and methamphetamine-induced locomotor stimulation and stereotyped behaviors in rats [S-7]. Despite these significant functional roles in the central nervous system, the presence of free D-amino acids in mammalian brain has not yet btien demonstrated, with the exception of the small amounts of free neutral amino acids in mice and human brains [8,9] and of free D-aspartate in adult rat and human brains (less than 3% of total aspartate) [l&12]. In the present study, we report the identification and the concentration of the free D-enantiomer of serine in adult rat brain using gas chromatographic (GC) analy- MATERIALS AND METHODSAll amino acids and trichloroacctic acid (TCA) were oblainrd rrom Nakardi Tcsquc (Japan). All solvcnls were HPLC grade and purchased from Kanto Chemicals (Japan). A pcntafluoropropionic anhydride (PFPA) was purchased from G.L.C. Scicncc (Japun). The column head pressure was I IO kPa. and the helium flow-mu on the column was 0.4 ml/min; the flow-rate (plus auxiliary gas) was 30 mllmin. The hydrogen flow-ralc and the air flow-rate al the dctcctor were 3.5 and I IO ml/min, rcspcctivcly. Peak arca was dclcrmined using a SIC chromalocorder I I intcgralor (Syslcm Inslrumcnu Co.). rWS umi/~v.si,sThe GC-MS analysis was pcrrormcd on a V.G. Masslab Trio-l mass spectrometer (Jasco, ImcrnaGonal Co., Japan), equipped with a Hcwlcu Packard 5890A gas chromalograph. The GC condilions wcrc the Same as for the GC analysis with the cxcplion oi a spiititisj. injection. The mass spcctromctcr con&ions wcrc: clcc~ron accclcraling voliugc, 70 cV; inicrracc tcmpcr?lurc, 170°C; photomul1iplicr 33

Microbiota have been shown to have a great influence on functions of intestinal epithelial cells (ECs). The role of indole as a quorum-sensing (QS) molecule mediating intercellular signals in bacteria has been well appreciated. However, it remains unknown whether indole has beneficial effects on maintaining intestinal barriers in vivo. In this study, we analyzed the effect of indole on ECs using a germ free (GF) mouse model. GF mice showed decreased expression of junctional complex molecules in colonic ECs. The feces of specific pathogen-free (SPF) mice contained a high amount of indole; however the amount was significantly decreased in the feces of GF mice by 27-fold. Oral administration of indole-containing capsules resulted in increased expression of both tight junction (TJ)- and adherens junction (AJ)-associated molecules in colonic ECs in GF mice. In accordance with the increased expression of these junctional complex molecules, GF mice given indole-containing capsules showed higher resistance to dextran sodium sulfate (DSS)-induced colitis. A similar protective effect of indole on DSS-induced epithelial damage was also observed in mice bred in SPF conditions. These findings highlight the beneficial role of indole in establishing an epithelial barrier in vivo.

No abstract

Many priniciples of sequence-specific DNA recognition have been established over the past decade, largely from structural studies of protein-DNA and drug-DNA complexes. On the basis of these principles, it has been possible to design or select variants of known structural motifs, including zinc-fingers and minor groove-binding drugs, that bind desired sequences. Here we describe a strategy, based on transcriptional termination in bacteria, to identify specific RNA-binding peptides using the arginine-rich RNA-binding motif as a framework. Peptides were isolated from two combinatorial libraries that bind tightly and specifically to the Rev response element of HIV. It appears that alpha-helical peptides resembling Rev were selected from one library whereas new peptides that probably do not form helices were selected from the other, suggesting that the arginine-rich motif may be a particularly versatile framework for recognizing RNA structures.

Salt stress is one of the most important factors limiting plant cultivation. Many investigations of plant response to high salinity have been performed using conventional transcriptomics and/or proteomics approaches. However, transcriptomics and proteomics techniques are not all-encompassing methods that can achieve exclusive insights into the metabolite networks contributing to biochemical reactions. Hence, the functions of the complex stress response pathways are yet to be determined, especially at the metabolic level. A time-course metabolic profiling with Arabidopsis thaliana cell cultures after the imposition of salt stress is reported in this study. Analyses of primary metabolites, especially small polar metabolites such as amino acids, sugars, sugar alcohols, organic acids, and amines, was performed by GC/MS and LC/MS at 0.5, 1, 2, 4, 12, 24, 48, and 72 h after a salt-stress treatment with 100 mM NaCl being the final concentration. The mass chromatographic data were converted into matrix data sets, which were subjected to data mining processes, including principal component analysis (PCA) and batch-learning self-organizing mapping analysis (BL-SOM). The mining results suggest that the methylation cycle for the supply of methyl groups, the phenylpropanoid pathway for lignin production, and glycinebetaine biosynthesis are synergetically induced as a short-term response against salt-stress treatment. The results also suggest the the co-induction of glycolysis and sucrose metabolism as well as co-reduction of the methylation cycle as long-term responses to salt stress.