Inositol hexaphosphate-induced cellular response in myeloid leukemia cells is mediated by nicotinamide adenine dinucleotide phosphate oxidase activation

OBJECTIVES: The objective of this study was to identify the role of reactive oxygen species (ROS) generated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, in inositol hexaphosphate (IP6)-induced metabolic disruption in human leukemia PLB-985 cells. METHODS: PLB-985 and X chromosome linked gp91-phox gene knockout (X-CGD) cells were treated with 5, 10, or 20 mM IP6 for 24 to 72 h. Cell growth was assayed using a highly water-soluble tetrazolium salt. The rate of apoptotic and necrotic cell death was determined with an Annexin V-fluorescein isothiocyanate/propidium iodide kit. The expression of CD11b as a marker of monocytic property and of LC3 as an autophagy marker was tested, using flow cytometry combined with fluorescent antibodies. RESULTS: Treatment with 5 and 10 mM IP6 for 24 h was found to suppress the growth of both cell lines, though the effect was more dramatic in PLB-985 cells. After 6-h treatment with 20 mM IP6, the necrosis rate of PLB-985 cells was significantly greater than that of X-CGD cells. Further, after 72-h treatment with 10 mM IP6, CD11b expression was observed in PLB-985 cells but inhibited in X-CGD cells. Autophagy monitoring after 6-h treatment with 10 mM IP6 revealed that LC3 expression was suppressed in PLB-985 cells, whereas it was somewhat increased in X-CGD cells. CONCLUSIONS: Our results suggest that NADPH oxidase activation mediates IP6-induced metabolic disruption associated with necrosis, differentiation, cell growth, and autophagy in PLB-985 cells

Alkane inducible proteins in Geobacillus thermoleovorans B23

<p>Abstract</p> <p>Background</p> <p>Initial step of β-oxidation is catalyzed by acyl-CoA dehydrogenase in prokaryotes and mitochondria, while acyl-CoA oxidase primarily functions in the peroxisomes of eukaryotes. Oxidase reaction accompanies emission of toxic by-product reactive oxygen molecules including superoxide anion, and superoxide dismutase and catalase activities are essential to detoxify them in the peroxisomes. Although there is an argument about whether primitive life was born and evolved under high temperature conditions, thermophilic archaea apparently share living systems with both bacteria and eukaryotes. We hypothesized that alkane degradation pathways in thermophilic microorganisms could be premature and useful to understand their evolution.</p> <p>Results</p> <p>An extremely thermophilic and alkane degrading <it>Geobacillus thermoleovorans </it>B23 was previously isolated from a deep subsurface oil reservoir in Japan. In the present study, we identified novel membrane proteins (P16, P21) and superoxide dismutase (P24) whose production levels were significantly increased upon alkane degradation. Unlike other bacteria acyl-CoA oxidase and catalase activities were also increased in strain B23 by addition of alkane.</p> <p>Conclusion</p> <p>We first suggested that peroxisomal β-oxidation system exists in bacteria. This eukaryotic-type alkane degradation pathway in thermophilic bacterial cells might be a vestige of primitive living cell systems that had evolved into eukaryotes.</p

2型糖尿病患者におけるセルフスティグマと自己管理行動の関係に関する研究

学位の種別: 課程博士審査委員会委員 : (主査)東京大学准教授 窪田 直人, 東京大学准教授 石川 ひろの, 東京大学准教授 豊川 智之, 東京大学教授 山本 則子, 東京大学准教授 吉内 一浩University of Tokyo(東京大学

Activation Process of [NiFe] Hydrogenase Elucidated by High-Resolution X-Ray Analyses: Conversion of the Ready to the Unready State

SummaryHydrogenases catalyze oxidoreduction of molecular hydrogen and have potential applications for utilizing dihydrogen as an energy source. [NiFe] hydrogenase has two different oxidized states, Ni-A (unready, exhibits a lag phase in reductive activation) and Ni-B (ready). We have succeeded in converting Ni-B to Ni-A with the use of Na2S and O2 and determining the high-resolution crystal structures of both states. Ni-B possesses a monatomic nonprotein bridging ligand at the Ni-Fe active site, whereas Ni-A has a diatomic species. The terminal atom of the bridging species of Ni-A occupies a similar position as C of the exogenous CO in the CO complex (inhibited state). The common features of the enzyme structures at the unready (Ni-A) and inhibited (CO complex) states are proposed. These findings provide useful information on the design of new systems of biomimetic dihydrogen production and fuel cell devices

The novel latex agglutination turbidimetric immunoassay system for simultaneous measurements of calprotectin and hemoglobin in feces

Background/Aims Fecal calprotectin (Fcal) as well as the fecal immunochemical test (FIT) are useful biomarkers for detecting activity and mucosal healing in inflammatory bowel diseases. Here, we report the performance of simultaneous measurements of Fcal and FIT for ulcerative colitis (UC) patients using the newly-developed latex agglutination turbidimetric immunoassay (LATIA) system. Methods Fcal and hemoglobin were measured by the LATIA system in 152 UC patients who underwent colonoscopy. Fcal was also quantified with a conventional enzyme-linked immunosorbent assay (ELISA). Fecal markers were evaluated in conjunction with the mucosal status of UC, which was assessed via the Mayo endoscopic subscore (MES) classification. Results The LATIA system could quantify calprotectin and hemoglobin simultaneously with the same fecal samples within 10 minutes. The values of the Fcal-LATIA closely correlated with those of the Fcal-ELISA (Spearman rank correlation coefficient, r=0.84; P Conclusions The performance of the novel Fcal-LATIA was equivalent to that of the conventional Fcal assay. Simultaneous measurements with FITs would promote the clinical relevance of fecal biomarkers in UC

Fluid-rock interaction recorded in black fault rocks in the Kodiak accretionary complex, Alaska

Ultrafine-grained black fault rocks (BFRs) in the Pasagshak Point Thrust of the Kodiak accretionary complex are examples of fault rocks that have recorded seismicity along an ancient subduction plate boundary. Trace element concentrations and 87Sr/86Sr ratios of BFRs and surrounding foliated/non-foliated cataclasites were measured to explore the nature of fluid-rock interactions along a subduction thrust. Foliated and non-foliated cataclasites do not show significant geochemical anomalies, suggesting that they were formed by slowly distributed shear. BFRs are characterized by Li and Sr enrichment, Rb and Cs depletion, and a low 87Sr/86Sr ratio. These geochemical signatures can be explained by fluid-rock interactions at >350°C, which result in preferential removal of Rb and Cs and formation of plagioclase under the presence of fluids with high Li and Sr concentrations and low 87Sr/86Sr ratios. Geochemical anomalies recorded by the BFRs indicate both frictional heating and external fluid influx into the subduction thrust

雌ラットにおいて生殖腺の状態とエストロゲン環境が視床下部オキシトシン遺伝子発現および血清オキシトシンレベルに及ぼす影響

Oxytocin (OT) and its receptor (OTR) play various roles in the central and peripheral regulation of appetite and body weight. Previously, we have shown that the administration of OT markedly decreased appetite and body weight gain in ovariectomized (OVX) obese rats. In addition, recent studies have shown that the endogenous OT system is also affected by endogenous or exogenous estrogen. In this study, we showed that ovariectomy decreased rats' hypothalamic OT/OTR mRNA and serum OT levels, but did not affect their visceral fat OTR mRNA levels. The chronic administration of estradiol (E2) abrogated these ovariectomy-induced changes; i.e., it increased the rats' hypothalamic OT/OTR mRNA and serum OT levels, and may be associated with reductions in food intake and body weight gain. In addition, acute E2 administration increased the rats' hypothalamic OTR mRNA and serum OT levels, but did not affect their hypothalamic OT mRNA levels. Taken together, these results suggest that endogenous OT and/or OTR expression might be positively regulated by E2 and that the suppressive effects of E2 on appetite and body weight gain might be mediated, at least in part, by the OT system. Thus, we consider that OT might be a target hormone to pursue subsequent interventions of menopause for menopause-induced metabolic disorders

Prompt Resolution of Hypoglycemia by Hepatic Transarterial Embolization for Malignant Insulinoma with Multiple Liver Metastases

A 45-year-old female who presented with loss of consciousness and a cold sweat was found to have a pancreatic tumor and multiple liver metastases. Laboratory studies showed marked hypoglycemia and inappropriately elevated serum insulin, C-peptide, and serum tumor markers. Fine needle aspiration revealed Grade 3 small-cell type primary pancreatic neuroendocrine carcinoma. Consequently, the diagnosis of malignant insulinoma was made. Transarterial embolization (TAE) for hepatic metastases resulted in the reduction of tumor volume and prompt resolution of hypoglycemic attacks, whereas diazoxide and systemic chemotherapy had been ineffective for controlling blood glucose levels, and octreotide was unavailable due to the allergic effect. This case report highlights the potential usefulness of TAE for malignant insulinomas in the management of hypoglycemia

Structural insights into the G protein selectivity revealed by the human EP3-Gi signaling complex

熱、炎症などに関与するプロスタグランジン受容体EP3シグナリング複合体の可視化 --緑内障、高眼圧症治療薬の合理的設計に貢献--. 京都大学プレスリリース. 2022-09-15.Prostaglandin receptors have been implicated in a wide range of functions, including inflammation, immune response, reproduction, and cancer. Our group has previously determined the crystal structure of the active-like EP3 bound to its endogenous agonist, prostaglandin E₂. Here, we present the single-particle cryoelectron microscopy (cryo-EM) structure of the human EP3-Gi signaling complex at a resolution of 3.4 Å. The structure reveals the binding mode of Gi to EP3 and the structural changes induced in EP3 by Gi binding. In addition, we compare the structure of the EP3-Gi complex with other subtypes of prostaglandin receptors (EP2 and EP4) bound to Gs that have been previously reported and examine the differences in amino acid composition at the receptor-G protein interface. Mutational analysis reveals that the selectivity of the G protein depends on specific amino acid residues in the second intracellular loop and TM5

Conditioned medium from stem cells derived from human exfoliated deciduous teeth ameliorates NASH via the Gut-Liver axis

Non-alcoholic steatohepatitis (NASH) occurrence has been increasing and is becoming a major cause of liver cirrhosis and liver cancer. However, effective treatments for NASH are still lacking. We examined the benefits of serum-free conditioned medium from stem cells derived from human exfoliated deciduous teeth (SHED-CM) on a murine non-alcoholic steatohepatitis (NASH) model induced by a combination of Western diet (WD) and repeated administration of low doses of carbon tetrachloride intraperitoneally, focusing on the gut-liver axis. We showed that repeated intravenous administration of SHED-CM significantly ameliorated histological liver fibrosis and inflammation in a murine NASH model. SHED-CM inhibited parenchymal cell apoptosis and reduced the activation of inflammatory macrophages. Gene expression of pro-inflammatory and pro-fibrotic mediators (such as Tnf-α, Tgf-β, and Ccl-2) in the liver was reduced in mice treated with SHED-CM. Furthermore, SHED-CM protected intestinal tight junctions and maintained intestinal barrier function, while suppressing gene expression of the receptor for endotoxin, Toll-like receptor 4, in the liver. SHED-CM promoted the recovery of Caco-2 monolayer dysfunction induced by IFN-γ and TNF-α in vitro. Our findings suggest that SHED-CM may inhibit NASH fibrosis via the gut-liver axis, in addition to its protective effect on hepatocytes and the induction of macrophages with unique anti-inflammatory phenotypes