Fibroblast growth factors (Fgfs) were originally isolated as growth factors for fibroblasts. However, Fgfs are now recognized as polypeptide growth factors of ca. 150—250 amino acid residues with diverse biological activities and expression profiles. The Fgf signaling system has been identified in multicelluar but not in unicellular organisms. In contrast to the only two Fgf genes and one Fgf receptor (Fgfr) gene in Caenorhabditis elegans, both the human and mouse Fgf and Fgfr gene families comprise twenty-two and four members, respectively. Their evolutional processes indicate that the Fgf and Fgfr gene families greatly co-expanded during the evolution of early vertebrates. The expansion of the Fgf and Fgfr gene families has enabled this signaling system to acquire diversity of function and a nearly ubiquitous involvement in many developmental and physiological processes. The zebrafish fgf gene family comprises twenty-seven members with several paralogs generated by an additional genome duplication. The mouse and zebrafish are useful models for studying gene functions. Fgf knockout mice have been generated. Several Fgf knockout mice die in the embryonic or early postnatal stages, indicating crucial roles for these genes in various developmental processes. However, other Fgf knockout mice survive with subtle phenotypic alterations. Their functions might be redundant. Studies using zebrafish embryos with mutated or knockdown fgfs also indicate that fgfs play crucial roles in development in that species. Although most Fgfs act in development in a paracrine and/or autocrine manner, some have potential roles in metabolism in an endocrine manner. In humans, Fgf signaling disorders result in hereditary diseases and cancers.

View full abstract

A sensitive method for the determination of polyamines in mammalian cells was described using electrospray ionization and time-of-flight mass spectrometer. This method was 50-fold more sensitive than the previous method using ionspray ionization and quadrupole mass spectrometer. The method employed the partial purification and derivatization of polyamines, but allowed a measurement of multiple samples which contained picomol amounts of polyamines. Time required for data acquisition of one sample was approximately 2 min. The method was successfully applied for the determination of reduced spermidine and spermine contents in cultured cells under the inhibition of aminopropyltransferases. In addition, a new proper internal standard was proposed for the tracer experiment using ¹⁵N-labeled polyamines.

View full abstract

Darunavir (DRV) is a new protease inhibitor used to treat human immunodeficiency virus (HIV) type-1. The aim of this study was to validate the determination of plasma DRV concentrations using the HPLC method, a simple procedure for simultaneous determination of seven HIV protease inhibitors and efavirenz. The calibration curve was linear (range of 0.13 to 10.36 μg/ml). The average accuracy ranged from 100.7 to 105.6%. Both the interday and intraday coefficients of variation were less than 6.7%, which was similar to or much lower than previously reported values by the LC/MS/MS method. It is concluded that HPLC can be used to determine plasma DRV concentrations and routinely in the clinical setting; thus, this HPLC method enables further study of DRV pharmacokinetics in conventional hospital laboratories.

View full abstract

When a human leukemic cell line, HT93 was incubated with all-trans retinoic acid (ATRA), IL-5, or both, this cell line was differentiated into eosinophic lineage, in that an eosinophilic specific granule proteins, major basic protein (MBP) and eosinophil peroxidase (EPO) appeared. Both CD11b and CC chemokine receptor, CCR3 expression were upregulated, while CD71 expression was downregulated by ATRA or ATRA+IL-5. Concomitantly, marked production of eotaxin-2/CCL24 was observed, but no production of eotaxin-1/CCL11 and eotaxin-3/CCL26 was detected. Since only 20 to 30% cells incubated with ATRA became positive for CCR3, CCR3⁺ population was enriched by a magnetic activated cell sorter (MACS). Enriched CCR3⁺ population produced higher eotaxin-2/CCL24 than the CCR3⁻ population, indicating that differentiated eosinophils are capable of producing eotaxin-2/CCL24. During the ATRA-induced differentiation, expression of a transcriptional factor, GATA-1 was significantly increased. Introduction of siRNA against GATA-1 markedly reduced the ATRA-induced differentiation markers including CD11b and CCR3, as well as reduced eotaxin-2/CCL24 production. Finally, ATRA-induced differentiation and eotaxin-2/CCL24 production were greatly enhanced in the GATA-1-overexpressed clones. These results indicate that the ability to produce eotaxin-2/CCL24 is acquired during the differentiation into eosinophilic lineage which is dependent on GATA-1 expression.

View full abstract

Glycated human serum albumin (Glc-HSA) has previously been reported (Higai K., et al., 2006) to induce E-selectin expression on human umbilical vein endothelial cells through activation of NADPH oxidase; however, Glc-HSA signaling in monocytes remains obscure. To clarify the influence on human monocyte-derived U937 cells, U937 cells were stimulated with Glc-HSA and glycoaldehyde-dimer-modified HSA (GA-HSA) for 2 h in the absence and presence of the protein kinase C (PKC) inhibitor calphostin and the reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine (NAC) and NADPH oxidase inhibitor apocynin; interleukin-8 (IL-8) mRNA expression was determined by RT-PCR. As a result, IL-8 mRNA expression in U-937 cells was time- and dose-dependently enhanced by stimulation with Glc-HSA and GA-HSA. Furthermore, promoter activity of the IL-8 reporter gene was enhanced approximately 2-fold by stimulation with Glc-HSA and GA-HSA. Nuclear factor κB (NFκB) and activator protein-1 (AP-1) reporter genes were also enhanced although CCAAT/enhancer binding protein (C/EBP) was not affected. IL-8 mRNA expression was suppressed by NAC and apocynin but not calphostin in cells stimulated with Glc-HSA; however, its expression in cells stimulated with GA-HSA was suppressed by calphostin but not NAC. These results indicated that IL-8 mRNA expression was upregulated by NFκB and AP-1 in U937 cells stimulated with Glc-HSA and GA-HSA, but the signaling pathways were different.

View full abstract

We recently reported that C-terminal polyamine modification occurs when proteins are digested with trypsin in the presence of polyamine [Biochem. Biophys. Res. Commun., 356, 159—162 (2007)]. In the present study, the characteristics of this C-terminal modification in the presence of protease and amine were investigated. When hemoglobin (HB) was digested with trypsin in the presence of N-(2-pyridyl)-1,4-diaminobutane (Py4), formation of the modified peptide was dependent on time and on HB or Py4 concentration. When synthetic peptide was treated with trypsin in the presence of Py4, ca. 0.1% of the peptide was modified with Py4. When HB or cytochrome C was treated with a range of serine proteases in the presence of various amines (Py4, N-(2-pyridyl)-1,3-diaminopropane, tranexamic acid, isonicotinic acid hydrazide and ampicillin), the modified peptide was detected in all cases tested, thus suggesting that amine modification widely accompanies digestion by proteases.

View full abstract

To investigate the relationship between caspase-3-like protease activity, which has been suggested to be related to apoptosis, and DNA fragmentation, we measured changes in caspase-3-like activity and DNA fragmentation in the hippocampus of gerbils exposed to global ischemia induced by bilateral occlusion of the carotid arteries for 5 min. Caspase-3-like protease activity began to increase at day 4 post-ischemia, reached a peak at day 5, and declined thereafter. The levels of DNA fragmentation, evaluated in terms of terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end labeling (TUNEL) staining and cytosolic nucleosomes, in the ischemic hippocampus began to increase significantly at day 3 after ischemia, reached a peak at day 4, and decreased thereafter. Our data suggest that DNA fragmentation in ischemic hippocampus of gerbils precedes caspase-3-like protease activation. Our results indicate that a caspase-3-like protease-independent apoptotic pathway operates, at least at the onset of neuronal cell death, in the hippocampus of gerbils after global ischemia.

View full abstract

We have previously reported the expression of CYP genes in human myeloblastic and lymphoid cell lines, and the induction of the CYP3A4 and GSTP1 genes by oxidative stress in the human erythroleukemia cell line, K562. To further elucidate the role of drug metabolizing enzymes in hematogenesis, we have characterized the expression of CYP genes in hemin-induced differentiated K562 cells. After incubation with 50 μM hemin for 3 d, the expression of CYP1A1 and CYP3A4 genes was induced by 2.5- and 3.5-fold, respectively. In contrast, the CYP1B1 and CYP2E1 genes were downregulated in these cells to below 10% of the control levels. Moreover, these changes correlated with the hemin dose and culture time. Metabolism of midazolam, a probe substrate for CYP3A4, in the differentiated K562 cells increased by 2-folds, suggesting that the induction of CYP3A4 activity is consistent with the mRNA level. If these changes in the CYP expression profile in hematopoietic cells occurred, the susceptibility to xenobiotics and/or the therapeutic drugs of the cells might be influenced, and it also affects the metabolism of endogenous substrates, such as steroids and prostaglandins.

View full abstract

We determined the influence of siRNA (short interfering RNA) for expression of plasmid DNA (pDNA), when mismatched siRNA and pDNA encoding β-galactosidase (β-gal) were transfected into HeLa cells by the cotransfection method in which they were simultaneously added to the cells. Cationic liposomes (Lipofectamine2000) were used as a gene transfection reagent. The knockdown effect on β-gal was observed even when mismatched siRNA was used, and the effect depended on the amount of added mismatched siRNA. But, there was not a distinct difference of introduction of pDNA into cells between using mismatched siRNA and without using it. We considered that the cotransfection method should be avoided when we confirm RNAi efficiency. The reliable evaluation method for siRNA delivery in vitro was thus established by using NFAT reporter HeLa stable cell line or CHO (pMAM-luc) cell line that had DNA encoding luciferase. The following experimental conditions for each cell line were optimized: cell numbers seeded, total incubation times, concentrations of added inducers, and incubation times after addition of inducers. Transfection performance was compared for six commercially available reagents by this method. No commercially available transfection reagent, however, could reduce luciferase activity by less than one tenth without causing cellular cytotoxicity. Development of novel reagents providing higher transfection effects without cytotoxicity is needed.

View full abstract

The small ubiquitin-like modifier (SUMO) modification occurred at bud necks and sites of septum formation in hyphae of the opportunistic fungal pathogen Candida albicans. Three genes encoding putative SUMO deconjugation enzymes (Ulp, ubiquitin-like protein specific proteases) of C. albicans were obtained through sequence database searching with Ulp domain of Saccharomyces cerevisiae Ulp1 (ScUlp1). These genes were designated as CaULP1, CaULP2 and CaULP3. The open reading frames of three putative ULPs were cloned and expressed in Pichia pastoris, resulting recombinant proteins. Functional analysis of recombinant CaUlp1, CaUlp2 and CaUlp3 confirms that these proteins exhibit SUMO-processing activity. CaULP1, CaULP2 and CaULP3 only expressed active form enzyme in P. pastoris but not in Escherichia coli. The molecular weights of CaUlp1, CaUlp2 and CaUlp3 proteins expressed in P. pastoris were larger than theoretical molecular weights. This observation was in good agreement with result of Western blot analysis of CaUlp1 and CaUlp3 proteins in C. albicans. It was assumed that CaUlp1, CaUlp2 and CaUlp3 proteins may need post-translational modifications to exhibit SUMO-processing activity. To our knowledge, this is the first report on cloning and expression of Ulp genes from C. albicans. Furthermore RT-PCR and Western blot analysis show that CaULP2 has no detectable expression both in yeast and in hyphal forms of C. albicans.

View full abstract

Treatment of Xenopus blastula with activin converts undifferentiated presumptive ectoderm (animal cap) into mesoderm and endoderm in a dose-dependent manner. At low concentrations, activin induces ventral mesoderm such as blood cells. Here we show that activin-treated aggregates of animal cap cells prepared from undifferentiated presumptive ectoderm and transplanted into Xenopus embryos differentiated to form red blood cells and vascular endothelial cells. We compared gene expression profiles of the activin-treated with untreated aggregates of animal cap cells using microarray analysis. This revealed 838 clones including vascular-related genes that were expressed at levels at least 2-fold greater in the activin-treated aggregates than in the untreated controls. Of these, 356 were known Xenopus genes, 296 had homologues, and 186 were unknown genes. These findings identified novel vascular-related genes and provided insights into how the blood vessel system establishes in normal development.

View full abstract

Signal transducer and activator of transcription 3 (STAT3), which mediates biological actions in many physiological processes, is activated by cytokines and growth factors via specific tyrosine or serine phosphorylation, dimerization and nuclear translocation. A recent study has demonstrated, by using antibody to acetylated lysine, and a STAT3 mutant with Lys-685-to-Arg substitution, that STAT3 is acetylated at Lys-685 by histone acetyltransferase p300, and that acetylation at Lys-685 is critical for STAT3 activation. In the present study, we created an acetyl-specific antibody against STAT3 acetylated at Lys-685, and found that leukemia inhibitory factor (LIF) or interleukin (IL)-6 induced acetylation of STAT3 at Lys-685 in 293T and Hep3B cells. Moreover, acetylation of STAT3 at Lys-685 was suppressed by PI3K inhibitor LY294002, or a dominant negative Akt. Taken together, our findings demonstrate that endogenous STAT3 is acetylated at Lys-685 by LIF or IL-6 through PI3K/Akt activation.

View full abstract

Werner syndrome helicase (WRN) participates in a wide range of DNA activities, including replication, double-strand DNA break repair, telomere and retrovirus long terminal repeat maintenance. Mutations of the WRN gene cause Werner syndrome (WS), an autosomal recessive premature ageing disorder associated with various symptoms related to ageing. In this study, we investigated the siRNA that specifically down-regulates WRN expression. WRN silencing increased markedly the chemotherapeutic activity of camptothecin (CPT) on cancer cells in terms of the extent of efficacy and lowering effective drug dosage, accompanied by suppressing recovery from DNA damage caused by CPT. Here, we propose a potential combination therapy of WRN-siRNA and CPT, looking forward to minimizing the inevitable adverse effects associated with cancer chemotherapy.

View full abstract

Indole-3-carbinol (I3C) is a naturally occurring constituent of cruciferous vegetables. The aim of this study was to assess the in vitro antimicrobial activity of I3C and its mode of action. By using an NCCLS broth microdilution assay, the activity of I3C was evaluated against human pathogenic microorganisms including clinically isolated antibiotic-resistant bacterial strains. The results indicated that I3C exhibited broad spectrum antimicrobial activities. To elucidate the physiological changes of the fungal cells induced by I3C, we performed a flow cytometric analysis for a cell cycle. The results showed that I3C arrested the cell cycle at the G₂/M phase in Candida albicans. To understand the antifungal mode of action of I3C, the change in the membrane dynamics was monitored by using fluorescence changing experiments against C. albicans. The results suggest that I3C may exert antifungal activity by disrupting the structure of the cell membrane. The present study indicates that I3C has considerable antimicrobial activity, deserving further investigation for clinical applications.

View full abstract

In order to clarify the pathogenicity and the pathogenic factors of various Candida species strains, three strains, NIH A-207 and J-1012 (serotype A), and NIH B-792 (serotype B) of Candida albicans and two strains, ATCC 20408 (karyotype II) and ATCC 36232 (karyotype I) of C. stellatoidea, a synonym for C. albicans, were tested for their lethality to mice, adherence to Hela cells, hydrophobicity, and cell growth under acidic conditions, pH 2.0—5.9. The pathogenicity for mice of all the strains was observed in the order NIH B-792, ATCC 36232, J-1012, NIH A-207, and ATCC 20408. The pathogenicity for mice by all the strains used was well correlated with adherence to the Hela cells, the hydrophobicity, and the cell growth under the acidic condition, pH 2.0. These results emphasize that these specific properties of the C. albicans and C. stellatoidea strains play an important role in the pathogenesis of candidosis.

View full abstract

We cloned a gene related to multidrug resistance from a drug-resistant Klebsiella pneumoniae strain MGH78578. We designated the gene kdeA, which encodes a protein possessing 12 hydrophobic regions. The deduced amino acid sequence of KdeA is similar to that of MdfA, a well-characterized multidrug efflux pump from Escherichia coli. Introduction of the kdeA gene into cells of the drug-hypersusceptible E. coli strain KAM32 resulted in elevated minimum inhibitory concentrations of chloramphenicol, norfloxacin, acriflavine, and ethidium bromide. We observed elevated energy-dependent ethidium efflux activity with cells carrying kdeA compared with control cells. We also observed expression of kdeA in cells of K. pneumoniae under normal growth conditions.

View full abstract

A simple, quantitative, and reproducible model of lower limb ischemia was developed. Vascular injury was induced by ferric chloride (FeCl₃) solution to the rat iliac artery, after which blood flow in all of the lower limbs were continuously monitored using a scanning laser Doppler blood flowmeter. After FeCl₃ injury, a distinct decrease in blood flow in the ischemic lower limb was observed and blood flow did not recover during the 30 min after vascular injury. YM466, an oral direct factor Xa inhibitor, dose-dependently inhibited the reduction of peripheral blood flow. The area under the blood flow–time curve during 30 min after vascular injury improved dose-dependently, with significance at doses of 3 and 10 mg/kg. These results suggest that factor Xa inhibitors are effective in patients with peripheral arterial disease, and that this vascular injury model is a useful tool for the screening and evaluation of the efficacy of new antithrombotic agents.

View full abstract

Six chalcones from Angelica keiskei KOIDZUMI (Ashitaba in Japanese) and two chalcones from Humulus lupulus L. (hop) were examined for their cytotoxicity in two human neuroblastoma cell lines (IMR-32 and NB-39) and normal cells (primary culture of rat cerebellar granule cells) by [3-(4,5)-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. All chalcones exhibited cytotoxicity against neuroblastoma cells, and two of them (isobavachalcone and xanthoangelol H) had no effect on normal cells even at high concentration (10⁻⁴ m) exposure. Typical morphologic features of apoptosis, including cell shrinkage, chromatin condensation, nuclear fragmentation and formation of apoptotic bodies, were observed in isobavachalcone-treated cells by Hoechst 33342 staining. Western blot analysis showed that isobavachalcone significantly reduced pro-caspase-3 and pro-caspase-9, and subsequently increased the level of cleaved caspase-3 and cleaved caspase-9 in both neuroblastoma cell lines. Moreover, Bax was markedly induced by isobavachalcone application. These results suggest that isobavachalcone induces apoptotic cell death in neuroblastoma via the mitochondrial pathway and has no cytotoxicity against normal cells. Therefore, isobavachalcone may be applicable as an efficacious and safe drug for the treatment of neuroblastoma.

View full abstract

An analytical method of high performance capillary electrophoresis (HPCE) was developed to simultaneously separate and identify the component monosaccharides of Angelica sinensis polysaccharide fractions (APFs), named APF1, APF2 and APF3. The predominant sugars in APFs were identified as arabinose, glucose, rhamnose, galactose and galacturonic acid as well as trace amount of mannose and glucuronic acid, and the fractionation altered significantly the distribution of component monosaccharides in APFs. APF3 was the most active fraction to effectively inhibit H₂O₂-caused decrease of cell viability, lactate dehydrogenase (LDH) leakage and malondialdehyde (MDA) formation, and also reduced H₂O₂-caused decline of superoxide dismutase (SOD) activity and glutathione (GSH) depletion (p<0.05), followed by APF2 and APF1 in decreasing order. Furthermore, it was found that APFs (100 μg/ml) could protect macrophages by inhibiting the release of excess NO and reactive oxygen species (ROS) induced by high concentrations of H₂O₂ (0.8—1.6 mM).

View full abstract

Site-directed mutagenesis was used to investigate the molecular interactions involved in prazosin binding to the human α_1b-adrenergic receptor (α_1b-AR) receptor. Based on molecular modeling studies, Thr130 and Asp125 in transmembrane region III of the α_1b-AR receptor were found to interact with prazosin. Thr130 and Asp125 were mutated to alanine (Ala) and expressed in HEK293 cells. The radioligand [³H]prazosin did not show any binding to Asp125Ala mutant of α_1b-AR. Therefore, it was not possible to find any prazosin affinity to the mutant using the radioligand [³H]prazosin. The mutation also abolished phenylephrine-stimulated inositol phosphate (IP) formation of [³H]myo-inositol. On the other hand, the Thr130Ala mutant showed reduced binding affinity for [³H]prazosin (dissociation constant, K_d 674.27 pM versus 90.27 pM for the wild-type receptor) and had reduced affinity for both tamsulosin and prazosin (11-fold and 9-fold, respectively). However, the Thr130Ala mutant receptor retained the ability to stimulate the formation of [³H]myo-inositol. The results provide direct evidence that Asp125 and Thr130 are responsible for the interactions between α_1b-AR receptor and radioligand [³H]prazosin as well as tamsulosin.

View full abstract

Stress has been known to release corticotropin-releasing factor (CRF) and have an affect on sleep–wake patterns. However, there is no direct evidence of CRF receptor agonist and antagonist on sleep–wake patterns. Therefore, this study aimed to clarify this point by using radiotelemetry system in conscious rats. Wake, non-rapid eye-moving (NREM) sleep and rapid eye-moving (REM) sleep were analyzed by computer software, simultaneously measuring electroencephalogram and electromyogram. In the light period, urocortin (CRF receptor agonist: i.v.) significantly increased wake duration, and decreased NREM sleep duration. REM sleep was not affected. Astressin (CRF receptor antagonist: i.p.) significantly attenuated the changes induced by urocortin, although astressin itself did not affect the sleep–wake pattern in the light period at this dosage. These findings show that urocortin changes the sleep–wake pattern in the light period. Moreover, urocortin was found to change the sleep–wake pattern by acting on CRF receptor, as astressin significantly attenuated the urocortin-induced changes on sleep–wake patterns.

View full abstract

Glycyrrhizin is the major active component extracted from licorice (Glycyrrhiza glabra) roots, one of the most widely used herbal preparations for the treatment of liver disorders. This study evaluated the potential beneficial effect of glycyrrhizin in a mouse model of carbon tetrachloride (CCl₄)-induced liver injury. The mice were treated intraperitoneally with CCl₄ (0.5 ml/kg). They received glycyrrhizin (50, 100, 200, 400 mg/kg) 24 h and 0.5 h before and 4 h after administering CCl₄. The serum activities of aminotransferase and the hepatic level of malondialdehyde were significantly higher 24 h after the CCl₄ treatment, while the concentration of reduced glutathione was lower. These changes were attenuated by glycyrrhizin. CCl₄ increased the level of circulating tumor necrosis factor-α markedly, which was reduced by glycyrrhizin. The levels of hepatic inducible nitric oxide synthase, cyclooxygenase-2, and heme oxygenase-1 protein expression were markedly higher after the CCl₄ treatment. Glycyrrhizin diminished these alterations for inducible nitric oxide and cyclooxygenase-2 but the protein expression of heme oxygenase-1 was further elevated by the treatment of glycyrrhizin. CCl₄ increased the level of tumor necrosis factor-α, inducible nitric oxide synthase, cyclooxygenase-2, and heme oxygenase-1 mRNA expressions. The mRNA expression of heme oxygenase-1 was augmented by the glycyrrhizin treatment, while glycyrrhizin attenuated the increase in tumor necrosis factor-α, inducible nitric oxide synthase, and cyclooxygenase-2 mRNA expressions. These results suggest that glycyrrhizin alleviates CCl₄-induced liver injury, and this protection is likely due to the induction of heme oxygenase-1 and the downregulation of proinflammatory mediators.

View full abstract

It is known that female rats are resistant to ischemic acute renal failure (ARF), compared with male rats. To elucidate sex differences in ischemic ARF, we searched global protein expression in post-ischemic kidneys using proteomic techniques. Ischemic ARF was induced by 45-min ischemia followed by reperfusion. By proteomic analysis, many male- or female-dominant proteins were detected in sham-operated rat kidneys, and significantly increased or decreased proteins were found in post-ischemic kidneys 2 h after reperfusion, at which there were no significant deterioration in renal function of both sexes. We detected 86 proteins showing more than 1.5-fold significant alterations (p<0.01) in both sexes by ischemia/reperfusion (I/R) treatment. Among the altered proteins, we identified a significantly up-regulated protein in male rat kidneys, meprin α, a subunit of meprin which had been reported to play a role in the pathophysiology of I/R-induced ARF. In addition, it is known that a potent meprin α inhibitor, actinonin, can protect against I/R-induced renal injury when administered to male rats. We therefore compared the effect of actinonin on I/R-induced renal dysfunction between male and female rats. Renal function of both males and females showed significant deterioration when measured at 24 h after the reperfusion, although the degree of renal dysfunction was much less in females than in males. Pre-ischemic treatment with actinonin (30 mg/kg, i.v.) prevented the I/R-induced renal dysfunction in males but not in females. Our results provide information on differences in protein expression at an early phase after the reperfusion between male and female rats. Moreover, the present study suggests that up-regulation of meprin α in the post-ischemic kidney is at least partly involved in aggravation of I/R-induced renal injury in male rats. The possibility that meprin α is a key component of the sex difference in ischemic ARF, warrants further attention.

View full abstract

As part of our search for anti-arteriosclerosis agents from traditional Chinese medicines, the 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase (HCR)-inhibitory constituent, kakkalide, was isolated from the flower of Pueraria thunbergiana (PT, family Leguminosae). The antihyperlipidemic effects of kakkalide and its metabolite, irisolidone, which may be a bioactive form in vivo and potently inhibit the HCR activity, were investigated in vivo. Both the oral and interperitoneal administrations of kakkalide and irisolidone, with the exception of intraperitoneally treated kakkalide, potently lowered the serum levels of total cholesterol (TC) and triglyceride (TG) in Trition WR1339-induced hyperlipidemic mice. The oral administrations of kakkalide and irisolidone in hyperlipidemic mice induced, by the long-term feeding of a high fat diet, also potently reduced the serum levels of TC and TG and epididymal fat pad weight. These findings suggest that PT can improve hyperlipidemia, and the hypolipidemic effect may be due to HMG-CoA reductase.

View full abstract

Amentoflavone, which is a biflavone derived from various plants, has been known to possess various biological activities including anti-tumor and anti-inflammatory activity. In the previous study, we reported antifungal effect of amentoflavone isolated from an ethyl acetate extract of Selaginella tamariscina on human pathogenic fungi. Amentoflavone significantly inhibited the growth of fungal cells without hemolysis of human erythrocytes. In the present study, we investigated antifungal acting mode of amentoflavone in human pathogenic yeast Candida albicans. Anticandidal activity was exerted in an energy-independent manner presented by an antifungal assay in the presence of NaN₃, which is ATP-depleting agent as a metabolic inhibitor. To investigate the effects of amentoflavone on cellular physiology in C. albicans, we performed cell cycle analysis, and the analysis showed that amentoflavone significantly arrested cell cycles during the S-phase. These results demonstrated that amentoflavone has potent anticandidal activity with significant physiological changes inducing S-phase arrest in intracellular environment. Therefore, amentoflavone may be applied to a lead compound for the development of therapeutic agents, which can treat candidiasis resulted from candidal infections.

View full abstract

In this study, we examined the effect of N-trans-feruloyltyramine (FA) on melanogenesis in mouse B16 melanoma cells. Melanogenesis was inhibited by FA in a dose-dependent manner. FA exhibited a greater potency than kojic acid as a standard inhibitor of melanogenesis. Moreover, treatment of B16 melanoma cells with FA was found to cause marked decreases in the expression levels of tyrosinase. FA-induced downregulation of tyrosinase resulted in suppression of melanin biosynthesis in murine B16 melanoma cells.

View full abstract

To identify the effects of amino acids on the heat stability of ginsenoside Rb₁ (Rb₁), Rb₁ was heat-processed at 120 °C with or without glycine or L-arginine. Rb₁ was changed into 20(S)-Rg₃, 20(R)-Rg₃, Rk₁, and Rg₅ by heat-processing through glycosyl elimination and epimerization of carbon-20 by SN1 reaction. Similarly, Rb₁ was changed into 20(S)-Rg₃, 20(R)-Rg₃, Rk₁, and Rg₅ when it was heat-processed with the same amount of glycine, but the generated amount of 20(S)-Rg₃ was higher than when Rb₁ was heat-processed without amino acids, and a significant increase in Maillard reaction products (MRPs) was noted. On the other hand, there were no structural changes in Rb₁ and the generation of MRPs when Rb₁ was heat-processed with the same amount of L-arginine. The improved heat stability of Rb₁ brought about by the addition of L-arginine was thought to be closely related to its characteristics of interfering with nonenzymatic glycation and forming hydrogen bonds with Rb₁.

View full abstract

Cytotoxic T-lymphocyte antigen 4-immunoglobulin (CTLA4Ig) has immunosuppressive activity and the ability to induce immune tolerance. There has been no report of its glycosylation ratio or of the role of its glycans. We investigated the terminal sialylation of rice cell-derived recombinant human CTLA4Ig (rrhCTLA4Ig) using lectins. The glycosylation ratios of rrhCTLA4Ig and Chinese hamster ovary (CHO) cell-derived recombinant human CTLA4Ig (crhCTLA4Ig) were evaluated by chemical deglycosylation. After intravenous (i.v.) or subcutaneous (s.c.) administration to rats, the pharmacokinetics of rrhCTLA4Ig and crhCTLA4Ig as well as of their deglycosylated forms were evaluated. rrhCTLA4Ig does not have terminal sialic acids and its glycosylation ratio was slightly lower than that of crhCTLA4Ig. Its terminal elimination half-life (T_1/2) was shorter than that of crhCTLA4Ig following i.v. administration. However, the half-life was significantly prolonged and was similar with that of crhCTLA4Ig following s.c. administration. Moreover, the deglycosylated forms of both preparations were cleared from the circulation faster than the native forms. These results suggest that the presence of glycans on rrhCTLA4Ig and crhCTA4Ig are important for their in vivo stability. In addition, the glycan structure of rrhCTLA4Ig is more effective in maintaining in vivo stability after s.c. administration than after i.v. administration although the glycans on rrhCTLA4Ig lack terminal sialic acids, suggesting that its glycans have the potential for in vivo stability.

View full abstract

In this paper, the intestinal permeability of the inclusion complex of tanshinone IIA (TS IIA) with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) was investigated. The corresponding complexation of TS IIA–HP-β-CD was obtained by coevaporation and characterized by differential scanning calorimetry and X-ray diffraction. The recirculation intestinal perfusion technique in rats was used to study the absorption behavior of free and complexed TS IIA. The change of concentration of TS IIA was separately calculated according to Michaelis–Menten and the Fick's equation to investigate its absorption rate-limiting step. Using the mathematical models above, it was concluded that the limit step to absorption of TS IIA was the dissolution process. Different concentrations of complexed TS IIA were administrated to three intestinal segments, with the intestinal permeability ranging from 3.16×10⁻⁵ cm·s⁻¹ in the duodenum (50 μg·ml⁻¹) to 4.11×10⁻⁵ cm·s⁻¹ in the jejunum (100 μg·ml⁻¹). With the increase of dosage of complex, TS IIA's absorption did not show saturated phenomenon, suggesting its transport mechanism in vivo might primary be passive transport. Besides, the permeability of TS IIA was not apparently influenced by the perfusion section studied, which indicated that there might not exist specific absorption site for TS IIA.

View full abstract

TAS-103, 6-[[2-(dimethylamino)ethyl]amino]-3-hydroxy-7H-indeno-[2,1-c]quinolin-7-one dihydrochloride, is a dual topoisomerases I and II inhibitor. Antitumor activities of TAS-103 against fresh surgical specimens resected from 525 patients (32 types of tumors) were examined by flow cytometric (FCM) analysis of DNA integrity of tumor cells, and compared with those of five other investigational new drugs and 31 clinically available anticancer agents. Concentrations of clinically available anticancer agents were set at one-tenth of the peak plasma concentration (PPC) of the clinically recommended doses. On the other hand, since PPCs of investigational new drugs in humans were frequently unknown, these were estimated by a method that determines the theoretically achievable concentration in body fluid (TAC method). Correlations between TAC and PPC were examined for 16 clinically available anticancer agents, and it was found that TAC at 7n (the modified Fibonacci's dose-escalation scheme) of 14 drugs corresponded well with each one-tenth of PPC. By defining a 30% or more reduction in the integrated diploid peak as effective and a 60% or more reduction as definitely effective, TAS-103 at 5 μg/ml (7n) showed significantly higher effective rates and definitely effective rates than those of all other investigational new drugs, as well as almost all clinically available anticancer agents, against various malignancies, including non-small cell lung cancer, brain tumor and renal cancer. These results strongly suggest that TAS-103 will be expected to show excellent antitumor activities against a wide range of human tumors.

View full abstract

Treatment of Caco-2 cells with β-naphthoflavone (β-NF) and 1α,25-dihydroxyvitamin D₃ (VD₃) induces UDP-glucuronosyltransferases (UGTs) and cytochrome P450 (CYP) 3A4, respectively. In the present study, we evaluated the metabolism of carvedilol in β-NF- and VD₃-treated Caco-2 cells. The metabolism of R-carvedilol was not significant in non-treated Caco-2 cells, whereas S-carvedilol was significantly metabolized in the cells. The metabolism of R- and S-carvedilol was significantly increased by the treatment of Caco-2 cells with 50 μM β-NF for 3 d. In contrast, the treatment of Caco-2 cells with 250 nM VD₃ for 2 weeks did not induce a significant change in the metabolism of R- and S-carvedilol. The metabolism of carvedilol in β-NF-treated Caco-2 cells was markedly inhibited by a substrate of UGTs, baicalein. In addition, the expression of UGT1A1, 1A6, and 1A9 mRNA was increased in β-NF-treated Caco-2 cells as compared with non-treated cells. These findings indicated that carvedilol was metabolized stereoselectively by the β-NF-inducible enzyme in Caco-2 cells. The UGT1A subfamily in intestinal epithelial cells may be partly responsible for first-pass (presystemic) metabolism of the drug.

View full abstract

We demonstrate the preventive effect of bittern water (BW), which enables the effective intake of magnesium ion (Mg²⁺), on paw edema in adjuvant-induced arthritis (AA) rat. BW (five kinds; BW-1, 2, 3, 4, 5) containing 10—200 mg/l Mg²⁺ was used in this study. Arthritis was induced by the injection of 50 μl of a suspension of 10 mg/ml heat-killed butyricum (Mycobacterium butyricum) in Bayol F oil into the plantar region of the right hind foot and tail of rats. Paw edema of the right and left hind feet of AA rats were reduced by the administration of BW for 14 d after adjuvant injection in comparison with those of AA rats administered purified water. The preventive effect increased with the increasing Mg²⁺ content of the BW. In addition, a combination of indomethacin (IM, 2 mg/kg) and BW-5 (200 mg/l Mg²⁺) prevented paw edema of the right and left hind feet of AA rats in comparison with IM alone. The fate of plasma IM after the oral administration of the combined IM (2 mg/kg/d) and BW-5 was similar to that after the administration of IM alone. In conclusion, the oral administration of Mg²⁺ to AA rats potently prevents the development of inflammation, and the combination of IM and Mg²⁺ may provide an effective therapy of arthritic edema.

View full abstract

We studied the effects of ginsenosides and their metabolites on daunorubicin transport in multidrug-resistant P-glycoprotein (P-gp)-overexpressing KB-C2 cells. Ginsenoside Rg1, which is a protopanaxatriol-type ginseng saponin, did not have any effects on the accumulation of P-gp substrate daunorubicin. On the other hand, its metabolite M4, which has no sugar moiety, increased the accumulation 3.6-fold at 5 μM. Metabolites of protoanaxadiol-type saponin M1 and M12 also increased accumulation, but the effects were less than that of M4. The findings showed larger effects of metabolites without glucose moieties. Analysis of verapamil-stimulated ATPase activity in membrane vesicles expressing human P-gp suggested that the increased daunorubicin accumulation by M4 was at least partly due to ATPase inhibition of P-gp.

View full abstract

Recent studies suggest that capsaicin (Cap), a major constituent of hot pepper, may affect the function and permeability of the intestinal mucosa in vitro. However, the relationships between the dose of Cap and the barrier and/or transporter functions on intestinal epithelial cells are unknown. The aim of this study was to investigate whether Cap initiates cellular injury and alter epithelial permeability in Caco-2 cells. Cellular toxicity, as measured using a lactate dehydrogenase release assay, was not observed at high concentrations of Cap (up to 300 μM). When cell viability was measured by a WST-1 assay (tetrazolium salt-based assay), damage to Caco-2 monolayers was observed at doses of 200 and 300 μM of Cap. The barrier function of tight junctions was assessed by measuring transepithelial electrical resistance (TEER) in Caco-2 cells. Treatment of Caco-2 cells with Cap at doses above 100 μM significantly decreased the TEER compared to treatment with buffer alone for 2 h (p<0.05). We next examined the effects of Cap on the activity of P-glycoprotein (P-gp) found on transcellular transporters. At doses of 100 and 200 μM, Cap inhibited the transport of rhodamine 123 by P-gp-mediated efflux in Caco-2 cells. Cap thus exhibited inhibitory effects on P-gp. The results of this study indicate that Cap, a dietary phytochemical, causes functional and structural changes in Caco-2 cell monolayers at noncytotoxic doses (less than 100 μM of Cap). The concomitant administration of Cap with drugs that are substrates of P-gp might increase the plasma concentrations of such drugs.

View full abstract

Fluticasone propionate dry powder inhaler (FP-DPI) is widely used for the treatment of asthma. However, local adverse effects such as oropharyngeal candidiasis are often seen and mouth washing after inhaling is recommended. In our previous study, we reported a nonlinear relationship between the amount of drug residue and number of times mouth washing was employed. Thus, we developed a compartment model, in which the inhaled drugs were distributed in both easy and difficult to remove areas. Using this model, we analyzed drug removal efficiency in each area with different mouth washing procedures. Three methods of mouth washing were studied; gargling and rinsing in combination, rinsing alone, and gargling alone, following administration of FP-DPI by sprinkling or inhaling. The amounts of drugs recovered from areas considered to be easy to remove (X₁) and difficult to remove (X₂) were determined using a nonlinear least-squares program, while the removal efficiency of each of the 3 methods was also calculated. The ratios of X₁ after sprinkling and inhalation were 63.9% and 21.8%, respectively, while those of X₂ were 6.0% and 12.4%, respectively. The numbers of mouth washings required to remove half doses from easy and difficult to remove areas were 0.2 and 1.4 times, respectively, with a combination of gargling and rinsing following inhalation of FP-DPI, while those were 0.3 and 3.6 times, respectively, with rinsing alone, and 0.4 and 5.8 times, respectively, with gargling only, thus demonstrating significant differences among the mouth washing methods for efficiency in the difficult to remove area. The present results show that the employed methods of mouth washing had a significant influence on the removal of drug residues following inhalation of FP-DPI, with gargling and rinsing in combination considered to be the most effective.

View full abstract

Tryptanthrin originally isolated from Isatis tinctoria L. has been characterized to have anti-inflammatory activities through the dual inhibition of cyclooxygenase-2 and 5-lipoxygenase mediated prostaglandin and leukotriene syntheses. To characterize phase I metabolite(s), tryptanthrin was incubated with rat liver microsomes in the presence of NADPH-generating system. One metabolite was identified by liquid chromatography/electrospray ionization-tandem mass spectrometry. M1 could be identified as a metabolite mono-hydroxylated on the aromatic ring of indole moiety from the MS² spectra of protonated tryptanthrin and M1. The structure of metabolite was confirmed as 8-hydroxytryptanthrin with a chemically synthesized authentic standard. The formation of M1 was NADPH-dependent and was inhibited by SKF-525A, a general CYP-inhibitor, indicating the cytochrome P450 (CYP)-mediated reaction. In addition, it was proposed that M1 might be formed by CYP 1A in rat liver microsomes from the experiments with enriched rat liver microsomes.

View full abstract

Norepinephrinergic neurotransmission in the central nervous system have a major impact on the symptomatology in major depressive disorder (MDD), and genetic polymorphisms of norepinephrine transporter (NET) have a possibility to be involved in susceptibility to MDD. We investigated the association of the G1287A (rs5569) polymorphism of the NET gene and susceptibility to MDD by comparing 145 major depressive patients with 164 healthy individuals first in a Japanese population. The genotype frequencies in depressed patients and health volunteers of the NET G1287A polymorphism were 52.4% (G/G), 39.3% (G/A) and 8.3% (A/A) in depressed patients, 61.6% (G/G), 29.9% (G/A allele) and 8.5% (A/A) in healthy volunteers, respectively. The allele frequencies in depressed patients and health volunteers of the NET G1287A polymorphism were 72.1% (G allele) and 27.9% (A allele) in depressed patients, 76.5% (G allele) and 23.5% (A allele) in healthy volunteers, respectively. The genotype distribution and allele frequencies were not significantly different between major depressive patients and healthy volunteers. NET G1287A polymorphism appears not to be an important factor in susceptibility to MDD in a Japanese population.

View full abstract

The aim of this study was to test the hypothesis that vascular dysfunction in neonatal streptozotocin (n-STZ)-induced diabetic rats could be associated with alterations in blood pressure, hemodynamic profile, and levels of superoxide anion. Diabetes was induced by STZ injection (160 mg/kg, i.p.) in neonate (2-d-old) Wistar rats. Using intravital microscopy the changes in mesenteric arteriolar diameters to vasoconstrictor agent noradrenaline (NA) and the levels of superoxide anion, measured by hydroethidine microfluorography, were determined in anaesthetized control and n-STZ rats. Blood pressure (BP) was determined in anaesthetized and unanaesthetized animals. Heart rate, shear rate, and blood flow velocity were also assessed. n-STZ rats showed, after 8 weeks of STZ injection, increased BP (unanaesthetized animals), hyperactivity to NA, and increased superoxide anion levels. However, heart rate, arteriolar shear rate, and blood flow velocity were unchanged in n-STZ. In conclusion, the results of the current study describe a significant increase in blood pressure, hyperactivity to NA-mediated vasoconstriction, and increased superoxide levels measured by hydroethidine oxidation. Taken together, our findings demonstrate that the compromised ability of mesenteric microvessels to respond properly in n-STZ diabetic rats is associated with several vascular alterations.

View full abstract