Replication Study of ESCC Susceptibility Genetic Polymorphisms Locating in the ADH1B-ADH1C-ADH7 Cluster Identified by GWAS

China was one of the countries with highest esophageal squamous cell carcinoma (ESCC) incidence and mortality worldwide. Alcohol drinking has been identified as a major environmental risk-factor related to ESCC. The alcohol dehydrogenase (ADH) family are major enzymes involved in the alcohol-metabolizing pathways, including alcohol dehydrogenase 1B (ADH1B) and ADH1C. Interestingly, ADH1B and ADH1C genes locate tandemly with ADH7 in a genomic segment as a gene cluster, and are all polymorphic. Several ESCC susceptibility single nucleotide polymorphisms (SNPs) of the ADH1B-ADH1C-ADH7 cluster have been identified previously through a genome-wide association study (GWAS). In the study, we examined the association between five ADH1B-ADH1C-ADH7 cluster SNPs (rs1042026, rs17033, rs1614972, rs1789903 and rs17028973) and risk of developing ESCC. Genotypes were determined in two independent case-control sets from two regions of China. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression. Our data demonstrated that these ADH1B-ADH1C-ADH7 cluster SNPs confer susceptibility to ESCC in these two case-control sets, which were consistent to results of the previous GWAS.     

Product distribution and pre-steady-state kinetic analysis of Escherichia coli undecaprenyl pyrophosphate synthase reaction

Undecaprenyl pyrophosphate synthase (UPPs) catalyzes the condensation of eight molecules of isopentenyl pyrophosphate (IPP) with farnesyl pyrophosphate (FPP) to generate C(55) undecaprenyl pyrophosphate. We investigated the kinetics and mechanism of this reaction pathway using Escherichia coli UPPs. With a variety of different ratios of enzyme to substrate and FPP to IPP in the presence or absence of Triton, different product distributions were found. In the presence of excess FPP, the intermediates (C(25)-C(50)) accumulated. Under a condition with enzyme and FPP in excess of IPP, instead of C(20)-geranylgeranyl pyrophosphate, C(20), C(25), and C(30) were the major products. The UPPs steady-state k(cat) value (2.5 s(-1)) in the presence of 0.1% Triton was 190-fold larger than in the absence of Triton (0.013 s(-1)). The k(cat) value matched the rate constant of each IPP condensation obtained from the enzyme single-turnover experiments. This suggested that the IPP condensation rather than product release was the rate-limiting step in the presence of Triton. In the absence of Triton, the intermediates formed and disappeared in a similar manner under enzyme single turnover in contrast to the slow steady-state rate, which indicated a step after product generation was rate limiting. This was further supported by a burst product formation. Judging from the accumulation level of C(55), C(60), and C(65), their dissociation from the enzyme cannot be too slow and an even slower enzyme conformational change with a rate of 0.001 s(-1) might govern the UPPs reaction rate under the steady-state condition in the absence of Triton.     

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.     

Developing a series of conservative anchor markers and their application to phylogenomics of Laurasiatherian mammals

The availability of numerous universal markers and suitable phylogenetic analysis methods are both very important for phylogenomics inference. Based on PCR amplification, a total of 122 markers, which were amplified in 19 representative species, were developed for Laurasiatherian phylogenomics. Subsequently, we illustrated the utility of these newly developed markers using a subset of eight markers. We showed that both 'supermatrix' and 'supertree' trees generated similar topology, which accorded with the current understanding of the Laurasiatherian phylogeny in most aspects. Thus, markers developed here would be likely to make a contribution to resolving evolutionary relationships and inferring evolutionary histories of the Laurasiatherian mammals in the future.     

Vimentin is important in the neural differentiation of PC12 cells promoted by sialylation

Sialic acid modification is a kind of post-translational modification. To investigate the regulation effect of sialic acid on neural differentiation, we used CycloManN propanyl perac (CycloManN pro), a metabolic precursor of sialic acid, to treat PC12 cells. We noted that CycloManN pro indeed robustly promoted global sialylation detected by MAL II lectin blot in PC12 cells. Simultaneously, we interestingly found that the neurite outgrowth of PC12 cells was significantly promoted by the CycloManN pro treatment. The profile analysis of sialylated proteins showed that a protein band at 55KD was greatly enhanced especially in PC12L cells after CycloManN pro treatment. After enrichment with lectin MAL II, the proteins in this band were analyzed by mass spectrometry. The results showed that 23 proteins were in the band, but the score of vimentin was the highest among them. To investigate further the role of vimentin in the process of neurite differentiation, vimentin construct was transfected into PC12 cells. We interestingly observed that ectopic expression of vimentin significantly enhanced the neurite outgrowth induced by CycloManN pro. However, after three potential glycosylation sites (Ser-7, Thr-33, Ser-34:) of vimentin were mutated to alanine, overexpression of the mutated vimentin completely lost the enhancement activity for the neural differentiation even in the presence of CycloManN pro. Taken together, our study demonstrated that vimentin was important in the induction of neural differentiation by CycloManN pro.     

Ligation activity of FLP recombinase. The strand ligation activity of a site-specific recombinase using an activated DNA substrate.

The FLP protein of the 2-microns plasmid of yeast belongs to the integrase family of site-specific recombinases whose members form a covalent bond between a conserved tyrosine of the recombinase and the 3'-phosphoryl group at the site of cleavage. We have made an activated DNA substrate and have shown that FLP can promote efficient strand ligation without forming a covalent intermediate with the DNA substrate. The strand ligation activity of FLP is independent of its ability to cleave DNA. Since site-specific recombinases are members of the larger class of topoisomerases, these findings may be generally applicable to other members of this class of enzymes.     

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。     

Effect of red mold rice supplements on serum and meat cholesterol levels of broilers chicken

Monacolin K is a secondary metabolite produced by Monascus species. It was found that it is able to decrease cholesterol levels. In this study, red mold rice (RMR) was added to the diet of Arbor Acres broiler chickens, and the cholesterol level in meat, as well as the concentration of triglyceride, the high-density lipoprotein cholesterol (HDL-C), and the low-density lipoprotein cholesterol (LDL-C) in the serum were evaluated. Four-week-old broilers are studied and divided into four groups in that each group contains 15 subjects. A 3-week experimental feeding trial was conducted in which three groups of broilers were fed 2.0, 5.0, and 8.0% of RMR (RMR groups) within their diet, respectively, and the result was compared to the control group. The results indicated that for each RMR group, the cholesterol content was significantly lower than that of the control group; in addition, their meat products contain higher level of unsaturated fatty acids. Triglyceride and cholesterol concentration in serum was also found to be considerably lower in RMR groups when compared to control group. Finally, in RMR groups, HDL-C/LDL-C and HDL-C/cholesterol ratios were all higher than those of the control group. In short, the results demonstrated that the cholesterol levels could be lowered by adding RMR to the diet of chickens.     

Kinetics of the sodium-dependent glutamine transporter in human intestinal cell confluent monolayers.

The intestinal epithelium metabolism of glutamine plays a critical role in inter-organ nitrogen flow. Although it is known that glutamine is the primary oxidative energy source and nucleotide precursor in intestinal cells, the luminal uptake of glutamine by the apical surface of enterocytes is poorly understood. In this study we have uncovered the sodium-dependent transporter system responsible for L-glutamine uptake by the apical membrane of a human intestinal epithelial cell line. The sodium-dependent Michaelis constant (Km) = 247 +/- 45 microM glutamine, and Jmax = 4.44 +/- 0.65 x 10(-9) mole min-1(mg protein)-1 (37 degrees C). Glutamine shares the transporter with alanine, as demonstrated by unlabeled glutamine inhibition of [3H]alanine uptake kinetics with a purely competitive-type inhibition pattern, and glutamine inhibition Ki = 205 +/- 18 microM by Dixon analysis. The inhibition pattern for a series of amino acid analogs indicated that this intestinal apical membrane sodium-dependent transporter for glutamine is distinct from any other transport system found in membranes of non-intestinal cells.