Role of phosphodiesterase in cyclic AMP signaling in cultured rat granulosa cells

Inactivation of the cyclic nucleotide signal in granulosa cells depends on a complex array of cyclic nucleotide phosphodiesterases (PDE). In order to examine the role of PDE in cyclic AMP (cAMP) signaling in granulosa cells, the present study examined the expression of PDE4D proteins and regulation of cAMP-PDE activities in cultured rat granulosa cells. The results of immunoblot analyses showed that two predominant PDE4D subtypes of approximately 80 and 70 kDa appeared when immature rat granulosa cells were treated with FSH. However, these two new subtypes presumed to be PDE4D proteins were not influenced by treatments of DETA/NO, cGMP and PKB inhibitor, LY294002. Immature rat granulosa cells treated with medium alone displayed low cAMP-PDE activity throughout 48 h of culture while those treated with FSH (2 ng.mL-1) showed a marked increase in cAMP-PDE activity between 6 and 12 h of culture, followed by a decline. The findings from the present study indicate that the increased cAMP-PDE activity by FSH is mainly related to the changes of PDE4D protein levels. However, the inhibitory effects of NO on cAMP accumulation in rat granulosa cells are not via the increased cAMP-PDE activity.     

The MRL mouse heart healing response shows donor dominance in allogeneic fetal liver chimeric mice

We previously demonstrated that after a severe cryoinjury to the right ventricle of the heart, adult MRL mice display structural and functional recovery with myocardial tissue replacement resembling that seen in amphibians. The control non-regenerating adult C57BL/6 (B6) mouse shows a predominant scar response. In the present study, radiation chimeras reconstituted with fetal liver cells from either healer MRL or nonhealer B6 mice were generated to test for a transfer of phenotype. Allogeneic MRL fetal liver cells were injected into x-irradiated (9 Gy) B6 mice and B6 fetal liver cells were injected into x-irradiated MRL mice. In these allogeneic chimeras, the healing response to cardiac cryoinjury was predominantly of the donor phenotype. Thus, MRL fetal liver cells transferred the healing phenotype to the B6 nonhealer with the appearance of Y-chromosome positive, donor-derived cardiomyocytes in the injury site and MRL-like healing with little scar. Similarly, B6 fetal liver cells transferred the nonhealing phenotype to the MRL with little cardiomyocyte growth and an acellular B6-like scar. These results are in contrast to the ear hole closure response which was of the recipient phenotype. We conclude that, in the case of the heart, fetal liver-derived stem cells regulate regenerative healing.     

An ordered EST catalogue and gene expression profiles of cassava (<Emphasis Type="Italic">Manihot esculenta</Emphasis>) at key growth stages

A cDNA library was constructed from the root tissues of cassava variety Huanan 124 at the root bulking stage. A total of 9,600 cDNA clones from the library were sequenced with single-pass from the 5′-terminus to establish a catalogue of expressed sequence tags (ESTs). Assembly of the resulting EST sequences resulted in 2,878 putative unigenes. Blastn analysis showed that 62.6% of the unigenes matched with known cassava ESTs and the rest had no ‘hits’ against the cassava database in the integrative PlantGDB database. Blastx analysis showed that 1,715 (59.59%) of the unigenes matched with one or more GenBank protein entries and 1,163 (40.41%) had no ‘hits’. A cDNA microarray with 2,878 unigenes was developed and used to analyze gene expression profiling of Huanan 124 at key growth stages including seedling, formation of root system, root bulking, and starch maturity. Array data analysis revealed that (1) the higher ratio of up-regulated ribosome-related genes was accompanied by a high ratio of up-regulated ubiquitin, proteasome-related and protease genes in cassava roots; (2) starch formation and degradation simultaneously occur at the early stages of root development but starch degradation is declined partially due to decrease in UDP-glucose dehydrogenase activity with root maturity; (3) starch may also be synthesized in situ in roots; (4) starch synthesis, translocation, and accumulation are also associated probably with signaling pathways that parallel Wnt, LAM, TCS and ErbB signaling pathways in animals; (5) constitutive expression of stress-responsive genes may be due to the adaptation of cassava to harsh environments during long-term evolution.     

Biomass yields and energetic yields of oleaginous yeasts in batch culture

This article provides the analysis on biomass yields and energetic yields of the oleaginous yeasts. The biomass yields of the oleaginous yeasts are consistently lower than nonoleaginous microorganisms, whereas their energetic yields are higher. Data inconsistencies of literature are explained by the variation of energy contents of oleaginous yeasts.     

Evidence of hepatitis E virus replication on cell cultures.

Several human and animal cell lines have been used to grow hepatitis E virus. The strain SAR-55 was adapted only on PLF/PLC/5 cell line without any visible cytopathic effect. The growth of the SAR-55 was monitored by examining the positive and the negative strands of HEV-RNA. Stool samples, obtained from hospitalised acute hepatitis patients at the Fever Hospital of Alexandria (Egypt), were used to confirm the susceptibility of PLF/PLC/5 cells. After more than one-week's cultivation, three stool samples out of 17 IgM anti-HEV positive and 1 from 52 IgG anti-HEV positive patients showed a specific RT-PCR amplification product. The nucleotide sequences of the methyltransferase region of the genome in the isolates revealed the maximum homology with Burma strain with several point mutations.     

<Emphasis Type="Italic">Paradevosia shaoguanensis</Emphasis> gen. nov., sp. nov., Isolated from a Coking Wastewater

A Gram staining negative, rod-shaped, aerobic bacterial strain J5-3^T with a single polar flagellum was isolated from coking wastewater collected from Shaoguan, Guangdong, China. It was motile and capable of optimal growth at pH 6–8, 30 °C, and 0–2 % (w/v) NaCl. Its predominant fatty acids were 11-methyl C_18:1 ω7c (29.2 %), C_16:0 (20.6 %), C_19:0 cyclo ω8c (18.2 %), C_18:0 (11.0 %), and C_18:1 ω7c/C_18:1 ω6c (10.9 %) when grown on trypticase soy agar. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, two unknown glycolipids (GL1, GL2), and two unknown phospholipid (PL1, PL2). The predominant ubiquinone was Q-10, and the genome DNA G+C content was 61.7 mol %. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain J5-3^T belonged to the family Hyphomicrobiaceae in Alphaproteobacteria. It shared the 16S rRNA gene sequence similarities of 93.8–96.1 % with the genus Devosia, 94.5–94.8 % with the genus Pelagibacterium, and <92.0 % with all the other type strains in family Hyphomicrobiaceae. It can be distinguished from the closest phylogenetic neighbors based on several phenotypic and genotypic features, including α-galactosidase activity, tetracycline susceptibility, major fatty acid composition, polar lipid profile, DNA gyrase B subunit (gyrB) gene sequence, and random-amplified polymorphic DNA profile. Therefore, we consider strain J5-3^T to represent a novel species of a novel genus within the family Hyphomicrobiaceae, for which the name Paradevosia shaoguanensis gen. nov., sp. nov. is proposed. The type strain of Paradevosia shaoguanensis is J5-3^T (=CGMCC 1.12430^T =LMG 27409^T).     

Characteristic microbial community of a dry thermophilic methanogenic digester: its long-term stability and change with feeding

Thermophilic dry anaerobic digestion of sludge for cellulose methanization was acclimated at 53 °C for nearly 5 years using a waste paper-based medium. The stability of the microbial community structure and the microbial community responsible for the cellulose methanization were studied by 16S rRNA gene-based clone library analysis. The microbial community structure remained stable during the long-term acclimation period. Hydrogenotrophic methanogens dominated in methanogens and Methanothermobacter, Methanobacterium, Methanoculleus, and Methanosarcina were responsible for the methane production. Bacteria showed relatively high diversity and distributed mainly in the phyla Firmicutes, Bacteroidetes, and Synergistetes. Ninety percent of operational taxonomic units (OTUs) were affiliated with the phylum Firmicutes, indicating the crucial roles of this phylum in the digestion. Relatives of Clostridium stercorarium, Clostridium thermocellum, and Halocella cellulosilytica were dominant cellulose degraders. The acclimated stable sludge was used to treat garbage stillage discharged from a fuel ethanol production process, and the shift of microbial communities with the change of feed was analyzed. Both archaeal and bacterial communities had obviously changed: Methanoculleus spp. and Methanothermobacter spp. and the protein- and fatty acid-degrading bacteria became dominant. Accumulation of ammonia as well as volatile fatty acids led to the inhibition of microbial activity and finally resulted in the deterioration of methane fermentation of the garbage stillage.     

Mite allergen Der-p2 triggers human B lymphocyte activation and Toll-like receptor-4 induction

Background

Allergic disease can be characterized as manifestations of an exaggerated inflammatory response to environmental allergens triggers. Mite allergen Der-p2 is one of the major allergens of the house dust mite, which contributes to TLR4 expression and function in B cells in allergic patients. However, the precise mechanisms of Der-p2 on B cells remain obscure.

Methodology/Principal Findings

We investigated the effects of Der-p2 on proinflammatory cytokines responses and Toll-like receptor-4 (TLR4)-related signaling in human B cells activation. We demonstrated that Der-p2 activates pro-inflammatory cytokines, TLR4 and its co-receptor MD2. ERK inhibitor PD98059 significantly enhanced TLR4/MD2 expression in Der-p2-treated B cells. Der-p2 markedly activated mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1) and decreased p38 phosphorylation in B cells. MKP-1-siRNA downregulated TLR4/MD2 expression in Der-p2-treated B cells. In addition, Der-p2 significantly up-regulated expression of co-stimulatory molecules and increased B cell proliferation. Neutralizing Der-p2 antibody could effectively abrogate the Der-p2-induced B cell proliferation. Der-p2 could also markedly induce NF-κB activation in B cells, which could be counteracted by dexamethasone.

Conclusions/Significance

These results strongly suggest that Der-p2 is capable of triggering B cell activation and MKP-1-activated p38/MAPK dephosphorylation-regulated TLR4 induction, which subsequently enhances host immune, defense responses and development of effective allergic disease therapeutics in B cells.     

LTP inhibits LTD in the hippocampus via regulation of GSK3beta

Glycogen synthase kinase-3 (GSK3) has been implicated in major neurological disorders, but its role in normal neuronal function is largely unknown. Here we show that GSK3beta mediates an interaction between two major forms of synaptic plasticity in the brain, N-methyl-D-aspartate (NMDA) receptor-dependent long-term potentiation (LTP) and NMDA receptor-dependent long-term depression (LTD). In rat hippocampal slices, GSK3beta inhibitors block the induction of LTD. Furthermore, the activity of GSK3beta is enhanced during LTD via activation of PP1. Conversely, following the induction of LTP, there is inhibition of GSK3beta activity. This regulation of GSK3beta during LTP involves activation of NMDA receptors and the PI3K-Akt pathway and disrupts the ability of synapses to undergo LTD for up to 1 hr. We conclude that the regulation of GSK3beta activity provides a powerful mechanism to preserve information encoded during LTP from erasure by subsequent LTD, perhaps thereby permitting the initial consolidation of learnt information.     

食药用菌酸乳制作中深层发酵滤液添加量的比较

利用深层发酵培养基对两种食药用菌（香菇、猴头菌）进行深层发酵培养,然后分别将香菇（猴头菌）发酵滤液、奶粉、无菌水按不同比例配制成相应的复原奶,并接种乳酸菌制成酸乳。同时检测不同比例发酵滤液添加量所制得的酸乳的营养和理化特性,选择出了最佳比例的滤液添加量,即香菇滤液添加量以3份较好,而猴头菌则以4份滤液添加量最佳。