ARBM101 (Methanobactin SB2) Drains Excess Liver Copper via Biliary Excretion in Wilson's Disease Rats

BACKGROUND & AIMS

Excess copper causes hepatocyte death in hereditary Wilson's disease (WD). Current WD treatments by copper-binding chelators may gradually reduce copper overload; they fail, however, to bring hepatic copper close to normal physiological levels. Consequently, lifelong daily dose regimens are required to hinder disease progression. This may result in severe issues due to nonadherence or unwanted adverse drug reactions and also due to drug switching and ultimate treatment failures. This study comparatively tested bacteria-derived copper binding agents-methanobactins (MBs)-for efficient liver copper depletion in WD rats as well as their safety and effect duration.

METHODS

Copper chelators were tested in vitro and in vivo in WD rats. Metabolic cage housing allowed the accurate assessment of animal copper balances and long-term experiments related to the determination of minimal treatment phases.

RESULTS

We found that copper-binding ARBM101 (previously known as MB-SB2) depletes WD rat liver copper dose dependently via fecal excretion down to normal physiological levels within 8 days, superseding the need for continuous treatment. Consequently, we developed a new treatment consisting of repetitive cycles, each of ∼1 week of ARBM101 applications, followed by months of in-between treatment pauses to ensure a healthy long-term survival in WD rats.

CONCLUSIONS

ARBM101 safely and efficiently depletes excess liver copper from WD rats, thus allowing for short treatment periods as well as prolonged in-between rest periods.

Phenylbutyrate Ameliorates High-Fat Diet-Induced Obesity via Brown Adipose Tissue Activation

Obesity, which is characterized by an excessive accumulation of body fat, is one of the critical factors causing metabolic syndrome. Many studies have been performed to identify appropriate agents to control obesity, but toxicity remains a problem. Herein, we identified that phenylbutyrate (PBA), which has been used to treat urea cycle disorder with very low toxicity for a long time, efficiently inhibited high fat-induced body weight gain in a diet-induced obesity mouse model (DIO model). PBA treatment decreased body fat mass and increased lean composition. Moreover, PBA increased brown adipose tissue (BAT) activity by increasing glucose uptake, thereby improving glucose tolerance and insulin tolerance. Interestingly, PBA could induce the expression of liver type phosphofructokinase (PFKL), a key enzyme in the glycolytic pathway, and knocking down PFKL dramatically repressed the expression level of Ucp1 as well as those of Prdm16, Cidea, Pgc1α, and Pparγ, which are marker genes for BAT activation. These results strongly suggested that PBA could increase energy expenditure by increasing BAT activity via the induction of PFKL. Taken together, PBA could be used as a therapeutic agent for people with obesity to prevent the development of metabolic syndrome.

Therapeutic effect of dichloroacetate against atherosclerosis via hepatic FGF21 induction mediated by acute AMPK activation

Dyslipidemia-induced atherosclerosis, which has a risk of high morbidity and mortality, can be alleviated by metabolic activation associated with mitochondrial function. The effect of dichloroacetate (DCA), a general pyruvate dehydrogenase kinase (PDK) inhibitor, on in vivo energy expenditure in ApoE-/- mice fed a western diet (WD) has not yet been investigated. WD-fed ApoE-/- mice developed atherosclerotic plaques and hyperlipidemia along with obesity, which were significantly ameliorated by DCA administration. Increased oxygen consumption was associated with heat production in the DCA-treated group, with no change in food intake or physical activity compared with those of the control. These processes were correlated with the increased gene expression of Dio2 and Ucp-1, which represents brown adipose tissue (BAT) activation, in both WD-induced atherosclerosis and high-fat-induced obesity models. In addition, we found that DCA stimulated hepatic fibroblast growth factor 21 (Fgf21) mRNA expression, which might be important for lowering lipid levels and insulin sensitization via BAT activation, in a dose- and time-dependent manner associated with serum FGF21 levels. Interestingly, Fgf21 mRNA expression was mediated in an AMP-activated protein kinase (AMPK)-dependent manner within several minutes after DCA treatment independent of peroxisome proliferator-activated receptor alpha (PPARα). Taken together, the results suggest that enhanced glucose oxidation by DCA protects against atherosclerosis by inducing hepatic FGF21 expression and BAT activation, resulting in augmented energy expenditure for heat generation.

Pyruvate Dehydrogenase Kinase Is a Metabolic Checkpoint for Polarization of Macrophages to the M1 Phenotype

Metabolic reprogramming during macrophage polarization supports the effector functions of these cells in health and disease. Here, we demonstrate that pyruvate dehydrogenase kinase (PDK), which inhibits the pyruvate dehydrogenase-mediated conversion of cytosolic pyruvate to mitochondrial acetyl-CoA, functions as a metabolic checkpoint in M1 macrophages. Polarization was not prevented by PDK2 or PDK4 deletion but was fully prevented by the combined deletion of PDK2 and PDK4; this lack of polarization was correlated with improved mitochondrial respiration and rewiring of metabolic breaks that are characterized by increased glycolytic intermediates and reduced metabolites in the TCA cycle. Genetic deletion or pharmacological inhibition of PDK2/4 prevents polarization of macrophages to the M1 phenotype in response to inflammatory stimuli (lipopolysaccharide plus IFN-γ). Transplantation of PDK2/4-deficient bone marrow into irradiated wild-type mice to produce mice with PDK2/4-deficient myeloid cells prevented M1 polarization, reduced obesity-associated insulin resistance, and ameliorated adipose tissue inflammation. A novel, pharmacological PDK inhibitor, KPLH1130, improved high-fat diet-induced insulin resistance; this was correlated with a reduction in the levels of pro-inflammatory markers and improved mitochondrial function. These studies identify PDK2/4 as a metabolic checkpoint for M1 phenotype polarization of macrophages, which could potentially be exploited as a novel therapeutic target for obesity-associated metabolic disorders and other inflammatory conditions.

Relationship between hepcidin and GDF15 in anemic patients with type 2 diabetes without overt renal impairment

AIMS

Despite the absence of overt renal impairment and decreased erythropoietin (EPO) levels, patients are usually anemic. Hepcidin, which is induced by inflammatory stimuli, plays an important role in anemia in chronic disease. Growth differentiation factor 15 (GDF15) is a putative anti-inflammatory cytokine that is elevated in type 2 diabetes (T2DM). Hence, we investigated the relationship between hepcidin and GDF15 in anemic T2DM patients without overt renal impairment.

METHODS

Among 1150 patients who visited Kyungpook National University Hospital for T2DM between June 2006 and June 2014, we selected 55 anemic patients without overt renal impairment (serum creatinine <1.5 mg/dL or estimated glomerular filtration rate >60 mL/min/1.73 m(2)) and other co-morbid diseases, including malignancy, thyroid disease, rheumatic arthritis, liver disease, iron-deficiency anemia and other endocrine disease. We measured anthropometric and metabolic parameters, as well as measured the serum iron, ferritin, interleukin-6 (IL-6), erythropoietin, hepcidin-25 and GDF15 levels.

RESULTS

Anemic T2DM patients without overt renal impairment presented a greater inflammatory state, with increased serum hsCRP, ESR and IL-6 levels compared with non-anemic T2DM patients. Both hepcidin and GDF15 levels were increased and showed a positive correlation in anemic T2DM patients.

CONCLUSION

In the absence of overt renal impairment, anemia in T2DM is associated with chronic inflammation, inducing elevation of hepcidin and GDF15 levels independently of the erythropoietin level.

Efficient CO Oxidation at Low Temperature on Au(111)

The rate of CO oxidation to CO2 depends strongly on the reaction temperature and characteristics of the oxygen overlayer on Au(111). The factors that contribute to the temperature dependence in the oxidation rate are (1) the residence time of CO on the surface, (2) the island size containing Au-O complexes, and (3) the local properties, including the degree of order of the oxygen layer. Three different types of oxygen--defined as chemisorbed oxygen, a surface oxide, and a bulk oxide--are identified and shown to have different reactivity. The relative populations of the various oxygen species depend on the preparation temperature and the oxygen coverage. The highest rate of CO oxidation was observed for an initial oxygen coverage of 0.5 monolayers that was deposited at 200 K where the density of chemisorbed oxygen is maximized. The rate decreases when two-dimensional islands of the surface oxide are populated and further decreases when three-dimensional bulk gold oxide forms. Our results are significant for designing catalytic processes that use Au for CO oxidation, because they suggest that the most efficient oxidation of CO occurs at low temperature--even below room temperature--as long as oxygen could be adsorbed on the surface.

Water Dissociation Associated with NO2Coadsorption on Mo(110)-(1 × 6)-O: Effect of Coverage and Electronic Properties of Oxygen

Water dissociation on an oxygen-covered Mo(110) surface was investigated using temperature-programmed reaction spectroscopy (TPRS) and infrared reflectance absorbance spectroscopy (IRAS). Adsorbed hydroxyl formation is enhanced by increasing the coverage of chemisorbed oxygen prior to exposure to water up to saturation (0.66 ML). Additional oxidation of the surface using NO(2) suppresses the formation of hydroxyl species (OH). There is no detectable change in the reaction of NO(2) on Mo(110)-(1 x 6)-O when either the water or hydroxyl is adsorbed on the Mo(110)-(1 x 6)-O surface prior to NO(2) adsorption. In contrast, NO(2) induces the displacement of water into the gas phase and the conversion of hydroxyl species to molecular water. Infrared spectra show that the dissociation of NO(2) populates three types of terminal oxygen sites on Mo(110)-(1 x 6)-O, and the population of the terminal oxygen at step sites increases with respect to the amount of NO(2) deposited. Overall, these results suggest that the oxidic property of oxygen results in a lack of activity for the water dissociation.

The effects of N-methyl-N-nitrosourea and azoxymethane on focal cerebral infarction and the expression of p53, p21 proteins

If the activity of pro-apoptotic genes can be down-regulated by certain chemicals, cells may be protected from apoptosis. To test this hypothesis in a cerebral infarction model, we used N-methyl-N-nitrosourea (MNU) and azoxymethane (AOM), which were approved gene-modulating chemicals. A focal cerebral infarction was created by coagulation of the right middle cerebral artery and ipsilateral common carotid artery (CCA) and simultaneous transient occlusion of the contralateral CCA for 30 min in 25 adult Sprague-Dawley rats that were sacrificed 24 h later. In one group (n=7), MNU (5 mg/kg) was injected intravenously 30 min before initiation of ischemia. In another group (n=7), AOM (15 mg/kg) was administered intraperitoneally before 24 h of ischemia. The infarction volumes were checked and the brains were stained for p53 and p21 proteins. The width in micrometers of the peri-infarct area containing p53 or p21 protein-positive cells, and the number of p53 or p21 protein-positive cells (cells/HPF) were measured at an adjacent peri-infarct area. The AOM-treated group showed a significantly reduced infarction volume (by 42.5%, p<0.001), a significantly greater number of p53 positive cells (by 12.0%, p<0. 05), and a significantly wider p53 protein-positive area (by 15.6%, p<0.01) than the untreated group. AOM did not show any influence on the expression pattern of the p21 protein. MNU had no effect in the expression of p53 or p21 proteins. As a result, we concluded that AOM revealed a protective effect in ischemia by suppressing the pro-apoptotic activity of the p53 gene. Safer chemicals that can modulate apoptotic genes, if any, will provide a new therapeutic modality for cerebral infarction.

Flavonol glycoside gallate and ferulate esters from Persicaria lapathifolia as inhibitors of superoxide production in human monocytes stimulated by unopsonized zymosan

Aerial parts of Persicaria lapathifolia S.F. Gray (Polygonaceae) exhibited an inhibitory effect on superoxide production in unopsonized zymosan-stimulated human monocytes. Two known compounds, quercetin 3-O-beta-(2"-galloyl)-glucopyranoside and quercetin 3-O-beta-(2"-galloyl)-rhamnopyranoside, and a new compound, quercetin 3-O-beta-(6"-feruloyl)-galactopyranoside, were isolated as the inhibitors of superoxide production by activity-guided fractionation. IC50 values were shown at the concentrations of 2.1 microM by quercetin 3-O-beta-(2"-galloyl)-glucopyranoside, 1.9 microM by quercetin 3-O-beta-(2"-galloyl)-rhamnoypranoside, and 3.5 microM by quercetin 3-O-beta-(6"-feruloyl)-galactopyranoside whose inhibitory potencies were similar to oxyphenylbutazone (IC50 = 1.9 microM) as a positive control.

Inhibitory effect of luteolin 4'-O-glucoside from Kummerowia striata and other flavonoids on interleukin-5 bioactivity

Interleukin (IL)-5 is a chemotactic factor of eosinophils, and promotes the growth and survival of eosinophils, which plays an important role in the eosinophilia-associated allergic inflammation. In this study, luteolin 4'-O-glucopyranoside was identified as the IL-5 inhibitor from Kummerowia striata Thunb. (Leguminosae) by activity-guided fractionation followed by structural analysis compared with reported spectral data. The flavone compound exhibited dose-dependent inhibitory effect on IL-5 bioactivity with 95% inhibition at 30 microM, 79% at 15 microM, 60% at 7.5 microM, 54% at 3.8 microM and 29% at 1.9 microM, where 50% of inhibition (IC50) value was shown at the concentration of 3.7 microM. Furthermore, the inhibitory effect on IL-5 bioactivity by other flavonoid compounds available was estimated. In view of the IC50 values, the inhibitory potency on IL-5 bioactivity was in order of luteolin 4'-O-glucopyranoside > cosmosiin (14.2 microM) approximately equal to apigenin (16.4 microM) approximately equal to luteolin (18.7 microM) > quercimeritrin (27.3 microM) approximately equal to kaempferol (30.0 microM).

Rapid determination of in vivo and in vitro antibody responses by suspension hemolytic assay

A suspension hemolytic (SH) assay newly modified in this laboratory was applied to the measurement of primary IgM antibody responses, such as T-dependent, T-independent, and polyclonal B cell responses in in vivo and in vitro assays. All results of the SH assay were equal to those of the conventional plaque-forming cell (PFC) assay. With the SH assay in in vitro assays, we could separately measure the amount of the IgM that had been produced during the whole immunization period and measure the IgM newly produced during the shorter time of the assay. The immunomodulations by dioxin and glycopeptide were accurately evaluated by the SH and the PFC assay. Our study suggested that the SH assay modified in this laboratory was more advantageous because of the simplicity of the assay and better analysis of data than the PFC assay, and could be used as the primary method in studying the effects of pharmaceutical and toxic agents on humoral immune functions.

Incidence estimation of genitourinary cancer in Korea

A nation-wide study was performed to estimate the incidence of bladder, kidney, renal pelvis and ureter, prostate, testicular and other genitourinary cancer among Koreans in Korea using medical records of the inpatients of the beneficiaries of the Korea Medical Insurance Corporation (KMIC) from Jan. 1, 1989 to Dec. 31, 1989. The crude incidence rate of bladder cancer (ICD-9 188) is estimated to be 4.43 and 0.98 per 100,000 in males and females, respectively. Around 1,093 new cases of bladder cancer (895 male and 198 female) are estimated to occur in a year. The adjusted rate for the world population is 7.76 in males and 1.19 in females which is similar to that of Japanese in Osaka and Chinese in Shanghai, but lower than in American whites and blacks. The crude incidence of kidney, renal pelvis and ureteral cancer (ICD-9 189) is estimated to be 1.61 and 0.87 in males and females, respectively. Around 507 new cases of kidney, renal pelvis and ureteral cancer (332 male and 175 female) are estimated to occur in a year. The adjusted rate for the world population is 2.69 in males and 1.04 in females. In the prostate (ICD-9 185), the crude incidence rate of cancer is estimated to be 1.36. Around 274 new cases of prostate cancer are occurring in a year. The adjusted rate for the world population is 2.98 which is similar to the Chinese rate. The incidence of genitourinary cancer continuously increases with age.

Safety and immunogenicity of a new heat-inactivated hepatitis B virus vaccine in adult recipients

A new heat inactivated HBV vaccine has been evaluated for safety and immunogenicity in 203 adult recipients. The vaccine was found to be safe and highly immunogenic. Three doses of 3 micrograms given at 0, 1 and 6 months, resulted in 96% seroconversion. Three doses of 3 micrograms given at 0, 1 and 2 months produced, more rapidly, seroconversion in 92% of those immunized. Antibody to a pre-S determinant developed in four of six subjects tested.

Enzymatic studies on the skeletal myosin A and actomyosin of aging rats

Myosin A and actomyosin were isolated from the skeletal muscle of old and young rats. The velocity of the Ca2+ activated myosin A ATPase was increased in the case of the older animals. On the other hand the velocity of the Mg-2plus activated actomyosin ATPase was decreased in the skeletal muscle of the aging rats. At 5 X 10-5M EGTA concentration the inhibition of the Mg-2plus activated myosin B ATPase of the 1-month-old rats was two- to threefold smaller than that of the older animals. It was shown that the myosin A component of the actomyosin was responsible for the decreased troponin inhibition in the case of the 1-month-old rats. Between the ages of 1 month and 29 months the number of free myosin A SH groups decreases by 50%. The lipid peroxidation in the muscle of the 1-month-old animals.