Paradoxical effects of a stress signal on pro- and anti-apoptotic machinery in HTLV-1 tax expressing cells

Adult T-cell leukemia (ATL) and HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) are associated with Human T-cell lymphotropic virus type 1 (HTLV-1) infection. The viral transactivator, Tax is able to mediate the cell cycle progression by targeting key regulators of the cell cycle such as p21/waf1, p16/ink4a, p53, cyclins D1-3/cdk complexes, and the mitotic spindle checkpoint MAD apparatus, thereby deregulating cellular DNA damage and checkpoint control. Genome expression profiling of infected cells exemplified by the development of DNA microarrays represents a major advance in genome-wide functional analysis. Utilizing cDNA microarray analysis, we have observed an apparent opposing and paradoxical regulatory network of host cell gene expression upon the introduction of DNA damage stress signal. We find the apparent induction of cell cycle inhibitors, and pro- as well as anti-apoptotic gene expression is directly linked to whether cells are at either G1, S, or G2/M phases of the cell cycle. Specifically, a G1/S block is induced by p21/waf1 and p16/ink4a, while pro-apoptotic expression at S, and G2/M is associated with caspase activation, and anti-apoptotic gene expression is associated with up regulation of Bcl-2 family member, namely bfl-1 gene. Therefore, the microarray results indicating expression of both pro- and anti-apoptotic genes could easily be explained by the particular stage of the cell cycle. Mechanism and the functional outcome of induction for both pathways are discussed.     

Engulfment protein GULP is regulator of transforming growth factor-β response in ovarian cells

Transforming growth factor β (TGF-β) is a key regulatory molecule with pleiotropic effects on cell growth, migration, and invasion. As a result, impairment of proper TGF-β signaling is central to tumorigenesis and metastasis. The TGF-β receptor V (TGFBRV or LRP1) has been shown to be responsible for TGF-β-mediated cell growth inhibition in Chinese hamster ovary (CHO) cells. The LRP1 adapter protein GULP mediates internalization of the various LRP1-specific ligands, and we hypothesize that GULP acts as a novel regulator of TGF-β signaling in ovarian cells. CHO cells that overexpress exogenous GULP (FL) demonstrate enhancement in growth inhibition, migration, and invasion from TGF-β treatment, whereas cells that lack GULP (AS) show impairment of growth inhibition and decreased migration and invasion. The enhanced TGF-β response in FL cells was confirmed by a prolonged TGF-β-induced SMAD3 phosphorylation, whereas a shortening of the phosphorylation event is observed in AS cells. Mechanistically, the presence of GULP retains the TGF-β in a signaling-competent early endosome for enhanced signaling. To address this mechanism in a physiological setting, TGF-β insensitive ovarian adenocarcinoma cells (HEY) have a very low GULP expression level, similar to the observation made in a wide selection of human ovarian adenocarcinomas. Transfection of GULP into the HEY cells restored the TGF-β responsiveness, as measured by SMAD3 phosphorylation and impairment of cell growth. Because GULP expression positively regulates TGF-β signaling leading to growth inhibition, this may represent an attractive target to achieve TGF-β responsiveness in ovarian cells.     

用改良的MTT法测定rhG-CSF活性

ＭＴＴ测定法是根据线粒体脱氢酶催化ＭＴＴ形成蓝色甲■的多少来检测活细胞数和功能状态的,但原始方法中存在着一些问题,如敏感性偏低、有机溶剂产生蛋白质沉淀以及产物的溶解度偏低等。为了摸索测定 ｒｈＧ－ＣＳＦ活性的最适条件,我们以 ＮＦＳ－６０细胞为对象,比较了多种溶解缓冲液,并且对细胞数、ＭＴＴ浓度及保留时间、溶解液用量等条件进行了选择。结果表明,ＤＭＦ－２０％ＳＤＳ和 ２０％ＳＤＳ的效果最好,测定时细胞数为每孔 １０００个细胞,所加 ＭＴＴ浓度为 １ｍｇ／ｍｌ,保留时间为 ４ ｈ,溶解液的用量为每孔 １００μｌ。     

The effect of mesenchymal stromal cells on doxorubicin-induced nephropathy in rats

Background aimsThe potential protective effects of mesenchymal stromal cells (MSCs) on some kidney diseases has been reported. However, the effect of MSCs on doxorubicin-induced nephropathy is still poorly understood.MethodsRats with doxorubicin-induced kidney injuries were treated with human cord-derived MSCs. Human MSCs were first labeled with 5-bromo-2′-deoxyuridine to track their homing in kidneys after infusion.ResultsAlleviation of proteinuria, decreased serum albumin, alleviation of lipid disorders and histologic alterations were found in rats 4 weeks after treatment with MSCs, particularly in rats that were given repeat doses. Decreases in serum levels of interleukin-6, tumor necrosis factor-α and prostaglandin E₂ and decreases in messenger RNA levels of kidney tissue cylooxygenase-2 and EP4 were found in MSC-treated rats. MSC-treated rats also displayed an increase in serum interleukin-10 levels.ConclusionsThese results indicate that MSCs ameliorate doxorubicin-induced kidney injuries and inflammation, suggesting a potential clinical treatment for inflammatory kidney diseases.     

Host cellular signaling induced by influenza virus

A wide range of host cellular signal transduction pathways can be stimulated by influenza virus infection. Some of these signal transduction pathways induce the host cell’s innate immune response against influenza virus, while others are essential for efficient influenza virus replication. This review examines the cellular signaling induced by influenza virus infection in host cells, including host pattern recognition receptor (PRR)-related signaling, protein kinase C (PKC), Raf/MEK/ERK and phosphatidylinositol- 3-kinase (PI3K)/Akt signaling, and the corresponding effects on the host cell and/or virus, such as recognition of virus by the host cell, viral absorption and entry, viral ribonucleoprotein (vRNP) export, translation control of cellular and viral proteins, and virus-induced cell apoptosis. Research into influenza virus-induced cell signaling promotes a clearer understanding of influenza virus-host interactions and assists in the identification of novel antiviral targets and antiviral strategies.     

Mitochondrial genome nucleotide substitution pattern between domesticated silkmoth, Bombyx mori, and its wild ancestors, Chinese Bombyx mandarina and Japanese Bombyx mandarina

Bombyx mori and Bombyx mandarina are morphologically and physiologically similar. In this study, we compared the nucleotide variations in the complete mitochondrial (mt) genomes between the domesticated silkmoth, B. mori, and its wild ancestors, Chinese B. mandarina (ChBm) and Japanese B. mandarina (JaBm). The sequence divergence and transition mutation ratio between B. mori and ChBm are significantly smaller than those observed between B. mori and JaBm. The preference of transition by DNA strands between B. mori and ChBm is consistent with that between B. mori and JaBm, however, the regional variation in nucleotide substitution rate shows a different feature. These results suggest that the ChBm mt genome is not undergoing the same evolutionary process as JaBm, providing evidence for selection on mtDNA. Moreover, investigation of the nucleotide sequence divergence in the A+T-rich region of Bombyx mt genomes also provides evidence for the assumption that the A+T-rich region might not be the fastest evolving region of the mtDNA of insects.     

The complete mitochondrial genome of the wild silkworm moth, Actias selene

The complete mitochondrial genome (mitogenome) of Actias selene (Lepidoptera: Saturniidae) was determined to be 15,236 bp, including 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and a control region. The arrangement of 13 PCGs was similar to that of other sequenced lepidopterans. The AT skew of the mitogenome of A. selene was slightly negative, indicating a higher number of T compared to A nucleotides. The nucleotide composition of the mitogenome of A. selene was also biased toward A+T nucleotides (78.91%). All PCGs were initiated by ATN codons, except for the gene encoding cytochrome c oxidase subunit 1 (cox1), which may be initiated by the TTAG, as observed in other lepidopterans. Three genes, including cox1, cox2, and nad5, had incomplete stop codons consisting of just a T. With an exception for trnS1(AGN), all the other tRNA genes displayed a typical clover-leaf structure of mitochondrial tRNA. The A+T-rich region of the mitogenome of A. selene was 339 bp in length, and contains several features common to the Lepidopteras, including non-repetitive sequences, a conserved structure combining the motif ATAGA and an 18-bp poly-T stretch and a poly-A element upstream of trnM gene. Phylogenetic analysis showed that A. selene was close to Saturniidae.     

Recovery of phosphorous from swine wastewater through crystallization

All the phosphate rock Japan needs must be presently imported from abroad because the country has no subterranean phosphorous resources. Therefore, there is a need to accelerate the development of and establish the technologies for phosphorous recovery from waste and wastewater. Swine wastewater has a high potential for phosphorous recovery in Japan. A reactor for removing and recovering phosphorous from swine wastewater was designed with dual functions, crystallization through aeration and separation of formed struvite by settling. However, a dehydration, composting and characterization process was first needed before using sediment sludge, including struvite, on farmland, since the struvite will settle along with huge amounts of other suspended solids (organic matter). For the recovery of pure struvite, an accumulation device was designed and its efficiency examined. The device has a struvite-accumulation face made of stainless steel wire mesh (1 mm in diameter, 1 cm(2) square) to reduce its total weight. During submergence in the aeration column of the demonstration reactor, struvite cross-bridged and accumulated on the face of the device. The struvite could be scraped off easily with only a light brushing, and was found to be approximately 95% pure. Because this device is a very simple structure, it is thought to be acceptable to swine farmers.     

观赏植物分子育种研究进展

分子育种技术在跨越种间隔离障碍、加速育种进程和获得新奇特变异方面具有传统育种技术无法比拟的优势。将其用于观赏植物育种将会极大地提升产品品质并可增强产业竞争力。该文综述了近10年来观赏植物分子育种的研究进展,希望能为国内观赏植物研究者提供一份参考资料。     

Nitidine chloride inhibited the expression of S phase kinase-associated protein 2 in ovarian cancer cells

Nitidine chloride (NC) has been reported to exert its anti-tumor activity in various types of human cancers. However, the molecular mechanism of NC-mediated tumor suppressive function is largely unclear. In the current study, we used several approaches such as MTT, FACS, RT-PCR, Western blotting analysis, invasion assay, transfection, to explore the molecular basis of NC-triggered anti-cancer activity. We found that NC inhibited cell growth, induced cell apoptosis, caused cell cycle arrest in ovarian cancer cells. Emerging evidence has demonstrated that Skp2 plays an important oncogenic role in ovarian cancer. Therefore, we also explored whether NC exerts its biologic function via downregulation of Skp2 in ovarian cancer cells. We observed that NC significantly inhibited the expression of Skp2 in ovarian cancer cells. Notably, overexpression of Skp2 abrogated the anti-cancer activity induced by NC in ovarian cancer cells. Consistently, downregulation of Skp2 expression enhanced the sensitivity of ovarian cancer cells to NC treatment. Thus, inactivation of Skp2 by NC could be a novel strategy for the treatment of human ovarian cancer.