花生四烯酸代谢相关酶和ERK与乳腺癌转移关系

花生四烯酸代谢相关酶环加氧酶(COX)、脂氧合酶(LOX)和活化的胞外信号调节激酶（p-ERK1/2）等与乳腺癌发生发展具有密切关系.为了进一步阐明它们在乳腺癌转移中的作用及其分子机制,应用反转录PCR（RT-PCR）、免疫印迹和免疫组化等方法,分别检测了乳腺癌细胞系、乳腺癌组织、癌旁组织和转移淋巴结组织中COX-2、5-LOX、12R-LOX、cPLA2和p-ERK1/2的表达水平.结果显示,与对照组相比,在具有高转移潜能的乳腺癌LM MCF-7细胞和MDA-MB-231细胞以及转移淋巴结组织中,COX-2、5-LOX、12R-LOX、cPLA2和p-ERK1/2均有较高水平表达.进而发现,p-ERK1/2的特异性抑制剂PD98059可拮抗LM-MCF-7细胞和MDA-MB-231细胞中COX-2、5-LOX、12R-LOX和cPLA2的高表达.上述结果表明,p-ERK1/2可以通过促进花生四烯酸代谢相关酶的表达促进乳腺癌细胞发生转移.     

Concurrent expression of heme oxygenase-1 and p53 in human retinal pigment epithelial cell line

Heme oxygenase-1 (HO-1) is a stress-responsive protein that is known to regulate cellular functions such as cell proliferation, inflammation, and apoptosis. Here, we investigated the effects of HO activity on the expression of p53 in the human retinal pigment epithelium (RPE) cell line ARPE-19. Cobalt protoporphyrin (CoPP) induced the expression of both HO-1 and p53 without significant toxicity to the cells. In addition, the blockage of HO activity with the iron chelator DFO or with HO-1 siRNA inhibited the CoPP-induced expression of p53. Similarly, zinc protoporphyrin (ZnPP), an inhibitor of HO, suppressed p53 expression in ARPE-19 cells, although ZnPP increased the level of HO-1 protein while inhibiting HO activity. Also, CoPP-induced p53 expression was not affected by the formation of reactive oxygen species (ROS). Based on these results, we conclude that HO activity is involved in the regulation of p53 expression in a ROS-independent mechanism, and also suggest that the expression of p53 in ARPE-19 cells is associated with heme metabolites such as biliverdin/bilirubin, carbon monoxide, and iron produced by the activity of HO.     

Monitoring of Na<Superscript>+</Superscript>/K<Superscript>+</Superscript>-ATPase mRNA expression in the cinnamon clownfish, <Emphasis Type="Italic">Amphiprion melanopus</Emphasis>, exposed to an osmotic stress environment: profiles on the effects of exogenous hormone

We examined changes in the expression of Na⁺/K⁺-ATPase mRNA in the gills of the cinnamon clownfish using quantitative real-time PCR in an osmotically changing environment [seawater (35 psu; practical salinity unit, 1 psu ≈ 1‰) → brackish water (17.5 psu) and brackish water with prolactin]. The expression of Na⁺/K⁺-ATPase mRNA in gills was increased after the transfer to brackish water, and the expression was repressed by prolactin treatment. Also, activities of gill Na⁺/K⁺-ATPase and plasma cortisol levels increased after the transfer to brackish water and were repressed in brackish water with prolactin treatment. Na⁺/K⁺-ATPase-immunoreactive cells were almost consistently observed in the gill filaments, but absent from the lamella epithelia. The plasma osmolality level decreased in brackish water, but the level of this parameter increased in brackish water with prolactin treatment during salinity change. These results suggest that the Na⁺/K⁺-ATPase gene plays an important role in osmoregulation in gills, and prolactin improves the hyperosmoregulatory ability of cinnamon clownfish in a brackish water (hypoosmotic) environment.     

Spectrophotometric determination of peptide transport with chromogenic peptide mimetics

A spectrophotometric assay to determine peptide transport has been developed. Using two chromogenic peptide mimetics, L-phenylalanyl-L-2-sulfanilylglycine (PSG) and L-phenylalanyl-L-3-thiaphenylalanine (PSP), the peptide transport patterns in individual cell species can be evaluated effectively. After the addition of PSG to a HeLa cell suspension, sulfanilic acid accumulated progressively inside, but not outside, the cells, demonstrating that PSG was transported wholly intact. The addition of PSP to the same cell suspension was followed immediately by extracellular thiophenol production. Measurement of the rate of thiophenol release thereby provided direct determination of PSP transport. The thiophenol release was consistent with Michaelis-Menten kinetics, with a K(m) of 0.016 mM and a V(max) of 5.07 nmol/min (1 x 10(6) cells/ml, pH 7.4, 37 degrees C). The resulting kinetic constants estimated were in agreement with values determined by single-substrate enzyme kinetics. Using PSP, transport kinetics of various dipeptides was examined by competitive spectrophotometry. As a result, dipeptides tested could be ranked in order of kinetic power for their transport.     

Polycystic kidney disease and therapeutic approaches

Polycystic kidney disease (PKD) is a common genetic disorder in which extensive epithelial-lined cysts develop in the kidneys. In previous studies, abnormalities of polycystin protein and its interacting proteins, as well as primary cilia, have been suggested to play critical roles in the development of renal cysts. However, although several therapeutic targets for PKD have been suggested, no early diagnosis or effective treatments are currently available. Current developments are active for treatment of PKD including inhibitors or antagonists of PPAR-γ, TNF-α, CDK and VEGF. These drugs are potential therapeutic targets in PKD, and need to be determined about pathological functions in human PKD. It has recently been reported that the alteration of epigenetic regulation, as well as gene mutations, may affect the pathogenesis of PKD. In this review, we will discuss recent approaches to PKD therapy. It provides important information regarding potential targets for PKD.     

Production of nattokinase by high cell density fed-batch culture of Bacillus subtilis

Bacillus subtilis was cultivated to high cell density for nattokinase production by pH-stat fed-batch culture. A concentrated mixture solution of glucose and peptone was automatically added by acid-supplying pump when culture pH rose above high limit. Effect of the ratio of glucose to peptone in feeding solution was investigated on cell growth and nattokinase production by changing the ratio from 0.2 to 5 g glucose/g peptone. The highest cell concentration was 77 g/L when the ratio was 0.2 g glucose/g peptone. Cell concentration decreased with increasing the ratio of glucose to peptone in feeding solution, while the optimum condition existed for nattokinase production. The highest nattokinase activity was 14,500 unit/mL at a ratio of 0.33 g glucose/g peptone, which was 4.3 times higher than that in batch culture.     

BioPAX support in CellDesigner

MOTIVATION: BioPAX is a standard language for representing and exchanging models of biological processes at the molecular and cellular levels. It is widely used by different pathway databases and genomics data analysis software. Currently, the primary source of BioPAX data is direct exports from the curated pathway databases. It is still uncommon for wet-lab biologists to share and exchange pathway knowledge using BioPAX. Instead, pathways are usually represented as informal diagrams in the literature. In order to encourage formal representation of pathways, we describe a software package that allows users to create pathway diagrams using CellDesigner, a user-friendly graphical pathway-editing tool and save the pathway data in BioPAX Level 3 format. AVAILABILITY: The plug-in is freely available and can be downloaded at ftp://ftp.pantherdb.org/CellDesigner/plugins/BioPAX/ CONTACT: huaiyumi@usc.edu SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.     

Enhanced biological effects of Phe140Asn, a novel human granulocyte colony-stimulating factor mutant, on HL60 cells

Granulocyte colony-stimulating factor (G-CSF) is a cytokine secreted by stromal cells and plays a role in the differentiation of bone marrow stem cells and proliferation of neutrophils. Therefore, G-CSF is widely used to reduce the risk of serious infection in immunocompromised patients; however, its use in such patients is limited because of its non-persistent biological activity. We created an N-linked glycosylated form of this cytokine, hG-CSF (Phe140Asn), to assess its biological activity in the promyelocyte cell line HL60. Enhanced biological effects were identified by analyzing the JAK2/STAT3/survivin pathway in HL60 cells. In addition, mutant hG-CSF (Phe140Asn) was observed to have enhanced chemoattractant effects and improved differentiation efficiency in HL60 cells. These results suggest that the addition of N-linked glycosylation was successful in improving the biological activity of hG-CSF. Furthermore, the mutated product appears to be a feasible therapy for patients with neutropenia.     

纳络酮对东方蝾螈胚胎表皮传导的阻断作用

在胚胎发育的一定时期,表皮细胞呈现较强的β-内啡肽阳性免疫反应,而这时期正是表皮传导最活跃的时期。为了探索胚胎表皮传导和β-内啡肽-类阿片样多肽之间是否有关系,本实验采用纳络酮处理,发现表皮传导消失,待纳络酮作用消除后,表皮传导现象又再出现,说明纳络酮在胚胎表皮细胞传导中起了阻断的作用。