Yamogenin in fenugreek inhibits lipid accumulation through the suppression of gene expression in fatty acid synthesis in hepatocytes

Yamogenin is a diastereomer of diosgenin, which we have identified as the compound responsible for the anti-hyperlipidemic effect of fenugreek. Here, we examined the effects of yamogenin on the accumulation of triacylglyceride (TG) in hepatocytes, because yamogenin is also contained in fenugreek. It was demonstrated that yamogenin also inhibited TG accumulation in HepG2 hepatocytes and suppressed the mRNA expression of fatty acid synthesis-related genes such as fatty acid synthase and sterol response element-binding protein-1c. Indeed, yamogenin also antagonized the activation of the liver X receptor (LXR) in luciferase ligand assay similar to diosgenin. However, yamogenin could not exert such effects in the presence of T0901713, a potent agonist of LXR. These findings indicate that the effects of yamogenin on TG accumulation would be weaker than those of diosgenin, suggesting that the structural difference between yamogenin and diosgenin would be important for the inhibition of LXR activation.     

Polyethylene Glycol–Modified Papain Catalyzed Oligopeptide Synthesis from the Esters of l-Aspartic and l-Glutamic Acids in Benzene

Comparative studies were made of the polymerization of l-aspartic and l-glutamic acid dialkyl esters using polyethylene glycol–modified papain as a catalyst in phosphate buffer (pH 7.5) and in benzene. Changes in the substrate specificity of papain and in the composition of oligomerized products were observed. In the buffer, the diethyl and di-n-propyl esters of l-glutamic acid were sufficiently converted to high molecular weight oligomers with the accumulation of dimer and trimer, but l-aspartic acid esters were very poor substrates. In benzene, l-aspartic acid esters became more reactive than L-glutamic acid esters. In particular, from l-aspartic acid dimethyl ester the product, which was mainly composed of heptamer to decamer, was obtained in a 90% yield. The reaction in benzene required desalted substrates and a small amount of water to proceed extensively.     

QTL‐seq: rapid mapping of quantitative trait loci in rice by whole genome resequencing of DNA from two bulked populations

The majority of agronomically important crop traits are quantitative, meaning that they are controlled by multiple genes each with a small effect (quantitative trait loci, QTLs). Mapping and isolation of QTLs is important for efficient crop breeding by marker‐assisted selection (MAS) and for a better understanding of the molecular mechanisms underlying the traits. However, since it requires the development and selection of DNA markers for linkage analysis, QTL analysis has been time‐consuming and labor‐intensive. Here we report the rapid identification of plant QTLs by whole‐genome resequencing of DNAs from two populations each composed of 20–50 individuals showing extreme opposite trait values for a given phenotype in a segregating progeny. We propose to name this approach QTL‐seq as applied to plant species. We applied QTL‐seq to rice recombinant inbred lines and F₂ populations and successfully identified QTLs for important agronomic traits, such as partial resistance to the fungal rice blast disease and seedling vigor. Simulation study showed that QTL‐seq is able to detect QTLs over wide ranges of experimental variables, and the method can be generally applied in population genomics studies to rapidly identify genomic regions that underwent artificial or natural selective sweeps.     

Angiogenesis in the mouse retina: a model system for experimental manipulation

The vascular system of the mouse retina provides a useful model for analyzing the molecular and cellular mechanisms regulating angiogenesis because (1) hierarchical vascular networks are newly formed only after birth, (2) the cellular components involved in angiogenesis are well characterized, and (3) all the processes are accessible for monitoring and manipulation. In this article, we present an overview of our current understanding of the process of retinal angiogenesis and describe a number of methodologies applicable to experimental manipulation of the retinal vascular system.     

Involvement of inositol 1,4,5-trisphosphate in Ca2+ influx in thrombin stimulated human platelets

By incubating platelets at low temperature (10 degrees C), the relationship between Ca2+ mobilization and formation of inositol 1,4,5-trisphosphate (IP3) in thrombin stimulated platelets could be precisely investigated. In the presence of 1 mM EGTA, time dependent changes in the intracellular free calcium concentration [( Ca2+]i) were closely related to those in IP3 formation. Time course of the influx of external Ca2+, estimated by delta [Ca2+]i obtained by subtracting [Ca2+]i in the presence of 1 mM EGTA from that in the presence of 1 mM CaCl2 was also very similar to that of IP3 formed. Furthermore, the increase in delta [Ca2+]i was extremely well correlated with the amount of IP3 formed (Y = 49X - 34, r = 0.99). Thus, these data indicate that IP3 might be involved not only in intracellular Ca2+ mobilization but in Ca2+ influx of human platelets stimulated by thrombin.     

Electron microscopic and pharmacological studies on the rat median eminence

Summary The rat median eminence contains at least three kinds of granules or vesicles: 1. large electron-dense granules (perhaps carriers of neurohypophysial hormones), 2. small electron-dense granules with or without haloes (perhaps carriers of catecholamines) and 3. synaptic vesicle-like structures (perhaps carriers of acetylcholine). The former two electrondense granules exist in separate axons but they coexist with the latter vesicles in the same axons.The pars nervosa shows basically a similar structure to the median eminence. However, the axons containing the small electron-dense granules are very few. In the pars tuberalis, there are at least two types of cells: the cells of one type contain much cytoplasm with large round nuclei and those of the other type contain a small amount of cytoplasm with polymorphic nuclei. The cells of the former include multivesicular bodies and secretory granules, but those of the latter do not. Some of capillaries of the primary plexus are surrounded by the cells of the pars tuberalis on one side and by neurosecretory axon endings on the other side.The median eminence contains high concentration of acetylcholine or an acetylcholine-like substance and shows neurohypophysial hormone activity.Aided by Grant A-3678 from the United States National Institute of Arthritis and Metabolic Diseases. The authors are indebted to Dr. Welsh, Harvard University, for the kind gift of Mytolon.     

Induced pluripotent stem cell‐derived myeloid cells expressing OX40 ligand amplify antigen‐specific T cells in advanced melanoma

Immune checkpoint inhibitors improved the survival rate of patients with unresectable melanoma. However, some patients do not respond, and variable immune‐related adverse events have been reported. Therefore, more effective and antigen‐specific immune therapies are urgently needed. We previously reported the efficacy of an immune cell therapy with immortalized myeloid cells derived from induced pluripotent stem cells (iPS‐ML). In this study, we generated OX40L‐overexpressing iPS‐ML (iPS‐ML‐Zsgreen‐OX40L) and investigated their characteristics and in vivo efficacy against mouse melanoma. We found that iPS‐ML‐Zsgreen‐OX40L suppressed the progression of B16‐BL6 melanoma, and prolonged survival of mice with ovalbumin (OVA)‐expressing B16 melanoma (MO4). The number of antigen‐specific CD8⁺ T cells was higher in spleen cells treated with OVA peptide‐pulsed iPS‐ML‐Zsgreen‐OX40L than in those without OX40L. The OVA peptide‐pulsed iPS‐ML‐Zsgreen‐OX40L significantly increased the number of tumor‐infiltrating T lymphocytes (TILs) in MO4 tumor. Flow cytometry showed decreased regulatory T cells but increased effector and effector memory T cells among the TILs. Although we plan to use allogeneic iPS‐ML in the clinical applications, iPS‐ML showed the tumorgenicity in the syngeneic mice model. Incorporating the suicide gene is necessary to ensure the safety in the future study. Collectively, these results indicate that iPS‐ML‐Zsgreen‐OX40L therapy might be a new method for antigen‐specific cancer immunotherapy.     

Immunogenicity and safety of an inactivated quadrivalent influenza vaccine in healthy adults: a phase II,open‐label,uncontrolled trial in Japan

Two antigenically distinct B strain lineages of influenza virus have co‐circulated since the mid‐1980s; however, inactivated trivalent influenza vaccines contain only one B lineage. The mismatch between the circulating and vaccine lineages has been a worldwide issue. In this study, an inactivated quadrivalent influenza vaccine (QIV) candidate containing two B lineages was manufactured and its immunogenicity and safety evaluated in an open‐label, uncontrolled trial. In this phase II trial, 50 subjects aged 20–64 years received two doses of QIV s.c. 1 to 4 weeks apart. Sera were collected pre‐ and post‐vaccination and safety assessed from the first vaccination to 21 ± 7 days after the second vaccination. After the first vaccination, hemagglutination inhibition titers against each strain increased markedly; the seroconversion rate, geometric mean titer ratio and seroprotection rate being 94.0%, 24.93, and 100.0%, respectively, for the A/H1N1pdm09 strain; 94.0%, 12.47, and 98.0%, respectively, for the A/H3N2 strain; 54.0%, 4.99, and 66.0%, respectively, for B/Yamagata strain, and 72.0%, 6.23 and 80.0%, respectively, for the B/Victoria strain, thus fulfilling the criteria of the European Medical Agency's Committee for Medicinal Products for Human Use. Also, the QIV induced sufficient single radial hemolysis and neutralizing antibodies against all four vaccine strains. No noteworthy adverse events were noted. The results of this trial demonstrate that QIV is well tolerated and immunogenic for each strain, suggesting that QIV potentially improves protection against influenza B by resolving the issue of B lineage mismatch.     

Glutamate receptor δ1 induces preferentially inhibitory presynaptic differentiation of cortical neurons by interacting with neurexins through cerebellin precursor protein subtypes

Glutamate receptor (GluR) δ1 is widely expressed in the developing forebrain, whereas GluRδ2 is selectively expressed in cerebellar Purkinje cells. Recently, we found that trans-synaptic interaction of postsynaptic GluRδ2 and pre-synaptic neurexins (NRXNs) through cerebellin precursor protein (Cbln) 1 mediates excitatory synapse formation in the cerebellum. Thus, a question arises whether GluRδ1 regulates synapse formation in the forebrain. In this study, we showed that the N-terminal domain of GluRδ1 induced inhibitory presynaptic differentiation of some populations of cultured cortical neurons. When Cbln1 or Cbln2 was added to cultures, GluRδ1 expressed in HEK293T cells induced preferentially inhibitory presynaptic differentiation of cultured cortical neurons. The synaptogenic activity of GluRδ1 was suppressed by the addition of the extracellular domain of NRXN1α or NRXN1β containing splice segment 4. Cbln subtypes directly bound to the N-terminal domain of GluRδ1. The synaptogenic activity of GluRδ1 in the presence of Cbln subtypes correlated well with their binding affinities. When transfected to cortical neurons, GluRδ1 stimulated inhibitory synapse formation in the presence of Cbln1 or Cbln2. These results together with differential interactions of Cbln subtypes with NRXN variants suggest that GluRδ1 induces preferentially inhibitory presynaptic differentiation of cortical neurons by interacting with NRXNs containing splice segment 4 through Cbln subtypes.