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Biomedical subjects

E Wakabayashi

Publications and source records attributed to E Wakabayashi.

15 recordsLinked to original sources
PubMed2000

Formation of sarcoglycan complex with differentiation in cultured myocytes.

The sarcoglycan complex consists of four transmembrane protein subunits. Mutation of any one of the genes encoding these four subunits causes complete loss or marked decrease in expression of the whole complex, resulting in the phenotype of Duchenne-like autosomal recessive muscular dystrophy, termed sarcoglycanopathy. As the basis for understanding this process, we examined how the sarcoglycan complex is formed and associates with other proteins during myogenic differentiation, using a myogenic cell line. Accumulation of the sarcoglycan subunits and formation of the sarcoglycan complex were accomplished with myotube formation. In protein transport inhibition experiments with blefeldin A, we found that the sarcoglycan complex is formed in the endoplasmic reticulum and then associates with the dystroglycan complex and sarcospan en route from the Golgi apparatus to the cell surface. In early myotubes, limited kinds of incomplete sarcoglycan complexes were observed. Their analyses would provide information on the possible patterns of formation of the sarcoglycan complex.

Animals↗
PubMed1999

The human cytomegalovirus chemokine receptor US28 mediates vascular smooth muscle cell migration.

Human cytomegalovirus (HCMV) infection of smooth muscle cells (SMCs) in vivo has been linked to a viral etiology of vascular disease. In this report, we demonstrate that HCMV infection of primary arterial SMCs results in significant cellular migration. Ablation of the chemokine receptor, US28, abrogates SMC migration, which is rescued only by expression of the viral homolog and not a cellular G protein-coupled receptor (GPCR). Expression of US28 in the presence of CC chemokines including RANTES or MCP-1 was sufficient to promote SMC migration by both chemokinesis and chemotaxis, which was inhibited by protein tyrosine kinase inhibitors. US28-mediated SMC migration provides a molecular basis for the correlative evidence that links HCMV to the acceleration of vascular disease.

Blood Vessels↗
PubMed1999

Developmental expression of sarcoglycan gene products in cultured myocytes.

The sarcoglycan complex consists of four membrane-spanning proteins and was shown to be exclusively distributed in striated muscles. In this study, we analyzed the pattern of expression of the mRNAs and proteins of the sarcoglycan subunits during cell differentiation in a culture of myocytes. All four sarcoglycan mRNAs were detectable in proliferating cells, and expression of the alpha- and gamma-subunits was up-regulated by 20- and 50-fold following muscle cell fusion. However, sarcoglycan proteins were scarcely detectable in proliferating cells and were first detected 2 days after the induction to be differentiated. The accumulation of the sarcoglycan protein subunits was accompanied by cell differentiation. The discrepancy between the expression of the mRNAs and proteins of the sarcoglycan subunits in proliferating cells may be ascribed to rapid degradation of the protein.

Animals↗
PubMed1999

Loss of the sarcoglycan complex and sarcospan leads to muscular dystrophy in beta-sarcoglycan-deficient mice.

beta-Sarcoglycan, one of the subunits of the sarcoglycan complex, is a transmembranous glycoprotein which associates with dystrophin and is the molecule responsible for beta-sarcoglycanopathy, a Duchenne-like autosomal recessive muscular dystrophy. To develop an animal model of beta-sarcoglycanopathy and to clarify the role of beta-sarcoglycan in the pathogenesis of the muscle degeneration in vivo, we developed beta-sarcoglycan-deficient mice using a gene targeting technique. beta-Sarcoglycan-deficient mice (BSG(-)(/-)mice) exhibited progressive muscular dystrophy with extensive degeneration and regeneration. The BSG(-)(/-)mice also exhibited muscular hypertrophy characteristic of beta-sarcoglycanopathy. Immunohistochemical and immunoblot analyses of BSG(-)(/-)mice demonstrated that deficiency of beta-sarcoglycan also caused loss of all of the other sarcoglycans as well as of sarcospan in the sarcolemma. On the other hand, laminin-alpha2, alpha- and beta-dystroglycan and dystrophin were still present in the sarcolemma. However, the dystrophin-dystroglycan complex in BSG(-)(/-)mice was unstable compared with that in the wild-type mice. Our data suggest that loss of the sarcoglycan complex and sarcospan alone is sufficient to cause muscular dystrophy, that beta-sarcoglycan is an important protein for formation of the sarcoglycan complex associated with sarcospan and that the role of the sarcoglycan complex and sarcospan may be to strengthen the dystrophin axis connecting the basement membrane with the cytoskeleton.

Animals↗
PubMed1998

Evidence of latency and reactivation of both herpes simplex virus (HSV)-1 and HSV-2 in the genital region.

While superinfection with different herpes simplex virus (HSV) types has been demonstrated in animals, the ability of the two HSV types to colonize and reactivate in the same anatomic region in humans has not been well demonstrated. In 6 patients, both HSV-1 and HSV-2 was recovered from genital lesions. In 4 of them, who initially acquired genital HSV-1 infection, subsequent HSV-2 infection presented as a prolonged episode of genital lesions and a marked increase in the frequency of genital recurrences. While most of the subsequent clinical reactivations were HSV-2, in 2 patients the recurrence rate of genital HSV-1 increased after the acquisition of HSV-2. These data demonstrate the ability of a second HSV type to infect the same anatomic region and illustrate the difference in reactivation frequency of the two types in the same person. Typing of HSV isolates may be useful in persons with recent alteration in recurrence rates of genital HSV.

Adult↗
PubMed1997

The fourth component of the sarcoglycan complex.

We found a novel dystrophin-associated protein (DAP) exhibiting almost the same mobility as gamma-sarcoglycan on SDS-PAGE. This novel DAP with basic charge is separated from gamma-sarcoglycan by 2-dimensional PAGE or de-N-glycosylation followed by SDS-PAGE. This DAP is most likely the rabbit homologue of "delta-sarcoglycan", the gamma-sarcoglycan-like protein identified previously [Nigro et al. (1996) Hum. Mol. Genet. 5, 1179-1186], since an internal amino acid sequence from the DAP matched the predicted amino acid sequence of "human delta-sarcoglycan" within the limits of species difference and this DAP was recognized by anti-"delta-sarcoglycan" antibody. The DAP was found to be contained in the sarcoglycan fraction which was prepared by treatment of the dystrophin-DAP complex with n-octyl beta-D-glucoside and crosslinked with beta- and/or gamma-sarcoglycan by a chemical crosslinker, dithiobis(succinimidyl propionate). Therefore, we concluded that the DAP is the fourth component of the sarcoglycan complex.

Amino Acid Sequence↗
PubMed1995

[TIMPs (tissue inhibitors of metalloproteinases): their species, functions and effects on tumor metastasis].

TIMPs (tissue inhibitors of metalloproteinases) belong to a family composed of three members: TIMP-1, -2 and -3. They possess a high degree similarity in their structure including 12 conserved cystenyl residues at the same relative positions. Recently, they have been shown to inhibit not only proteolytic activities of metalloproteinases but also tumor cells metastasis in vitro and in vivo. In this review, we summarize their structure information, inhibitory mechanism of metalloproteinases, TIMPs-like secretory inhibitors, other biological functions of TIMPs such as growth-regulating activity, their chromosomal localizations and related diseases. We also mention their inhibitory effects on tumor cells metastasis in vitro and in vivo, and their clinical applications.

Glycoproteins↗
PubMed1994

In vitro antibacterial activity of AM-1155, a novel 6-fluoro-8-methoxy quinolone.

The in vitro antibacterial activity of AM-1155 against a wide variety of clinical isolates was compared with those of other fluoroquinolones. The MICs of AM-1155 for 90% of Staphylococcus aureus, Streptococcus pneumoniae, and Enterococcus faecalis isolates tested were 0.10, 0.39, and 0.78 microgram/ml, respectively. The antibacterial activity of AM-1155 against gram-positive bacteria and anaerobes was comparable to those of sparfloxacin and tosufloxacin. AM-1155 inhibited 90% of most species of the family Enterobacteriaceae at a concentration of 0.39 microgram/ml. AM-1155 generally had activity comparable to that of sparfloxacin against gram-negative bacteria. AM-1155 showed moderate activity against methicillin- and quinolone-resistant S. aureus. AM-1155 demonstrated bactericidal activity at the MIC. The frequency of occurrence of spontaneous mutants resistant to four times the MIC of AM-1155 was < 1 x 10(9) for S. aureus, Escherichia coli, and Pseudomonas aeruginosa. AM-1155 strongly inhibited the supercoiling activities of DNA gyrases purified from E. coli and S. aureus.

Anti-Infective Agents↗
PubMed1993

[Iron deficient erythropoiesis in the young females--analysis by Percoll discontinuous density gradient].

To observe changes in erythropoiesis in iron deficient subjects, we fractioned red cells by discontinuous density gradient using Percoll. Blood samples were taken from 57 young females of 19-21 years old without abnormal history or abnormal biochemical profiles except anemia or iron deficiency. 6 layers gradient were made and 7 fractions (F1 to F7, from the top to the bottom) were obtained. In the lightness fraction (F3 in nonanemic subjects), reticulocytes were concentrated. From patterns of Hemoglobin A1c concentrations of the fractions, it was inferred that red cells with heavier density were older in ages. In cases with iron deficiency or resulting anemia, low density fraction(s) increased in percentage, with relative decrease in that of higher density fractions, as a result of impairment in hemoglobin production. Subjects in whom the lowest density fraction (F3) was less than 5% were regarded to be normal in terms of erythropoiesis, because the fractional pattern was comparable to that of the normal adult males. Among 57 females examined, 24 (52.6%) showed iron deficient erythropoiesis and 6 (10.5%) were iron deficiency anemia (hemoglobin < 120 g/l). The density gradient fractionation of the red cells was proved to be useful in analyzing abnormal erythropoiesis.

Adult↗
PubMed1989

Crystallization of a new class of microbial ribonuclease from Rhizopus niveus.

Crystals of ribonuclease Rh, a new class of microbial ribonuclease from Rhizopus niveus, were obtained from polyethylene glycol 8000 solution by a vapour diffusion technique in the hanging drop mode. Two crystal forms, type I and type II, were obtained from the same droplet solution. Both forms belong to the space group P2(1)2(1)2(1), but their cell dimensions are markedly different: a = 68.3 A, b = 73.0 A, c = 50.0 A for type I and a = 67.5 A, b = 72.3 A, c = 44.2 A for type II. The type I crystals diffract beyond 2.0 A resolution and are suitable for X-ray structure analysis at high resolution.

Crystallization↗
PubMed1988

Primary structure of a base non-specific ribonuclease from Rhizopus niveus.

The primary structure of a base non-specific ribonuclease from Rhizopus niveus (RNase Rh) was determined by nucleotide sequence analysis of the DNA fragment encoding RNase Rh gene including signal peptide sequence, and amino acid sequence analysis of the peptide obtained from RNase Rh and RNase Rh' (a protease-modified RNase Rh created during the course of purification). The sequence determined was: MKAVLALATLIGSTLASSCSSTA LSCSNSANSDTCCSPEYGLVVLNMQWAPGYGPANAFTLHGLWPDKCSGAYAPSGGCDSN RASSSIASVIKSKDSSLYNSMLTYWPSNQGNNNVFWSHEWSKHGTCVSTYDPDCYDNYE EGEDIVDYFQKAMDLRSQYNVYKAFSSNGITPGGTYTATEMQSAIESYFGAKAKIDCSSG TLSDVALYFYVRGRDTYVITDALSTGSCSGDVEYPTK (the sequence of signal peptide is underlined). The sequence indicates that the homology with the sequence of RNase T2 from A. oryzae with the same base specificity is about 42% and that the sequences around the two histidine residues which are supposed to be involved in the active site are fairly conserved.

Amino Acid Sequence↗