The identification of a novel <Emphasis Type="Italic">Pleurotus ostreatus</Emphasis> dsRNA virus and determination of the distribution of viruses in mushroom spores

Double-stranded RNAs and virus particles were identified in Pleurotus ostreatus strain Shin-Nong in Korea. Isometric virus particles with a diameter of 33 nm were purified, which are similar to other Pleurotus viruses reported previously. This strain contains 5 dsRNAs, 8.0, 2.5, 2.4, 2.0, and 1.8 kb in size. The virus particles contain 2 dsRNAs, designated RNA-1 (2.5 kb), and RNA-2 (2.4 kb) which is a typical pattern of Partitiviridae. A non-encapsidated dsRNA of about 8.0 kb also was identified. Partial cDNA from RNA-1 was cloned, and sequence analysis revealed that this gene codes for RdRp. The comparison of the sequence from partial cDNA clone showed 35% amino acid homology with the C-terminal end of the RdRp gene of Helicobasidum mompa virus and Rosalinia necatrix virus. Specific primers designed from the partial sequences successfully amplified RT-PCR product from the infected mycelium and a single spore culture. We used these primers to determine the pattern of distribution of viruses in spores. Of the 96 different single spore cultures generated from Shin-Nong strain, a specific RT-PCR product was identified in 25 cultures, indicating that about 26% of basidiospores contain viruses.     

Angiotensin II-induced differentiation of adipose tissue-derived mesenchymal stem cells to smooth muscle-like cells

Angiotensin II (Ang II) is involved in the development of cardiovascular disease and vascular remodeling. In this study, we demonstrate that treatment of human adipose tissue-derived mesenchymal stem cells (hADSCs) with Ang II increased the expression of smooth muscle-specific genes, including alpha-smooth muscle actin (alpha-SMA), calponin, h-caldesmon, and smooth muscle myosin heavy chain (SM-MHC), and also elicited the secretion of transforming growth factor-beta1 (TGF-beta1) and delayed phosphorylation of Smad2. The Ang II-induced expression of alpha-SMA and delayed phosphorylation of Smad2 were blocked by pretreatment of the cells with a TGF-beta type I receptor kinase inhibitor, SB-431542, small interference RNA-mediated depletion of endogenous Smad2, and adenoviral expression of Smad7. Furthermore, the Ang II-induced TGF-beta1 secretion, alpha-SMA expression, and delayed phosphorylation of Smad2 in hADSCs were abrogated by the MEK inhibitor U0126, suggesting a pivotal role of MEK/ERK pathway in the Ang II-induced activation of TGF-beta1-Smad2 signaling pathway. The smooth muscle-like cells which were differentiated from hADSCs by Ang II treatment exhibited contraction in response to 60mM KCl. These results suggest that Ang II induces differentiation of hADSCs to contractile smooth muscle-like cells through ERK-dependent activation of the autocrine TGF-beta1-Smad2 crosstalk pathway.     

Inhibition of casein kinase 1-epsilon induces cancer-cell-selective,PERIOD2-dependent growth arrest

Background  

Kinases are under extensive investigation as targets for drug development. Discovering novel kinases whose inhibition induces cancer-cell-selective lethality would be of value. Recent advances in RNA interference have enabled the realization of this goal.     

Regulation of in vitro calcium phosphate mineralization by combinatorially selected hydroxyapatite-binding peptides

We report selection and characterization of hydroxyapatite-binding heptapeptides from a peptide-phage library and demonstrate the effects of two peptides, with different binding affinities and structural properties, on the mineralization of calcium phosphate mineral. In vitro mineralization studies carried out using one strong- and one weak-binding peptide, HABP1 and HABP2, respectively, revealed that the former exhibited a drastic outcome on mineralization kinetics and particle morphology. Strong-binding peptide yielded significantly larger crystals, as observed by electron microscopy, in comparison to those formed in the presence of a weak-binding peptide or in the negative control. Molecular structural studies carried out by circular dichroism revealed that HABP1 and HABP2 differed in their secondary structure and conformational stability. The results indicate that sequence, structure, and molecular stability strongly influence the mineralization activity of these peptides. The implication of the research is that the combinatorially selected short-sequence peptides may be used in the restoration or regeneration of hard tissues through their control over of the formation of calcium phosphate biominerals.     

Indoleamine 2,3-dioxygenase-expressing dendritic cells are involved in the generation of CD4+CD25+ regulatory T cells in Peyer's patches in an orally tolerized, collagen-induced arthritis mouse model

Introduction

The present study was devised to understand the role of systemic indoleamine 2,3-dioxygenase (IDO) in the tolerance induction for orally tolerized mice in collagen-induced arthritis (CIA). We examined whether IDO-expressing dendritic cells (DCs) are involved in the generation of CD4⁺CD25⁺ regulatory T cells during the induction of oral tolerance in a murine CIA model.

Methods

Type II collagen was fed six times to DBA/1 mice beginning 2 weeks before immunization, and the effect on arthritis was assessed. To examine the IDO expression, the DCs of messenger RNA and protein were analyzed by RT-PCR and Flow cytometry. In addition, a proliferative response assay was also carried out to determine the suppressive effects of DCs through IDO. The ability of DCs expressing IDO to induce CD4⁺CD25⁺ T regulatory cells was examined.

Results

CD11c⁺ DCs in Peyer's patches from orally tolerized mice expressed a higher level of IDO than DCs from nontolerized CIA mice. IDO-expressing CD11c⁺ DCs were involved in the suppression of type II collagen-specific T-cell proliferation and in the downregulation of proinflammatory T helper 1 cytokine production. The suppressive effect of IDO-expressing CD11c⁺ DCs was mediated by Foxp3⁺CD4⁺CD25⁺ regulatory T cells.

Conclusion

Our data suggest that tolerogenic CD11c⁺ DCs are closely linked with the induction of oral tolerance through an IDO-dependent mechanism and that this pathway may provide a new therapeutic modality to treat autoimmune arthritis.     

Antizyme suppression leads to an increment of the cellular redox potential and an induction of HIF-1alpha: its involvement in resistance to gamma-radiation

The mammalian antizyme (AZ) promotes ubiqutin-independent degradation of ornithine decarboxylase, a key enzyme in polyamine biosynthesis. This study shows that AZ suppression in human lung carcinoma A549 cells caused growth defects and death, but made the cells resistant to DNA damaging agents such as gamma-radiation and cisplatin. In these cells, the cellular redox potential (glutathione/glutathione disulfide [GSH/GSSG] ratio) was increased and thus intracellular reactive oxygen species were severely diminished, which might cause growth defects and cell death. The increase of cellular redox potential was mainly caused by dramatic increase of the cytoplasmic nicotinamide adenine dinucleotide phosphate (NADP)(+)-dependent isocitrate dehydrogenase, which generates the reducing equivalents NADPH. In the AZ-suppressed cells, the hypoxia inducible factor 1alpha (HIF-1alpha) was also increased. As in other cases which showed an increment of HIF-1alpha and the cellular redox potential, the AZ-suppressed cells showed resistance to gamma-radiation and anticancer drugs. Therefore, these facts might be considered as important for the use of radio- and chemotherapy on tumor cells which show an unbalance in their polyamine levels.     

A catalog of neutral and deleterious polymorphism in yeast

The abundance and identity of functional variation segregating in natural populations is paramount to dissecting the molecular basis of quantitative traits as well as human genetic diseases. Genome sequencing of multiple organisms of the same species provides an efficient means of cataloging rearrangements, insertion, or deletion polymorphisms (InDels) and single-nucleotide polymorphisms (SNPs). While inbreeding depression and heterosis imply that a substantial amount of polymorphism is deleterious, distinguishing deleterious from neutral polymorphism remains a significant challenge. To identify deleterious and neutral DNA sequence variation within Saccharomyces cerevisiae, we sequenced the genome of a vineyard and oak tree strain and compared them to a reference genome. Among these three strains, 6% of the genome is variable, mostly attributable to variation in genome content that results from large InDels. Out of the 88,000 polymorphisms identified, 93% are SNPs and a small but significant fraction can be attributed to recent interspecific introgression and ectopic gene conversion. In comparison to the reference genome, there is substantial evidence for functional variation in gene content and structure that results from large InDels, frame-shifts, and polymorphic start and stop codons. Comparison of polymorphism to divergence reveals scant evidence for positive selection but an abundance of evidence for deleterious SNPs. We estimate that 12% of coding and 7% of noncoding SNPs are deleterious. Based on divergence among 11 yeast species, we identified 1,666 nonsynonymous SNPs that disrupt conserved amino acids and 1,863 noncoding SNPs that disrupt conserved noncoding motifs. The deleterious coding SNPs include those known to affect quantitative traits, and a subset of the deleterious noncoding SNPs occurs in the promoters of genes that show allele-specific expression, implying that some cis-regulatory SNPs are deleterious. Our results show that the genome sequences of both closely and distantly related species provide a means of identifying deleterious polymorphisms that disrupt functionally conserved coding and noncoding sequences.     

Change in platelet endothelial cell adhesion molecule-1 immunoreactivity in the dentate gyrus in gerbils fed a folate-deficient diet

Folate deficiency increases stroke risk. We examined whether folate deficiency affects platelet endothelial cell adhesion molecule-1 (PECAM-1), which is an immunoglobulin-associated cell adhesion molecule and mediates the final common pathway of neutrophil transendothelial migration, in blood vessels in the gerbil dentate gyrus after transient forebrain ischemia. Gerbils were exposed to a folic acid-deficient diet (FAD) for 3 months and then subjected to common carotid artery occlusion for 5 min. In the control diet (CD)- and FAD-treated sham-operated groups, weak PECAM-1 immunoreactivity was detected in the blood vessels located in the dentate gyrus. PECAM-1 immunoreactivity in both groups was increased by 4 days after ischemic insult. PECAM-1 immunoreactivity in the FAD-treated group was twice as high that in the CD-treated-sham-operated group 4 days after ischemic insult. Western blot analyses showed that the change patterns in PECAM-1 protein levels in the dentate gyrus in both groups after ischemic insult were similar to changes in PECAM-1 immunohistochemistry in the ischemic dentate gyrus. Our results suggest that folate deficiency enhances PECAM-1 in the dentate gyrus induced by transient ischemia.     

韩国新纪录属拟纹赤眼蜂属及一新种记述(膜翅目,赤眼蜂科)

首次报道了拟纹赤眼蜂属Lathromeroidea Girault在韩国的分布,并记述了1新种,多齿拟纹赤眼蜂Lathromeriodea multidenta sp.nov.。新种与L.ajmerensis Yousuf＆Shafee相似,但新种痣脉短于缘脉的一半,痣后脉较为发达,产卵器着生于腹部腹面基部;新种与L.silvarum Nowicki也相似,但前者个体较大,上颚具5齿,第3～5节棒节长度比例也不相同。正模标本保存于韩国首尔国立大学无脊椎动物资源库,副模保存于新疆大学生命科学与技术学院昆虫研究室。