Continuous intake of a high-fat diet beyond one generation promotes lipid accumulation in liver and white adipose tissue of female mice

Lipid metabolism in a child may be altered when the mother has a high-fat diet (HFD), but it is unclear whether the lipid metabolism of future offspring (grandchildren) is also changed under these circumstances. In this study, we examined the influence of intake of an HFD beyond one generation on offspring in normal mice. Parent mice fed an HFD were bred and the resultant second and third generations were also fed an HFD. The diets used in the study had approximately 20% more energy than a standard chow diet. Changes in lipid metabolism were examined in each generation. Intake of an HFD from generation to generation promoted lipid accumulation in the white adipose tissue of female mice, increased lipid, glucose and insulin levels in the serum, increased the activities of enzymes associated with fatty acid metabolism in the liver, promoted lipid accumulation in hepatocytes and adipocytes and increased the mRNA levels of Cdkn1a in the liver and white adipose tissue. These results suggest that activation of Cdkn1a promoted lipid accumulation in the liver and white adipose tissue of third-generation female mice that were offspring from earlier generations fed HFDs. Moreover, intake of a high-energy diet beyond one generation led to offspring with obesity, fatty liver and hyperinsulinemia.     

Toxicoproteomic analysis of a mouse model of nonsteroidal anti-inflammatory drug-induced gastric ulcers

Nonsteroidal anti-inflammatory drugs (NSAIDs) are valuable agents; however, their use has been limited by their association with mucosal damage in the upper gastrointestinal tract. NSAIDs inhibit cyclooxygenase and consequently block the synthesis of prostaglandins, which have cytoprotective effects in gastric mucosa; these effects on prostaglandins have been thought to be major cause of NSAID-induced ulceration. However, studies indicate that additional NSAID-related mechanisms are involved in formation of gastric lesions. Here, we used a toxicoproteomic approach to understand cellular processes that are affected by NSAIDs in mouse stomach tissue during ulcer formation. We used fluorogenic derivatization-liquid chromatography-tandem mass spectrometry (FD-LC-MS/MS)-which consists of fluorogenic derivatization, separation and fluorescence detection by LC, and identification by LC-tandem mass spectrometry-in this proteomic analysis of pyrolic stomach from control and diclofenac (Dic)-treated mice. FD-LC-MS/MS results were highly sensitive; 10 differentially expressed proteins were identified, and all 10 were more highly expressed in Dic-treated mice than in control mice. Specifically, expression levels of 78 kDa glucose-regulated protein (GRP78), heat shock protein beta-1 (HSP27), and gastrin were more than 3-fold higher in Dic-treated mice than in control mice. This study represents a first step to ascertain the precise actors of early NSAID-induced ulceration.     

Expression screening of 17q12-21 amplicon reveals GRB7 as an ERBB2-dependent oncogene

Gene amplification is a major genetic alteration in human cancers. Amplicons, amplified genomic regions, are believed to contain "driver" genes responsible for tumorigenesis. However, the significance of co-amplified genes has not been extensively studied. We have established an integrated analysis system of amplicons using retrovirus-mediated gene transfer coupled with a human full-length cDNA set. Applying this system to 17q12-21 amplicon observed in breast cancer, we identified GRB7 as a context-dependent oncogene, which modulates the ERBB2 signaling pathway through enhanced phosphorylation of ERBB2 and Akt. Our work provides an insight into the biological significance of gene amplification in human cancers.     

Efficient and Reproducible Myogenic Differentiation from Human iPS Cells: Prospects for Modeling Miyoshi Myopathy In Vitro

The establishment of human induced pluripotent stem cells (hiPSCs) has enabled the production of in vitro, patient-specific cell models of human disease. In vitro recreation of disease pathology from patient-derived hiPSCs depends on efficient differentiation protocols producing relevant adult cell types. However, myogenic differentiation of hiPSCs has faced obstacles, namely, low efficiency and/or poor reproducibility. Here, we report the rapid, efficient, and reproducible differentiation of hiPSCs into mature myocytes. We demonstrated that inducible expression of myogenic differentiation1 (MYOD1) in immature hiPSCs for at least 5 days drives cells along the myogenic lineage, with efficiencies reaching 70–90%. Myogenic differentiation driven by MYOD1 occurred even in immature, almost completely undifferentiated hiPSCs, without mesodermal transition. Myocytes induced in this manner reach maturity within 2 weeks of differentiation as assessed by marker gene expression and functional properties, including in vitro and in vivo cell fusion and twitching in response to electrical stimulation. Miyoshi Myopathy (MM) is a congenital distal myopathy caused by defective muscle membrane repair due to mutations in DYSFERLIN. Using our induced differentiation technique, we successfully recreated the pathological condition of MM in vitro, demonstrating defective membrane repair in hiPSC-derived myotubes from an MM patient and phenotypic rescue by expression of full-length DYSFERLIN (DYSF). These findings not only facilitate the pathological investigation of MM, but could potentially be applied in modeling of other human muscular diseases by using patient-derived hiPSCs.     

Phosphorylation of neuroglycan C, a brain-specific transmembrane chondroitin sulfate proteoglycan, and its localization in the lipid rafts

Neuroglycan C (NGC) is a brain-specific transmembrane chondroitin sulfate proteoglycan. In the present study, we examined whether NGC could be phosphorylated in neural cells. On metabolic labeling of cultured cerebral cortical cells from the rat fetus with (32)P(i), serine residues in NGC were radiolabeled. Some NGC became detectable in the raft fraction from the rat cerebrum, a signaling microdomain of the plasma membrane, with cerebral development. NGC from the non-raft fraction, not the raft fraction, could be phosphorylated by an in vitro kinase reaction. The phosphorylation of NGC was inhibited by adding to the reaction mixture a recombinant peptide representing the ectodomain of NGC, but not by adding a peptide representing its cytoplasmic domain. NGC could be labeled by an in vitro kinase reaction using [gamma-(32)P]GTP as well as [gamma-(32)P]ATP, and this kinase activity was partially inhibited by 5,6-dichloro-1-beta-d-ribofuranosylbenzimidazole, a selective inhibitor of casein kinase II. In addition to the intracellular phosphorylation, NGC was also phosphorylated at the cell surface by an ectoprotein kinase. This is the first report to demonstrate that NGC can be phosphorylated both intracellularly and pericellularly, and our findings suggest that a kinase with a specificity similar to that of casein kinase II is responsible for the NGC ectodomain phosphorylation.     

Westerdykella globosa,a proposal for a new combination

The surface ornamentation of ascospores ofPreussia globosa was compared in an isolate from paddy soil in Japan and a culture derived from the holotype. The ascospores of two cultures were characterized by the surface ornamentation of a single, semicircular spiral ridge. This new finding strongly suggested that the fungus should be transferred to the genusWesterdykella. Therefore, the morphological and cultural characters of the fungus were re-examined, and the new combinationWesterdykella globosa is herein proposed.     

Solution NMR views of dynamical ordering of biomacromolecules

Background

To understand the mechanisms related to the ‘dynamical ordering’ of macromolecules and biological systems, it is crucial to monitor, in detail, molecular interactions and their dynamics across multiple timescales. Solution nuclear magnetic resonance (NMR) spectroscopy is an ideal tool that can investigate biophysical events at the atomic level, in near-physiological buffer solutions, or even inside cells.

Regulation of Cellular Senescence by Polycomb Chromatin Modifiers through Distinct DNA Damage- and Histone Methylation-Dependent Pathways

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