The Influence of a High‐Fat Dietary Environment in the Fetal Period on Postnatal Metabolic and Immune Function

Few reports show whether a high‐fat (HF) dietary environment in the fetal period affects immune function or the development of lifestyle‐related disease at maturity. We examined the influence of an HF dietary environment in the fetal period on postnatal metabolic and immune function. A total of 16 pregnant mice were given control (CON) diet and 16 were given HF diet in the gestational period, from mating to delivery. After delivery lactating mice were given either CON or HF diet, resulting in four groups. After weaning, the offspring mice were given the same diet that their mothers received during lactation. HF dietary intake in the postnatal period increased fat pad weights, serum glucose, and leptin levels. An HF diet in the fetal period resulted in fewer splenic lymphocytes, a thinner thymic cortex, and impaired antigen‐specific immune reactions. Furthermore, tumor necrosis factor (TNF)‐α production and serum triglyceride levels were elevated in the fetal HF group. In addition, the HF‐HF group showed a consistent decrease in ovalbumin (OVA)‐specific IgG and elevation of IgE, associated with advanced fatty changes in the liver. Results from this study suggest that HF environment during the fetal period induces epigenetic propensity toward obesity and immunological burden in part due to increased adipose tissue mass, significant reduction in the number of immune cells and decreased activities of immune cells.     

Selective Enhancement of Donor Hematopoietic Cell Engraftment by the CXCR4 Antagonist AMD3100 in a Mouse Transplantation Model

The interaction between stromal cell-derived factor-1 (SDF-1) with CXCR4 chemokine receptors plays an important role in hematopoiesis following hematopoietic stem cell transplantation. We examined the efficacy of post transplant administration of a specific CXCR4 antagonist (AMD3100) in improving animal survival and in enhancing donor hematopoietic cell engraftment using a congeneic mouse transplantation model. AMD3100 was administered subcutaneously at 5 mg/kg body weight 3 times a week beginning at day +2 post-transplant. Post-transplant administration of AMD3100 significantly improves animal survival. AMD3100 reduces pro-inflammatory cytokine/chemokine production. Furthermore, post transplant administration of AMD3100 selectively enhances donor cell engraftment and promotes recovery of all donor cell lineages (myeloid cells, T and B lymphocytes, erythrocytes and platelets). This enhancement results from a combined effect of increased marrow niche availability and greater cell division induced by AMD3100. Our studies shed new lights into the biological roles of SDF-1/CXCR4 interaction in hematopoietic stem cell engraftment following transplantation and in transplant-related mortality. Our results indicate that AMD3100 provides a novel approach for enhancing hematological recovery following transplantation, and will likely benefit patients undergoing transplantation.     

Hypotonic buffer induces meiosis and formation of anucleate cytoplasmic islands in the egg of the two-spotted cricket Gryllus bimaculatus

In insects, egg activation is known to occur in vivo and independently of fertilization, but its mechanisms are poorly understood. To gain understanding of these mechanisms, an attempt was made to activate the egg of Gryllus bimaculatus in vitro. It was found that meiosis resumed and was completed in unfertilized eggs treated with hypotonic buffer. Early developmental processes in activated, unfertilized eggs were investigated and compared with those in fertilized eggs. Mitosis did not progress, resulting in formation of anucleate cytoplasmic islands (pseudoenergids). Development in the activated, unfertilized eggs stopped at this stage and both yolk subdivision and cellularization did not occur. To elucidate the role of the nucleus in the developmental process to the syncytial stage in fertilized eggs, eggs were treated with aphidicolin to inhibit DNA polymerization. It was found that pseudoenergids also formed in these aphidicolin-treated fertilized eggs. These results demonstrate that pseudoenergids can increase in number independently of nuclei, suggesting that the cytoplasm rather than the nucleus plays the primary role in development to the syncytial stage in G. bimaculatus.     

piggyBac-mediated somatic transformation of the two-spotted cricket, Gryllus bimaculatus

Transgenic insects have been artificially produced to study functions of interesting developmental genes, using insect transposons such as piggyBac. In the case of the cricket, however, transgenic animals have not yet been successfully artificially produced. In the present study, we examined whether the piggyBac transposon functions as a tool for gene delivery in embryos of Gryllus bimaculatus. We used either a piggyBac helper plasmid or a helper RNA synthesized in vitro as a transposase source. An excision assay revealed that the helper RNA was more effective in early Gryllus eggs to transpose a marker gene of eGFP than the helper plasmid containing the piggyBac transposase gene driven by the G. bimaculatus actin3/4 promoter. Further, only when the helper RNA was used, somatic transformation of the embryo with the eGFP gene was observed. These results suggest that the piggyBac system with the helper RNA may be effective for making transgenic crickets.     

Substrate specificity of aminopeptidase from the mid-gut gland of the scallop (Patinopecten yessoensis)

An action for various peptides and a kinetic study for amino acid p-nitroanilides (pNAs) and 4-methylcoumaryl-7-amides (MCAs) were performed with purified aminopeptidase from the mid-gut of the scallop. The enzyme preferred dipeptides having Ala, Met, and Phe in the amino-terminal or the penultimate position from the amino-termini. The catalytic efficiencies, k(cat)/K(m) values for Ala-pNA and MCA were the highest in the tested substrates, and those for pNA and MCA substrates having Met or Phe were the next highest. The enzyme was found to be a new alanine-specific aminopeptidase.     

Long-term proliferation in culture and germline transmission of mouse male germline stem cells

Spermatogenesis is a complex process that originates in a small population of spermatogonial stem cells. Here we report the in vitro culture of spermatogonial stem cells that proliferate for long periods of time. In the presence of glial cell line-derived neurotrophic factor, epidermal growth factor, basic fibroblast growth factor, and leukemia inhibitory factor, gonocytes isolated from neonatal mouse testis proliferated over a 5-month period (>10(14)-fold) and restored fertility to congenitally infertile recipient mice following transplantation into seminiferous tubules. Long-term spermatogonial stem cell culture will be useful for studying spermatogenesis mechanism and has important implications for developing new technology in transgenesis or medicine.     

BAK alters neuronal excitability and can switch from anti- to pro-death function during postnatal development

BAK is a pro-apoptotic BCL-2 family protein that localizes to mitochondria. Here we evaluate the function of BAK in several mouse models of neuronal injury including neuronotropic Sindbis virus infection, Parkinson's disease, ischemia/stroke, and seizure. BAK promotes or inhibits neuronal death depending on the specific death stimulus, neuron subtype, and stage of postnatal development. BAK protects neurons from excitotoxicity and virus infection in the hippocampus. As mice mature, BAK is converted from anti- to pro-death function in virus-infected spinal cord neurons. In addition to regulating cell death, BAK also protects mice from kainate-induced seizures, suggesting a possible role in regulating synaptic activity. BAK can alter neurotransmitter release in a direction consistent with its protective effects on neurons and mice. These findings suggest that BAK inhibits cell death by modifying neuronal excitability.     

Crystal structures of deoxy- and carbonmonoxyhemoglobin F1 from the hagfish Eptatretus burgeri

Hagfish are extremely primitive jawless fish of disputed ancestry. Although generally classed with lampreys as cyclostomes ("round mouths"), it is clear that they diverged from them several hundred million years ago. The crystal structures of the deoxy and CO forms of hemoglobin from a hagfish (Eptatretus burgeri) have been solved at 1.6 and 2.1 A, respectively. The deoxy crystal contains one dimer and two monomers in a unit cell, with the dimer being similar to that found in lamprey deoxy-Hb, but with a larger interface and different relative orientation of the partner chains. Ile(E11) and Gln(E7) obstruct ligand binding in the deoxy form and make room for ligands in the CO form, but no interaction path between the two hemes could be identified. The BGH core structure, which forms the alpha1beta1 interface of all vertebrate alpha2beta2 tetrameric Hbs, is conserved in hagfish and lamprey Hbs. It was shown previously that human and cartilaginous fish Hbs have independently evolved stereochemical mechanisms other than the movement of the proximal histidine to regulate ligand binding at the hemes. Our results therefore suggest that the formation of the alpha2beta2 tetramer using the BGH core and the mechanism of quaternary structure change evolved between the branching points of hagfish and lampreys from other vertebrates.     

Jatropham derivatives and steroidal saponins from the bulbs of Lilium hansonii.

Two new jatropham derivatives and three new steroidal saponins were isolated from the fresh bulbs of Lilium hansonii, along with previously known compounds. The structures of the new compounds were elucidated, on the basis of spectroscopic data and chemical evidence, and by comparing them with those of known compounds, as (-)-5-hydroxy-3-methyl-3-pyrrolin-2-one (jatropham) 5-O-beta-D-glucopyranosyl-(1----3)-beta-D-glucopyranoside, (2S*,4R*)-1-(3-methyl-2-oxo-3-pyrrolinyl)-4-methyl-5-oxo-2-pyrr olidinecarboxyli c acid, 26-O-beta-D-glucopyranosyl-(25R)-5 alpha-furostan-3 beta,22 zeta-diol 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[beta-D-glucopyranosyl-(1----4)]- beta-D-glucopyranoside, (25R)-5 alpha-spirostan-3 beta,12 alpha-diol 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[beta-D-glucopyranosyl-(1----4)]- beta-D-glucopyranoside and (25R)-spirost-5-en-3 beta,12 alpha-diol 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[beta-D-glucopyranosyl-(1----4)]- beta-D-glucopyranoside, respectively. The stereostructure of jatropham dimer, the plain structure of which was presented previously, was confirmed by X-ray crystallographic analysis. The inhibitory activity on cyclic AMP phosphodiesterase of the steroidal saponins was evaluated.     

Non-canonical functions of hunchback in segment patterning of the intermediate germ cricket Gryllus bimaculatus

In short and intermediate germ insects, only the anterior segments are specified during the blastoderm stage, leaving the posterior segments to be specified later, during embryogenesis, which differs from the segmentation process in Drosophila, a long germ insect. To elucidate the segmentation mechanisms of short and intermediate germ insects, we have investigated the orthologs of the Drosophila segmentation genes in a phylogenetically basal, intermediate germ insect, Gryllus bimaculatus (Gb). Here, we have focused on its hunchback ortholog (Gb'hb), because Drosophila hb functions as a gap gene during anterior segmentation, referred as a canonical function. Gb'hb is expressed in a gap pattern during the early stages of embryogenesis, and later in the posterior growth zone. By means of embryonic and parental RNA interference for Gb'hb, we found the following: (1) Gb'hb regulates Hox gene expression to specify regional identity in the anterior region, as observed in Drosophila and Oncopeltus; (2) Gb'hb controls germband morphogenesis and segmentation of the anterior region, probably through the pair-rule gene, even-skipped at least; (3) Gb'hb may act as a gap gene in a limited region between the posterior of the prothoracic segment and the anterior of the mesothoracic segment; and (4) Gb'hb is involved in the formation of at least seven abdominal segments, probably through its expression in the posterior growth zone, which is not conserved in Drosophila. These findings suggest that Gb'hb functions in a non-canonical manner in segment patterning. A comparison of our results with the results for other derived species revealed that the canonical hb function may have evolved from the non-canonical hb functions during evolution.