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Minaguchi J.,Rakuno Gakuen University | Tometsuka C.,Nippi Inc. | Koyama Y.-I.,Nippi Inc. | Koyama Y.-I.,Japan Institute of Leather Research | And 7 more authors.
Food Science and Technology Research | Year: 2012

Beneficial effects of collagen peptide ingestion to reduce serum triacylglycerides have been reported, suggesting that the physiological conditions of adipocytes are modulated following collagen peptide ingestion. In this study, the effects of prolylhydroxyproline, a major digestive product of ingested collagen peptide in the blood, on the differentiation of mouse 3T3-L1 preadipocytes in vitro were investigated. 3T3-L1 preadipocytes were induced to differentiate to adipocytes and treated with prolylhydroxyproline, or with an amino acid mixture of proline and hydroxyproline as a control. The amount of lipid was not affected by these treatments. However, the size of the lipid droplet was significantly smaller when treated with prolylhydroxyproline compared to the amino acid mixture or the non-treated control. Proton-coupled oligopeptide transporters were expressed in non-differentiated and/or differentiated 3T3-L1 cells. These results suggest that prolylhydroxyproline might modulate the morphology of lipid droplets by incorporation into adipocytes through the transporters.


Ogata K.,Japan Institute of Leather Research | Kumazawa Y.,Japan Institute of Leather Research | Koyama Y.,Japan Institute of Leather Research | Yoshimura K.,Tokyo Metropolitan Leather Technology Center | Takahashi K.,Tokyo University of Agriculture and Technology
Journal of the Society of Leather Technologists and Chemists | Year: 2015

Hexavalent chromium (Cr6+) causes dermatitis and cancer, and is often quantified from chrometanned leather. Analysis for Cr6+ is generally carried out after extraction into 0.1 M potassium phosphate buffer (P-buffer pH8.0) according to the method of ISO 17075. However, since the pH value of chrometanned leather and sweat due to wear are on the acidic side, the above method for Cr6+ should be validated using acidic extracts. In the present study, acidic extracts from chrome-tanned leather were analyzed for Cr6+ comparing the results with those using alkaline extracts. A sample of commercial chrome-tanned leather was used to investigate the influence of pH on the extractability of Cr6+. Chromium was extracted from the leather with P-buffer (pH3.0-11.0), acidic artificial perspiration (pH5.5) or 0.2% sodium sulfate (pH5.5). The contents of total chromium (Cr) and Cr6+ in each extract were respectively measured by inductive coupled plasma atomic emission spectroscopy and colorimetry with diphenylcarbazide. Less Cr was extracted in the range of pH5.5- 8.0, whereas more Cr was extracted in the more acidic and alkaline regions. By contrast, the amount of Cr6+ extracted increased moderately with increasing pH. When the P-buffer extract (pH8.0) was adjusted to pH3.0-11.0, the amount of Cr6+ increased with increasing pH, suggesting occurrence of a reversible conversion between Cr6+ and Cr3+. The extraction with P-buffer (pH8.0) may thus provide a falsely high value due to this conversion. P-buffer (pH5.5) showed a significantly higher extraction of Cr6+ than tests with artificial perspiration (pH5.5) and 0.2% sodium sulfate (pH5.5). The residue remaining after each extraction was re-extracted with a fresh aliquot of the appropriate extractant. The amount of Cr6+ in the second extract with P-buffer (pH5.5) exhibited a low extractability (about 9% of the amount of the first), whereas artificial perspiration (pH5.5), 0.2% sodium sulfate (pH5.5), and P-buffer (pH 8.0) showed a high extractability (about 41-67% of the amount of the first). It is thus concluded that extracting with P-buffer (pH5.5) is most efficient of the tested extractants for analyzing Cr6+ from chrome-tanned leather.


Ogata K.,Japan Institute of Leather Research | Kumazawa Y.,Japan Institute of Leather Research | Koyama Y.,Japan Institute of Leather Research | Yoshimura K.,Tokyo Metropolitan Leather Technology Center | Takahashi K.,Tokyo University of Agriculture and Technology
XXXIII IULTCS Congress | Year: 2015

Hexavalent chromium (Cr6+) induces dermatitis and cancer, and is often quantified from chrome-Tanned leather could be generated by oxidation of trivalent chromium (Cr3+) under a certain condition. In particular, much amount of Cr6+ has been determined by the heat-Aging treatment by pre-heating at 80°C for 24 h according to the method of ISO 17075 due to promoting generation of Cr6+ from Cr3+ in chrome-Tanned leather. It is thus strongly desired that the generation of Cr6+ could be effectively inhibited by a suitable manner. We have previously reported that 0.1 M potassium phosphate buffer (P-buffer; pH 5.5) would be highly efficient as an extractant in measuring Cr6+ from chrome-Tanned leather. In this study, some controlling materials Cr3+ such as stabilizing agent of Cr3+, radical scavenger, and reducing agent, were applied to inhibit generation of Cr6+ for chrome-Tanned leather even if heat-Aged. Collagen peptide (CP-10) with low-molecular weight (Mw about 10,000) 2, 6-di-T-buthyl-4-methylphenol (BHT) and 3(2)-T-buthyl-4-hydroxyanisole (BHA), and ascorbic acid (AsA) were used as a stabilizing agent through reacting with Cr3+, scavenger of radicals generated at the initiation of oxidation of fatliquoring agent, and reducing agent adjusting reducing enviroment, respectively. Chrome-Tanned leather was treated with these controlling materials, and then the resulting leather samples were extracted with P-buffer (pH 5.5) to determine the amount of Cr6+ in the extract. Consequently, CP-Treatment considerably reduced generation of Cr6+ probably due to stabilization of Cr3+ complex with coordination of CP. BHT-and BHA-, and AsA-Treatments also showed considerable reduction probably due to scavenging radical from oxidative products of fatliquoring agent, and due to adjusting reducing environment, respectively. However, the individual treatment with the controlling material could not result in complete inhibition. Combined treatment was thus carried out. Concequently, coupled treatment with BHA + CP and and BHA + AsA exhibited synergy reduction of the Cr6+-generation, in particular, combined treatment with BHA + AsA + CP completely inhibited generation of Cr6+ from the heat-Aged leather sample.


Nakayama H.,Wakayama Prefectural Fisheries Experimental Station | Tanaka K.,Nippi Research Institute of Biomatrix | Teramura N.,Nippi Research Institute of Biomatrix | Hattori S.,Nippi Research Institute of Biomatrix | Hattori S.,Japan Institute of Leather Research
Bioscience, Biotechnology and Biochemistry | Year: 2016

The collagenase activity and the fpcol gene were examined in Flavobacterium psychrophilum isolates from cold-water disease (CWD)-affected ayu, Plecoglossus altivelis. Collagenase expression was closely related to the accumulated mortality of CWD-affected ayu. RT-qPCR and bacterial challenge experiments showed that F. psychrophilum ayu isolate WA-1 expressed the fpcol gene more actively and was more virulent than ayu isolate WA-2. The amago (Oncorhynchus masou) isolate WB-1, which possesses a pseudo-fpcol gene, was not harmful to ayu. Hitherto, the well-studied metalloproteases Fpp1 and Fpp2 have been considered virulence factors. However, the most virulent isolate against ayu (WA-1) showed no Fpp activity because of a deletion mutation or an insertion of a transposon in the fpp genes. The less virulent WA-2 isolate showed only Fpp1 activity. Taken together, these results suggest that collagenolytic activity, but not Fpp activity, is related to the virulence of F. psychrophilum isolates in CWD-affected ayu. © 2015 Japan Society for Bioscience, Biotechnology, and Agrochemistry.


Ueno T.,Nippi Research Institute of Biomatrix | Kaneko K.,Japan National Institute of Infectious Diseases | Sata T.,Japan National Institute of Infectious Diseases | Sata T.,Toyama Institute of Health | And 4 more authors.
Nucleic Acids Research | Year: 2012

A coiled-coil microtubule-bundling protein, p180, was originally identified as one of the ribosome receptor candidates on the rough endoplasmic reticulum (ER) and is highly expressed in secretory tissues. Recently, we reported that p180 plays crucial roles in upregulating collagen biosynthesis, mainly by facilitating ribosome association on the ER. Here, we provide evidence that p180 is required to form translationally active polysome/translocon complexes on the ER. Assembly of highly-developed polysomes on the ER was severely perturbed upon loss of p180. p180 associates with polysome/translocon complexes through multiple contact sites: it was coimmunoprecipitated with the translocon complex independently of ribosomes, while it can also bind to ribosomal large subunit specifically. The responsible domain of p180 for membrane polysome assembly was identified in the C-terminal coiled-coil region. The degree of ribosome occupation of collagen and fibronectin mRNAs was regulated in response to increased traffic demands. This effect appears to be exerted in a manner specific for a specified set of mRNAs. Collectively, our data suggest that p180 is required to form translationally active polysome/translocon complexes on the ER membrane, and plays a pivotal role in highly efficient biosynthesis on the ER membrane through facilitating polysome formation in professional secretory cells. © 2011 The Author(s).

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