Involvement of liver aldehyde oxidase in the reduction of nicotinamide N-oxide

The present paper describes that mammalian liver aldehyde oxidase is involved in the reduction of nicotinamide N-oxide to nicotinamide. Rabbit liver aldehyde oxidase supplemented with its electron donor exhibited a significant nicotinamide N-oxide reductase activity under anaerobic conditions. Liver cytosols from rabbits, hogs, guinea pigs, hamsters, rats and mice, all of them, similarly exhibited the N-oxide reductase activity in the presence of an electron donor of aldehyde oxidase, but not xanthine oxidase. The cytosolic N-oxide reductase activity was almost completely inhibited by menadione, an inhibitor of aldehyde oxidase.     

Evaluation of Fucosylated Haptoglobin and Mac-2 Binding Protein as Serum Biomarkers to Estimate Liver Fibrosis in Patients with Chronic Hepatitis C

Fucosylated haptoglobin (Fuc-Hpt) and Mac-2 binding protein (Mac-2 bp) are identified as cancer biomarkers, based on the results from a glyco-proteomic analysis. Recently, we reported that these glyco-biomarkers were associated with liver fibrosis and/or ballooning hepatocytes in patients with nonalcoholic fatty liver disease (NAFLD). We evaluated the ability of these glycoproteins to estimate liver fibrosis in 317 patients with chronic hepatitis C. We measured the serum Fuc-Hpt and Mac-2 bp levels using a lectin-antibody ELISA and ELISA, respectively. The serum levels of both Fuc-Hpt and Mac-2 bp increased with the progression of liver fibrosis. The multivariate analysis revealed that Mac-2 bp was an independent factor associated with moderate liver fibrosis (F ≥ 2). In contrast, Fuc-Hpt was an independent factor associated with advanced liver fibrosis (F ≥ 3). In terms of evaluating liver fibrosis, the serum levels of these glycomarkers were correlated with well-known liver fibrosis indexes, such as the aspartate aminotransferase to platelet ratio index (APRI) and Fibrosis-4 (FIB4) index. An assay that combined the APRI or FIB4 index and the Fuc-Hpt or Mac-2 bp levels increased the AUC value for diagnosing hepatic fibrosis. Interestingly, the cumulative incidence of hepatocellular carcinoma (HCC) was significantly higher in the patients with elevated serum levels of Fuc-Hpt and Mac-2 bp. In conclusion, both Fuc-Hpt and Mac-2 bp could be useful glyco-biomarkers of liver fibrosis and predictors of HCC in patients with chronic hepatitis C.     

Single-cell cloning and expansion of human induced pluripotent stem cells by a microfluidic culture device

The microenvironment of cells, which includes basement proteins, shear stress, and extracellular stimuli, should be taken into consideration when examining physiological cell behavior. Although microfluidic devices allow cellular responses to be analyzed with ease at the single-cell level, few have been designed to recover cells. We herein demonstrated that a newly developed microfluidic device helped to improve culture conditions and establish a clonality-validated human pluripotent stem cell line after tracing its growth at the single-cell level. The device will be a helpful tool for capturing various cell types in the human body that have not yet been established in vitro.     

Purification of NADPH-linked alpha,beta-ketoalkene double bond reductase from rat liver

NADPH-linked alpha,beta-ketoalkene double bond reductase was purified from rat liver cytosol by fractionation with ammonium sulfate, and chromatography with DEAE-cellulose. AF-Blue Toyopearl and hydroxyapatite. The purified enzyme was homogeneous by the criterion of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular weight of the enzyme was estimated to be 39,500 by the electrophoresis and by HPLC gel filtration on a TSK gel G3000 SWXL column. The double bond of 2-alkenals was also reduced by the enzyme, but to a lesser extent. The enzyme activity was inhibited by 5,5'-dithiobis(2-nitrobenzoic acid), p-chloromercuribenzoic acid, N-ethylmaleimide, iodoacetamide, dicumarol, quercitrin, and disulfirum. However, the enzyme was insensitive to oxygen.     

Apurinic/apyrimidinic endonuclease sensitive sites as intermediates in the in vitro degradation of deoxyribonucleic acid by neocarzinostatin

Neocarzinostatin (NCS) induces alkali-labile sites in DNA which are stabilized by NaBH4 reduction. The stabilized sites are sensitive to an AP endonuclease from human lymphoma cells. NCS-induced degradation of supercoiled Col E1 DNA proceeds in stepwise fashion with apurinic/apyrimidinic (AP) sites as intermediates. Degradation is increased when reaction occurs in the presence of AP endonuclease, and DNA reacted with NCS can be shown to have numerous AP endonuclease sensitive sites.     

Ecosystem engineering by a canopy‐forming kelp facilitates the recruitment of native oysters

Ecosystem engineers are species that influence the abiotic and biotic environment around them and may assist the restoration of associated species, including other habitat‐forming species. We deployed an array of 28 artificial reefs with transplanted Ecklonia radiata, the dominant canopy‐forming kelp species across southern Australia, to investigate how the patch size and density of E. radiata influenced the establishment of the associated communities of plants and animals. Many of the reefs were rapidly colonized by Ostrea angasi, a critically depleted reef‐forming oyster. Over the 24‐month deployment of the reefs, thick oyster mats formed across the entire surface of many of the reefs with estimated biomass densities exceeding 5 kg of live oysters/m²; however, oyster density was dependent on E. radiata patch size and density. Increasing patch size and the presence of kelp resulted in significantly higher densities of oysters 5 months after the reefs were deployed and at the end of the experiment, where oysters were approximately three times more numerous on reefs with kelp compared to those without kelp. E. radiata appeared to facilitate the establishment of O. angasi largely through its capacity to reduce benthic light and thus suppress competition from turfing algae. These results may inform the development of novel approaches to tackle recruitment bottlenecks affecting the restoration of O. angasi reefs.     

Molecular characterization of the membrane-bound quinol peroxidase functionally connected to the respiratory chain

Here, we report for the first time quinol peroxidase (QPO), an enzyme that uses ubiquinol-1 as an electron donor for the reduction of H(2)O(2) to water. We purified QPO to > 90% purity from the membrane fraction of Actinobacillus actinomycetemcomitans. QPO is a 53.6-kDa protein that contains three heme c molecules. The qpo gene was predicted to encode a putative bacterial cytochrome c peroxidase with N-terminal extensions containing an additional potential heme c-binding motif. Although qpo has high sequence homology to bacterial cytochrome c peroxidases, QPO did not catalyze peroxidation in the presence of horse heart cytochrome c. In addition, the cytoplasmic membrane of A. actinomycetemcomitans had apparent QPO-dependent peroxidase activity in the presence of NADH or succinate, which are substrates for the respiratory chain. Based on these findings, we present a new mechanism for the scavenging of reactive oxygen species in which quinol in the respiratory chain is consumed.