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Biomedical subjects

K Mizuno

Publications and source records attributed to K Mizuno.

At least 37 records · Page 2Linked to original sources

SAGE mRNA expression in advanced-stage lung cancers.

AIMS: SAGE and HAGE are recently isolated genes, which were thought to be expressed tumour-specifically, and are potentially coding for tumour-specific antigens recognized by T lymphocytes. The expression of these genes may serve as a useful diagnostic marker in detecting malignant disease. We report the correlation of SAGE and HAGE expression with clinicopathological features in patients with lung cancer who had undergone surgery. METHODS: Expression of SAGE and HAGE messenger RNA was evaluated by reverse transcription-polymerase chain reaction (RT-PCR) in 102 lung carcinomas and adjacent histological normal lung samples using LightCycler. RESULTS: SAGE/GAPDH mRNA expression was not significantly different between the tumour of lung cancer tissue (3.777+/-10.802) and normal lung tissue (3.028+/-3.356, p=0.7283). There was no relationship between SAGE gene expression and age, gender or N-status. SAGE/GAPDH expression was significantly higher in stage III-IV lung cancer (6.180+/-16.475) than in stage I lung cancer (1.534+/-2.591, p=0.0393). SAGE/GAPDH expression was also significantly higher in T4 lung cancer (9.183+/-23.117) than in T2 lung cancer (2.676+/-5.943, p=0.0362) and T1 lung cancer (2.373+/-3.433, p=0.0371). CONCLUSIONS: Detection for SAGE mRNA expression is possible in lung cancer samples. There was no relationship between HAGE gene expression and clinicopathological factor, such that the usefulness of detection for HAGE mRNA expression is limited for lung cancer.

Antigens, Neoplasm↗

Angioarrestin mRNA expression in early-stage lung cancers.

AIMS: Angioarrestin is a recently isolated gene, which has a novel function as an angiogenesis inhibitor. Angiogenesis plays an important role in tumorigenesis. It has been reported that the angioarrestin expression was decreased in lung cancer. We attempted to determine the influence of angioarrestin expression on clinicopathological features in patients with lung cancer who had undergone surgery. METHODS: Expression of angioarrestin messenger RNA was evaluated by a quantitative reverse transcription-polymerase chain reaction (RT-PCR) in 93 lung carcinomas and adjacent histological normal lung samples using LightCycler. RESULTS: Angioarrestin/GAPDH mRNA expression was significantly decreased in the tumor of lung cancer tissue (86.676+/-123.505) than in the normal lung tissue (1154.218+/-2003.508, p<0.0001), although only four lung cancer tissues had more than one tumor/normal ratio of angioarrestin/GAPDH mRNA expression. There was no relationship between angioarrestin gene expression and age, gender or T-status. However, decreased angioarrestin/GAPDH expression was especially seen at stage I lung cancer (54.156+/-62.783) when compared to stage II-IV lung cancer (110.315+/-151.359, p=0.0316). Decreased angioarrestin/GAPDH expression was especially seen at N0 lung cancer (56.396+/-69.941) when compared to N2 lung cancer (137.522+/-180.489, p=0.0362). CONCLUSIONS: The decreased expression of angioarrestin mRNA was the early phase phenomena for tumor progression from lung cancer. Alternatively, loss of antianiogenesis might play a role in oncogenesis for lung cancer.

Angiopoietin-Like Protein 1↗

Radical scavenging glycoprotein inhibiting cyclooxygenase-2 and thromboxane A2 synthase from aloe vera gel.

An active glycoprotein fraction containing 58 % protein was isolated from Aloe vera gel by precipitation with 55 % ammonium sulfate followed by gel permeation using DEAE-Sephacel A-25, Sepharose 6B and Sephadex G-50 columns in a yield of 3 x 10 -3 %. The glycoprotein fraction showed a single band corresponding to a subunit of verectin at the same position when stained with both Coomassie brilliant blue and periodic acid-Schiff reagents on 18 % SDS-PAGE. The molecular weight (14 kDa) was confirmed by Sephadex G-50 column chromatography. The glycoprotein fraction showed a radical scavenging activity against superoxide anion generated by the xanthine-xanthine oxidase system as well as inhibition of cyclooxygenase-2 and reduction of thromboxane A 2 synthase level in vitro.

Aloe↗

Feeding behaviour of infants with cleft lip and palate.

AIM: To determine whether the feeding behaviour of infants with cleft lip and palate is improved with a type-P teat, which is widely used in Japan by such infants, compared with a standard teat. The difference in intra-oral movements between the type-P teat, modified for the evaluation of feeding behaviour, and an unmodified type-P teat was also compared using ultrasonography. METHODS: In part 1 of the study, 15 infants aged 2 to 3 mo and 7 infants aged 2 wk were evaluated for sucking pressure, expression pressure, frequency and duration of sucking. All the infants had a complete unilateral cleft lip and palate without any other abnormalities. In part 2, an ultrasonographic analysis of intra-oral movement was done for 5 infants enrolled in part 1 of the study. RESULTS: Sucking pressure did not occur in all infants. It was found that feeding efficiency improved with the type-P teat compared with the standard teat. The expression pressure with the type-P teat was significantly higher than that with the standard teat, and the feeding frequency with the type-P teat was lower than that with the standard teat. CONCLUSION: A type-P teat is suitable for infants with cleft lip and palate who have sucking difficulties. However, a type-P nipple with a squeezable bottle does not fully solve the feeding problems of infants with cleft lip and palate. New artificial teats that allow a higher expression pressure are desirable, and the measurement of the expression pressure may be helpful in the evaluation of artificial nipples.

Cleft Lip↗

Lack of contact transmission of recombinant Marek's disease virus type 1 expressing the fusion protein of Newcastle disease virus.

To clarify the level of excretion of a recombinant Marek's disease virus type 1 (rMDV1) that confers good protection in chickens against both Marek's and Newcastle diseases, even in the presence of maternal antibodies, contact transmission tests were conducted. Naïve chickens kept in the same cage or room with chickens inoculated with rMDV1 did not produce antibodies against MDV1 or the fusion protein of Newcastle disease virus. Moreover, the rMDV1 was not isolated from the dander of chickens inoculated with rMDV1. Even under the stressful conditions of forced molting and a high temperature environment, rMDV1 was not isolated from the dander of inoculated birds. The viral DNA, however, was detected from the dander of chickens inoculated with rMDV1 as well as a commercial vaccine. These findings indicate that dander from chickens inoculated with rMDV1 includes viral DNA, but does not contain infectious virus.

Animals↗

Binding of 14-3-3beta regulates the kinase activity and subcellular localization of testicular protein kinase 1.

Testicular protein kinase 1 (TESK1) is a serine/threonine kinase that phosphorylates cofilin and induces actin cytoskeletal reorganization. The kinase activity of TESK1 is stimulated by integrin-mediated signaling pathways, but the mechanism of regulation has remained unknown. By using the yeast two-hybrid system, we identified 14-3-3beta to be the binding protein of TESK1. Specific interaction between TESK1 and 14-3-3beta became evident in in vitro and in vivo co-precipitation assays. 14-3-3beta interacts with TESK1 through the C-terminal region of TESK1 and in a manner dependent on the phosphorylation of Ser-439 within an RXXSXP motif. Binding of 14-3-3beta inhibited the kinase activity of TESK1. During cell spreading on fibronectin, the TESK1/14-3-3beta interaction significantly decreased, in a time course that inversely correlated with increase in TESK1 kinase activity. Thus, the dissociation of 14-3-3beta from a TESK1/14-3-3beta complex is likely to be involved in the integrin-mediated TESK1 activation. In HeLa cells, TESK1, together with 14-3-3beta, accumulated at the cell periphery when cells were plated on fibronectin, whereas they were diffusely distributed in the cytoplasm in the case of non-stimulated cells. We propose that 14-3-3beta plays important roles in regulating the kinase activity of TESK1 and localizing TESK1 to cell adhesion sites following integrin stimulation.

14-3-3 Proteins↗

Gas6 induces mesangial cell proliferation via latent transcription factor STAT3.

Mesangial cell proliferation is essential for the pathogenesis and progression of glomerular disease. Previously, we showed that Gas6 plays a pivotal role in mesangial cell proliferation in vitro and in vivo. In the present study, we identified downstream targets of Gas6 signaling to examine the role in mesangial cell proliferation in vitro and in vivo. We found that Gas6 tyrosine phosphorylates STAT3 (signal transducers and activators of transcription) with concomitant translocation to the nucleus and induces STAT3-dependent transcriptional activation in cultured mesangial cells. Expressing dominant negative STAT3 inhibited Gas6-mediated transcriptional activation of STAT3 and abolished Gas6-induced mesangial cell proliferation. In a model of mesangial proliferative glomerulonephritis, STAT3 is phosphorylated in mesangial cells, and its phosphorylation peaks at day 8 after the injection of anti-Thy1.1 antibody. Inhibition of Gas6 by warfarin and the extracellular domain of its receptor, Axl, abolished phosphorylation of STAT3 in vivo. Thus, our in vitro and in vivo findings indicate that autocrine growth factor Gas6 induces mesangial cell proliferation via latent transcription factor STAT3. Therefore, STAT3 might be a new therapeutic target for kidney disease induced by mesangial proliferation.

Animals↗

Cell-type-specific expression of a TESK1 promoter-linked lacZ gene in transgenic mice.

Testicular protein kinase 1 (TESK1) is a serine/threonine kinase highly expressed in testicular germ cells and has the potential to phosphorylate cofilin and induce actin cytoskeletal reorganization. We examined the expression of a lacZ reporter gene linked to a 9.0-kb 5'-flanking region of TESK1 gene in transgenic mice. A high level of lacZ expression was observed in testicular germ cells only at stages after pachytene spermatocytes, the expression patterns being similar to those of TESK1 mRNA in rat testis, determined by in situ hybridization. Expression of lacZ was also detected in renal proximal tubules, cardiac myocytes, and specific neurons in the central nervous system in adult transgenic mice. Whole-mount staining revealed the expression of lacZ in neural tissues in embryonic mice. These results suggest the cell-type- and stage-specific expression of TESK1 gene and the diverse and specific physiological functions of TESK1, including those in spermatogenesis and neural development.

Animals↗

Water-soluble and water-insoluble glucans produced by Escherichia coli recombinant dextransucrases from Leuconostoc mesenteroides NRRL B-512F.

Two dextransucrase genes, dsrS and dsrT5, from Leuconostoc mesenteroides NRRL B-512F were expressed in Escherichia coli, and recombinant dsrT5 dextransucrase was shown to produce a water-insoluble glucan. In contrast, native dextran from L. mesenteroides B-512F is water-soluble. The water-insoluble glucan was shown by 13C NMR and glycosyl-linkage composition analysis to contain about 50% 6-linked Glcp and 40% 3-linked Glcp. The 'primitive' B-512F strain is suggested to have produced water-insoluble glucan containing 3-linked Glcp. The glucans produced by dextransucrases expressed in E. coli contained 4-linked Glcp, as shown by glycosyl-linkage composition analysis. The amount of 4-linked Glcp was increased when the truncated, water-insoluble, glucan-producing dextransucrase, which does not have C-terminal repeating units, was added to the water-soluble, glucan-producing dextransucrase. Trace amounts of 4-linked Glcp were also detected in the dextran obtained from the B-512F culture supernatant, in dextran produced by dextransucrase purified from the B-512F strain culture supernatant, and in clinical dextran. The results of glycosyl-linkage composition analysis suggest that dextransucrases produce 4-linked Glcp as well as 6- and 3-linked Glcp.

Escherichia coli↗

Sacral radiculopathy secondary to multicentric osteosarcoma.

STUDY DESIGN: A case of multicentric osteosarcoma presenting with sacral radiculopathy is reported. OBJECTIVE: To present unusual clinical and radiologic findings of multicentric osteosarcoma. SUMMARY OF BACKGROUND DATA: Multicentric osteosarcoma is a rare variant of osteosarcoma. To the authors' knowledge, no cases of multicentric osteosarcoma presenting as sacral radiculopathy have been reported previously. METHODS: A 14-year-old boy had a large sacral tumor extending into the spinal canal, which was found to account for the initial symptoms, which mimicked those of herniated nucleus pulposus. At diagnosis, a bone survey showed multiple foci of osteosarcoma in the long bones. RESULTS: The patient was treated with chemotherapy, but died of the disease 8 months after the initial presentation. CONCLUSION: Multicentric osteosarcoma should be considered in the differential diagnosis for a pediatric patient with low back pain and sciatica.

Adolescent↗

Cofilin phosphorylation and actin reorganization activities of testicular protein kinase 2 and its predominant expression in testicular Sertoli cells.

We previously identified testicular protein kinase 1 (TESK1), which phosphorylates cofilin and induces actin cytoskeletal reorganization. We now report identification and characterization of another member of a TESK family, testicular protein kinase 2 (TESK2), with 48% amino acid identity with TESK1. Like TESK1, TESK2 phosphorylated cofilin specifically at Ser-3 and induced formation of actin stress fibers and focal adhesions. Both TESK1 and TESK2 are highly expressed in the testis, but in contrast to TESK1, which is predominantly expressed in testicular germ cells, TESK2 is expressed predominantly in nongerminal Sertoli cells. Thus, TESK1 and TESK2 seem to play distinct roles in spermatogenesis. In HeLa cells, TESK1 was localized mainly in the cytoplasm, whereas TESK2 was localized mainly in the nucleus, which means that TESK1 and TESK2 likely have distinct cellular functions. Because the kinase-inactive mutant of TESK2 was localized in the cytoplasm, nuclear/cytoplasmic localization of TESK2 depends on its kinase activity. A TESK2 mutant lacking the C-terminal noncatalytic region had about a 10-fold higher kinase activity in vitro and, when expressed in HeLa cells, induced punctate actin aggregates in the cytoplasm and unusual condensation and fragmentation of nuclei, followed by apoptosis. Thus, we propose that the C-terminal region plays important roles in regulating the kinase activity and cellular functions of TESK2.

Actin Depolymerizing Factors↗

The YXXQ motif in gp 130 is crucial for STAT3 phosphorylation at Ser727 through an H7-sensitive kinase pathway.

The signal transducer and activator of transcription (STAT) 3 is essential for mediating signals from the receptors for a variety of cytokines and growth factors, including IL-6 and EGF, and from cytoplasmic tyrosine kinases. Upon stimulation, STAT3 is phosphorylated at Ser727 and Tyr705. However, the role of phosphorylation at Ser727, and the kinase pathways responsible for this phosphorylation in IL-6 signaling remain obscure. Here we show that IL-6 activates at least two distinct STAT3 serine kinase pathways and that an H7-sensitive pathway is dominant over a PD98059-sensitive one in HepG2 cells stimulated with a low concentration of IL-6. The analysis, using a series of chimeric receptors containing the extracellular domain of the G-CSF receptor, the truncated form of gp 130, and additional short peptides at the gp 130 carboxy-terminus, showed that the YXXQ motif of gp 130 was sufficient for the H7-sensitive STAT3 Ser727 phosphorylation. This YXXQ-mediated pathway does not involve Erk, p38, JNK, or PKCdelta, and requires a site in the region from 533 to 711 of STAT3 for phosphorylation in vivo. Moreover, we show that Ser727 is required for full transcriptional activity of STAT3 for two different response elements. Thus, the YXXQ motif regulates STAT3 activities in two ways in response to even a low concentration of IL-6: it recruits STAT3 to the receptor for tyrosine phosphorylation, and activates an unidentified H7-sensitive pathway leading to the serine phosphorylation of STAT3.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

Photoallylation and photoreduction of cyclohexylidenepropanedinitrile by use of allyltrimethylsilane via photoinduced electron transfer: control of the product ratio depending on pK(a) values of additives.

Irradiation of an acetonitrile solution containing cyclohexylidenepropanedinitrile (1) and allyltrimethylsilane (2) in the presence of phenanthrene afforded two kinds of allylated products (3, 4) and a reduction product (5). The product ratio of 3, 4, and 5 dramatically changed depending on the pK(a) values of additives.

Journal Article↗

Prevention of hepatitis C virus infection in a chimpanzee by vaccination and epitope mapping of antiserum directed against hypervariable region 1.

We previously reported on a chimpanzee immunized with both putative envelope glycoproteins (E1 and E2) of hepatitis C virus (HCV), strain HCV-N2, and synthetic peptides of hypervariable region 1 (HVR1) of a different isolate, HCV-#6. The chimpanzee showed complete protection against HCV-#6 infection only when the titer of anti-HVR1 increased, suggesting that an immune response to the HVR1 is more essential in protecting a chimpanzee from HCV infection than an immune response to E1 and E2. In this study, we immunized this chimpanzee with only synthetic HVR1 peptides after anti-E1 and anti-E2 antibody levels dropped and then rechallenged with 10 infectious chimpanzee doses of HCV. The immunized animal was protected, and neutralization of HCV with the antiserum from the protected animal was achieved by inoculating another chimpanzee with HCV preneutralized by this antiserum mixture. Epitope analysis of HVR1 by Pin-ELISA using this antiserum seemed to demonstrate that the antibody response was directed mainly against the C terminus of HVR1. Moreover, our results showed that, if a part of the sequences was conserved, a broad cross-reactivity of the antiserum could be observed, even if amino-acid sequences in this epitope were substituted for those of other HCV strains.

Journal Article↗

Atypical protein kinase C is involved in the evolutionarily conserved par protein complex and plays a critical role in establishing epithelia-specific junctional structures.

We have previously shown that during early Caenorhabditis elegans embryogenesis PKC-3, a C. elegans atypical PKC (aPKC), plays critical roles in the establishment of cell polarity required for subsequent asymmetric cleavage by interacting with PAR-3 [Tabuse, Y., Y. Izumi, F. Piano, K.J. Kemphues, J. Miwa, and S. Ohno. 1998. Development (Camb.). 125:3607--3614]. Together with the fact that aPKC and a mammalian PAR-3 homologue, aPKC-specific interacting protein (ASIP), colocalize at the tight junctions of polarized epithelial cells (Izumi, Y., H. Hirose, Y. Tamai, S.-I. Hirai, Y. Nagashima, T. Fujimoto, Y. Tabuse, K.J. Kemphues, and S. Ohno. 1998. J. Cell Biol. 143:95--106), this suggests a ubiquitous role for aPKC in establishing cell polarity in multicellular organisms. Here, we show that the overexpression of a dominant-negative mutant of aPKC (aPKCkn) in MDCK II cells causes mislocalization of ASIP/PAR-3. Immunocytochemical analyses, as well as measurements of paracellular diffusion of ions or nonionic solutes, demonstrate that the biogenesis of the tight junction structure itself is severely affected in aPKCkn-expressing cells. Furthermore, these cells show increased interdomain diffusion of fluorescent lipid and disruption of the polarized distribution of Na(+),K(+)-ATPase, suggesting that epithelial cell surface polarity is severely impaired in these cells. On the other hand, we also found that aPKC associates not only with ASIP/PAR-3, but also with a mammalian homologue of C. elegans PAR-6 (mPAR-6), and thereby mediates the formation of an aPKC-ASIP/PAR-3-PAR-6 ternary complex that localizes to the apical junctional region of MDCK cells. These results indicate that aPKC is involved in the evolutionarily conserved PAR protein complex, and plays critical roles in the development of the junctional structures and apico-basal polarization of mammalian epithelial cells.

Actins↗