Non-invasive diagnosis of cutaneous leishmaniasis by the direct boil loop-mediated isothermal amplification method and MinION™ nanopore sequencing

Cutaneous leishmaniasis (CL) is gaining attention as a public health problem. We present two cases of CL imported from Syria and Venezuela in Japan. We diagnosed them as CL non-invasively by the direct boil loop-mediated isothermal amplification method and an innovative sequencing method using the MinION? sequencer. This report demonstrates that our procedure could be useful for the diagnosis of CL in both clinical and epidemiological settings.     

Cell cycle specificity of tumor necrosis factor and its receptor

Phase specificity in the TNF cytotoxic effect and the number of TNF binding receptors was investigated using L-M cells incubated synchronously from the S phase. TNF cytotoxicity was observed to occur at various levels during the cell cycle, with peak effect in the G2-M phase. Analysis with 125I-labeled TNF to determine the number of receptors binding TNF in the various cell phases shewed a phase specificity with the maximum number occurring in the G2-M phase, similar to the peak in cytotoxicity. The results suggest the existence of a cell cycle specificity in the cytotoxicity of TNF which is apparently related to changes in the number of receptors capable of binding TNF.     

In vitro release of growth hormone-releasing factor from rat hypothalamus: effect of insulin-like growth factor-1

The release of growth hormone-releasing factor (GHRF) from rat hypothalamus was investigated in vitro. After 60 min preincubation the released GHRF from sliced rat hypothalamic fragments during 60 min incubation was detected by a highly specific and sensitive radioimmunoassay for rat GHRF. The release of GHRF was Ca2+-dependent and enhanced by high concentration of K+. Insulin-like growth factor-1 (IGF-1) significantly decreased GHRF release to 65% and 84% of the control at concentrations of 10(-8) M and 10(-7) M, respectively. These results suggest that this in vitro system is useful for the investigation of the mechanism of GHRF release from the hypothalamus and that IGF-1 is probably involved in the feedback inhibition of growth hormone secretion by attenuating GHRF release from the hypothalamus besides countering the effect of GHRF on the pituitary.     

Cloning and nucleotide sequence of the mono- and diacylglycerol lipase gene (mdlB) of Aspergillus oryzae

Abstract Aspergillus oryzae IFO4202 produces at least two extracellular lipolytic enzymes L1 and L2 (cutinase, and mono- and diacylglycerol lipase, respectively). Southern hybridization of restriction enzyme-digested genomic DNA fragments with 23mer oligonucleotides synthesized according to the amino acid sequence of the L2 as probe suggested the presence of the L2 gene (tentatively designated as mdlB ) and an additional weakly hybridizing region. A fragment containing the genomic mdlB gene was cloned in Escherichia coli . Nucleotide sequencing of the fragment revealed an open reading frame, comprising 1021 nucleotides, which contains two introns (51 and 52 nucleotides). Putative polyadenylation signals were found 182 and 287 bp downstream of the stop codon. The deduced amino acid sequence of the mdlB gene corresponds to 306 amino acid residues including a leader sequence of 28 amino acids and is highly similar to that of the mdlA gene of Penicillium camembertii . Three residues presumed to form the catalytic triad (serine, aspartic acid and histidine) of lipases were also conserved.     

A case for regulatory B cells

B cells are typically characterized by their ability to produce Abs, including autoantibodies. However, B cells possess additional immune functions, including the production of cytokines and the ability to function as a secondary APC. As with T cells, the B cell population contains functionally distinct subsets capable of performing both pathogenic and regulatory functions. Recent studies indicate that regulatory B cells develop in several murine models of chronic inflammation, including inflammatory bowel disease, rheumatoid arthritis, and experimental autoimmune encephalomyelitis. The regulatory function may be directly accomplished by the production of regulatory cytokines IL-10 and TGF-beta and/or by the ability of B cells to interact with pathogenic T cells to dampen harmful immune responses. In this review, we make a case for the existence of regulatory B cells and discuss the possible developmental pathways and functional mechanisms of these B cells.     

Metabolomics for metabolically manipulated plants: effects of tryptophan overproduction

Advances in molecular breeding technologies have enabled manipulation of the concentrations of specific plant components by modifying the genes that play a key role in their production. This has provided new opportunities to enhance the nutritional quality of major crops. However, given that metabolic pathways form a highly integrated network, any alteration in a given biosynthetic pathway is most likely to effect secondary and unpredicted changes in the metabolite profile of other pathways. Metabolomics technologies can contribute to the efficient detection of such unexpected effects caused by genetic modification. This has relevance not only from the perspective of safety evaluations of newly developed crops, but to basic science focused on uncovering hitherto unknown regulatory mechanisms associated with the biosynthesis and catabolism of primary and secondary metabolites in plants. In this review, recent advances in plant metabolic engineering for the overproduction of tryptophan (Trp), one of the essential amino acids, are described. In particular, the efficacy of a transgene OASA1D that encodes a mutant anthranilate synthase (AS) α subunit of rice in specifically elevating levels of Trp without marked secondary effects on the metabolite profile of rice is demonstrated. Related topics, such as regulation of Trp biosynthesis, possible interactions between the biosyntheses of Trp and other aromatic amino acids, and translocation of Trp in are discussed based on findings derived from metabolomic analyses of Trp-overproducing transgenic plants.     

Salmonid olfactory system-specific protein (N24) exhibits glutathione S-transferase class pi-like structure

A salmonid olfactory system-specific protein (N24) that has been identified in lacustrine sockeye salmon (Oncorhynchus nerka) was characterized by biochemical and molecular biological techniques. N24 is a homodimer, and the intact molecular mass is estimated as approximately 43.3 kDa by gel filtration. Furthermore, N24 was located only in the cytosolic fraction of the olfactory tissues as determined by subcellular fractionation. cDNA encoding the lacustrine sockeye salmon N24 was isolated and sequenced. This cDNA contained a coding region encoding 216 amino acid residues and the molecular mass of this protein is calculated to be 242,224.77. The protein and nucleotide sequencing demonstrates the existence of a remarkable homology between N24 and glutathione S-transferase (GST; EC 2.5.1.18) class pi enzymes. Northern analysis showed that N24 mRNA with a length of 950 bases is expressed in lacustrine sockeye salmon olfactory epithelium. Olfactory receptor cells showed strong hybridization signals for N24 mRNA in the olfactory epithelium. N24 demonstrated glutathione binding activity in affinity-purified GST column experiments. The present study describes for the first time cDNA cloning of GST in fish olfactory epithelium.     

Insulin signalling and insulin actions in the muscles and livers of insulin-resistant, insulin receptor substrate 1-deficient mice.

We and others recently generated mice with a targeted disruption of the insulin receptor substrate 1 (IRS-1) gene and demonstrated that they exhibited growth retardation and had resistance to the glucose-lowering effect of insulin. Insulin initiates its biological effects by activating at least two major signalling pathways, one involving phosphatidylinositol 3-kinase (PI3-kinase) and the other involving a ras/mitogen-activated protein kinase (MAP kinase) cascade. In this study, we investigated the roles of IRS-1 and IRS-2 in the biological action in the physiological target organs of insulin by comparing the effects of insulin in wild-type and IRS-1-deficient mice. In muscles from IRS-1-deficient mice, the responses to insulin-induced PI3-kinase activation, glucose transport, p70 S6 kinase and MAP kinase activation, mRNA translation, and protein synthesis were significantly impaired compared with those in wild-type mice. Insulin-induced protein synthesis was both wortmannin sensitive and insensitive in wild-type and IRS-1 deficient mice. However, in another target organ, the liver, the responses to insulin-induced PI3-kinase and MAP kinase activation were not significantly reduced. The amount of tyrosine-phosphorylated IRS-2 (in IRS-1-deficient mice) was roughly equal to that of IRS-1 (in wild-type mice) in the liver, whereas it only 20 to 30% of that of IRS-1 in the muscles. In conclusion, (i) IRS-1 plays central roles in two major biological actions of insulin in muscles, glucose transport and protein synthesis; (ii) the insulin resistance of IRS-1-deficient mice is mainly due to resistance in the muscles; and (iii) the degree of compensation for IRS-1 deficiency appears to be correlated with the amount of tyrosine-phosphorylated IRS-2 (in IRS-1-deficient mice) relative to that of IRS-1 (in wild-type mice).     

Brain-Derived Neurotrophic Factor Stimulates Interactions of Shp2 with Phosphatidylinositol 3-Kinase and Grb2 in Cultured Cerebral Cortical Neurons

Shp2, a protein tyrosine phosphatase possessing SH2 domains, is utilized in the intracellular signaling of various growth factors. Shp2 is highly expressed in the CNS. Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, which also shows high levels of expression in the CNS, exerts neurotrophic and neuromodulatory effects in CNS neurons. We examined how BDNF utilizes Shp2 in its signaling pathway in cultured cerebral cortical neurons. We found that BDNF stimulated coprecipitation of several tyrosine-phosphorylated proteins with anti-Shp2 antibody and that Grb2 and phosphatidylinositol 3-kinase (PI3-K) were coprecipitated with anti-Shp2 antibody in response to BDNF. In addition, both anti-Grb2 and anti-PI3-K antibodies coprecipitated Shp2 in response to BDNF. The BDNF-stimulated coprecipitation of the tyrosine-phosphorylated proteins, Grb2, and PI3-K with anti-Shp2 antibody was completely inhibited by K252a, an inhibitor of TrkB receptor tyrosine kinase. This BDNF-stimulated Shp2 signaling was markedly sustained as well as BDNF-induced phosphorylation of TrkB and mitogen-activated protein kinases. In PC12 cells stably expressing TrkB, both BDNF and nerve growth factor stimulated Shp2 signaling similarly to that by BDNF in cultured cortical neurons. These results indicated that Shp2 shows cross-talk with various signaling molecules including Grb2 and PI3-K in BDNF-induced signaling and that Shp2 may be involved in the regulation of various actions of BDNF in CNS neurons.