, in developmental processes that involve cilia. We find that Diversin is specifically localized to the basal body compartment near the base of the cilium in Xenopus multi-ciliated skin cells. Overexpression of Diversin RNA disrupted basal body polarization in these cells, suggesting that tightly regulated control of Diversin levels is crucial for this process. In cells depleted of endogenous Diversin, basal body structure appeared abnormal and this was accompanied by disrupted polarity, shortened or absent cilia and defective ciliary flow. These results are consistent with the involvement of Diversin in processes that are related to the acquisition of cell polarity and require ciliary functions. 相似文献
996.
Ogawa K Takemoto N Ishii M Pasquale EB Nakajima T 《Histochemistry and cell biology》2011,136(6):617-636
Eph receptors and ephrin ligands are membrane-bound cell–cell communication molecules with well-defined roles in development.
However, their expression and functions in the gastric epithelium are virtually unknown. We detected several EphB receptors
and ephrin-Bs in the gastric corpus mucosa of the adult rodent stomach by RT-PCR amplification. Immunostaining showed complementary
expression patterns, with EphB receptors preferentially expressed in the deeper regions and ephrin-Bs in the superficial regions
of the gastric units. EphB1, EphB2 and EphB3 are expressed in mucous neck, chief and parietal cells, respectively. In contrast,
ephrin-B1 is in pit cells and proliferating cells of the isthmus. In a mouse ulcer model, EphB2 expression was upregulated
in the regenerating epithelium and expanded into the isthmus. Thus, EphB/ephrin-B signaling likely occurs preferentially in
the isthmus, where receptor-ligand overlap is highest. We show that EphB signaling in primary gastric epithelial cells promotes
cell retraction and repulsion at least in part through RhoA activation. Based on these findings, we propose that the EphB-positive
progeny of gastric stem cells migrates from the isthmus toward the bottom of the gastric glands due to repulsive signals arising
from contact with ephrin-Bs, which are preferentially expressed in the more superficial regions of the isthmus and gastric
pits. 相似文献
997.
998.
Sugimoto N Iwaki T Chardwiriyapreecha S Shimazu M Kawano M Sekito T Takegawa K Kakinuma Y 《Bioscience, biotechnology, and biochemistry》2011,75(2):385-387
The fission yeast Schizosaccharomyces pombe has a homolog of the budding yeast Atg22p, which is involved in spore formation (Mukaiyama H. et al., Microbiology, 155, 3816-3826 (2009)). GFP-tagged Atg22p in the fission yeast was localized to the vacuolar membrane. Upon disruption of atg22, the amino acid levels of the cellular fraction as well as the vacuolar fraction decreased. The uptake of several amino acids, such as lysine, histidine, and arginine, was impaired in atg22Δ cells. S. pombe Atg22p plays an important role in the compartmentalization of amino acids. 相似文献
999.
Izumo T Maekawa T Ida M Kishi A Akatani K Kitagawa Y Kiso Y 《Bioscience, biotechnology, and biochemistry》2011,75(2):370-372
We investigated the effect of ingesting Lactobacillus pentosus S-PT84 on the interferon-α (IFN-α) production from splenocytes and plasmacytoid dendritic cells by virus stimulation. IFN-α production by the Lactobacillus pentosus S-PT84 ingestion group was significantly greater under the virus-infected condition than that by the control group. Lactobacillus pentosus S-PT84 could enhance the production of IFN-α which is known as an important cytokine for preventing virus infection. It may therefore become a prophylactic tool against such virus infection. 相似文献
1000.
Fukamizo T Sato H Mizuhara M Ohnuma T Gotoh T Hiwatashi K Takahashi S 《Bioscience, biotechnology, and biochemistry》2011,75(9):1763-1769
Autographa californica multiple nucleopolyhedrovirus (AcMNPV) chitinase is involved in the final liquefaction of infected host larvae. We purified the chitinase rapidly to homogeneity from Sf-9 cells infected with AcMNPV by a simple procedure using a pepstatin-aminohexyl-Sepharose column. In past studies, a recombinant AcMNPV chitinase was found to exhibit both exo- and endo-chitinase activities by analysis using artificial substrates with a fluorescent probe. In this study, however, we obtained more accurate information on the mode of action of the chitinase by HPLC analysis of the enzymatic products using natural oligosaccharide and polysaccharide substrates. The AcMNPV chitinase hydrolyzed the second β-1,4 glycosidic linkage from the non-reducing end of the chitin oligosaccharide substrates [(GlcNAc)(n), n=4, 5, and 6], producing the β-anomer of (GlcNAc)?. The mode of action was similar to that of Serratia marcescens chitinase A (SmChiA), the amino acid sequence of which is 60.5% homologous to that of the AcMNPV enzyme. The enzyme also hydrolyzed solid β-chitin, producing only (GlcNAc)?. The AcMNPV chitinase processively hydrolyzes solid β-chitin in a manner similar to SmChiA. The processive mechanism of the enzyme appears to be advantageous in liquefaction of infected host larvae. 相似文献