Enzyme inactivation and quality preservation of sake by high-pressure carbonation at a moderate temperature

The effect of a high-pressure carbonation treatment on the change in quality of sake during storage was investigated. Measurements of the amino acidity and isovaleraldehyde content of carbonated sake (20 MPa pressure at 40, 45 and 50 degrees C for 7, 21 and 33 min, respectively) as well as of heat-treated sake (reaching temperature of 65 degrees C and immediately cooled) were almost unchanged during storage at 3 and 20 degrees C. Glucose in the sake subjected to these treatments was retained at an almost constant under the same storage conditions, except for the sake carbonated at 40 degrees C and stored at 20 degrees C. In contrast, the amino acidity, and glucose and isovaleraldehyde contents of non-pasteurized (fresh) sake increased during storage at both temperatures. The sake samples subjected to the carbonation treatment and heat treatment both gave better sensory scores than the fresh sake sample after 6 month of storage at 3 and 20 degrees C, especially at 3 degrees C for the flavor. These results suggest that the high-pressure carbonation treatment is an effective new technique for preserving the quality of sake.     

Exploiting the Extraordinary Genetic Polymorphism of Ciona for Developmental Genetics with Whole Genome Sequencing

Studies in tunicates such as Ciona have revealed new insights into the evolutionary origins of chordate development. Ciona populations are characterized by high levels of natural genetic variation, between 1 and 5%. This variation has provided abundant material for forward genetic studies. In the current study, we make use of deep sequencing and homozygosity mapping to map spontaneous mutations in outbred populations. With this method we have mapped two spontaneous developmental mutants. In Ciona intestinalis we mapped a short-tail mutation with strong phenotypic similarity to a previously identified mutant in the related species Ciona savignyi. Our bioinformatic approach mapped the mutation to a narrow interval containing a single mutated gene, α-laminin3,4,5, which is the gene previously implicated in C. savignyi. In addition, we mapped a novel genetic mutation disrupting neural tube closure in C. savignyi to a T-type Ca²⁺ channel gene. The high efficiency and unprecedented mapping resolution of our study is a powerful advantage for developmental genetics in Ciona, and may find application in other outbred species.     

miR-33a-5p in small extracellular vesicles as non-invasive biomarker for oxaliplatin sensitivity in human colorectal cancer cells

microRNAs (miRNAs) contained in small extracellular vesicles (sEVs) are candidates for non-invasive biomarkers. Oxaliplatin (L-OHP) has been approved for advanced colorectal cancer (CRC) chemotherapy. However, the response to L-OHP differs among CRC patients. In addition, CRC cells often acquire the resistance to L-OHP. This study aimed at the prediction of L-OHP sensitivity by measuring extracellular miRNAs levels. Firstly, we compared intracellular miRNAs expressions in L-OHP-sensitive CRC cells (SW620 and HCT116 cells) with those in acquired and intrinsic L-OHP-resistant cells. In microarray and real-time RT-PCR analyses, the intracellular miR-33a-5p, miR-210–3p, and miR-224–5p expressions were lower in acquired and intrinsic L-OHP-resistant CRC cells than sensitive cells. Furthermore, in SW620 cells, L-OHP sensitivity was decreased by miR-33a-5p inhibitor. On the other hand, miR-210–3p or miR-224–5p inhibitor did not affect L-OHP sensitivity in SW620 cells. Secondly, the amount of miR-33a-5p, miR-210–3p, and miR-224–5p in sEVs was compared. The amount of miR-33a-5p and miR-210–3p in sEVs secreted from acquired and intrinsic L-OHP-resistant cells tended to be small. miR-224–5p was not detected in sEVs secreted from three types of CRC cells examined. To the best of our knowledge, this is the first study demonstrating that miR-33a-5p and/or miR-210–3p in sEVs would be candidates for biomarkers of L-OHP sensitivity. In particular, miR-33a-5p is a promising candidate because it would be directly involved in L-OHP sensitivity.     

GPAT2, a mitochondrial outer membrane protein,in piRNA biogenesis in germline stem cells

piRNA (PIWI-interacting RNA) is a germ cell–specific small RNA in which biogenesis PIWI (P-element wimpy testis) family proteins play crucial roles. MILI (mouse Piwi-like), one of the three mouse PIWI family members, is indispensable for piRNA production, DNA methylation of retrotransposons presumably through the piRNA, and spermatogenesis. The biogenesis of piRNA has been divided into primary and secondary processing pathways; in both of these MILI is involved in mice. To analyze the molecular function of MILI in piRNA biogenesis, we utilized germline stem (GS) cells, which are derived from testicular stem cells and possess a spermatogonial phenotype. We established MILI-null GS cell lines and their revertant, MILI-rescued GS cells, by introducing the Mili gene with Sendai virus vector. Comparison of wild-type, MILI-null, and MILI-rescued GS cells revealed that GS cells were quite useful for analyzing the molecular mechanisms of piRNA production, especially the primary processing pathway. We found that glycerol-3-phosphate acyltransferase 2 (GPAT2), a mitochondrial outer membrane protein for lysophosphatidic acid, bound to MILI using the cells and that gene knockdown of GPAT2 brought about impaired piRNA production in GS cells. GPAT2 is not only one of the MILI bound proteins but also a protein essential for primary piRNA biogenesis.     

Isobutanol production from cellobiose in Escherichia coli

Converting lignocellulosics into biofuels remains a promising route for biofuel production. To facilitate strain development for specificity and productivity of cellulosic biofuel production, a user friendly Escherichia coli host was engineered to produce isobutanol, a drop-in biofuel candidate, from cellobiose. A beta-glucosidase was expressed extracellularly by either excretion into the media, or anchoring to the cell membrane. The excretion system allowed for E. coli to grow with cellobiose as a sole carbon source at rates comparable to those with glucose. The system was then combined with isobutanol production genes in three different configurations to determine whether gene arrangement affected isobutanol production. The most productive strain converted cellobiose to isobutanol in titers of 7.64?±?0.19 g/L with a productivity of 0.16 g/L/h. These results demonstrate that efficient cellobiose degradation and isobutanol production can be achieved by a single organism, and provide insight for optimization of strains for future use in a consolidated bioprocessing system for renewable production of isobutanol.     

Paraoxonase gene Gln192Arg (Q192R) polymorphism is associated with coronary artery spasm

We recently reported that oxidative stress is involved in the pathogenesis of coronary spasm. We hypothesized that oxidative-stress-related genetic factors and certain polymorphisms in the paraoxonase gene (PON1) and platelet-activating factor acetylhydrolase (PAF-AH) might influence the pathogenesis of coronary spasm. We therefore examined the possible association between the PON1 Q192R or PAF-AH V279F polymorphisms and coronary spasm in 214 patients with coronary spasm and 212 control subjects. Genotypes were determined by polymerase chain reaction/restriction fragment length polymorphism analysis. The incidence of the PON1-192R allele was significantly higher in the coronary spasm group than in the control group (65% vs 53%; P=0.0005). The PAF-AH-279F allele was not associated with coronary spasm (15% vs. 16%; P=0.8781). Multiple logistic regression analysis with forward stepwise selection involving the PON1-192R allele and the environmental risk factors revealed that the most predictive independent risk factor for coronary spasm was the PON1-192R allele (significance=0.0016, OR=2.52), followed by cigarette smoking (significance=0.0007, OR=2.01). We also measured plasma levels of TBARS (thiobarbituric acid-reactive substances) as a marker of oxidative stress. TBARS levels were higher in R/R types than in Q/Q types (2.115+/-0.086 nmol/ml [ n=25] vs 1.676+/-0.102 nmol/ml [ n=11], P<0.01). Thus, there is a significant association between the PON1-192R allele and coronary spasm; the PON1-192R allele may play an important role in the genesis of coronary spasm, probably by attenuating the suppression of oxidative stress.     

The Cell Adhesion Molecule Necl-4/CADM4 Serves as a Novel Regulator for Contact Inhibition of Cell Movement and Proliferation

Contact inhibition of cell movement and proliferation is critical for proper organogenesis and tissue remodeling. We show here a novel regulatory mechanism for this contact inhibition using cultured vascular endothelial cells. When the cells were confluently cultured, Necl-4 was up-regulated and localized at cell–cell contact sites where it cis-interacted with the vascular endothelial growth factor (VEGF) receptor. This interaction inhibited the tyrosine-phosphorylation of the VEGF receptor through protein-tyrosine phosphatase, non-receptor type 13 (PTPN13), eventually reducing cell movement and proliferation. When the cells were sparsely cultured, Necl-4 was down-regulated but accumulated at leading edges where it inhibited the activation of Rho-associated protein kinase through PTPN13, eventually facilitating the VEGF-induced activation of Rac1 and enhancing cell movement. Necl-4 further facilitated the activation of extracellular signal-regulated kinase 1/2, eventually enhancing cell proliferation. Thus, Necl-4 serves as a novel regulator for contact inhibition of cell movement and proliferation cooperatively with the VEGF receptor and PTPN13.