Funahashi A.,Kagoshima University |
Komatsu M.,Kagoshima University |
Furukawa T.,Kagoshima UniversityKagoshima |
Furukawa T.,Cancer Therapy and Research Center |
And 9 more authors.
Comparative Biochemistry and Physiology Part - C: Toxicology and Pharmacology | Year: 2016
Green fluorescent protein (GFP) from eel (Anguilla japonica) muscle (eelGFP) is unique in the vertebrates and requires bilirubin as a ligand to emit fluorescence. This study was performed to clarify the physiological function of the unique GFP. Investigation of susceptibility to oxidative stress was carried out using three types of cell lines including jellyfish (Aequorea coerulescens) GFP (jfGFP)-, or eel GFP (eelGFP)-expressing HEK293 cells, and control vector-transfected HEK293 cells. Binding of eelGFP to bilirubin was confirmed by the observation of green fluorescence in HEK293-eelGFP cells. The growth rate was compared with the three types of cells in the presence or absence of phenol red which possessed antioxidant activity. The growth rates of HEK293-CV and HEK293-jfGFP under phenol red-free conditions were reduced to 52 and 31% of those under phenol red. Under the phenol red-free condition, HEK293-eelGFP had a growth rate of approximately 70% of the phenol red-containing condition. The eelGFP-expressing cells were approximately 2-fold resistant to oxidative stress such as H2O2 exposure. The fluorescence intensity partially decreased or disappeared after exposure to H2O2, and heterogeneous intensity of fluorescence was also observed in isolated eel skeletal muscle cells. These results suggested eelGFP, but not jfGFP, coupled with bilirubin provided the antioxidant activity to the cells as compared to non-bound free bilirubin. © 2016 Elsevier Inc. All rights reserved.
Zhao X.,Kagoshima UniversityKagoshima |
Zheng S.-H.,Saga University |
Arima S.,Saga University
Plant Production Science | Year: 2014
Nitrogen assimilation during seed filling limits the seed yield in soybean. Seed nitrogen dependence on either redistributed nitrogen or absorbed nitrogen from soil during seed filling shows varietal differences. The objective of this study was to investigate the timing of nitrogen enrichment for effective nitrogen assimilation. Two soybean cultivars Sachiyutaka and Tamahomare were sown in the pots filled with well-washed fine sand. The plants were well watered with nutrient solution containing 100 ppm nitrogen and other nutrient elements before and after the treatment. The treatments were conducted from reproductive stage R1 to R5 or from R5 to R7 by applying the nutrient solution with different nitrogen concentrations. The high nitrogen concentration from R1 to R5 delayed the decline in SPAD value and leaf nitrogen concentration and improved the seed yield performance in Sachiyutaka, whereas stimulated the decline in SPAD value and leaf nitrogen concentration and had no effect on seed yield in Tamahomare. However, high nitrogen concenntration during R5 to R7 delayed the decline in SPAD value and leaf nitrogen concentration and improved the yield performance more significantly in Tamahomare than in Sachiyutaka. The large seed yield increase by nitrogen enrichment during R5 to R7 in Tamahomare could be caused by both the high photosynthetic rate and vigorous nitrogen uptake during seed filling. These results suggested that the most effective timing of nitrogen enrichment during the reproductive growth period to increase seed yield varies with the cultivar due to the difference in the pattern of nitrogen assimilation. © 2014 by The Crop Science Society of Japan.
Shiozaki K.,Kagoshima University |
Shiozaki K.,Kagoshima UniversityKagoshima |
Harasaki Y.,Kagoshima University |
Fukuda M.,Kagoshima University |
And 7 more authors.
Biochimie | Year: 2016
Sialidase Neu3b is an unique enzyme conserved in medaka and tilapia, but not in mammals. Previous study revealed that medaka Neu3b is localized at cytosol and is a ganglioside-specific sialidase. Neu3b functions, however, have not been understood, while Neu3a sialidase, which is widely conserved from human to fish, is known as a regulator of neurite formation. Here, we investigated the biological function of Neu3b for C2C12 myoblast cell differentiation. Bioinformatics analysis using genome browser revealed the presence of neu3b gene in some orders of fish species such as Beloniformes, Perciformes and Cyprinodontiformes. With the treatment of 2% horse serum, Neu3b-overexpression accelerated myoblast cell differentiation to myotubes accompanied with up-regulation of myogenesis biomarkers mRNA, myod and myog. Neu3b altered ganglioside composition in C2C12 cells results showing a decrease in GM2, and the increase of Lac-Cer, while desialylation of glycoproteins were not detected. Contrary to cell differentiation, Neu3b cell proliferation was suppressed in normal growth medium. To understand the mechanism of the alteration of cell differentiation and proliferation, phosphorylation of signal molecules in EGFR/ERK pathway was investigated. Neu3b induced a decline in phosphorylation of ERK and EGFR. Surprisingly, immuno-blot and real-time PCR analysis revealed that down-regulation of egfr gene could be involved in the acceleration of cell differentiation by Neu3b. These results suggested that Neu3b sialidase is a positive regulator for myoblast differentiation, similar with mammalian cytosolic sialidase Neu2. © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.