Pacer Is a Mediator of mTORC1 and GSK3-TIP60 Signaling in Regulation of Autophagosome Maturation and Lipid Metabolism

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Multilocus patterns of genetic variation across Cryptosporidium species suggest balancing selection at the gp60 locus

Cryptosporidium is an apicomplexan protozoan that lives in most vertebrates, including humans. Its gp60 gene is functionally involved in its attachment to host cells, and its high level of genetic variation has made it the reference marker for sample typing in epidemiological studies. To understand the origin of such high diversity and to determine the extent to which this classification applies to the rest of the genome, we analysed the patterns of variation at gp60 and nine other nuclear loci in isolates of three Cryptosporidium species. Most loci showed low genetic polymorphism (π_S <1%) and similar levels of between‐species divergence. Contrastingly, gp60 exhibited very different characteristics: (i) it was nearly ten times more variable than the other loci; (ii) it displayed a significant excess of polymorphisms relative to between‐species differences in a maximum‐likelihood Hudson–Kreitman–Aguadé test; (iii) gp60 subtypes turned out to be much older than the species they were found in; and (iv) showed a significant excess of polymorphic variants shared across species from random expectations. These observations suggest that this locus evolves under balancing selection and specifically under negative frequency‐dependent selection (FDS). Interestingly, genetic variation at the other loci clusters very well within the groups of isolates defined by gp60 subtypes, which may provide new tools to understand the genome‐wide patterns of genetic variation of the parasite in the wild. These results suggest that gp60 plays an active and essential role in the life cycle of the parasite and that genetic variation at this locus might be essential for the parasite's long‐term success.     

Analysis of population structure among Korean and Japanese Legionella pneumophila isolates using hsp60 sequences

The population structure of Korean (150 strains) and Japanese (92 strains) Legionella pneumophila isolates along with 18 reference strains were investigated using hsp60 sequence (1647 bp) analysis. Twelve clonal subgroups (hsP-I to hsP-X and hsF-I and hsF-II) were designated on the hsp60 tree, inferred from representative sequences using the neighbor-joining method. Some of the isolates showed unique subgroups depending on the source of isolates, including hsP-I, hsF-I, and hsF-II from cooling tower water, and subgroups hsP-VIII and hsP-X from circulating hot water bath. These subgroups may be useful for epidemiological studies to chase or specify sources of infection in Korea and Japan.     

60Co-γ射线诱变选育富硒酵母菌株

本试验以产朊假丝酵母菌(Candida utilis)为出发菌株,通过60Co-γ射线诱变,采用Na2SeO3抗性平板初筛和摇瓶培养复筛的方法,获得了一株高硒和高硒蛋氨酸含量的菌株CU7,与出发菌株相比,生物量达到10.58g/L、总硒提高了2.01倍.硒蛋氨酸的含量提高了2.44倍,硒蛋氨酸与总硒的比值也由49.85...     

Proteome analysis of rat liver mitochondria reveals a possible compensatory response to endotoxic shock

Organ failure induced by endotoxic shock has recently been associated with affected mitochondrial function. In this study, effects of in vivo lipopolysaccharide-challenge on protein patterns of rat liver mitochondria in treated animals versus controls were studied by two-dimensional electrophoresis (differential image gel electrophoresis). Significant upregulation was found for ATP-synthase alpha chain and superoxide dismutase [Mn]. Our data suggest that endotoxic shock mediated changes in the mitochondrial proteome contribute to a compensatory reaction (adaptation to endotoxic shock) rather than to a mechanism of cell damage.     

Effect of the β-amyloid peptide Aβ<Subscript>25–35</Subscript> and fullerene C<Subscript>60</Subscript> on the activity of enzymes in erythrocytes

The effect of the β-amyloid peptide Aβ_25–35 and fullerene C₆₀ on the activity of the cytoplasmic enzymes lactate dehydrogenase (LDH) and glutathione peroxidase (GLP), and membrane-bound phosphofructokinase (PFK) and Na⁺,K⁺-ATPase in human erythrocytes has been studied. When used in combination, the cytotoxins decrease the activity of LDH and PFK in a nonadditive manner; in this case, Aβ_25–35 protects PFK against the inhibitory effect of C₆₀. The activity of LDH, GLP, and PFK decreases within the first 2–20 min of incubation of erythrocytes with Aβ_25–35 in the absence of glucose. The addition of glucose sharply decreases the inhibitory action of Aβ_25–35 on LDH and GLP but does not affect the fourfold decrease in activity of PFK; the activity of membrane-bound Na⁺,K⁺-ATPase does not depend on the presence of glucose. Possible mechanisms of interaction of Aβ_25–35 and fullerene C₆₀ with the erythrocyte membrane and enzymes are discussed.     

A comparison of in vitro anticancerous activity and mechanism of ethanolic extracts from different Ganoderma genus

Five ethanolic extracts from the mycelia of Ganoderma lucidum, G. tsugae, G. oerstedii, G. subamboinense, and G. resinaceum were respectively studied on their anticancerous activities against leukemic HL-60 cell line in vitro. Results showed that all five extracts potently inhibited HL-60 proliferation. The extract from G. lucidum mycelia exerted the highest activity. Annexin V/PI bivariate flow cytometric analysis further revealed that the five extracts significantly induced early apoptosis in HL-60 cells. The results illustrate that not only G. lucidum but also other Ganoderma species can inhibit cancer cells, and their mechanisms are related to induction of apoptosis. __________ Translated from Journal of Shanghai Normal University (Natural Sciences), 2005, 34(2): 77–81 [译自: 上海师范大学学报 (自然科学版), 2005, 34(2): 77–81]     

基于CdSe掺杂锐钛矿TiO_2的可见光体外灭活HL60细胞实验研究

用超声驱动方法合成了CdSe/TiO_2复合纳米粒子,并通过扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、紫外可见光(UV-Vis)吸收光谱和荧光(FS)光谱对CdSe/TiO_2复合纳米粒子进行表征。使用CCK-8法测定CdSe/TiO_2对白血病细胞的可见光光催化活性并通过SEM研究HL60细胞的表面超微结构形态。实验结果表明,用CdSe/TiO_2复合纳米粒子处理的组中观察到明显的HL60细胞生长抑制,并且HL60细胞在CdSe掺杂TiO_2复合纳米粒子作用下的PDT效率显著高于TiO_2,表明可以通过CdSe的修饰有效增强TiO_2的可见光光催化活性。此外,CdSe/TiO_2在可见光辐照下在4μg/m L的终值浓度下显示非常高的光动力效率,达76%。荧光光谱分析表明,CdSe/TiO_2复合纳米粒子可能通过分离光生空穴电子对提高此复合纳米粒子的光催化活性,从而提高CdSe/TiO_2对HL60细胞的PDT灭活效率。     

Phospholipid chlorohydrins cause ATP depletion and toxicity in human myeloid cells

Chlorohydrins of stearoyl-oleoyl phosphatidylcholine (SOPC), stearoyl-linoleoyl phosphatidylcholine, and stearoyl-arachidonyl phosphatidylcholine were incubated with cultured myeloid cells (HL60) for 24 h, and the cellular ATP level was measured using a bioluminescent assay. The chlorohydrins caused significant depletion of cellular ATP in the range 10–100 μM. The ATP depletion by the phospholipid chlorohydrins was slightly less than that of 4-hydroxy-2-nonenal, but greater than that of hexanal, trans-2-nonenal, and autoxidised palmitoyl-arachidonoyl phosphatidylcholine. SOPC chlorohydrin was also found to cause loss of viability in U937 cells, and thus phospholipid chlorohydrins could contribute to the formation of a necrotic core in advanced atherosclerotic lesions.