Administration of a maple syrup extract to mitigate their hepatic inflammation induced by a high-fat diet: a transcriptome analysis

Effects of the administration of maple syrup extract (MSX) on hepatic gene expression were investigated in mice fed a high-fat diet. Gene annotation enrichment analysis based on gene ontology revealed some changes in the expression of genes related to lipid metabolism and the immune response in MSX-fed mice. Detailed analysis of these data indicated that MSX ingestion mitigates hepatic inflammation.     

Transcriptome analysis of soybean (Glycine max) root genes differentially expressed in rhizobial,arbuscular mycorrhizal,and dual symbiosis

Journal of Plant Research - Soybean (Glycine max) roots establish associations with nodule-inducing rhizobia and arbuscular mycorrhizal (AM) fungi. Both rhizobia and AM fungi have been shown to...     

Conformational change of ascidiacyclamide caused by asymmetric modification for an isoleucine residue: structural analyses of [Gly], [Leu], and [Phe]ascidiacyclamides by x-ray diffraction and NMR spectroscopy

Ascidiacyclamide, a cytotoxic cyclic peptide from tunicate, is composed of unusual amino acids and has a repeated sequence, c[-thiazole-D-Val-oxazoline-L-Ile-]2 ([Ile]ASC). The symmetric chemical structure has been assumed to be correlated with the cytotoxicity, and it is reasonable to consider that the disturbance of its structure from the C2 symmetry results in the changes of conformation and activity. In order to quantitatively estimate the molecular conformation-activity relationship, an isoleucine residue was substituted by Gly, Leu, or Phe to disturb the C2 symmetry. The conformations of three derivatives were examined by nmr spectroscopy and the crystal structure of [Leu]ASC was also analyzed by x-ray diffraction method. The 1H-nmr experiments and the constrained molecular dynamics simulations showed the twisted "figure 8" conformers for [Gly] and [Phe]ASCs and the "square" conformer for [Leu]ASC in the DMSO solution. The x-ray crystal analysis of [Leu]ASC also revealed the square form similar to the solution structure. On the other hand, their cytotoxic activities were measured using L1210 leukemia cells and were related with the bulkiness and/or hydrophobicity of the side chain of the substituted amino acid; [Phe] > or = [Ile] > [Leu] > [Gly]ASCs. As an attempt to consider the correlation between the activity and conformer, the accessible surface area (ASA) was calculated for each derivative to estimate the size or bulkiness of its conformation. Although the ASAs of nmr structures were not directly related to the type of conformer (figure 8 or square form), it was an important probe to consider the cytotoxicity of each derivative.     

Development of definitive endoderm from embryonic stem cells in culture

The cellular and molecular events regulating the induction and tissue-specific differentiation of endoderm are central to our understanding of the development and function of many organ systems. To define and characterize key components in this process, we have investigated the potential of embryonic stem (ES) cells to generate endoderm following their differentiation to embryoid bodies (EBs) in culture. We found that endoderm can be induced in EBs, either by limited exposure to serum or by culturing in the presence of activin A (activin) under serum-free conditions. By using an ES cell line with the green fluorescent protein (GFP) cDNA targeted to the brachyury locus, we demonstrate that endoderm develops from a brachyury(+) population that also displays mesoderm potential. Transplantation of cells generated from activin-induced brachyury(+) cells to the kidney capsule of recipient mice resulted in the development of endoderm-derived structures. These findings demonstrate that ES cells can generate endoderm in culture and, as such, establish this differentiation system as a unique murine model for studying the development and specification of this germ layer.     

Stable isotope labeling of Arabidopsis thaliana for an NMR-based metabolomics approach

Nuclear magnetic resonance (NMR) will become a key technology in plant metabolomics with the use of stable isotope labeling and advanced hetero-nuclear NMR methodologies. To demonstrate the power of this approach, we performed multi-dimensional hetero-nuclear NMR analysis of metabolic movement of carbon and nitrogen nuclei in Arabidopsis thaliana. First, distinct ethanol-stress response was investigated using (13)C-labeled wild type and an ethanol-hypersensitive mutant plants. Furthermore, we followed nitrogen fluxes in (15)N-labeled seeds during the initiation of germination in vivo. The future role of stable isotope-labeling combined with advanced hetero-nuclear NMR in plant metabolomics is discussed.