Prediction of the coding sequences of mouse homologues of FLJ genes: the complete nucleotide sequences of 110 mouse FLJ-homologous cDnas identified by screening of terminal sequences of cDNA clones randomly sampled from size-fractionated libraries.

We have been conducting a mouse cDNA project to predict protein-coding sequences of mouse KIAA-homologous genes since 2001. As an extension of this project, we also started to accumulate mouse cDNA clones homologous to the human FLJ cDNA clones which are another long cDNA resource produced in our institute. We have isolated the cDNA clones from size-fractionated cDNA libraries derived from five different mouse tissues and natural killer T-cells. Although the human FLJ cDNA clones were originally derived from human spleen libraries, one-third of their mouse homologues were obtained from the brain library. We designated these homologues "mFLJ" plus a 5-digit number and herein characterized 110 mFLJ cDNA clones. We assigned an integrity of the CDSs from the comparison of the 110 cDNA clones with the corresponding human FLJ cDNA clones. The average size of the 110 mouse cDNA sequences was 3.8 kb and that of the deduced amino acid sequences from their longest CDS in each cDNA was 663 amino acid residues. Homology and/or motif search against public databases revealed new domains and/or motifs in 26 mFLJ gene products which provide additional speculation regarding the function of FLJ genes.     

Hydrogen peroxide spraying alleviates drought stress in soybean plants

To ascertain the effect of exogenously applied hydrogen peroxide (H₂O₂) on drought stress, we examined whether the spraying of soybean leaves with H₂O₂ would alleviate the symptoms of drought stress. Pre-treatment by spraying leaves with H₂O₂ delayed foliar wilting caused by drought stress compared to leaves sprayed with distilled water (DW). Additionally, the relative water content of drought-stressed leaves pre-treated with H₂O₂ was higher than that of leaves pre-treated with DW. Therefore, we analyzed the effect of H₂O₂ spraying on photosynthetic parameters and on the biosynthesis of oligosaccharides related to water retention in leaves during drought stress. Under conditions of drought stress, the net photosynthetic rate and stomatal conductance of leaves pre-treated with H₂O₂ were higher than those of leaves pre-treated with DW. In contrast to DW spraying, H₂O₂ spraying immediately caused an increase in the mRNA levels of d-myo-inositol 3-phosphate synthase 2 (GmMIPS2) and galactinol synthase (GolS), which encode key enzymes for the biosynthesis of oligosaccharides known to help plants tolerate drought stress. In addition, the levels of myo-inositol and galactinol were higher in H₂O₂-treated leaves than in DW-treated leaves. These results indicated that H₂O₂ spraying enabled the soybean plant to avoid drought stress through the maintenance of leaf water content, and that this water retention was caused by the promotion of oligosaccharide biosynthesis rather than by rapid stomatal closure.     

Spinal Cord Stimulation Exerts Neuroprotective Effects against Experimental Parkinson’s Disease

In clinical practice, deep brain stimulation (DBS) is effective for treatment of motor symptoms in Parkinson’s disease (PD). However, the mechanisms have not been understood completely. There are some reports that electrical stimulation exerts neuroprotective effects on the central nervous system diseases including cerebral ischemia, head trauma, epilepsy and PD, although there are a few reports on neuroprotective effects of spinal cord stimulation (SCS). We investigated the neuroprotective effects of high cervical SCS on PD model of rats. Adult female Sprague-Dawley rats received hour-long SCS (2, 50 or 200 Hz) with an epidural electrode at C1–2 level for 16 consecutive days. At 2 days after initial SCS, 6-hydroxydopamine (6-OHDA) was injected into the right striatum of rats. Behavioral evaluations of PD symptoms were employed, including cylinder test and amphetamine-induced rotation test performed at 1 and 2 weeks after 6-OHDA injection. Animals were subsequently euthanized for immunohistochemical investigations. In order to explore neurotrophic and growth factor upregulation induced by SCS, another cohort of rats that received 50 Hz SCS was euthanized at 1 and 2 weeks after lesion for protein assays. Behavioral tests revealed that the number of amphetamine-induced rotations decreased in SCS groups. Immunohistochemically, tyrosine hydroxylase (TH)-positive fibers in the striatum were significantly preserved in SCS groups. TH-positive neurons in the substantia nigra pars compacta were significantly preserved in 50 Hz SCS group. The level of vascular endothelial growth factor (VEGF) was upregulated by SCS at 1 week after the lesion. These results suggest that high cervical SCS exerts neuroprotection in PD model of rats, at least partially by upregulation of VEGF. SCS is supposed to suppress or delay PD progression and might become a less invasive option for PD patients, although further preclinical and clinical investigations are needed to confirm the effectiveness and safety.     

Galectin-9 Enhances Cytokine Secretion,but Suppresses Survival and Degranulation,in Human Mast Cell Line

Galectin-9 (Gal-9), a lectin having a β-galactoside-binding domain, can induce apoptosis of Th1 cells by binding to TIM-3. In addition, Gal-9 inhibits IgE/Ag-mediated degranulation of mast cell/basophilic cell lines by binding to IgE, thus blocking IgE/Ag complex formation. However, the role of Gal-9 in mast cell function in the absence of IgE is not fully understood. Here, we found that recombinant Gal-9 directly induced phosphorylation of Erk1/2 but not p38 MAPK in a human mast cell line, HMC-1, which does not express FcεRI. Gal-9 induced apoptosis and inhibited PMA/ionomycin-mediated degranulation of HMC-1 cells. On the other hand, Gal-9 induced cytokine and/or chemokine production by HMC-1 cells, dependent on activation of ERK1/2 but not p38 MAPK. In addition, the lectin activity of Gal-9 was required for Gal-9-mediated cytokine secretion by HMC-1 cells. These observations suggest that Gal-9 has dual properties as both a regulator and an activator of mast cells.     

Studies on the Glucanase of Sclerotinia Libertiana

Glucanase-treatment of yeast cells was shown to increase the glucose fermenting activity, and decrease the sucrose and maltose fermenting activity. Also, lipase–and phospholipase–treatment decreased the fermenting activity on these sugars. However, the effects on the disaccharide fermenting activity could be reversed under various growth conditions of the yeast cells.

From these results, structural factors envolved in the transport of fermentable sugars into yeast cells are discussed.     

Evolution of restriction sites of ribosomal DNA in natural populations of the field mouse,Apodemus speciosus

An analysis by restriction endonuclease digestion of ribosomal DNA (rDNA) was carried out in natural populations of Apodemus speciosus, a field mouse that is endemic to Japan. Two restriction sites, the EcoRI (E3) and DraI (D4) sites, in the nontranscribed spacer region downstream from the gene for 28S RNA showed polymorphism within and between individuals in the populations from the Japanese main islands. By contrast, populations from the small adjoining islands which are thought to have separated from the main islands 1–2 × 10⁴ years ago showed relatively low levels of polymorphism within and between individuals, i.e., one of the polymorphic bands in the case of each enzyme was predominant in these populations, irrespective of the variants. These results indicate that the rate of fixation of site variations depends on population size and that the direction of fixation is random. Furthermore, each polymorphic restriction site seems to be fixed independently.Correspondence to: H. Suzuki     

Free amino acid changes in the cerebral cortex of experimental uremic rat

The levels of free amino acids in the cerebral cortex of acute and chronic uremic rats were examined. Amino acids significantly elevated were aspartate, glutamine, glycine, histidine, ornithine, phenylalanine, phosphoethanolamine and taurine, whereas 1-methyl histidine and 3-methyl histidine were specifically detected in uremic rats. Glutamate, arginine and carnosine disclosed a significant reduction. There was no change in the concentrations of γ-aminobutyrate and alanine. The above findings were essentially identical in both acute and chronic uremia. It was conjectured that these changes of amino acid levels in the brain might participate in the progress of uremic encephalopathy.     

Inhibition of chromosome separation in fertilized starfish eggs by kalihinol F, a topoisomerase I inhibitor obtained from a marine sponge

Kalihinol F, a naturally occurring diterpene from a marine sponge, Acanthella sp., inhibited chromosome separation in fertilized starfish (Asterina pectinifera) eggs but allows the first cleavage to occur, thereby forming unseparated metaphase chromosomes which were elongated between the two daughter cells. The chromosomes were eventually torn off in the embryonic cells. Most of the cells gradually lost the chromosomes during the cell cycle progression. The embryonic development halted at the morula stage just before the onset of blastulation. The mitotic failure occurred when kalihinol F was applied to a fertilized egg during the second meiotic process, but not after the completion of the second meiotic division. Kalihinol F inhibited topoisomerase I activity in vitro, but had no effects on activities of DNA polymerases alpha, beta, and gamma, and of topoisomerase II. These results suggest that the topoisomerase I plays an essential role in meiosis II in this species.