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991.
The suppression subtractive hybridization technique was used to identify differentially expressed genes between hormone-autotrophic and hormone-dependent Panax ginseng callus lines. A tonoplast intrinsic protein cDNA (PgTIP1) was found to be highly and specifically expressed in hormone-autotrophic ginseng cells, which was slightly up-regulated by cytokinin while significantly down-regulated when treated with auxin. PgTIP1 encodes a polypeptide of 250 amino acids which shows sequence and structure similarity with tonoplast aquaporins in plants. The water channel activity of PgTIP1 was demonstrated by its expression in Xenopus laevis oocytes. When over-expressed in Arabidopsis thaliana, PgTIP1 substantially altered the plant's vegetative and reproductive growth and development. Arabidopsis plants over-expressing PgTIP1 showed significantly enhanced seed size and seed mass plus greatly increased growth rate compared with those of the wild type. Moreover, the seeds from PgTIP1 over-expressing Arabidopsis had 1.85-fold higher fatty acid content than the wild-type control. These results demonstrate a significant function of PgTIP1 in the growth and development of plant cells.  相似文献   
992.
Stomach lineage specific gene products act as a protective barrier in the normal stomach and their expression maintains the normal physiological processes, cellular integrity and morphology of the gastric wall. However, the regulation of stomach lineage specific genes in gastric cancer (GC) is far less clear. In the present study, we sought to investigate the role and regulation of stomach lineage specific gene set (SLSGS) in GC. SLSGS was identified by comparing the mRNA expression profiles of normal stomach tissue with other organ tissue. The obtained SLSGS was found to be under expressed in gastric tumors. Functional annotation analysis revealed that the SLSGS was enriched for digestive function and gastric epithelial maintenance. Employing a single sample prediction method across GC mRNA expression profiles identified the under expression of SLSGS in proliferative type and invasive type gastric tumors compared to the metabolic type gastric tumors. Integrative pathway activation prediction analysis revealed a close association between estrogen-α signaling and SLSGS expression pattern in GC. Elevated expression of SLSGS in GC is associated with an overall increase in the survival of GC patients. In conclusion, our results highlight that estrogen mediated regulation of SLSGS in gastric tumor is a molecular predictor of metabolic type GC and prognostic factor in GC.  相似文献   
993.
Leucine-enkephalin (Leu-enk) is an endogenous opioid peptide and highly conserved throughout the vertebrates. Despite its conserved nature, the immunoregulatory property of Leu-enk is explored only in mammals. The present study describes the immunomodulatory role of Leu-enk in a lower vertebrate, spotted murrel Channa punctatus. Leu-enk increased the percentage phagocytosis and phagocytic index, though its stimulatory effect on phagocytosis markedly decreased at concentrations higher than 10?9 M. Moreover, it had bell-shaped stimulatory effect also on the superoxide production by phagocytes. On the other hand, Leu-enk showed bimodal effects on nitrite release. The lower concentrations of Leu-enk produced inhibitory effect, while higher concentrations had stimulatory effect on nitrite release. Interestingly, the Leu-enk-induced increase in nitrite release was unaltered by non-selective opioid receptor antagonist though the same completely antagonized the inhibitory effect of Leu-enk on nitrite release and the stimulatory effect on phagocytosis and superoxide production. This suggests that the stimulatory effect of Leu-enk on nitrite production is mediated by the non-opioid receptor. Further, δ-opioid receptor was precisely seen involved in mediating the stimulatory effect of Leu-enk on phagocytosis and superoxide production, or inhibitory effect on nitrite release. It can be concluded that Leu-enk regulates the innate immune response of splenic phagocytes acting via both opioid and non-opioid receptor in the fish C. punctatus.  相似文献   
994.
Betulinic acid and its derivatives as anti-angiogenic agents   总被引:2,自引:0,他引:2  
Betulinic acid (1) significantly caused cytotoxicity to endothelial cell line ECV304 (IC(50) 1.26+/-0.44 microg/mL) in a 5-day MTT assay. Novel and more potent derivatives of betulinic acid (2, 4, 6-8) have been synthesized with IC(50) less than 0.4 microg/mL. The endothelial cell specificity against human tumor cell lines DU145, L132, A549, and PA-1 were determined. Further betulinic acid (1) inhibited TLS formation of ECV304 cells on Matrigel(TM) by 5.5% while its derivatives caused an inhibition of 13.1-49.2%.  相似文献   
995.
996.
997.
膜窖是脂筏的一种特殊类型,在哺乳动物的内皮细胞、脂肪细胞及平滑肌细胞质膜上分布尤为丰富。近年来对于膜窖的区室化调节与生理功能及其应用于药物设计方面的研究日益受到关注,如利用基因剔除、荧光共振能量转移等技术研究窖蛋白功能及膜窖内信号蛋白的互相作用,从而为新型药物的设计打下理论基础。  相似文献   
998.
Early infancy, the period when offspring rely not only on their own immunity to combat food‐borne antigens but also acquire immunity through maternal sources (via transplacental routes and breast milk), is critical for immune system development Hence the present study was designed to evaluate the effect on offspring of administration of probiotic‐containing fermented milk (PFM) either to mothers during the suckling period or to their offspring after weaning either separately or sequentially. PFM‐fed mice showed enhanced leukocyte functionality in offspring as evidenced by significantly (P < 0.05) increased release of lysosomal enzymes (β‐galactosidase, β‐glucuronidase) in peritoneal fluid and nitric oxide production in culture supernatants of activated macrophages. Further, remarkably reduced levels (P < 0.01) of inflammatory markers (TNF‐α, monocyte chemotactic protein‐1) and allergic antibodies (total and milk specific IgE) were observed in offspring where PFM was fed either to them or to their mothers. However, considerably increased levels (P < 0.05) of SIgA were found in the guts of control and experimental groups animals irrespective of their exposure to PFM. Restoration of Th1/Th2 homeostasis further confirmed the useful effects of PFM supplementation by shifting the cytokine profile (IL‐4, IFN‐γ and IL‐10) with increased IFN‐γ/IL‐4 and reduced IgE/Ig2Ga ratios. Hence, it is logical to conclude that administration of Lactobacillus rhamnosus‐containing (MTCC:5897) fermented milk to mothers during the suckling period and to their offspring after weaning has beneficial effects on the development of newborns immune systems; this effect appears to be more pronounced when mothers are fed with it.  相似文献   
999.
1000.
Intermediate-conductance K(+) (Kcnn4) channels in the apical and basolateral membranes of epithelial cells play important roles in agonist-induced fluid secretion in intestine and colon. Basolateral Kcnn4 channels have been well characterized in situ using patch-clamp methods, but the investigation of Kcnn4 channels in apical membranes in situ has been hampered by a layer of mucus that prevents seal formation. In the present study, we used patch-clamp methods to characterize Kcnn4 channels in the apical membrane of IEC-18 cells, a cell line derived from rat small intestine. A monolayer of IEC-18 cells grown on a permeable support is devoid of mucus, and tight junctions enable selective access to the apical membrane. In inside-out patches, Ca(2+)-dependent K(+) channels observed with iberiotoxin (a Kcnma1/large-conductance, Ca(2+)-activated K(+) channel blocker) and apamin (a Kcnn1-3/small-conductance, Ca(2+)-activated K(+) channel blocker) present in the pipette solution exhibited a single-channel conductance of 31 pS with inward rectification. The currents were reversibly blocked by TRAM-34 (a Kcnn4 blocker) with an IC(50) of 8.7 ± 2.0 μM. The channels were not observed when charybdotoxin, a peptide inhibitor of Kcnn4 channels, was added to the pipette solution. TRAM-34 was less potent in inhibiting Kcnn4 channels in patches from apical membranes than in patches from basolateral membranes, which was consistent with a preferential expression of Kcnn4c and Kcnn4b isoforms in apical and basolateral membranes, respectively. The expression of both isoforms in IEC-18 cells was confirmed by RT-PCR and Western blot analyses. This is the first characterization of Kcnn4 channels in the apical membrane of intestinal epithelial cells.  相似文献   
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