Nup211, the fission yeast homolog of Mlp1/Tpr,is involved in mRNA export

Synthetic lethal mutants have been previously isolated in fission yeast Schizosaccharomyces pombe, which genetically interact with spmex67, in order to identify the genes involved in mRNA export. The nup211 gene was isolated by complementation of the growth defect in one of the synthetic lethal mutants, SLMex2, under synthetic lethal condition. We showed that Nup211, fission yeast homolog of Mlpl/Mlp2/Tpr, is essential for vegetative growth and Nup211-GFP proteins expressed at endogenous level are localized mainly in nuclear periphery. The accumulation of poly(A)⁺ RNA in the nucleus is exhibited when expression of nup211 is repressed or over-expressed. These results suggest that the Nup211 protein plays a pivotal role of mRNA export in fission yeast.     

Induction of growth phase-specific autolysis in <Emphasis Type="Italic">Bacillus subtilis</Emphasis> 168 by growth inhibitors

Growth phase-specific autolysis of Bacillus subtilis by inhibitors of membrane permeability, inhibitors of macromolecule biosynthesis, inhibitors of cell wall biosynthesis and detergents were tested and characterized in glucose limited liquid medium. The minimum autolysin induction concentration (MAIC) of test compounds, which was at least l/20th lower than the conventional autolysis induction concentration, induced autolysis only for cells at the glucose exhaustion point (diauxic point) of the growth phase, while it was not induced for cells at pre- and post-diauxic points. Inhibitors of macromolecule synthesis that are not known for inducing autolysis, such as chloramphenicol, rifampicin, nalidixic acid, and detergents, also induced specific autolysis. Two types of autolysis corresponding to the concentrations of compounds are distinguished: concentration-sensitive and concentration-insensitive types.     

Effect of SiO2-ionized loess on the treatment of tinea pedis

SiO₂-ionized loess was prepared from the reaction of loess and sodium hydroxide at 1,400°C. The antifungal activity of SiO₂-ionized loess against Trichophyton tonsurans, causing tinea, was examined by comparing against that of untreated loess. Soap containing SiO₂-ionized loess was used for clinical efficacy tests in the evaluation of the treatment of tinea pedis. The mineral components in loess were maintained after the reaction and the content of ignite loss was decreased to 0.64%, compared to loess. The antifungal ratio reached 56.8% on medium containing 2.0% SiO₂-ionized loess and 81.1% on medium containing greater than 3.0% SiO₂-ionized loess. However, medium containing untreated loess had no antifungal activity. A clinical efficacy test revealed that soap containing the SiO₂-ionized loess led to a significant improvement in symptoms, with the efficacy increasing as the duration of treatment increased.     

Preliminary estimation of chum salmon stock composition in the Bering Sea and North Pacific Ocean using polymorphic microsatellite DNA markers

Variation at the three microsatellite (ms) DNA loci in chum salmon was applied to estimate preliminarily the stock composition using a conditional maximum likelihood method in more than 700 fish collected from 14 stations in the Bering Sea and adjacent North Pacific Ocean during September 2003. Regional stock assignment accuracy with these msDNA markers was nearly the same as the previous estimation with mitochondrial (mt) DNA for the Japanese and North American stocks, but decreased for Russian stocks. The temporal stock estimation with msDNA gave a nonrandom distribution pattern of chum stocks, in that the Japanese and Russian stocks increased in the western to central Bering Sea, and the North American stocks were abundant in the eastern Bering Sea and near the Aleutian Islands. However, predominance of the North American stocks in nearly all of the surveyed area was different from the previous mtDNA estimation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Glycogen synthase kinase-3β regulates etoposide-induced apoptosis via Bcl-2 mediated caspase-3 activation in C3H10T1/2 cells

Glycogen synthase kinase-3β (GSK3β) controls the survival of osteoblasts during bone development through Wnt canonical signaling. GSK3β is a key factor for osteoblastogenesis, but relatively less is known regarding its role in osteoblast apoptosis. Genotoxic stress induced by etoposide promoted apoptotic signaling by GSK3β activation in C3H10T1/2 cells, a mouse mesenchymal cell line. Etoposide led to the time-dependent activation of GSK3β and caspase-3, which resulted in PARP cleavage. LiCl (a specific inhibitor) and siRNA (gene knock-down) of GSK3β prevented the effects of etoposide on apoptosis. Staurosporine also induced apoptosis in C3H10T1/2 cells, but LiCl could not rescue. Bcl-2 was decreased in the cells by exposure to etoposide. LiCl completely recovered Bcl-2 expression as shown by both the mRNA and the protein expression levels. In conclusion, etoposide-induced apoptosis in C3H10T1/2 cells is mediated by GSK3β, which leads to caspase-3 activation via decrease in Bcl-2 expression. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Expression regulation and function of Pref-1 during adipogenesis of human mesenchymal stem cells (MSCs)

Preadipocyte Factor 1 (Pref-1), also known as Delta-like Protein 1 (DLK-1) is an epidermal growth factor-like domain-containing trans-membrane protein that is involved in adipogenesis and cell fate decision. Its function in adipogenesis is reported inconsistently based on different cellular model systems. Here, by using human mesenchymal stem cells (MSCs), we show that Pref-1 is modulated by both dexamethasone and 3-isobutyl-1methylxanthine (IBMX), two components of the adipogenic induction mixture during the adipogenesis in vitro. IBMX induces the expression of Pref-1 in a time- and dose-dependent manner through cyclic AMP and cyclic GMP independent pathway and attenuates adipocyte differentiation by down-regulating PPARγ (peroxisome proliferator activated receptor gamma) expression. Dexamethasone, on the other hand, is capable of subduing the inhibitory effect of IBMX-induced Pref-1 and initiating the adipogenesis by up-regulating PPARγ expression. Moreover, the treatment of IBMX or dexamethasone alone fails to develop MSCs into mature adipocytes, however, treating cells with both IBMX and dexamethasone leads to a complete adipocyte differentiation as evaluated by lipid-droplet formation. Taken together, our study demonstrates that IBMX accelerates accumulation of lipid in MSCs only under the circumstance that the negative effect of Pref-1 induced by IBMX on the adipogenesis is overcome by dexamethasone.     

Mytilid mussels: global habitat engineers in coastal sediments

Dense beds of mussels of the family Mytilidae occur worldwide on soft-bottoms in cold and warm temperate coastal waters and have usually been considered hot spots of biodiversity. We examined intertidal mussel beds at four distant locations around the globe with the same sampling method, to find out whether this “hot spot” designation holds universally. We studied species assemblages within the matrices of byssally interconnected mussels engineered by Mytilus edulis in the North Sea, by mixed Perumytilus purpuratus and Mytilus chilensis at the southern Chilean coast, by Musculista senhousia in the Yellow Sea and by Xenostrobus inconstans at the coast of southern Australia. In all cases, species assemblages inside mussel beds were significantly different from those outside with many species being restricted to one habitat type. However, species richness and diversity were not generally higher in mussel beds than in ambient sediments without mussels. In the North Sea (M. edulis) and at the Chilean coast (P. purpuratus, M. chilensis), mussel beds have markedly higher species numbers and diversities than surrounding sediments, but this was not the case for mussel beds in Australia (X. inconstans) and the Yellow Sea (M. senhousia) where numbers of associated species were only slightly higher and somewhat lower than in adjacent sediments, respectively. In conclusion, although soft bottom mytilid mussels generally enhance habitat heterogeneity and species diversity at the ecosystem level, mussel beds themselves are not universal centres of biodiversity, but the effects on associated species are site specific.     

Modeling the Growth/No-Growth Boundaries of Postprocessing Listeria monocytogenes Contamination on Frankfurters and Bologna Treated with Lactic Acid

This study developed models to predict lactic acid concentration, dipping time, and storage temperature combinations determining growth/no-growth interfaces of Listeria monocytogenes at desired probabilities on bologna and frankfurters. L. monocytogenes was inoculated on bologna and frankfurters, and 75 combinations of lactic acid concentrations, dipping times, and storage temperatures were tested. Samples were stored in vacuum packages for up to 60 days, and bacterial populations were enumerated on tryptic soy agar plus 0.6% yeast extract and Palcam agar on day zero and at the end point of storage. The combinations that allowed L. monocytogenes increases of ≥1 log CFU/cm² were assigned the value of 1 (growth), and the combinations that had increases of <l log CFU/cm² were given the value of 0 (no growth). These binary growth response data were fitted to logistic regression to develop a model predicting probabilities of growth. Validation with existing data and various indices showed acceptable model performance. Thus, the models developed in this study may be useful in determining probabilities of growth and in selecting lactic acid concentrations and dipping times to control L. monocytogenes growth on bologna and frankfurters, while the procedures followed may also be used to develop models for other products, conditions, or pathogens.     

Interleukin-6 induces proinflammatory signaling in Schwann cells: A high-throughput analysis

Interleukin-6 plays an important role in peripheral nerve regeneration. We recently reported that IL-6 targets Schwann cells in the peripheral nerve for its function. In this study, we analyzed genes whose expression is regulated by IL-6 in a cell line derived from Schwann cells, the peripheral glia, using the Illumina gene microarray. At measurements 3 and 12 h after IL-6 treatment, 35 genes were found to be upregulated by IL-6. Most upregulated genes were proinflammatory genes that are known to be induced in inflammatory conditions. Interestingly, the expression of immunoproteasome subunits was upregulated by IL-6 in Schwann cells. Treatment with forskolin, an agent that mimics axonal signaling, suppressed the expression of IL-6-inducible genes. Finally, we found for the first time that sciatic nerve injury induced immunoproteasome expression in vivo. These findings indicate that IL-6 is involved in peripheral nerve regeneration by regulating proinflammatory signaling in Schwann cells.