Time filter

Source Type

Osaka, Japan

Soai University is a private university in the city of Osaka, Japan. It was established in 1888, initially as a women's university. Famous people with ties to Soai include alumni Hideo Ishikawa, Haruko Okamoto, Mihoko Shuku, and Yasuhito Sugiyama. Wikipedia.

Endo-Umeda K.,Nihon University | Yasuda K.,Toyama Prefectural University | Sugita K.,University of Tokyo | Honda A.,Tokyo Medical University | And 5 more authors.
Journal of Steroid Biochemistry and Molecular Biology | Year: 2014

7-Dehydrocholesterol (7-DHC) is a common precursor of vitamin D3 and cholesterol. Although various oxysterols, oxygenated cholesterol derivatives, have been implicated in cellular signaling pathways, 7-DHC metabolism and potential functions of its metabolites remain poorly understood. We examined 7-DHC metabolism by various P450 enzymes and detected three metabolites produced by sterol 27-hydroxylase (CYP27A1) using high-performance liquid chromatography. Two were further identified as 25-hydroxy-7-DHC and 26/27-hydroxy-7-DHC. These 7-DHC metabolites were detected in serum of a patient with Smith-Lemli-Opitz syndrome. Luciferase reporter assays showed that 25-hydroxy-7-DHC activates liver X receptor (LXR) α, LXRβ and vitamin D receptor and that 26/27-hydroxy-7-DHC induces activation of LXRα and LXRβ, although the activities of both compounds on LXRs were weak. In a mammalian two-hybrid assay, 25-hydroxy-7-DHC and 26/27-hydroxy-7-DHC induced interaction between LXRα and a coactivator fragment less efficiently than a natural LXR agonist, 22(R)-hydroxycholesterol. These 7-DHC metabolites did not oppose agonist-induced LXR activation and interacted directly to LXRα in a manner distinct from a potent agonist. These findings indicate that the 7-DHC metabolites are partial LXR activators. Interestingly, 25-hydroxy-7-DHC and 26/27-hydroxy-7-DHC suppressed mRNA expression of sterol regulatory element-binding protein 1c, an LXR target gene, in HepG2 cells and HaCaT cells, while they weakly increased mRNA levels of ATP-binding cassette transporter A1, another LXR target, in HaCaT cells. Thus, 7-DHC is catabolized by CYP27A1 to metabolites that act as selective LXR modulators. © 2013 Elsevier Ltd. All rights reserved.

Munetsuna E.,Toyama Prefectural University | Munetsuna E.,Health Science University | Kawanami R.,Toyama Prefectural University | Nishikawa M.,Toyama Prefectural University | And 7 more authors.
Molecular and Cellular Endocrinology | Year: 2014

1α-Hydroxylation of 25-hydroxyvitamin D3 is believed to be essential for its biological effects. In this study, we evaluated the biological activity of 25(OH)D3 itself comparing with the effect of cell-derived 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3). First, we measured the cell-derived 1α,25(OH)2D3 level in immortalized human prostate cell (PZ-HPV-7) using [3H]-25(OH)D3. The effects of the cell-derived 1α,25(OH)2D3 on vitamin D3 24-hydroxylase (CYP24A1) mRNA level and the cell growth inhibition were significantly lower than the effects of 25(OH)D3 itself added to cell culture. 25-Hydroxyvitamin D3 1α-hydroxylase (CYP27B1) gene knockdown had no significant effects on the 25(OH)D3-dependent effects, whereas vitamin D receptor (VDR) gene knockdown resulted in a significant decrease in the 25(OH)D3-dependent effects. These results strongly suggest that 25(OH)D3 can directly bind to VDR and exerts its biological functions. DNA microarray and real-time RT-PCR analyses suggest that semaphorin 3B, cystatin E/M, and cystatin D may be involved in the antiproliferative effect of 25(OH)D3. © 2013 Elsevier Ireland Ltd.

Kasai N.,Toyama Prefectural University | Ikushiro S.,Toyama Prefectural University | Hirosue S.,Mercian Corporation | Arisawa A.,Mercian Corporation | And 5 more authors.
Journal of Biochemistry | Year: 2010

We cloned full-length cDNAs of 130 cytochrome P450s (P450s) derived from Phanerochaete chrysosporium and successfully expressed 70 isoforms in Saccharomyces cerevisiae. To elucidate substrate specificity of P. chrysosporium P450s, we examined various substrates including steroid hormones, several drugs, flavonoids and polycyclic aromatic hydrocarbons using the recombinant S. cerevisiae cells. Of these P450s, two CYPs designated as PcCYP50c and PcCYP142c with 14% identity in their amino acid sequences catalyse 3'-hydroxylation of flavone and O-deethylation of 7-ethoxycoumarin. Kinetic data of both enzymes on both reactions fitted not to the Michaelis-Menten equation but to Hill's equation with a coefficient of 2, suggesting that two substrates bind to the active site. Molecular modelling of PcCYP50c and a docking study of flavone to its active site supported this hypothesis. The enzymatic properties of PcCYP50c and PcCYP142c resemble mammalian drug-metabolizing P450s, suggesting that their physiological roles are metabolism of xenobiotics. It is noted that these unique P. chrysosporium P450s have a potential for the production of useful flavonoids.

Hayashi K.,Toyama Prefectural University | Yasuda K.,Toyama Prefectural University | Sugimoto H.,RIKEN | Ikushiro S.,Toyama Prefectural University | And 7 more authors.
FEBS Journal | Year: 2010

Our previous studies revealed that the double variant of cytochrome P450 (CYP)105A1, R73V/R84A, has a high ability to convert vitamin D3 to its biologically active form, 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3], suggesting the possibility for R73V/R84A to produce 1α,25(OH)2D3. Because Actinomycetes, including Streptomyces, exhibit properties that have potential advantages in the synthesis of secondary metabolites of industrial and medical importance, we examined the expression of R73V/R84A in Streptomyces lividans TK23 cells under the control of the tipA promoter. As expected, the metabolites 25-hydroxyvitamin D3 [25(OH)D3] and 1α,25(OH) 2D3 were detected in the cell culture of the recombinant S. lividans. A large amount of 1α,25(OH)2D3, the second-step metabolite of vitamin D3, was observed, although a considerable amount of vitamin D3 still remained in the culture. In addition, novel polar metabolites 1α,25(R),26(OH)3D3 and 1α,25(S),26(OH)3D3, both of which are known to have high antiproliferative activity and low calcemic activity, were observed at a ratio of 5 : 1. The crystal structure of the double variant with 1α,25(OH)2D3 and a docking model of 1α,25(OH)2D3 in its active site strongly suggest a hydrogen-bond network including the 1α-hydroxyl group, and several water molecules play an important role in the substrate-binding for 26-hydroxylation. In conclusion, we have demonstrated that R73V/R84A can catalyze hydroxylations at C25, C1 and C26 (C27) positions of vitamin D3 to produce biologically useful compounds. © 2010 FEBS.

Fujiwara N.,Osaka City University | Naka T.,Osaka City University | Naka T.,MBR Co. | Ogawa M.,University of Occupational and Environmental Health Japan | And 4 more authors.
Tuberculosis | Year: 2012

Mycobacterium smegmatis is a rapidly growing, non-pathogenic mycobacterium, and M. smegmatis strain mc 2155 in particular has been used as a tool for molecular analysis of mycobacteria because of its high rate of transformation. We examined another strain, M. smegmatis J15cs, which has the advantage of surviving for six days in murine macrophages. The J15cs strain produces a rough dry colony, and we hypothesized that the long survival of the J15cs strain was correlated with its cell wall components. Therefore, the lipid compositions of these two strains were compared. The subclasses and carbon species of the mycolic acids were very similar, and the major glycolipids and phospholipids were expressed in both strains. However, apolar glycopeptidolipids were deleted only in the J15cs strain. The presence of apolar glycopeptidolipids gives the cell wall a different structure. Moreover, the apolar glycopeptidolipids were recognized by macrophages via toll-like receptor 2, but not 4. We concluded that the absence of apolar glycopeptidolipids is a definitive feature of the J15cs strain, and affects its morphology and survival in host cells. © 2011 Elsevier Ltd. All rights reserved.

Discover hidden collaborations