Aurora A polyubiquitinates the BRCA1-interacting protein OLA1 to promote centrosome maturation.

The BRCA1-interacting protein Obg-like ATPase 1 (OLA1) functions in centriole duplication. In this study, we show the role of the mitotic kinase Aurora A in the reduction of centrosomal OLA1. Aurora A binds to and polyubiquitinates OLA1, targeting it for proteasomal degradation. NIMA-related kinase 2 (NEK2) phosphorylates the T124 residue of OLA1, increases binding of OLA1 to Aurora A and OLA1 polyubiquitination by Aurora A, and reduces centrosomal OLA1 in G2 phase. The kinase activity of Aurora A suppresses OLA1 polyubiquitination. The decrease in centrosomal OLA1 caused by Aurora A-mediated polyubiquitination promotes the recruitment of pericentriolar material proteins in G2 phase. The E3 ligase activity of Aurora A is critical for centrosome amplification induced by its overexpression. The results suggest a dual function of Aurora A as an E3 ubiquitin ligase and a kinase in the regulation of centrosomal OLA1, which is essential for proper centrosome maturation in G2 phase.

Therapeutic response and prognostic factors of 14 dogs undergoing transcatheter arterial embolization for hepatocellular masses: A retrospective study.

BACKGROUND: Information regarding the therapeutic effect and outcome of transcatheter arterial embolization (TAE) for hepatic masses is limited in veterinary medicine. HYPOTHESIS/OBJECTIVES: To analyze the therapeutic response, outcome (overall survival), and their predictors in dogs that underwent TAE for primary hepatocellular masses. We hypothesized that larger pre-TAE tumors would be associated with worse outcomes. ANIMALS: Fourteen client-owned dogs. METHODS: Retrospective study. Medical records between 1 September 2016 and 30 April 2022 were reviewed to identify dogs treated with TAE for hepatic masses diagnosed as hepatocellular origin by cytological or histopathological examination. Computed tomography images were compared before and after TAE. The univariate Cox proportional hazards test was performed to assess the associations between variables and survival. Univariate linear regression analysis was performed to assess the associations between variables and the tumor reduction percentage: ([post-TAE volume - pre-TAE volume]/pre-TAE volume) × 100. RESULTS: The median survival time was 419 days (95% confidence interval, 82-474). History of intra-abdominal hemorrhage (P = .03) and pre-TAE tumor volume/body weight (P = .009) were significantly associated with overall survival. The mean reduction percentage was -51% ± 40%. Pre-TAE tumor volume/body weight ratio (cm3 /kg; P = .02, correlation coefficient = 0.704) was significantly correlated with the volume reduction percentage. CONCLUSIONS: History of intra-abdominal hemorrhage and large pre-TAE tumor volume/body weight ratio could be predictive factors for adverse outcomes after TAE. Pre-TAE tumor volume/body weight ratio could be a predictive factor for therapeutic effect.

Potential Anti-allergic Effects of Bibenzyl Derivatives from Liverworts, Radula perrottetii.

The liverwort Radula perrottetii contains various bibenzyl derivatives which are known to possess various biological activities, such as anti-inflammatory effects. Mast cells (MC) play crucial roles in allergic and inflammatory diseases; thus, inhibition of MC activation is pivotal for the treatment of allergic and inflammatory disorders. We investigated the effects of perrottetin D (perD), isolated from Radula perrottetii, and perD diacetate (Ac-perD) on antigen-induced activation of MCs. Bone marrow-derived MCs (BMMCs) were generated from C57BL/6 mice. The degranulation ratio, histamine release, and the interleukin (IL)-4 and leukotriene B4 productions on antigen-triggered BMMC were investigated. Additionally, the effects of the bibenzyls on binding of IgE to FcεRI were observed by flow cytometry, and signal transduction proteins was examined by Western blot. Furthermore, binding of the bibenzyls to the Fyn kinase domain was calculated. At 10 µM, perD decreased the degranulation ratio (p < 0.01), whereas 10 µM Ac-perD down-regulated IL-4 production (p < 0.05) in addition to decreasing the degranulation ratio (p < 0.01). Both compounds tended to decrease histamine release at a concentration of 10 µM. Although 10 µM perD reduced only Syk phosphorylation, 10 µM Ac-perD diminished phosphorylation of Syk, Gab2, PLC-γ, and p38. PerD appeared to selectively bind Fyn, whereas Ac-perD appeared to act as a weak but broad-spectrum inhibitor of kinases, including Fyn. In conclusion, perD and Ac-perD suppressed the phosphorylation of signal transduction molecules downstream of the FcεRI and consequently inhibited degranulation, and/or IL-4 production. These may be beneficial potential lead compounds for the development of novel anti-allergic and anti-inflammatory drugs.

Biological treatment of non-biodegradable azo-dye enhanced by zero-valent iron (ZVI) pre-treatment.

Zero-valent iron (ZVI) pre-treatment in sequential strategy for removal of non-biodegradable azo-dye Orange II by activated-sludge was quantitatively examined. The decolorization and TOC (total organic carbon) removal of Orange II by ZVI pre-treatment were examined in the ranges of pH from 3 to 11 and ZVI dosage from 500 to 2000 mgL-1. While the decolorization was enhanced with decreasing pH and the optimal pH for decolorization was found at pH 3, the TOC removal rate at pH 3 remained at 22.2% and the maximum TOC removal rate of 78.2% was obtained at pH 4. The decolorization and TOC removal of Orange II were monotonously increased with increasing ZVI dosage. To quantify the ZVI pre-treatment, the contributions of redox degradation, complexation/precipitation and adsorption to TOC removal by ZVI were defined. Novel kinetic models for the ZVI pre-treatment and activated-sludge post-treatment were developed. The proposed kinetic models satisfactorily predicted the transitional behaviors of the ZVI pre-treatment and activated-sludge post-treatment and the contributions of redox degradation, complexation/precipitation and adsorption to TOC removal by the ZVI pre-treatment. The complete removal of non-biodegradable azo-dye Orange II of 300 mgL-1 was accomplished by 78.2% removal after 360 min ZVI pre-treatment with the ZVI dosage of 1000 mgL-1 at pH 4 and subsequently 21.8% removal after 480 min activated-sludge post-treatment. The ZVI pre-treatment integrated with activated-sludge post-treatment was proved to be an effective strategy for treating non-biodegradable pollutants.

A SNP in a Steroidogenic Enzyme Is Associated with Phenotypic Sex in Seriola Fishes.

Vertebrate sex development consists largely of two processes: "sex determination," the initial bifurcation of sexual identity, and "sex differentiation," which subsequently facilitates maleness or femaleness according to the sex determination signal. Steroid hormones promote multiple types of sexual dimorphism in eutherian mammals and avians [1-3], in which they are indispensable for proper sex differentiation. By contrast, in many poikilothermic vertebrates, steroid hormones have been proposed to be key players in sex determination as well as sex differentiation [4-8]. This hypothesis was introduced more than 50 years ago but has never been rigorously tested due to difficulties in discriminating the roles of steroids in sex determination and differentiation. We found that a missense SNP in the gene encoding the steroidogenic enzyme 17ß-hydroxysteroid dehydrogenase 1 (Hsd17b1) was perfectly associated with ZZ/ZW sex determination in Seriola fishes. Biochemical analyses revealed that a glutamate residue present specifically in Z-type HSD17B1 attenuated interconversion between 17-keto and 17ß-hydroxy steroids relative to the allelic product from the W chromosome, which harbors glycine at that position, by disrupting the hydrogen bond network between the steroid and the enzyme's catalytic residues. Hsd17b1 mRNA is constitutively expressed in undifferentiated and differentiating gonads of both genotypic sexes, whereas W-type mRNA is expressed only in genotypic females. Meanwhile, Cyp19a1 is predominantly expressed in differentiating ovary. We conclude that the combination of Hsd17b1 alleles determines sex by modulating endogenous estrogen levels in Seriola species. These findings strongly support the long-standing hypothesis on steroids in sex determination.

Oxidized unsaturated fatty acids induce apoptotic cell death in cultured cells.

Polyunsaturated fatty acids are oxidized by non­enzymatic or enzymatic reactions. The oxidized products are multifunctional. In this study, we investigated how oxidized fatty acids inhibit cell proliferation in cultured cells. We used polyunsaturated and saturated fatty acids, docosahexaenoic acid (DHA; 22:6), eicosapentaenoic acid (EPA; 20:5), linoleic acid (LA; 18:2), and palmitic acid (16:0). Oxidized fatty acids were produced by autoxidation of fatty acids for 2 days in the presence of a gas mixture (20% O2 and 80% N2). We found that oxidized polyunsaturated fatty acids (OxDHA, OxEPA and OxLA) inhibited cell proliferation much more effectively compared with un­oxidized fatty acids (DHA, EPA and LA, respectively) in THP­1 (a human monocytic leukemia cell line) and DLD­1 (a human colorectal cancer cell line) cells. In particular, OxDHA markedly inhibited cell proliferation. DHA has the largest number of double bonds and is most susceptible to oxidation among the fatty acids. OxDHA has the largest number of highly active oxidized products. Therefore, the oxidative levels of fatty acids are associated with the anti­proliferative activity. Moreover, caspase­3/7 was activated in the cells treated with OxDHA, but not in those treated with DHA. A pan­caspase inhibitor (zVAD­fmk) reduced the cell death induced by OxDHA. These results indicated that oxidized products from polyunsaturated fatty acids induced apoptosis in cultured cells. Collectively, the switch between cell survival and cell death may be regulated by the activity and/or number of oxidized products from polyunsaturated fatty acids.

Linkage of iron elution and dissolved oxygen consumption with removal of organic pollutants by nanoscale zero-valent iron: Effects of pH on iron dissolution and formation of iron oxide/hydroxide layer.

The iron elution and dissolved oxygen (DO) consumption in organic pollutant removal by nanoscale zero-valent iron (nZVI) was examined in the range of solution pH from 3.0 to 9.0. Their behaviors were linked with the removal of organic pollutant through the dissolution of iron and the formation of iron oxide/hydroxide layer affected strongly by solution pH and DO. As an example of organic pollutants, azo-dye Orange II was chosen in this study. The chemical composition analyses before and after reaction confirmed the corrosion of nZVI into ions, the formation of iron oxide/hydroxide layer on nZVI surface and the adsorption of the pollutant and its intermediates. The complete decolorization of Orange II with nZVI was accomplished very quickly. On the other hand, the total organic carbon (TOC) removal was considerably slow and the maximum TOC removal was around 40% obtained at pH 9.0. The reductive cleavage of azo-bond by emitted electrons more readily took place as compared with the cleavage of aromatic rings of Orange II leading to the degradation to smaller molecules and subsequently the mineralization. A reaction kinetic model based on the Langmuir-Hinshelwood/Eley-Rideal approach was developed to elucidate mechanisms for organic pollutant removal controlled by the formation of iron oxide/hydroxide layer, the progress of which could be characterized by considering the dynamic concentration changes in Fe(2+) and DO. The dynamic profiles of Orange II removal linked with Fe(2+) and DO could be reasonably simulated in the range of pH from 3.0 to 9.0.

Purification and enzymatic characterization of a novel ß-1,6-glucosidase from Aspergillus oryzae.

In this study, among the 10 genes that encode putative ß-glucosidases in the glycoside hydrolase family 3 (GH3) with a signal peptide in the Aspergillus oryzae genome, we found a novel gene (AO090038000425) encoding ß-1,6-glucosidase with a substrate specificity for gentiobiose. The transformant harboring AO090038000425, which we named bglH, was overexpressed under the control of the improved glaA gene promoter to form a small clear zone around the colony in a plate assay using 4-methylumbelliferyl ß-d-glucopyranoside as the fluorogenic substrate for ß-glucosidase. We purified BglH to homogeneity and enzymatically characterize this enzyme. The thermal and pH stabilities of BglH were higher than those of other previously studied A. oryzae ß-glucosidases, and BglH was stable over a wide temperature range (4°C-60°C). BglH was inhibited by Hg(2+), Zn(2+), glucono-δ-lactone, glucose, dimethyl sulfoxide, and ethanol, but not by ethylenediaminetetraacetic acid. Interestingly, BglH preferentially hydrolyzed gentiobiose rather than other oligosaccharides and aryl ß-glucosides, thereby demonstrating that this enzyme is a ß-1,6-glucosidase. To the best of our knowledge, this is the first report of the purification and characterization of ß-1,6-glucosidase from Aspergillus fungi or from other eukaryotes. This study suggests that it may be possible to find a more suitable ß-glucosidase such as BglH for reducing the bitter taste of gentiobiose, and thus for controlling the sweetness of starch hydrolysates in the food industry via genome mining.

Removal of cationic dye methylene blue by zero-valent iron: Effects of pH and dissolved oxygen on removal mechanisms.

Effects of pH and dissolved oxygen on mechanisms for decolorization and total organic carbon (TOC) removal of cationic dye methylene blue (MB) by zero-valent iron (ZVI) were systematically examined. Decolorization and TOC removal of MB by ZVI are attributed to the four potential mechanisms, i.e. reduction, degradation, precipitation and adsorption. The contributions of four mechanisms were quantified at pH 3.0, 6.0 and 10.0 in the oxic and anoxic systems. The maximum efficiencies of decolorization and TOC removal of MB were found at pH 6.0. The TOC removal efficiencies at pH 3.0 and 10.0 were 11.0 and 17.0%, respectively which were considerably lower as compared with 68.1% at pH 6.0. The adsorption, which was favorable at higher pH but was depressed by the passive layer formed on the ZVI surface at alkaline conditions, characterized the effects of pH on decolorization and TOC removal of MB. The efficiencies of decolorization and TOC removal at pH 6.0 under the anoxic condition were 73.0 and 59.0%, respectively, which were comparable to 79.9 and 55.5% obtained under the oxic condition. In the oxic and anoxic conditions, however, the contributions of removal mechanisms were quite different. Although the adsorption dominated the decolorization and TOC removal under the oxic condition, the contribution of precipitation was largely superior to that of adsorption under the anoxic condition.