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Mizukami C.,Hokkaido University | Spiliotis M.,University of Bern | Gottstein B.,University of Bern | Yagi K.,Hokkaido Institute of Public Health | And 2 more authors.
Parasitology International | Year: 2010

We investigated the potential of gene silencing in Echinococcus multilocularis protoscoleces using RNA interference (RNAi). For the introduction of siRNA, soaking and electroporation were first examined for their effects on the viability of protoscoleces and their efficacy for siRNA introduction. Consequently, electroporation using 100. V and 800. μF showed the optimal results. This electroporation procedure was then evaluated for its ability to induce RNAi in protoscoleces using siRNAs targeting the 14-3-3 and elp genes. It was found that the levels of 14-3-3 and elp mRNA in 14-3-3 siRNA- and elp siRNA-treated protoscoleces were reduced to 21.8 ± 2.6 and 35.5 ± 0.4% of those of the untreated control by day 3, respectively. Moreover, the target proteins significantly decreased in the siRNA-treated samples by day 15. In the analysis of viability, the untreated control, electroporation control, 14-3-3 siRNA-treated, and elp siRNA-treated samples displayed 98.4 ± 1.4, 83.0 ± 2.5, 58.0 ± 23.0, and 55.1 ± 14.6% viability, respectively, on day 15. In conclusion, we successfully demonstrated that RNAi mediated the knock-down of target gene expression in E. multilocularis protoscoleces at both the transcriptional and translational levels. © 2010 Elsevier Ireland Ltd.

Okano M.,Hokkaido Institute of Public Health
Current Pediatric Reviews | Year: 2015

Chronic active Epstein-Barr virus infection (CAEBV) is characterized mainly by prolonged or intermittent fever, lymphadenopathy and hepatosplenomegaly without definite underlying diseases at the diagnosis. Patients with CAEBV also may have various life-threatening conditions including hematological, neurological, pulmonary, cardiac, digestive tract, ocular and/or dermal disorders. Additionally, during the course of illness, they often develop hematological malignancies such as T cell, NK cell or B cell lymphoproliferative disorder (LPD) and/or lymphoma. No causative pathogenetic mechanisms have been sufficiently clarified, and additionally no promising efficacious treatment was demonstrated except for the hematopoietic stem cell transplantation (HSCT) in cases who develop T cell or NK cell LPD or lymphoma. This minireview outlines the recent development for the comprehensive viewpoints of CAEBV mainly regarding to virological, immunological, pathological and therapeutical progresses. © 2015 Bentham Science Publishers.

Watanabe Y.,Hiroshima University | Watanabe Y.,Nihon Pharmaceutical University | Kojima H.,Hokkaido Institute of Public Health | Takeuchi S.,Hokkaido Institute of Public Health | And 5 more authors.
Toxicology and Applied Pharmacology | Year: 2015

Benzophenone-3 (2-hydroxy-4-methoxybenzophenone; BP-3) is widely used as sunscreen for protection of human skin and hair from damage by ultraviolet (UV) radiation. In this study, we examined the metabolism of BP-3 by rat and human liver microsomes, and the estrogenic and anti-androgenic activities of the metabolites. When BP-3 was incubated with rat liver microsomes in the presence of NADPH, 2,4,5-trihydroxybenzophenone (2,4,5-triOH BP) and 3-hydroxylated BP-3 (3-OH BP-3) were newly identified as metabolites, together with previously detected metabolites 5-hydroxylated BP-3 (5-OH BP-3), a 4-desmethylated metabolite (2,4-diOH BP) and 2,3,4-trihydroxybenzophenone (2,3,4-triOH BP). In studies with recombinant rat cytochrome P450, 3-OH BP-3 and 2,4,5-triOH BP were mainly formed by CYP1A1. BP-3 was also metabolized by human liver microsomes and CYP isoforms. In estrogen reporter (ER) assays using estrogen-responsive CHO cells, 2,4-diOH BP exhibited stronger estrogenic activity, 2,3,4-triOH BP exhibited similar activity, and 5-OH BP-3, 2,4,5-triOH BP and 3-OH BP-3 showed lower activity as compared to BP-3. Structural requirements for activity were investigated in a series of 14 BP-3 derivatives. When BP-3 was incubated with liver microsomes from untreated rats or phenobarbital-, 3-methylcholanthrene-, or acetone-treated rats in the presence of NADPH, estrogenic activity was increased. However, liver microsomes from dexamethasone-treated rats showed decreased estrogenic activity due to formation of inactive 5-OH BP-3 and reduced formation of active 2,4-diOH BP. Anti-androgenic activity of BP-3 was decreased after incubation with liver microsomes. © 2014 Elsevier Inc.

Kojima H.,Hokkaido Institute of Public Health | Takeuchi S.,Hokkaido Institute of Public Health | Itoh T.,Asahikawa Medical College | Iida M.,Otsuka Pharmaceutical Factory Inc. | And 2 more authors.
Toxicology | Year: 2013

Various organophosphate flame retardants (OPFRs) are widely used in building materials, textiles and electric appliances, and have been reported to cause indoor environmental pollution in houses and office buildings. In this study, using cell-based transactivation assays, we characterized the agonistic and/or antagonistic activities of 11 OPFRs against human nuclear receptors; estrogen receptor α (ERα), ERβ, androgen receptor (AR), glucocorticoid receptor (GR), thyroid hormone receptor α1 (TRα1), TRβ1, retinoic acid receptor α (RARα), retinoid X receptor α (RXRα), pregnane X receptor (PXR), peroxisome proliferator-activated receptor α (PPARα), and PPARγ. Of the 11 OPFRs tested, triphenyl phosphate (TPhP) and tricrecyl phosphate (TCP) showed ERα and/or ERβ agonistic activity. In addition, tributyl phosphate (TBP), tris(1,3-dichloro-2-propyl) phosphate (TDCPP), TPhP and TCP showed AR antagonistic activity, and TBP, tris(2-ethylhexyl) phosphate (TEHP), TDCPP, TPhP and TCP showed GR antagonistic activity. Furthermore, we found that seven compounds, TBP, tris(2-chloro-1-methylethyl) phosphate (TCPP), TEHP, tris(2-butoxyethyl) phosphate (TBEP), TDCPP, TPhP, and TCP, display PXR agonistic activity. However, none of test compounds showed agonistic or antagonistic activity against TRα/β, or agonistic activity against RARα, RXRα or PPARα/γ. Taken together, these results suggest that several OPFRs may have potential endocrine disrupting effects via ERα, ERβ, AR, GR and PXR. © 2013 Elsevier Ireland Ltd.

Matsumoto J.,Hokkaido University | Matsumoto J.,Nihon University | Kouguchi H.,Hokkaido Institute of Public Health | Oku Y.,Hokkaido University | Yagi K.,Hokkaido Institute of Public Health
Parasitology International | Year: 2010

We investigated parasite establishment, subsequent larval development and antibody responses in gerbils, cotton rats and 4 inbred mouse strains until 16. weeks post inoculation (p.i.) with 200 eggs of Echinococcus multilocularis. The rate of parasite establishment in the liver determined at 4. weeks p.i. was highest in DBA/2, followed by AKR/N, C57BL/10 and C57BL/6 mice, whereas gerbils harboured few parasite foci. The accurate number of liver lesions in cotton rats could not be determined due to rapid growth and advanced multivesiculation of the parasite observed at 2. weeks p.i. The course of larval development was most advanced in DBA/2 mice with mature protoscolex formation at 16. weeks p.i., followed by AKR/N harbouring metacestodes with sparsely distributed immature protoscoleces. On the other hand, C57BL/6 and C57BL/10 mice had infertile metacestodes without any protoscolex formation. The parasite growth in mice was totally slower than those in gerbils and cotton rats. Specific IgG and IgM responses against 3 types of native crude antigens of larval E. multilocularis were evaluated using somatic extracts of and vesicle fluid of metacestode, and somatic extracts from purified protoscoleces. The 4 mouse strains demonstrated basically similar kinetics with apparent IgG and IgM increases at 9. weeks p.i. and thereafter, except C57BL/10, exhibited higher levels of IgM against crude antigens at some time point of infection. On the other hand, a follow-up determination of specific IgG and IgM levels against recombinant antigens from larval E. multilocularis revealed that each mouse strain showed different antibody-level kinetics. The findings in the present study demonstrate that the course of host-parasite interactions in primary alveolar echinococcosis, caused by larval E. multilocularis, clearly varies among intermediate host rodents with different genetic backgrounds. © 2010 Elsevier Ireland Ltd.

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