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Roles of the hypocretin/orexins in the regulation of sleep and wakefulness
2008
Terao, A.(Hokkaido Univ., Sapporo (Japan)) | Haruyama, T. | Kimura, K.
Hypocretin/orexin is produced exclusively in the dorsal and lateral hypothalamus but its projection is widespread within the brain and plays important roles. In this paper, we review the independent discoveries of the hypocretin/orexin peptides, the neuroanatomy of this system, and the link to the sleep disorder narcolepsy that has led to the idea that this system plays a crucial role in the regulation of sleep and wakefulness.
Mostrar más [+] Menos [-]Establishment of a laboratory colony of taiga tick Ixodes persulcatus for tick-borne pathogen transmission studies
2008
Konnai, S.(Hokkaido Univ., Sapporo (Japan)) | Saito, Y. | Nishikado, H. | Yamada, S. | Imamura, S. | Mori, A. | Ito, T. | Onuma, M. | Ohashi, K.
Ixodes persulcatus Schulze (I. persulcatus) is distributed in Russia and Far East Asia including Japan, and has been implicated as the vector of several human pathogens. In particular, I. persulcatus acts as the only tick vector for human lyme borreliosis in Japan. In order to elucidate the mechanism of transmission of I. persulcatus-borne pathogens, we developed a laboratory colony of I. persulcatus. Ticks were fed on Syrian hamster and engorged ticks that had dropped off the animals were collected and maintained to allow them to molt. Tick rearing was performed in incubator at 20degC with 95% relative humidity and 12-hour light/dark photo-period regimen. We found out that adult females fed for 8+-2 days and had a pre-oviposition period lasting for 7+-2 days. The minimum egg incubation period was 1 month with the hatched larvae feeding for 3+-1 days and molting to nymphs 3-4 months thereafter. Meanwhile, the nymphs fed for 4+-1 days and molted to adult 2-3 months thereafter. For future analysis of gene expression profiles in I. persulcatus, we cloned and sequenced the actin gene (a housekeeping gene), and found that it is 92.7% to 98.6% homologous to the published sequences of related ixodid ticks. This laboratory colony of I. persulcatus will facilitate investigations on the role of tick-derived molecules on the transmission of I. persulcatus-borne pathogens and will be important for identification of potential anti-tick vaccine and acaricide target molecules.
Mostrar más [+] Menos [-]Effects of anti-tick cocktail vaccine against Rhipicephalus appendiculatus
2008
Imamura, S.(Hokkaido Univ., Sapporo (Japan)) | Konnai, S. | da Silva Vaz, I.Jr. | Yamada, S. | Nakajima, C. | Ito, Y. | Tajima, T. | Yasuda, J. | Simuunza, M. | Onuma, M. | Ohashi, K.
Rhipicephalus appendiculatus serpin-3 (RAS-3), R. appendiculatus serpin-4 (RAS-4) and a 36kDa immuno-dominant protein of R. appendiculatus (RIM36) were reported as candidate antigens for the anti-tick vaccine to control ixodid ticks. In the present study, we generated recombinant proteins of RAS-3 (rRAS-3), RAS-4 (rRAS-4) and RIM36 (rRIM36), and assessed their potency as an anti-tick cocktail vaccine in cattle model. RT-PCR analysis showed that RAS-3, RAS-4 and RIM136 transcripts were detected in both adult male and female ticks during feeding. Immunization of cattle with the combination of rRAS-3, rRAS-4 and rRIM36 had raised antibodies against all recombinants and anti-sera had reacted with the molecules from the tick salivary gland extract. Tick infestation challenge demonstrated protective immunity against female ticks, resulting in mortality rates of 39.5 and 12.8 % for the vaccinated and control groups, respectively. Moreover, the mortality rate of Theileria parva-infected female ticks was 48.5 and 10.8 % in the vaccinated and control group, respectively. In order to evaluate the levels of pathogen transmission capacity by T. parva-infected ticks fed on immunized cattle, the occurrence of T. parva in the bovine parotid lymph node and peripheral blood was also determined and quantified by real-time PCR. Although the infection with T. parva could not be protected by the vaccine, the occurrence of pathogen in peripheral blood was delayed 1 to 2 days after the infestation challenge in vaccinated group. These results suggest that this cocktail vaccine plays a role in the prevention of tick infestation.
Mostrar más [+] Menos [-]A BOLD-fMRI study of cerebra activation induced by injection of algesic chemical substances into the anesthetized rat forepaw
2008
Asanuma, T.(Hokkaido Univ., Sapporo (Japan)) | Yasui, H. | Sato, M. | Inanami, O. | Kuwabara, M.
This study was performed to examine whether the brain activities induced by noxious algesic chemical substances in anesthetized animals could be detected by blood oxygen-level-dependent functional magnetic resonance imaging (BOLD-fMRI). Multislice gradient echo images of the primary somatosensory cortex were obtained using a 7.05 T superconducting system and a one-turned surface coil centered over the primary somatosensory cortex of the 1.0%-isoflurane-anesthetized rat. The Z-score t-map of BOLD signals and its time-course analysis revealed that subcutaneous injection of formalin into the left forepaw immediately induced an early response in the contralateral primary sensory cortex lasting for a few minutes, followed by a late response until 20 min after stimulation. In contrast, injection of capsaicin into the left forepaw evoked only the early response. Furthermore, pretreatment with morphine completely abolished these responses induced by the chemical algesic substances. Thus BOLD-fMRI is a useful method to analyze the brain activities of painful stimulation in anesthetized animals.
Mostrar más [+] Menos [-]Identification of genes for two major sialoglycoproteins, glycophorin A and glycophorin C in canine red cell membranes
2008
Sato, K.(Hokkaido Univ., Sapporo (Japan)) | Otsuka, Y. | Arashiki, N. | Komatsu, T. | Wang, C.C. | Tamahara, S. | Inaba, M.
Glycophorins are the major sialoglycoproteins in red blood cell membranes, possessing various physiological and pathological roles. We examined membrane glycoproteins in canine red cells and cloned cDNAs for two major glycophorins, glycophorins A (GPA) and C (GPC) from bone marrow cells. Periodic acid-Schiff staining and immunoblotting analyses showed that canine red cell membranes contained several glycoproteins immunoreactive to an anti-bovine GPC antibody, whereas the most abundant sialoglycoproteins, the candidates for GPA, did not react with an anti-human GPA antibody. The amino acid sequences of the extracellular domains of GPA and GPC had no significant homology to those from other mammalian species, including humans, and had O-linked and/or N-linked glycosylation sites. On the other hand, the C-terminal cytoplasmic domain and/or the transmembrane helices of GPA and GPC were conserved among species, indicating some functional significance of those regions in red cell membranes that include dimerization of GPA in the membrane-spanning region, and association of GPC with membrane skeletal proteins through binding with protein 4.1 and p55 in the cytoplasmic domain. These findings provide insights for clinical studies to evaluate the involvement of GPA and GPC in the pathogenesis of red cell diseases.
Mostrar más [+] Menos [-]Expression of alpha-hemoglobin stabilizing protein and cellular prion protein in a subclone of murine erythroleukemia cell line MEL
2008
Otsuka, Y.(Hokkaido Univ., Sapporo (Japan)) | Ito, D. | Katsuoka, K. | Arashiki, N. | Komatsu, T. | Inaba, M.
alpha-Hemoglobin stabilizing protein (AHSP) functions as the erythroid-specific molecular chaperon for alpha-globin. AHSP gene expression has been reported to be downregulated in hematopoietic tissues of animals suffering from prion diseases though the mechanism remains to be clarified. Herein, we demonstrate that MELhipod8 cells, a subclone of murine erythroleukemia (MEL) cells, have prion protein (PrPsup(C)) on the cell surface and have highly inducible expression of the AHSP and alpha- and beta-globin genes, resembling the expression pattern of the PrP and AHSP genes in bipotential erythroid- and megakaryocyte-lineage cells followed by erythroid differentiation in normal erythropoiesis. Moreover, MELhipod8 cells exhibit greater effective erythroid differentiation with a population of hemoglobinized normoblast-like cells than that observed for the parental MEL cells. These findings suggest that MELhipod8 cells could provide a mechanism for downregulation of the AHSP gene in prion diseases.
Mostrar más [+] Menos [-]Downregulation of male-specific cytochrome P450 by profenofos
2008
Moustafa, G.G.(Hokkaido Univ., Sapporo (Japan)) | Ibrahim, Z.S. | Ahmed, M.M. | Ghoneim, M.H. | Sakamoto, K.Q. | Ishizuka, M. | Fujita, S.
The health hazards of individual organophosphorus insecticides have been characterized by their acute toxicity, mainly by investigating their cholinesterase inhibition. However, the chronic effects of most of these toxicants on the drug-metabolizing enzymes have not been investigated. Profenofos (O-4-bromo-2-chlorophenyl O-ethyl S-propyl phosphorothioate) is an organophosphorus pesticide widely used in cotton cultivation. In the present study, we investigated the effect of profenofos on male-specific cytochrome P450 (CYP) enzymes in adult Wistar rats. We orally administered 17.8 mg/kg body weight, twice weekly for 65 days. Profenofos downregulated levels of hepatic and testicular CYP2C11 and CYP3A2 mRNA and protein expression. Testicular aromatase (CYP19A) mRNA was decreased in the profenofos-treated rats compared to controls. Overall, the present study suggests that profenofos acts as an endocrine disruptor of male-specific CYP enzymes and affects testosterone concentration, which implicates its deleterious effects on animal or human males chronically exposed to organophosphorus pesticide.
Mostrar más [+] Menos [-]Protection by Nigella sativa against carbon tetrachloride-induced downregulation of hepatic cytochrome p450 isozymes in rats
2008
Ibrahim, Z.S.(Hokkaido Univ., Sapporo (Japan)) | Ishizuka, M. | Soliman, M. | ElBohi, K. | Sobhy, W. | Muzandu, K. | Elkattawy, A.M. | Sakamoto, K.Q. | Fujita, S.
Nigella sativa (family Ranunculaceae ) is an annual plant that has been traditionally used on the Indian subcontinent and in Middle Eastern countries. In this study, we investigated the effect of N. sativa oil on the drug-metabolizing cytochrome P450 (CYP) enzymes and whether it has a protective effect against the acute hepatotoxicity of CCl4. Intraperitoneal injection of rats with CCl4 drastically decreased CYP2E1, CYP2B, CYP3A2, CYP2C11, and CYP1A2 mRNA and protein expressions. Oral administration of 1 ml/kg N. sativa oil every day for one week prior to CCl4 injection alleviated CCl4-induced suppression of CYP2B, CYP3A2, CYP2C11, and CYP1A2. Moreover, CCl4 increased iNOS and TNFalpha mRNA, while N. sativa oil administration for one week prior to CCl4 injection downregulated the CCl4-induced iNOS mRNA and up-regulated IL-10 mRNA. These results indicate that N. sativa oil administration has a protective effect against the CCl4-mediated suppression of hepatic CYPs and that this protective effect is partly due to the downregulation of NO production and up-regulation of the anti-inflamnatory IL-10.
Mostrar más [+] Menos [-]Development of vaccine strains of H5 and H7 influenza viruses
2008
Soda, K.(Hokkaido Univ., Sapporo (Japan)) | Sakoda, Y. | Isoda, N. | Kajihara, M. | Haraguchi, Y. | Shibuya, H. | Yoshida, H. | Sasaki, T. | Sakamoto, R. | Saijo, K. | Hagiwara, J. | Kida, H.
To establish vaccine strains of H5 and H7 influenza viruses, A/duck/Hokkaido/Vac-1/04 (H5N1) [Vac-1/04 (H5N1)], A/duck/Hokhaido/Vac-3/07 (H5N1) [Vac-3/07 (H5N1)], and A/duck/Hokkaido/Vac-2/04 (H7N7) [Vac-2/04 (H7N7)] were generated from non-pathogenic avian influenza viruses isolated from migratory ducks. Vac-1/04 (H5N1) and Vac-3/07 (H5N1) were generated by genetic reassortment between H5N2 or H5N3 virus as an HA gene provider and H7N1 or H6N1 virus as an NA gene provider. Vac-2/04 (H7N7) was a genetic reassortant obtained using H7N7 and H9N2 viruses to give high growth character of the H9N2 virus in chicken embryonated eggs. The results of sequence analyses and experimental infections revealed that these H5N1 and H7N7 reassortant viruses were non-pathogenic in chickens and embryos, and had good growth potential in embryonated eggs. These viruses should be useful to develop vaccines against H5 and H7 highly pathogenic avian influenza viruses.
Mostrar más [+] Menos [-]Characterization and epitope mapping of monoclonal antibodies to the nucleocapsid protein of severe acute respiratory syndrome coronavirus
2008
Kariwa, H.(Hokkaido Univ., Sapporo (Japan)) | Noda, H. | Nakauchi, M. | Ishizuka, M. | Hashiguchi, K. | Hashimoto, S. | Yoshii, K. | Asano, A. | Agui, T. | Kogaki, H. | Kurano, Y. | Uchida, Y. | Fujii, N. | Okada, M. | Takashima, I.
The sudden emergence of severe acute respiratory syndrome (SARS) at the end of 2002 resulted in 774 reported deaths from more than 8000 cases worldwide. As no effective vaccines or antiviral agents are available, the most effective measure to prevent the expansion of a SARS epidemic is the rapid diagnosis and isolation of SARS patients. To establish specific diagnostic methods, we generated nine clones of monoclonal antibodies to nucleocapsid protein (NP) of SARS-coronavirus (SARS-CoV). On immunofluorescent antibody assay and Western blotting analysis, none of the monoclonal antibodies showed cross-reactivity to authentic and recombinant NPs of human coronavirus (HCoV) 229E strain. To determine the region on the NP molecule where the monoclonal antibodies bind, we generated four truncated recombinant NPs and analyzed the reactivity between monoclonal antibodies and truncated NPs. Two monoclonal antibodies reacted with a truncated NP covering from amino acid residues 111 to 230, and seven reacted with another truncated NP covering from amino acid residues 221 to 340. Epitope mapping analysis indicated that monoclonal antibody SN5-25 recognized the amino acid sequence Qsup(245)TVTKKsup(250) on SARS-NP. Within the epitope, Q245, T246, V247, K249, and K250 appeared to form an essential motif for monoclonal antibody SN5-25 to bind. The information about binding sites and epitopes of monoclonal antibodies may be useful for the development of new diagnostic methods for SARS and for analyzing the function of N protein of SARS-CoV.
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