Time filter

Source Type

Shimonoseki, Japan

Suda A.,Kyushu University | Kaiya H.,Japan National Cardiovascular Center Research Institute | Nikaido H.,Seikai National Fisheries Research Institute | Shiozawa S.,Seikai National Fisheries Research Institute | And 3 more authors.
General and Comparative Endocrinology | Year: 2012

Full length cDNA and gene encoding ghrelin precursor and mature ghrelin peptide were identified from the stomach of Pacific bluefin tuna, Thunnus orientalis, which has unique metabolic physiology and high commercial value at fishery markets. Quantitative expression analysis was conducted for the gastric ghrelin and pepsinogen 2 genes during the early stage of somatic growth from the underyearling to yearling fish. The full length cDNA of bluefin tuna ghrelin precursor has a length of 470. bp and the deduced precursor is composed of 107 amino acids. The ghrelin gene is 1.9. kbp in length and has a 4 exon-3 intron structure. The major form of mature ghrelin in the stomach was an octanoylated 20-amino acid peptide with C-terminal amidation, while overall 12 different forms of ghrelin peptides, including short form of 18-amino acid peptide and seven kinds of acyl modifications were identified. The expression profiles of the gastric ghrelin and pepsinogen 2 genes showed no significant changes related to the early growth stages. The present results suggest that digestive physiology has already been functional in this growth stage of the juvenile bluefin tuna and ghrelin may have a role in the sustained digestive and metabolic activities. © 2012 Elsevier Inc.

Zhang W.,Fudan University | Okimura T.,Hayashikane Sangyo Co. | Xu L.,Fudan University | Zhang L.,Fudan University | And 5 more authors.
Oncotarget | Year: 2016

Our previous study demonstrated that ascophyllan, a sulfated polysaccharide purified from brown alga, has immune-activating effects. In this study, we evaluated ascophyllan as an adjuvant for its therapeutic and preventive effect on tumor in a mouse melanoma model. Ascophyllan induced migration of DCs to spleen and tumor-draining lymph node (drLN) in a mouse B16 melanoma model. Moreover, ascophyllan induced activation of dendritic cells (DCs), and promoted IFN-?- and TNF-a-producing Th1 immune responses in tumor-bearing mice. In addition, treatment with a combination of ascophyllan and ovalbumin (OVA) in the tumor-bearing mice promoted proliferation of OVA-specific CD4 and CD8 T cells and migration of those cells into the tumor, consequently inhibiting the tumor growth. Immunization with the combination of ascophyllan and OVA caused enhanced OVA-specific antibody production and memory T cell responses compared to OVA immunization alone, and almost completely prevented B16-OVA tumor growth upon subsequent tumor challenge. Finally, the combination of ascophyllan and OVA prevented B16-OVA tumor invasion and metastasis into the liver. Thus, these results demonstrate that ascophyllan can function as an adjuvant to induce DC activation, antigen specific CTL activation, Th1 immune response and antibody production, and hence may be useful as a therapeutic and preventive tumor vaccine.

Fujii K.,Yamaguchi University | Nakashima H.,Yamaguchi University | Hashidzume Y.,Yamaguchi University | Uchiyama T.,Hayashikane Sangyo Co. | And 2 more authors.
Journal of Applied Phycology | Year: 2010

We determined the nutritional profile of Monoraphidium sp. GK12, a newly isolated astaxanthin (AXA)-producing microalga, and investigated its potential use as a functional aquafeed by evaluating its effect on prawn pigmentation. GK12 contained high levels of pantothenic acid. The β-carotene content of GK12 was higher than that of Haematococcus, a well-studied AXA producer, and was similar to that of Spirulina. GK12 also had a high content of unsaturated fatty acids, of which linolenic acid (C18:3 n-3) was the most plentiful. A GK12-containing feed resulted in significant pigmentation of the prawns, comparable to that of prawns fed on synthetic AXA or Haematococcus. A GK12-containing feed also increased the survival rate of the prawns. Therefore, in addition to improving cultivation methods for Haematococcus, further research is needed into the use of GK12 as an alternative AXA source and as an ingredient of functional aquafeed for farmed fish. © Springer Science+Business Media B.V. 2009.

Jiang Z.,Nagasaki University | Okimura T.,Hayashikane Sangyo Co. | Yokose T.,Nagasaki University | Yokose T.,11 Health | And 3 more authors.
Journal of Bioscience and Bioengineering | Year: 2010

The effects of fucose-containing sulfated polysaccharides, ascophyllan and fucoidan, isolated from the brown alga Ascophyllum nodosum, on the growth of various cell lines (MDCK, Vero, PtK1, CHO, HeLa, and XC) were investigated. In a colony formation assay, ascophyllan and fucoidan showed potent cytotoxic effects on Vero and XC cells, while other cell lines were relatively resistant to these polysaccharides. Almost no significant effects of these polysaccharides were observed in the cell lines tested using the Alamar blue cytotoxicity assay over 48 h with varying initial cell densities (2500-20,000 cells/well) in growth medium. Interestingly, a significant growth promoting effect of ascophyllan on MDCK cells was observed, whereas treatment with fucoidan showed growth suppressive effects on this cell line under the same experimental conditions. These results suggest that ascophyllan is distinguishable from fucoidan in terms of their bioactivities. This is the first report of the growth promoting effects of a sulfated fucan on a mammalian cell line under normal growth conditions. © 2010 The Society for Biotechnology, Japan.

Zhang W.,Fudan University | Du J.-Y.,Fudan University | Jiang Z.,Nagasaki University | Okimura T.,Hayashikane Sangyo Co. | And 3 more authors.
Marine Drugs | Year: 2014

Marine-derived sulfated polysaccharides have been shown to possess certain anti-virus, anti-tumor, anti-inflammatory and anti-coagulant activities. However, the in vivo immunomodulatory effects of marine-derived pure compounds have been less well characterized. In this study, we investigated the effect of ascophyllan, a sulfated polysaccharide purified from Ascophyllum nodosum, on the maturation of mouse dendritic cells (DCs) in vitro and in vivo. Ascophyllan induced up-regulation of co-stimulatory molecules and production of pro-inflammatory cytokines in bone marrow-derived DCs (BMDCs). Moreover, in vivo administration of ascophyllan promotes up-regulation of CD40, CD80, CD86, MHC class I and MHC class II and production of IL-6, IL-12 and TNF-α in spleen cDCs. Interestingly, ascophyllan induced a higher degree of co-stimulatory molecule up-regulation and pro-inflammatory cytokine production than fucoidan, a marine-derived polysaccharide with well-defined effect for promoting DC maturation. Ascophyllan also promoted the generation of IFN-γ-producing Th1 and Tc1 cells in the presence of DCs in an IL-12-dependent manner. Finally, myeloid differentiation primary response 88 (MyD88) signaling pathway was essential for DC maturation induced by ascophyllan. Taken together, these results demonstrate that ascophyllan induces DC maturation, and consequently enhances Th1 and Tc1 responses in vivo. This knowledge could facilitate the development of novel therapeutic strategies to combat infectious diseases and cancer. © 2014 by the authors; licensee MDPI.

Discover hidden collaborations