Shinya Satoh - Academia.edu (original) (raw)
Papers by Shinya Satoh
Hepatitis C virus proteins are produced by proteolytic processing of the viral precursor polyprot... more Hepatitis C virus proteins are produced by proteolytic processing of the viral precursor polyprotein that is encoded in the largest open reading frame of the viral genome. Processing of the nonstructural viral polypro- tein requires the viral serine-type proteinase present in nonstructural protein 3 (NS3). The cleavage of the junction between NS4B and NS5A is mediated by NS3 only when
Nippon Jibiinkoka Gakkai Kaiho, 2013
Neurochemistry International, 2010
Proceedings of the National Academy of Sciences of the United States of America, Sep 20, 2005
Angiopoietin-like protein (Angptl) 1 and Angptl2, which are considered orphan ligands, are highly... more Angiopoietin-like protein (Angptl) 1 and Angptl2, which are considered orphan ligands, are highly homologous, particularly in the fibrinogen-like domain containing the putative receptor binding site. This similarity suggests potentially cooperative functions between the two proteins. In this report, the function of Angptl1 and Angptl2 is analyzed by using morpholino antisense technology in zebrafish. Knockdown of both Angptl1 and Angptl2 produced severe vascular defects due to increased apoptosis of endothelial cells at the sprouting stage. In vitro studies showed that Angptl1 and Angptl2 have antiapoptotic activities through the phosphatidylinositol 3-kinase/Akt pathway, and coinjection of constitutively active Akt/protein kinase B mRNA rescued impaired vascular development seen in double knockdown embryos. These results provide a physiological demonstration of the cooperative interaction of Angptl1 and Angptl2 in endothelial cells through phosphatidylinositol 3-kinase/Akt mediated antiapoptotic activities.
Journal of Basic and Clinical Medicine, Aug 1, 2014
Molecular Vision, Feb 1, 2008
Folia Pharmacologica Japonica
PLoS ONE, 2014
The most distinguishing genetic feature of hepatitis C virus (HCV) is its remarkable diversity an... more The most distinguishing genetic feature of hepatitis C virus (HCV) is its remarkable diversity and variation. To understand this feature, we previously performed genetic analysis of HCV in the long-term culture of human hepatoma HuH-7-derived HCV RNA-replicating cell lines. On the other hand, we newly established HCV RNA-replicating cell lines using human hepatoma Li23 cells, which were distinct from HuH-7 cells. Li23-derived HCV RNA-replicating cells were cultured for 4 years. We performed genetic analysis of HCVs recovered from these cells at 0, 2, and 4 years in culture. Most analysis was performed in two separate parts: one part covered from the 5'-terminus to NS2, which is mostly nonessential for RNA replication, and the other part covered from NS3 to NS5B, which is essential for RNA replication. Genetic mutations in both regions accumulated in a time-dependent manner, and the mutation rates in the 5'-terminus-NS2 and NS3-NS5B regions were 4.0-9.0×10(-3) and 2.7-4.0×10(-3) base substitutions/site/year, respectively. These results suggest that the variation in the NS3-NS5B regions is affected by the pressure of RNA replication. Several in-frame deletions (3-105 nucleotides) were detected in the structural regions of HCV RNAs obtained from 2-year or 4-year cultured cells. Phylogenetic tree analyses clearly showed that the genetic diversity of HCV was expanded in a time-dependent manner. The GC content of HCV RNA was significantly increased in a time-dependent manner, as previously observed in HuH-7-derived cell systems. This phenomenon was partially due to the alterations in codon usages for codon optimization in human cells. Furthermore, we demonstrated that these long-term cultured cells were useful as a source for the selection of HCV clones showing resistance to anti-HCV agents. Long-term cultured HCV RNA-replicating cells are useful for the analysis of evolutionary dynamics and variations of HCV and for drug-resistance analysis.
PloS one, 2015
Ribavirin (RBV) is a potential partner of interferon-based therapy and recently approved therapy ... more Ribavirin (RBV) is a potential partner of interferon-based therapy and recently approved therapy using direct acting antivirals for patients with chronic hepatitis C. However, the precise mechanisms underlying RBV action against hepatitis C virus (HCV) replication are not yet understood. To clarify this point, we attempted to develop RBV-resistant cells from RBV-sensitive HCV RNA-replicating cells. By repetitive RBV (100 μM) treatment (10 weeks) of 3.5-year-cultured OL8 cells, in which genome-length HCV RNA (O strain of genotype 1b) efficiently replicates, dozens of colonies that survived RBV treatment were obtained. These colonies were mixed together and further treated with high doses of RBV (up to 200 μM). By such RBV treatment, we successfully established 12 RBV-survived genome-length HCV RNA-replicating cell lines. Among them, three representative cell lines were characterized. HCV RNA replication in these cells resisted RBV significantly more than that in the parental OL8 cell...
Developmental neurobiology, Jan 30, 2014
The histone modification H3K27me3 regulates transcription negatively, and Jmjd3 and Ezh2 demethyl... more The histone modification H3K27me3 regulates transcription negatively, and Jmjd3 and Ezh2 demethylate and methylate H3K27me3 and H3K27, respectively. We demonstrated previously that Jmjd3 plays pivotal roles in the differentiation of subsets of bipolar (BP) cells by regulating H3K27me3 levels at the Bhlhb4 and Vsx1 loci, both of which are transcription factors essential for the maturation of BP cell subsets. In this study, we examined the role of Ezh2 in retinal development using retina-specific Ezh2 conditional knockout mice (Ezh2-CKO). The eyes of the Ezh2-CKO mice were microphthalemic, and the proliferation of retinal cells was diminished postnatally in Ezh2-CKO. Differentiation of all examined retinal subsets was observed with higher proportion of BP cell subsets, which was determined by immunostaining using specific retinal markers. The onsets of Müller glia and rod photoreceptor differentiation were accelerated. The expression of Bhlhb4 was increased in postnatal retinas, which...
Nihon Jibiinkoka Gakkai kaiho, 2013
The right nonrecurrent inferior laryngeal nerve (NRILN), which is usually associated with the rig... more The right nonrecurrent inferior laryngeal nerve (NRILN), which is usually associated with the right aberrant subclavian artery, is a risk factor of nerve injury during thyroid surgery. Therefore the presence of the NRILN should be diagnosed if possible before surgery. The aim of this study was to investigate the usefulness of computed tomography (CT) and ultrasonography (US) for preoperative diagnosis of the right-sided NRILN. We reviewed 1,561 patients who underwent thyroid surgery, during which the right inferior laryngeal nerve was exposed, at Yamashita thyroid and parathyroid clinic from April 2006 to April 2012. All medical records, CT findings and ultrasonograms of these patients were reviewed retrospectively. We recognized 11 patients who had the right-sided NRILN from the total of 1561 patients (0.71%). Ten of 1086 patients who underwent CT, had a right aberrant subclavian artery. CT findings were enabled us to predict the existence of the right NRILN before surgery. The sen...
Molecular vision, 2008
Glycoprotein m6a (M6a) is a cell-surface glycoprotein that belongs to the myelin proteolipid prot... more Glycoprotein m6a (M6a) is a cell-surface glycoprotein that belongs to the myelin proteolipid protein family. M6a is expressed mainly in the nervous system, and its expression and function in mammalian retina have not been described. Using proteomics analysis of mouse retinal membrane fractions, we identified M6a as a retinal membrane protein that is strongly expressed at embryonic stages. Our aim was to reveal the function of M6a in development of mouse retina in this work. Detailed expression pattern of M6a was examined by immunostaining using frozen sections of mouse retina obtained at various developmental stages. For functional analysis of M6a in mouse retinal development, we performed retorovirus-mediated overexpression of M6a in mouse retinal explant culture. Then, cell differentiation, proliferation and structural maturation of the cells were examined. M6a transcripts were strongly expressed in embryonic retina. After completion of retinal differentiation, the level of expres...
International journal of oncology, 2000
Aneuploidy and hyperploidy are often detected in malignant melanoma by cytogenetic analysis and f... more Aneuploidy and hyperploidy are often detected in malignant melanoma by cytogenetic analysis and flow cytometric analysis of DNA content. To determine the ploidy of cells in surgical specimens of melanin-producing tumors of Japanese patients, we performed fluorescence in situ hybridization (FISH) using touch smear technique to count the number of chromosomes 18 and X + Y in interphase nuclei using alpha-satellite DNA probes, D18Z1, DXZ1 and DYZ3. A normal melanocyte strain showed two D18Z1 and two [DXZ1+DYZ3] signals per nucleus, indicating 2N, and a malignant melanoma cell line showed 4 per nucleus, indicating 4N, consistent with results of cytogenetic and flow cytometric analyses. Therefore we employed this FISH method to analyze ploidy of surgical specimens. Specimens obtained from 8 patients with nevus cell nevus showed 2 FISH signals per nucleus. On the other hand, in all specimens obtained from 8 patients with malignant melanoma (6 primary and 2 metastatic melanoma), 65-90% of ...
Journal of virology, 1995
A transient protein expression system in COS-1 cells was used to study the role of hepatitis C vi... more A transient protein expression system in COS-1 cells was used to study the role of hepatitis C virus (HCV)-encoded NS4A protein on HCV nonstructural polyprotein processing. By analyzing the protein expression and processing of a deletion mutant polypeptide, NS delta 4A, which encodes the entire putative HCV nonstructural polyprotein except the region encoding NS4A, the versatile functions of NS4A were revealed. Most of the NS3 processed from NS delta 4A was localized in the cytosol fraction and was degraded promptly. Coproduction of NS4A stabilizes NS3 and assists in its localization in the membrane. NS4A was found to be indispensable for cleavage at the 4B/5A site but not essential for cleavage at the 5A/5B site in NS delta 4A. The functioning of NS4A as a cofactor for cleavage at the 4B/5A site was also observed when 30 amino acids around this site was used as a substrate and a serine proteinase domain of 167 amino acids, from Gly-1049 to Ser-1215, was used as an enzyme protein, s...
Journal of virology, 1995
Two proteins, a 56-kDa protein (p56) and a 58-kDa protein (p58), are produced from the hepatitis ... more Two proteins, a 56-kDa protein (p56) and a 58-kDa protein (p58), are produced from the hepatitis C virus (HCV) nonstructural region 5A (NS5A). Recently, we found that both proteins are phosphorylated at serine residues and that p58 is a hyperphosphorylated form of p56. Furthermore, hyper-phosphorylation depends on the production of an intact form of the HCV NS4A protein. To clarify the nature of NS5A phosphorylation, pulse-chase analysis was performed with a transient protein production system in cultured cells. The study indicated that basal and hyperphosphorylation of NS5A occurred after proteolytic production of NS5A was complete. In an attempt to identify the location of the hyperphosphorylation sites in p58, proteins with sequential deletions from the C-terminal region of NS5A and with mutations of possible phosphorylated serine residues to a neutral amino acid, alanine, were constructed. The deleted or mutated proteins were then tested for hyperphosphorylation in the presence ...
Journal of virology, 1996
In addition to NS3 protease, the NS4A protein is required for efficient cleavage of the nonstruct... more In addition to NS3 protease, the NS4A protein is required for efficient cleavage of the nonstructural protein region of the hepatitis C virus polyprotein. To investigate the function and the sequence of NS4A required for the enhancement of NS3 protease activity, we developed an in vitro NS3 protease assay system consisting of three purified viral elements: (i) a recombinant NS3 protease which was expressed in Escherichia coli as a maltose-binding protein-NS3 fusion protein (MBP-NS3), (ii) synthetic NS4A fragments, and (iii) a synthetic peptide substrate which mimics the NS5A/5B junction. We showed that the NS3 protease activity of MBP-NS3 was enhanced in a dose-dependent manner by 4A18-40, which is a peptide composed of amino acid residues 18 to 40 of NS4A. The optimal activity was observed at a 10-fold molar excess of 4A18-40 over MBP-NS3. The coefficient for proteolytic efficiency, kcat/Km, of NS3 protease was increased by about 40 times by the addition of a 10-fold molar excess o...
Hepatitis C virus proteins are produced by proteolytic processing of the viral precursor polyprot... more Hepatitis C virus proteins are produced by proteolytic processing of the viral precursor polyprotein that is encoded in the largest open reading frame of the viral genome. Processing of the nonstructural viral polypro- tein requires the viral serine-type proteinase present in nonstructural protein 3 (NS3). The cleavage of the junction between NS4B and NS5A is mediated by NS3 only when
Nippon Jibiinkoka Gakkai Kaiho, 2013
Neurochemistry International, 2010
Proceedings of the National Academy of Sciences of the United States of America, Sep 20, 2005
Angiopoietin-like protein (Angptl) 1 and Angptl2, which are considered orphan ligands, are highly... more Angiopoietin-like protein (Angptl) 1 and Angptl2, which are considered orphan ligands, are highly homologous, particularly in the fibrinogen-like domain containing the putative receptor binding site. This similarity suggests potentially cooperative functions between the two proteins. In this report, the function of Angptl1 and Angptl2 is analyzed by using morpholino antisense technology in zebrafish. Knockdown of both Angptl1 and Angptl2 produced severe vascular defects due to increased apoptosis of endothelial cells at the sprouting stage. In vitro studies showed that Angptl1 and Angptl2 have antiapoptotic activities through the phosphatidylinositol 3-kinase/Akt pathway, and coinjection of constitutively active Akt/protein kinase B mRNA rescued impaired vascular development seen in double knockdown embryos. These results provide a physiological demonstration of the cooperative interaction of Angptl1 and Angptl2 in endothelial cells through phosphatidylinositol 3-kinase/Akt mediated antiapoptotic activities.
Journal of Basic and Clinical Medicine, Aug 1, 2014
Molecular Vision, Feb 1, 2008
Folia Pharmacologica Japonica
PLoS ONE, 2014
The most distinguishing genetic feature of hepatitis C virus (HCV) is its remarkable diversity an... more The most distinguishing genetic feature of hepatitis C virus (HCV) is its remarkable diversity and variation. To understand this feature, we previously performed genetic analysis of HCV in the long-term culture of human hepatoma HuH-7-derived HCV RNA-replicating cell lines. On the other hand, we newly established HCV RNA-replicating cell lines using human hepatoma Li23 cells, which were distinct from HuH-7 cells. Li23-derived HCV RNA-replicating cells were cultured for 4 years. We performed genetic analysis of HCVs recovered from these cells at 0, 2, and 4 years in culture. Most analysis was performed in two separate parts: one part covered from the 5'-terminus to NS2, which is mostly nonessential for RNA replication, and the other part covered from NS3 to NS5B, which is essential for RNA replication. Genetic mutations in both regions accumulated in a time-dependent manner, and the mutation rates in the 5'-terminus-NS2 and NS3-NS5B regions were 4.0-9.0×10(-3) and 2.7-4.0×10(-3) base substitutions/site/year, respectively. These results suggest that the variation in the NS3-NS5B regions is affected by the pressure of RNA replication. Several in-frame deletions (3-105 nucleotides) were detected in the structural regions of HCV RNAs obtained from 2-year or 4-year cultured cells. Phylogenetic tree analyses clearly showed that the genetic diversity of HCV was expanded in a time-dependent manner. The GC content of HCV RNA was significantly increased in a time-dependent manner, as previously observed in HuH-7-derived cell systems. This phenomenon was partially due to the alterations in codon usages for codon optimization in human cells. Furthermore, we demonstrated that these long-term cultured cells were useful as a source for the selection of HCV clones showing resistance to anti-HCV agents. Long-term cultured HCV RNA-replicating cells are useful for the analysis of evolutionary dynamics and variations of HCV and for drug-resistance analysis.
PloS one, 2015
Ribavirin (RBV) is a potential partner of interferon-based therapy and recently approved therapy ... more Ribavirin (RBV) is a potential partner of interferon-based therapy and recently approved therapy using direct acting antivirals for patients with chronic hepatitis C. However, the precise mechanisms underlying RBV action against hepatitis C virus (HCV) replication are not yet understood. To clarify this point, we attempted to develop RBV-resistant cells from RBV-sensitive HCV RNA-replicating cells. By repetitive RBV (100 μM) treatment (10 weeks) of 3.5-year-cultured OL8 cells, in which genome-length HCV RNA (O strain of genotype 1b) efficiently replicates, dozens of colonies that survived RBV treatment were obtained. These colonies were mixed together and further treated with high doses of RBV (up to 200 μM). By such RBV treatment, we successfully established 12 RBV-survived genome-length HCV RNA-replicating cell lines. Among them, three representative cell lines were characterized. HCV RNA replication in these cells resisted RBV significantly more than that in the parental OL8 cell...
Developmental neurobiology, Jan 30, 2014
The histone modification H3K27me3 regulates transcription negatively, and Jmjd3 and Ezh2 demethyl... more The histone modification H3K27me3 regulates transcription negatively, and Jmjd3 and Ezh2 demethylate and methylate H3K27me3 and H3K27, respectively. We demonstrated previously that Jmjd3 plays pivotal roles in the differentiation of subsets of bipolar (BP) cells by regulating H3K27me3 levels at the Bhlhb4 and Vsx1 loci, both of which are transcription factors essential for the maturation of BP cell subsets. In this study, we examined the role of Ezh2 in retinal development using retina-specific Ezh2 conditional knockout mice (Ezh2-CKO). The eyes of the Ezh2-CKO mice were microphthalemic, and the proliferation of retinal cells was diminished postnatally in Ezh2-CKO. Differentiation of all examined retinal subsets was observed with higher proportion of BP cell subsets, which was determined by immunostaining using specific retinal markers. The onsets of Müller glia and rod photoreceptor differentiation were accelerated. The expression of Bhlhb4 was increased in postnatal retinas, which...
Nihon Jibiinkoka Gakkai kaiho, 2013
The right nonrecurrent inferior laryngeal nerve (NRILN), which is usually associated with the rig... more The right nonrecurrent inferior laryngeal nerve (NRILN), which is usually associated with the right aberrant subclavian artery, is a risk factor of nerve injury during thyroid surgery. Therefore the presence of the NRILN should be diagnosed if possible before surgery. The aim of this study was to investigate the usefulness of computed tomography (CT) and ultrasonography (US) for preoperative diagnosis of the right-sided NRILN. We reviewed 1,561 patients who underwent thyroid surgery, during which the right inferior laryngeal nerve was exposed, at Yamashita thyroid and parathyroid clinic from April 2006 to April 2012. All medical records, CT findings and ultrasonograms of these patients were reviewed retrospectively. We recognized 11 patients who had the right-sided NRILN from the total of 1561 patients (0.71%). Ten of 1086 patients who underwent CT, had a right aberrant subclavian artery. CT findings were enabled us to predict the existence of the right NRILN before surgery. The sen...
Molecular vision, 2008
Glycoprotein m6a (M6a) is a cell-surface glycoprotein that belongs to the myelin proteolipid prot... more Glycoprotein m6a (M6a) is a cell-surface glycoprotein that belongs to the myelin proteolipid protein family. M6a is expressed mainly in the nervous system, and its expression and function in mammalian retina have not been described. Using proteomics analysis of mouse retinal membrane fractions, we identified M6a as a retinal membrane protein that is strongly expressed at embryonic stages. Our aim was to reveal the function of M6a in development of mouse retina in this work. Detailed expression pattern of M6a was examined by immunostaining using frozen sections of mouse retina obtained at various developmental stages. For functional analysis of M6a in mouse retinal development, we performed retorovirus-mediated overexpression of M6a in mouse retinal explant culture. Then, cell differentiation, proliferation and structural maturation of the cells were examined. M6a transcripts were strongly expressed in embryonic retina. After completion of retinal differentiation, the level of expres...
International journal of oncology, 2000
Aneuploidy and hyperploidy are often detected in malignant melanoma by cytogenetic analysis and f... more Aneuploidy and hyperploidy are often detected in malignant melanoma by cytogenetic analysis and flow cytometric analysis of DNA content. To determine the ploidy of cells in surgical specimens of melanin-producing tumors of Japanese patients, we performed fluorescence in situ hybridization (FISH) using touch smear technique to count the number of chromosomes 18 and X + Y in interphase nuclei using alpha-satellite DNA probes, D18Z1, DXZ1 and DYZ3. A normal melanocyte strain showed two D18Z1 and two [DXZ1+DYZ3] signals per nucleus, indicating 2N, and a malignant melanoma cell line showed 4 per nucleus, indicating 4N, consistent with results of cytogenetic and flow cytometric analyses. Therefore we employed this FISH method to analyze ploidy of surgical specimens. Specimens obtained from 8 patients with nevus cell nevus showed 2 FISH signals per nucleus. On the other hand, in all specimens obtained from 8 patients with malignant melanoma (6 primary and 2 metastatic melanoma), 65-90% of ...
Journal of virology, 1995
A transient protein expression system in COS-1 cells was used to study the role of hepatitis C vi... more A transient protein expression system in COS-1 cells was used to study the role of hepatitis C virus (HCV)-encoded NS4A protein on HCV nonstructural polyprotein processing. By analyzing the protein expression and processing of a deletion mutant polypeptide, NS delta 4A, which encodes the entire putative HCV nonstructural polyprotein except the region encoding NS4A, the versatile functions of NS4A were revealed. Most of the NS3 processed from NS delta 4A was localized in the cytosol fraction and was degraded promptly. Coproduction of NS4A stabilizes NS3 and assists in its localization in the membrane. NS4A was found to be indispensable for cleavage at the 4B/5A site but not essential for cleavage at the 5A/5B site in NS delta 4A. The functioning of NS4A as a cofactor for cleavage at the 4B/5A site was also observed when 30 amino acids around this site was used as a substrate and a serine proteinase domain of 167 amino acids, from Gly-1049 to Ser-1215, was used as an enzyme protein, s...
Journal of virology, 1995
Two proteins, a 56-kDa protein (p56) and a 58-kDa protein (p58), are produced from the hepatitis ... more Two proteins, a 56-kDa protein (p56) and a 58-kDa protein (p58), are produced from the hepatitis C virus (HCV) nonstructural region 5A (NS5A). Recently, we found that both proteins are phosphorylated at serine residues and that p58 is a hyperphosphorylated form of p56. Furthermore, hyper-phosphorylation depends on the production of an intact form of the HCV NS4A protein. To clarify the nature of NS5A phosphorylation, pulse-chase analysis was performed with a transient protein production system in cultured cells. The study indicated that basal and hyperphosphorylation of NS5A occurred after proteolytic production of NS5A was complete. In an attempt to identify the location of the hyperphosphorylation sites in p58, proteins with sequential deletions from the C-terminal region of NS5A and with mutations of possible phosphorylated serine residues to a neutral amino acid, alanine, were constructed. The deleted or mutated proteins were then tested for hyperphosphorylation in the presence ...
Journal of virology, 1996
In addition to NS3 protease, the NS4A protein is required for efficient cleavage of the nonstruct... more In addition to NS3 protease, the NS4A protein is required for efficient cleavage of the nonstructural protein region of the hepatitis C virus polyprotein. To investigate the function and the sequence of NS4A required for the enhancement of NS3 protease activity, we developed an in vitro NS3 protease assay system consisting of three purified viral elements: (i) a recombinant NS3 protease which was expressed in Escherichia coli as a maltose-binding protein-NS3 fusion protein (MBP-NS3), (ii) synthetic NS4A fragments, and (iii) a synthetic peptide substrate which mimics the NS5A/5B junction. We showed that the NS3 protease activity of MBP-NS3 was enhanced in a dose-dependent manner by 4A18-40, which is a peptide composed of amino acid residues 18 to 40 of NS4A. The optimal activity was observed at a 10-fold molar excess of 4A18-40 over MBP-NS3. The coefficient for proteolytic efficiency, kcat/Km, of NS3 protease was increased by about 40 times by the addition of a 10-fold molar excess o...