Faculty Profiles - SATO, Chihiro

Inflammation-dependent changes in alpha 2,3-, alpha 2,6-, and alpha 2,8-sialic acid glycotopes on serum glycoproteins in mice Reviewed

Hypoxic culture induces expression of Sialin, a sialic acid transporter, and cancer-associated gangliosides containing non-human sialic acid on human cancer cells. , Reviewed

Yin, J., Hashimoto, A., Izawa, M., Miyazaki, K., Chen G-Y., Takematsu, H., Kozutsumi, Y., Suzuki, A., Furuhata, K., Cheng, F.-L. Lin, C.-H., Sato, C., Kitajima, K., and Kannagi, R.

Cancer Res. Vol. 66 page： 2937-2945 2006

Flagellasialin: a novel sulfated alpha2,9-linked polysialic acid glycoprotein of sea urchin sperm flagella. Reviewed

Miyata S, Sato C, Kumita H, Toriyama M, Vacquier VD, Kitajima K.

Glycobiology Vol. 16 page： 1229-12241 2006

Language：English Publishing type：Research paper (scientific journal)

A novel α2,9-linked polysialic acid-containing glycoprotein of sea urchin sperm flagella was previously identified and named “flagellasialin". Flagellasialin from Hemicentrotus pulcherrimus shows a diverse relative molecular mass on SDS-PAGE of 40-80 kDa. Its glycan structures were determined as HSO3→8Neu5Acα2→9(Neu5Acα2→9)n-2Neu5Acα2→6GalNAcα1→Thr (n, averaging 15) [Miyata et al. (2004) Glycobiology, 14, 827-840]. In this study, we purified flagellasialin, and cloned its cDNA. Flagellasialin is a 96-amino acid, threonine-rich, heavily O-glycosylated (80-90% by weight) glycoprotein with a single transmembrane segment at its C-terminus and no apparent cytosolic domain. Of 12 extracellular Thr residues, eight are O-glycosylated and three are non-glycosylated. Flagellasialin is highly expressed in testis, but cannot be detected in ovary. The amino acid sequences of flagellasialin from three sea urchin species (H. pulcherrimus, Strongylocentrotus purpuratus and S. franciscanus) are identical, but some species differences exist in the three core glycan structures to which the sulfated α2,9-linked polyNeu5Ac chain is linked. Finally, a specific antibody against the α2,9-linked polyNeu5Ac structure inhibits sperm motility and reduces fertilization, implicating flagellasialin as a regulator of these critical processes.

*Identification of disialic acid-containing glycoproteins in mouse serum. Reviewed

Yasukawa, Z., Sato, C., Sano, K., Ogawa, H. and Kitajima, K.

Glycobiology Vol. 15 page： 827-837 2006

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

Serum glycoproteins are involved in various biological activities such as removal of exogenous antigen, fibrinolysis, transport of metal. They are also useful markers of inflammation and diseases. Although it is known that the amount of sialic acid increases after inflammation, little attention has been paid to the presence of linkage specific epitope in serum,especially, the α2,8-linkage. In the previous study, we demonstrated that four components in mouse serum contain the α2,8-linked disialic acid, based on the immunoreactivity with mAb.2-4B that is specific to Neu5Gcα2→(8Neu5Gcα2→)n-1, n≥2 (Yasukawa, Z. et al. (2005) Glycobiology 15, 827-837). In this study, we purified three components, 30kDa-gp, 70kDa-gp, and 120kDa-gp and identified as the light chain of immunoglobulins, vitronectin, and plasminogen, respectively, using MALDI-TOF MS analyses. The modifications of these proteins with the α2,8-linked disialic acid was chemically confirmed by fluorometric C7/C9 analyses and acid hydrolysates-DMB methods. We also showed that the light chains of IgG, IgM and IgE are commonly modified with the α2,8-linked disialic acid. In addition, not only mouse vitronectin but also rat vitronectin was also modified with disialic acid and the amount of disialylation on vitronectin decreased after hepatectomy. These results indicate that disialic acid-modification on serum glycoprotein has some biological meanings in immunological events and fibrinolysis.

Involvement of the alpha2,8-polysialyltransferases II/STX and IV/PST in the biosynthesis of polysialic acid chains on the O-linked glycoproteins in rainbow trout ovary. Reviewed

Asahina S, Sato C, Matsuno M, Matsuda T, Colley K, Kitajima K. Asahina S, Sato C, Matsuno M, Matsuda T, Colley K, Kitajima K.

J Biochem. Vol. 140 page： 687-701 2006

Oral ingestion of mannose alters the expression level of deaminoneuraminic acid (KDN) in mouse organs. Reviewed

Go, S., Sato, C., and Kitajima, K.

Glycoconjugate J. Vol. 23 page： 411-421 2006

Weaning-induced expression of a milk-fat globule protein, MFG-E8, in mouse mammary glands, as demonstrated by the analyses of its mRNA, protein and phosphatidylserine-binding activity. Reviewed

Nakatani H, Aoki N, Nakagawa Y, Jin-No S, Aoyama K, Oshima K, Ohira S, Sato C, Nadano D, Matsuda T.

Biochem J. Vol. 395 page： 21-30 2006

Weaning-induced expression of a milk-fat globule protein, MFG-E8, in mouse mammary glands, as demonstrated by the analyses of its mRNA, protein and phosphatidylserine-binding activity. Reviewed

Nakatani H, Aoki N, Nakagawa Y, Jin-No S, Aoyama K, Oshima K, Ohira S, Sato C, Nadano D, Matsuda T

Biochem J. Vol. 395 page： 21-30 2006

Hypoxic culture induces expression of Sialin, a sialic acid transporter, and cancer-associated gangliosides containing non-human sialic acid on human cancer cells. , Reviewed

Yin, J, Hashimoto, A, Izawa, M, Miyazaki, K, Chen G-Y, Takematsu, H, Kozutsumi, Y, Suzuki, A, Furuhata, K, Cheng, F.-L. Lin, C.-H, Sato, C, Kitajima, K, Kannagi, R

Cancer Res. Vol. 66 page： 2937-2945 2006

Oral ingestion of mannose alters the expression level of deaminoneuraminic acid (KDN) in mouse organs. Reviewed

Go, S, Sato, C, Kitajima, K

Glycoconjugate J. Vol. 23 page： 411-421 2006

Involvement of the alpha2,8-polysialyltransferases II/STX and IV/PST in the biosynthesis of polysialic acid chains on the O-linked glycoproteins in rainbow trout ovary. Reviewed

Asahina S, Sato C, Matsuno M, Matsuda T, Colley K, Kitajima, K, Asahina S, Sato C, Matsuno M, Matsuda T, Colley K, Kitajima K

J Biochem. Vol. 140 page： 687-701 2006

Z Yasukawa, C Sato, K Kitajima

GLYCOBIOLOGY Vol. 15 ( 9 ) page： 827 - 37 2005.9

Language：English Publishing type：Research paper (scientific journal) Publisher：OXFORD UNIV PRESS INC

The expression of acute-phase serum proteins increases in response to inflammatory stimuli. Most of these proteins are glycoproteins that often contain sialic acids (Sia). It is unknown, however, how the expression of Sia in these glycoproteins changes during inflammation. This study demonstrates changes in the alpha 2,3-, alpha 2,6-, and alpha 2,8-Sia glycotopes on serum glycoproteins in response to turpentine oil-induced inflammation, based on lectin- and immunoblot analyses by using sialyl linkage-specific lectins, Maackia amurensis for the alpha 2,3-Sia glycotope and Sambucus sieboldiana for the alpha 2,6-Sia glycotopes, and monoclonal antibody 2413 (mAb.2-413) recognizing the di- and oligomers of the alpha 2,8-Neu5Gc residue. There was an increase in a limited number of sialoglycoproteins containing the alpha 2,3-, alpha 2,6-, or alpha 2,8-Sia glycotopes. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of the expression profiles of mRNAs for the known sialyltransferases in mouse liver during inflammation indicated the up-regulated expression of P-galactoside alpha 2,3-sialyltransferases (ST3Gal I and ST3Gal III) and P-N-acetylgalactosaminide alpha 2,6-sialyltransferase (ST6GalNAc VI) as well as P-galactoside alpha 2,6-sialyltransferase (ST6Gal 1) mRNAs. Notably, ST3Gal I and III and ST6GalNAc VI are involved in the synthesis of the alpha 2,3- and alpha 2,6-Sia glycotopes on O-glycan chains and possibly on gangliosides, whereas ST6Gal I is specific for N-glycan chains. These results provide evidence for the inflammation-induced expression of sialyl glycotopes in serum glycoproteins. We demonstrated that inflammation significantly increased the expression of an unknown 32-kDa glycoprotein containing the alpha 2,8-Sia glycotope. The mechanism for the increase in glycoprotein in inflamed mouse serum remains to be examined, as mRNA expression for all of the alpha 2,8-sialyltransferases (ST8Sia I-VI) was unchanged during inflammation.

DOI： 10.1093/glycob/cwi068

Crystallization and preliminary X-ray analysis of mitochondrial presequence receptor Tom20 in complexes with a presequence from aldehyde dehydrogenase

Igura M, Ose T, Obita T, Sato C, Maenaka K, Endo T, Kohda D

ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS Vol. 61 ( 5 ) page： 514-517 2005.5

Distal myopathy with rimmed vacuoles - Impaired O-glycan formation in muscular glycoproteins

Tajima Y, Uyama E, Go S, Sato C, Tao N, Kotani M, Hino H, Suzuki A, Sanai Y, Kitajima K, Sakuraba H

AMERICAN JOURNAL OF PATHOLOGY Vol. 166 ( 4 ) page： 1121-1130 2005.4

Distal myopathy with rimmed vacuoles - Impaired O-glycan formation in muscular glycoproteins Reviewed

Y Tajima, E Uyama, S Go, C Sato, N Tao, M Kotani, H Hino, A Suzuki, Y Sanai, K Kitajima, H Sakuraba

AMERICAN JOURNAL OF PATHOLOGY Vol. 166 ( 4 ) page： 1121 - 30 2005.4

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER SOC INVESTIGATIVE PATHOLOGY, INC

Distal myopathy with rimmed vacuoles (DMRV), is an autosomal recessive disorder with early adult onset, displays distal dominant muscular involvement and is characterized by the presence of numerous rimmed vacuoles in the affected muscle fibers. The pathophysiology of DMRV has not been clarified yet, although the responsible gene was identified as that encoding UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase involved in the biosynthesis of sialic acids. To identify defective carbohydrate moieties of muscular glycoproteins; from DMRV patients, frozen skeletal muscle sections from seven patients with DMRV, as well as normal and pathological controls, were treated with or without sialidase or N-glycosidase F followed by lectin staining and lectin blotting analysis. The sialic acid contents of the O-glycans in the skeletal muscle specimens from the DMRV patients were also measured. We found that Aracbis hypogaea agglutinin (PNA) lectin reacted strongly with sarcolemmal glycoproteins in the DMRV patients but not with those in control subjects. a-Dystroglycan from the DMRV patients strongly associated with PNA lectin, although that from controls did not. The sialic acid level of the O-glycans in the DMRV muscular glycoproteins with molecular weights of 30 to 200 kd was reduced to 60 to 80% of the control level. The results show that impaired sialyl O-glycan formation in muscular glycoproteins, including a-dystroglycan, occurs in DMRV.

DOI： 10.1016/S0002-9440(10)62332-2

Differentiation of noncancerous tissue and cancer lesions by apparent diffusion coefficient values in transition and peripheral zones of the prostate

Sato C, Naganawa S, Nakamura T, Kumada H, Miura S, Takizawa O, Ishigaki T

JOURNAL OF MAGNETIC RESONANCE IMAGING Vol. 21 ( 3 ) page： 258-262 2005.3

Development of a simple and efficient method for assaying cytidine monophosphate sialic acid synthetase activity using an enzymatic reduced nicotinamide adenine dinucleotide/oxidized nicotinamide adenine dinucleotide converting system Reviewed

A Fujita, C Sato, AK Munster-Kuhnel, R Gerardy-Schahn, K Kitajima

ANALYTICAL BIOCHEMISTRY Vol. 337 ( 1 ) page： 12 - 21 2005.2

Language：English Publishing type：Research paper (scientific journal) Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE

A new reliable method to assay the activity of cytidine monophosphate sialic acid (CMP-Sia) synthetase (CSS) has been developed. The activation of sialic acids (Sia) to CMP-Sia is a prerequisite for the de novo synthesis of sialoglycoconjugates. In vertebrates, CSS has been cloned from human, mouse, and rainbow trout, and the crystal structure has been resolved for the mouse enzyme. The mouse and rainbow trout enzyme have been compared with respect to substrate specificity, demonstrating that the mouse enzyme exhibits a pronounced specificity for N-acetylneuraminic acid (Neu5Ac), while the rainbow trout CSS is equally active with either of three Sia species, Neu5Ac, N-glycolylneuraminic acid (Neu5Gc), and deaminoncuraminic acid (KDN). However, molecular details that explain the pronounced substrate specificities are unknown. Understanding the catalytic mechanisms of these enzymes is of major importance, since CSSs play crucial roles in cellular sialylation patterns and thus are potential drug targets in a number of pathophysiological situations. The availability of the cDNAs and the obtained structural data enable rational approaches; however, these efforts are limited by the lack of a reliable high-throughput assay system. Here we describe a new assay system that allows product quantification in a reduced nicotinamide adenine dinucleotide (NADH)-dependent color reaction. The activation reaction catalyzed by CSS, CTP + Sia --> CMP-Sia + pyrophosphate, was evaluated by a consumption of Sia, which corresponds to that of NADH on the following two successive reactions: (i) Sia --> pyruvate + ManNAc (or Man), catalyzed by a sialic acid lyase (SAL), and (ii) pyruvate + NADH --> lactate + oxidized nicotinamide adenine dinucleotide (NAD+), catalyzed by a lactate dehydrogenase (LDH). Consumption of NADH can be photometrically monitored on a microtiter plate reader for a number of test samples at the same time. Furthermore, based on the quantification of CSS used in the SAL/LDH assay, relative activities toward Sia derivatives have been obtained. The preference of mouse CSS toward Neu5Ac and the ability of the rainbow trout enzyme to activate both KDN and Neu5Ac were confirmed. Thus, this simple and time-saving method is suitable for a systematic comparison of enzyme activity of structurally mutated enzymes based on the relative specific activity. (C) 2004 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.ab.2004.10.033