Nod2, a Nod1/Apaf-1 family member that is restricted to monocytes and activates NF-kappaB

Apaf-1 and Nod1 are members of a protein family, each of which contains a caspase recruitment domain (CARD) linked to a nucleotide-binding domain, which regulate apoptosis and/or NF-kappaB activation. Nod2, a third member of the family, was identified. Nod2 is composed of two N-terminal CARDs, a nucleotide-binding domain, and multiple C-terminal leucine-rich repeats. Although Nod1 and Apaf-1 were broadly expressed in tissues, the expression of Nod2 was highly restricted to monocytes. Nod2 induced nuclear factor kappaB (NF-kappaB) activation, which required IKKgamma and was inhibited by dominant negative mutants of IkappaBalpha, IKKalpha, IKKbeta, and IKKgamma. Nod2 interacted with the serine-threonine kinase RICK via a homophilic CARD-CARD interaction. Furthermore, NF-kappaB activity induced by Nod2 correlated with its ability to interact with RICK and was specifically inhibited by a truncated mutant form of RICK containing its CARD. The identification of Nod2 defines a subfamily of Apaf-1-like proteins that function through RICK to activate a NF-kappaB signaling pathway.     

Feedback inhibition of amidophosphoribosyltransferase regulates the rate of cell growth via purine nucleotide, DNA, and protein syntheses

To clarify the contributions of amidophosphoribosyltransferase (ATase) and its feedback regulation to the rates of purine de novo synthesis, DNA synthesis, protein synthesis, and cell growth, mutated human ATase (mhATase) resistant to feedback inhibition by purine ribonucleotides was engineered by site-directed mutagenesis and expressed in CHO ade (-)A cells (an ATase-deficient cell line of Chinese hamster ovary fibroblasts) and in transgenic mice (mhATase-Tg mice). In Chinese hamster ovary transfectants with mhATase, the following parameters were examined: ATase activity and its subunit structure, the metabolic rates of de novo and salvage pathways, DNA and protein synthesis rates, and the rate of cell growth. In mhATase-Tg mice, ATase activity in the liver and spleen, the metabolic rate of the de novo pathway in the liver, serum uric acid concentration, urinary excretion of purine derivatives, and T lymphocyte proliferation by phytohemagglutinin were examined. We concluded the following. 1) ATase and its feedback inhibition regulate not only the rate of purine de novo synthesis but also DNA and protein synthesis rates and the rate of cell growth in cultured fibroblasts. 2) Suppression of the de novo pathway by the salvage pathway is mainly due to the feedback inhibition of ATase by purine ribonucleotides produced via the salvage pathway, whereas the suppression of the salvage pathway by the de novo pathway is due to consumption of 5-phosphoribosyl 1-pyrophosphate by the de novo pathway. 3) The feedback inhibition of ATase is more important for the regulation of the de novo pathway than that of 5-phosphoribosyl 1-pyrophosphate synthetase. 4) ATase superactivity leads to hyperuricemia and an increased bromodeoxyuridine incorporation in T lymphocytes stimulated by phytohemagglutinin.     

Growth and carotenoid production of Thraustochytrium sp. CHN-1 cultured under superbright red and blue light-emitting diodes

Isomers of astaxanthin produced by Thraustochytrium sp. CHN-1 are identified as (3S,3S')-trans-astaxanthin, (3R,3R')-trans-astaxanthin and (3S,3S')-cis-astaxanthin by chirality column HPLC, and 1H and 13C NMR. We studied the effects of light generated by superbright blue, red and near-red LEDs on the growth and carotenoid production of Thraustochytrium sp. CHN-1. Thraustochytrium sp. CHN-1 responded to blue LEDs light: It produced carotenoid pigments (astaxanthin)     

A mutant with constitutive sexual organ development in<Emphasis Type="Italic"> Marchantia polymorpha</Emphasis> L.

In lower land plants, genes controlling the transition from vegetative growth to sexual reproduction have not yet been identified. In the dioecious liverwort Marchantia polymorpha, the transition to sexual reproduction accompanied by the formation of sexual organs on the gametophytic thallus is initiated under long-day conditions. By particle bombardment-mediated mutagenesis, we generated a mutant of M. polymorpha that constitutively forms sexual organs. This mutant is fully fertile, showing that the mutation does not affect formation of male or female sexual organs per se. Genetic analysis reveals that this phenotype is caused by mutation of a single autosomal locus, suggesting that this mutation defines or controls a gene regulating the transition to sexual reproduction in M. polymorpha.     

Growth,net photosynthesis and leaf nutrient status of <Emphasis Type="Italic">Fagus crenata</Emphasis> seedlings grown in brown forest soil acidified with H<Subscript>2</Subscript>SO<Subscript>4</Subscript> or HNO<Subscript>3</Subscript> solution

To obtain basic information for evaluating critical loads of acid deposition for protecting Japanese beech forests, growth, net photosynthesis and leaf nutrient status of Fagus crenata seedlings grown for two growing seasons in brown forest soil acidified with H₂SO₄ or HNO₃ solution were investigated. The whole-plant dry mass of the seedlings grown in the soil acidified by the addition of H₂SO₄ or HNO₃ solution was significantly less than that of the seedlings grown in the control soil not supplemented with H⁺ as H₂SO₄ or HNO₃ solution. However, the degrees of reduction in the whole-plant dry mass and net photosynthetic rate of the seedlings grown in the soil acidified by the addition of H⁺ as H₂SO₄ solution at 100 mg l^–1 on the basis of air-dried soil volume (S-100 treatment) were greater than those of the seedlings grown in the soil acidified by the addition of H⁺ as HNO₃ solution at 100 mg l^–1 (N-100 treatment). The concentrations of Al and Mn in the leaves of the seedlings grown in the S-100 treatment were significantly higher than those in the N-100 treatment. A positive correlation was obtained between the molar ratio of (Ca+Mg+K)/(Al+Mn) in the soil solution and the relative whole-plant dry mass of the seedlings grown in the acidified soils to that of the seedlings grown in the control soil. Based on the results, we concluded that the negative effects of soil acidification due to sulfate deposition are greater than those of soil acidification due to nitrate deposition on growth, net photosynthesis and leaf nutrient status of F. crenata, and that the molar ratio of (Ca+Mg+K)/(Al+Mn) in soil solution is a suitable soil parameter for evaluating critical loads of acid deposition in efforts to protect F. crenata forests in Japan.     

Expression of cys-cys chemokine ligand 21 on human gingival lymphatic vessels

The cys-cys (C-C) chemokine ligand 21 is a member of the C-C chemokines that constitute a group of heparin-binding cytokines with a pattern of four or six conserved cysteines. The CCL21 is known to be expressed in secondary lymphoid tissues, however it has rarely been reported for the expression on peripheral lymphatic vessels in somatic tissue. Here we investigated the expression of CCL21 on lymphatic vessels identified by anti-desmoplakin in uninflamed and inflamed human gingiva. In uninflamed tissue the expression of CCL21 was detected on lymphatic vessels in gingiva. In uninflamed gingiva the expression of CCL21 was detected on all lymphatic capillaries of the mucosal connective tissue papillae. There were two types of collecting lymphatic vessels in the lamina propria mucosae expressing CCL21 strongly or very weakly. In inflamed gingiva no expression of CCL21 was detected on lymphatic vessels. In all tissue sections no blood vessels expressing CCL21 were observed. These results may suggest that the expression of CCL21 is predominantly induced in the peripheral lymphatic endothelium of the uninflamed mucosal microcirculation, and that under inflamed conditions a reduction of CCL21 occurs in lymphatic endothelium.     

The interleukin-1 RN polymorphism and Helicobacter pylori infection in the development of duodenal ulcer

BACKGROUND: The host genetic factors that determine the clinical outcomes for Helicobacter pylori-infected individuals remain unclear. AIMS: To elucidate the relations among interleukin-1 locus polymorphisms, and H. pylori infection in the development of duodenal ulcers. MATERIALS AND METHODS: In a case-control study involving 168 control subjects and 147 patients with duodenal ulcer, biallelic polymorphisms of two interleukin-1 loci, IL-1B(-511) and IL-1B(+3954), as well as the penta-allelic variable number of tandem repeats of interleukin-1 receptor antagonist IL-1RN, were genotyped, and the H. pylori states of controls and patients were examined. RESULTS: Helicobacter pylori infection, male gender and the carriage of IL-1RN*2 independently increased the risk of duodenal ulcer with odds ratios of 6.4 (95% confidence interval, 3.7-11.0), 1.9 (95% confidence interval, 1.1-3.4) and 2.7 (95% confidence interval, 1.1-6.8), respectively. Statistical analysis revealed an interaction between IL-1RN*2 and H. pylori infection with the duodenal ulcer risk conferred by the H. pylori infection substantially increased (odds ratios, 22.6; 95% confidence interval, 5.9-86.5) by the carriage of IL-1RN*2. In addition, a synergistic interaction between IL-1RN*2 and blood group O existed. The combined risk of H. pylori infection, the carriage of IL-1RN*2 and blood group O for duodenal ulcer was 27.5 (95% confidence interval, 3.1-243.6). CONCLUSIONS: This work is the first to verify IL-1RN*2 as an independent factor that governs the development of duodenal ulcers. Our data indicate that H. pylori infection and IL-1RN*2 synergistically determine susceptibility to duodenal ulcer. The blood group phenotype is possibly a crucial determinant for the outcome of the impact of an interleukin-1 locus polymorphism on H. pylori-infected individuals.     

Organization of a sterol-rich membrane domain by cdc15p during cytokinesis in fission yeast

Many membrane processes occur in discrete membrane domains containing lipid rafts, but little is known about how these domains are organized and positioned. In the fission yeast Schizosaccharomyces pombe, a sterol-rich membrane domain forms at the cell-division site. Here, we show that formation of this membrane domain is independent of the contractile actin ring, septation, mid1p and the septins, and also requires cdc15p, an essential contractile ring protein that associates with lipid rafts. cdc15 mutants have membrane domains in the shape of spirals. Overexpression of cdc15p in interphase cells induces abnormal membrane domain formation in an actin-independent manner. We propose that cdc15p functions to organize lipid rafts at the cleavage site for cytokinesis.     

DNA hybridization in nanostructural molecular assemblies enables detection of gene mutations without a fluorescent probe

We have developed a simple single nucleotide polymorphisms (SNPs) analysis utilizing DNA hybridization in nanostructural molecular assemblies. The novel technique enables the detection of a single-base mismatch in a DNA sequence without a fluorescent probe. This report describes for the first time that DNA hybridization occurs in the nanostructural molecular assemblies (termed reverse micelles) formed in an organic medium. The restricted nanospace in the reverse micelles amplifies the differences in the hybridization rate between mismatched and perfectly matched DNA probes. For a model system, we hybridized a 20-mer based on the p53 gene sequence to 20-mer complementary oligonucleotides with various types of mismatches. Without any DNA labeling or electrochemical apparatus, we successfully detected the various oligonucleotide mismatches by simply measuring the UV absorbance at 260 nm.     

C17,20-lyase inhibitors I. Structure-based de novo design and SAR study of C17,20-lyase inhibitors

Novel nonsteroidal C(17,20)-lyase inhibitors were synthesized using de novo design based on its substrate, 17 alpha-hydroxypregnenolone, and several compounds exhibited potent C(17,20)-lyase inhibition. However, in vivo activities were found to be short-lasting, and in order to improve the duration of action, a series of benzothiophene derivatives were evaluated. As a result, compounds 9h, (S)-9i, and 9k with nanomolar enzyme inhibition (IC(50)=4-9 nM) and 9e (IC(50)=27 nM) were identified to have powerful in vivo efficacy with extended duration of action. The key structural determinants for the in vivo efficacy were demonstrated to be the 5-fluoro group on the benzothiophene ring and the 4-imidazolyl moiety. Superimposition of 9k and 17 alpha-hydroxypregnenolone demonstrated their structural similarity and enabled rationalization of the pharmacological results. In addition, selected compounds were also identified to be potent inhibitors of human enzyme with IC(50) values of 20-30 nM.