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Biomedical subjects

Takashi Hashimoto

Publications and source records attributed to Takashi Hashimoto.

At least 37 records · Page 2Linked to original sources
PubMed2005

Fucoxanthin induces cell cycle arrest at G0/G1 phase in human colon carcinoma cells through up-regulation of p21WAF1/Cip1.

Fucoxanthin, a natural carotenoid, has been reported to have antitumorigenic activity in mouse colon, skin and duodenum models. The present study was designed to evaluate the molecular mechanisms of fucoxanthin against colon cancer using the human colon adenocarcinoma cell lines. Fucoxanthin reduced the viability of WiDr cells in a dose-dependent manner accompanied by the induction of cell cycle arrest during the G0/G1 phase at 25 microM and apoptosis at 50 microM. Fucoxanthin at 25 microM inhibited the phosphorylation of the retinoblastoma protein (pRb) at Ser780 and Ser807/811 24 h after treatment without changes in the protein levels of the D-types of cyclin and cyclin-dependent kinase (cdk) 4, whose complexes are responsible for the phosphorylation of pRb at these sites. A cdk inhibitory protein, p21WAF1/Cip1 increased 24 h after the treatment with 25 microM of fucoxanthin, but not p27Kip1. In addition, the mRNA of p21WAF1/Cip1 also increased in a dose-dependent manner. According to the experiments using the isogenic human colon adenocarcinoma cell lines, fucoxanthin failed to induce G0/G1 arrest in the p21-deficient HCT116 cells, but not in HCT116 wild-type cells. All of these findings showed that fucoxanthin inhibited proliferation of colon cancer cells. The inhibitory mechanism is due to the cell cycle arrest during the G0/G1 phase mediated through the up-regulation of p21WAF1/Cip1, which may be related to the antitumorigenic activity.

Antineoplastic Agents↗
PubMed2005

Novel keratin 5 and 14 gene mutations in patients with epidermolysis bullosa simplex from Poland.

Mutation analysis in keratins 5/14 (K5/14) had been performed in five Polish families with epidermolysis bullosa simplex (EBS) to extend genotype-phenotype correlation and to add to the mutation database. All the patients had been clinically classified into two subtypes of EBS; Weber-Cockayne (EBS-WC) and Dowling-Meara (EBS-DM) as well as one case of EBS with mottled pigmentation (EBS-MP). DNA from patients and their family members was assessed for mutations in K5 or 14 using polymerase chain reaction amplification and subsequent direct sequencing. We identified four different missense mutations in K5 and one missense mutation in K14. Three of these are novel. Mutations associated EBS-DM resided in the highly conserved 20 amino acids end of the 1A domain in K5. Direct nucleotide sequencing of a case of EBS-MP revealed a heterozygous P25L mutation in K5. However, no genotype-phenotype correlation was identified in families with EBS-WC. The present study demonstrates the first series of molecular genetic data in EBS from Poland.

Epidermolysis Bullosa Simplex↗
PubMed2005

Artepillin C in Brazilian propolis induces G(0)/G(1) arrest via stimulation of Cip1/p21 expression in human colon cancer cells.

Potential chemopreventive agents exist in foods. Artepillin C in Brazilian propolis was investigated for its effects on colon carcinogenesis. We had found that artepillin C was a bioavailable antioxidant, which could be incorporated into intestinal Caco-2 and hepatic HepG2 cells without any conjugation and inhibited the oxidation of intracellular DNA. Artepillin C was then added to human colon cancer WiDr cells. It dose-dependently inhibited cell growth, inducing G(0)/G(1) arrest. The events involved a decrease in the kinase activity of a complex of cyclin D/cyclin-dependent kinase 4 and in the levels of retinoblastoma protein phosphorylated at Ser 780 and 807/811. The inhibitors of the complex, Cip1/p21 and Kip1/p27, increased at the protein level. On the other hand, Northern blotting showed that artepillin C did not affect the expression of Kip1/p27 mRNA. According to the experiments using isogenic human colorectal carcinoma cell lines, artepillin C failed to induce G(0)/G(1) arrest in the Cip1/p21-deleted HCT116 cells, but not in the wild-type HCT116 cells. Artepillin C appears to prevent colon cancer through the induction of cell-cycle arrest by stimulating the expression of Cip1/p21 and to be a useful chemopreventing factor in colon carcinogenesis.

Blotting, Northern↗
PubMed2005

Kinetics of marked development of lung metastasis of rat prostatic carcinomas transplanted in syngeneic rats.

In order to investigate how and when metastases develop under experimental conditions, kinetics of the size and the number of lung metastasis lesions in F344 rats were examined after syngeneic transplantation of rat prostate carcinomas induced by 3,2'-dimethyl-4-aminobiphenyl (DMAB). Cell proliferation of the subcutaneous tumor and lung metastatic lesions was evaluated along with the expression of VEGF-A splicing variants and endostatin, serum VEGF levels and vascular density in the tumor. Several pieces of tumor tissue were introduced subcutaneously into two different sites on the dorsal side of F344 rats through a 14G needle. Average body weight of recipient rats markedly decreased despite only a gradual increase in tumor volume. The absolute total number of metastatic lesions in rats (n=5) were 2, 10, 19 and 194 at weeks 7.5, 9, 11 and 13, respectively, and a notable increase was observed at week 13. Similarly, the mitotic index of lung metastatic lesions increased remarkably at week 9 while the mitotic index and apoptotic index of transplanted tumors did not change throughout the experimental period. Expression of VEGF-A121, A164, A188 and endostatin, serum VEGF levels and vascular density did not correlate with the spread of lung lesions. In conclusion, both the number and the size of metastatic lesions increased at the same time after a notable increase in cell proliferation. Factors other than VEGF or endostatin may be involved in the mechanism of explosive lung metastasis spread.

Animals↗
PubMed2005

Childhood bullous pemphigoid successfully treated with diaminodiphenyl sulfone.

Bullous pemphigoid (BP) is an acquired autoimmune blistering disease which predominantly affects the elderly. It is rare in children and infants. We reported a 14-year-old girl presenting with a month history of relapsing tense bullae on the face and extremities. Histopathological examination of the lesional skin revealed a subepidermal bulla with infiltration of eosinophils, neutrophils, and lymphocytes. Direct immunofluorescence showed linear deposits of IgM and C3 at the basement membrane zone. Indirect immunofluorescence using normal human skin sections as a substrate detected IgG anti-basement membrane zone antibodies in the patient's serum and that using 1M NaCl split skin sections showed that the patient's antibodies bound to the epidermal side of the split skin. Immunoblot analysis using normal human epidermal extracts demonstrated the presence of autoantibodies against the 230-kDa BP antigen. Furthermore, the patient's serum reacted with the recombinant protein of the NC16a domain of the 180-kDa BP antigen by immunoblot analysis and enzyme-linked immunosorbent assay. Our patient showed significant improvement of the skin lesions with systemic administration of diaminodiphenyl sulfone.

Adolescent↗
PubMed2005

Altered microtubule dynamics by expression of modified alpha-tubulin protein causes right-handed helical growth in transgenic Arabidopsis plants.

The proper organization of cortical microtubule arrays is essential for anisotropic growth in plants but how distinct array patterns are formed is not understood. Here, we report a relationship between microtubule dynamics and array organization using transgenic plants expressing modified tubulins. When green fluorescent protein (GFP) or a hemaglutinin epitope tag was fused to the N-terminus of tubulins and expressed in Arabidopsis plants, these tubulins were incorporated into microtubules along with endogenous tubulins. Plants expressing the modified beta-tubulins were phenotypically normal and possessed transversely oriented cortical arrays in the epidermal cells of the root elongation zone; however, the expression of modified alpha-tubulins caused right-handed helical growth, increased trichome branching, and a shallow left-handed (S-form) helical array organization. In cells expressing the modified alpha-tubulins, microtubule dynamicity was suppressed and polymerization was promoted, and GFP-EB1 (End Binding 1) labeled larger regions of the microtubule end more frequently, when compared with control cells. We propose that the N-terminal appendage introduced into alpha-tubulin inhibits GTP hydrolysis, thus producing polymerization-prone microtubules with an extended GTP cap. Consistent with this interpretation, plants expressing an alpha-tubulin mutated in the GTPase-activating domain exhibited similar microtubule properties, with regard to dynamics and the localization of GFP-EB1, and showed right-handed helical growth.

Arabidopsis↗
PubMed2005

A case of pemphigus vulgaris accompanied by multiple myeloma.

Pemphigus is a mucocutaneous intraepithelial blistering disease caused by autoantibodies to epithelial cell adhesion molecules (desmoglein). The association between pemphigus and malignant neoplasm is well recognized. We present the case of a 62-year-old woman with pemphigus vulgaris accompanied by multiple myeloma. To the best of our knowledge, this is the first report of a case of pemphigus vulgaris concomitant with multiple myeloma. From the results of immunoblotting using normal human epidermal extracts and indirect immunofluorescence using rat bladder sections, and her clinical manifestations, our case does not seem to be one of paraneoplastic pemphigus.

Autoantibodies↗
PubMed2005

A case of mixed bullous disease of epidermolysis bullosa acquisita and linear IgA bullous dermatosis.

A 75-year-old Japanese male visited us with bullous eruptions on the extremities. Physical examination revealed large bullae on the hands, lower legs and feet. The oral mucosa was also involved. Histology disclosed subepidermal blister with inflammatory cell infiltrates in the dermis. Direct immunofluorescence showed deposits of IgG and IgA at the cutaneous basement membrane zone. Indirect immunofluorescence on 1 M NaCl-split human skin sections demonstrated that the patient's IgG antibodies reacted with the dermal side of the split, while IgA antibodies reacted with the epidermal side. Immunoblotting showed that the patient's serum reacted with the NC1 domain of type VII collagen (290-kDa epidermolysis bullosa acquisita antigen) as well as the 120-kDa linear IgA bullous dermatosis antigen, LAD-1. Systemic prednisolone resulted in a favorable response. From the clinicopathological findings, the present case is not consistent with either epidermolysis bullosa acquisita or IgA bullous dermatosis. Therefore, we regarded the case as mixed bullous disease of epidermolysis bullosa acquisita and linear IgA bullous dermatosis. Such a case has not been previously reported.

Administration, Oral↗
PubMed2005

Pemphigoid nodularis: two case studies and analysis of autoantibodies before and after the development of generalized blistering.

We report 45- and 61-year-old women with generalized prurigo nodularis-like eruption whose clinical, histologic and immunopathologic features were consistent with the diagnosis of pemphigoid nodularis. In one case, nodular lesions preceded the onset of generalized blistering by two years and in the other, no definite blister nor erosion was seen except for some appearing on the soles during the course of the disease. Western immunoblotting of EDTA-separated epidermal extracts revealed that the 230-kD bullous pemphigoid (BP) antigen was recognized by circulating autoantibodies in the patient sera, but the 180-kD BP antigen was not. The 180-kD BP antigen was recognized weakly by immunoblotting of the 180-kD BP antigen NC16a domain fusion protein, which shows high detection sensitivity. These findings suggested that weak reactivity of autoantibodies with either whole or a part of the 180-kD BP antigen molecule in some way accounts for negligible or localized blister-formation in this disorder. However, no particular change was noted in the reactivity with 180-kD BP antigen between the patient serum obtained before and after the development of generalized blistering. It is possible that different factors from the changes in serum reactivity with BP antigens may be involved in initiating generalized blistering.

Autoantibodies↗
PubMed2005

Atypical clinical appearance of pemphigus vulgaris on the face: case report.

Pemphigus vulgaris is an organ-specific autoimmune mucocutaneous disorder. In the majority of cases, the disease manifests initially with oral lesions, and may be limited to a single site for months before spreading. A 78-year-old woman with yellowish crusted areas on her left preauricular region and close to the medial angle of her right eye is presented. Although she described an episode of erosions on her lower lip, the involvement of mucosal surfaces was not noticed on examination. Before she presented to our Department, she was misdiagnosed as an actinic cheilitis and malignant skin tumor. Histopathologic examination and direct immunofluorescence confirmed the diagnosis of pemphigus vulgaris. Immunoblotting of epidermal extracts detected IgG antibodies against desmoglein 3 but not desmoglein 1, which was also confirmed by ELISA test. The patient responded favorably to systemic corticosteroid therapy combined with adjuvant immunosuppressive therapy, with complete clearance of the lesions.

Aged↗
PubMed2004

Plectin deficient epidermolysis bullosa simplex with 27-year-history of muscular dystrophy.

BACKGROUND: Epidermolysis bullosa simplex associated with muscular dystrophy is caused by plectin deficiency. OBJECTIVE: To report clinical, immunohistochemical, ultrastructural and molecular features of a 52-year-old Japanese patient affected with this disease, whose muscular disease had been followed-up for 27 years. METHODS: We performed histopathological study, immunofluorescence, electron microscopic study and mutation detection analysis for plectin. RESULTS: The patient developed blisters and erosions followed by nail deformity on the traumatized regions from birth. The skin lesions were continuously developed to date. The histopathological study showed subepidermal blister. Electron microscopic study showed blister formation inside the basal cells at the level just above the attachment plaque of hemidesmosome. Immunofluorescence showed complete loss of staining to plectin. The mutation analysis using protein truncation test and DNA sequencing revealed a C-to-T transition at nucleotide position 7006 of the plectin cDNA sequence, which lead a novel homozygous nonsense mutation (R2319X). CONCLUSION: From the above results, the diagnosis of epidermolysis bullosa simplex associated with muscular dystrophy was made. Slight muscular dystrophy was noticed at the age of 25 years. The muscular dystrophy gradually progressed and she could not walk at the age of 46 years. However, she can still breathe and swallow by herself. This is the patient of this disease with the longest follow-up, and may indicate the slow progress of muscular condition of this disease.

Base Sequence↗
PubMed2004

Plant-specific microtubule-associated protein SPIRAL2 is required for anisotropic growth in Arabidopsis.

In diffusely growing plant cells, cortical microtubules play an important role in regulating the direction of cell expansion. Arabidopsis (Arabidopsis thaliana) spiral2 (spr2) mutant is defective in directional cell elongation and exhibits right-handed helical growth in longitudinally expanding organs such as root, hypocotyl, stem, petiole, and petal. The growth of spr2 roots is more sensitive to microtubule-interacting drugs than is wild-type root growth. The SPR2 gene encodes a plant-specific 94-kD protein containing HEAT-repeat motifs that are implicated in protein-protein interaction. When expressed constitutively, SPR2-green fluorescent protein fusion protein complemented the spr2 mutant phenotype and was localized to cortical microtubules as well as other mitotic microtubule arrays in transgenic plants. Recombinant SPR2 protein directly bound to taxol-stabilized microtubules in vitro. Furthermore, SPR2-specific antibody and mass spectrometry identified a tobacco (Nicotiana tabacum) SPR2 homolog in highly purified microtubule-associated protein fractions from tobacco BY-2 cell cultures. These results suggest that SPR2 is a novel microtubule-associated protein and is required for proper microtubule function involved in anisotropic growth.

Amino Acid Sequence↗
PubMed2004

A semidominant mutation in an Arabidopsis mitogen-activated protein kinase phosphatase-like gene compromises cortical microtubule organization.

Reversible protein phosphorylation regulates many cellular processes, including the dynamics and organization of the microtubule cytoskeleton, but the events mediating it are poorly understood. A semidominant phs1-1 allele of the Arabidopsis thaliana PROPYZAMIDE-HYPERSENSITIVE 1 locus exhibits phenotypes indicative of compromised cortical microtubule functions, such as left-handed helical growth of seedling roots, defective anisotropic growth at low doses of microtubule-destabilizing drugs, enhancement of the temperature-sensitive microtubule organization1-1 phenotype, and less ordered and more fragmented cortical microtubule arrays compared with the wild type. PHS1 encodes a novel protein similar to mitogen-activated protein kinase (MAPK) phosphatases. In phs1-1, a conserved Arg residue in the noncatalytic N-terminal region is exchanged with Cys, and the mutant PHS1 retained considerable phosphatase activity in vitro. In mammalian MAPK phosphatases, the corresponding region serves as a docking motif for MAPKs, and analogous Arg substitutions severely inhibit the kinase-phosphatase association. Transgenic studies indicate that the phs1-1 mutation acts dominant negatively, whereas the null phs1-2 allele is recessive embryonic lethal. We propose that the PHS1 phosphatase regulates more than one MAPK and that a subset of its target kinases is involved in the organization of cortical microtubules.

Amino Acid Sequence↗
PubMed2004

Caffeine inhibits cell proliferation by G0/G1 phase arrest in JB6 cells.

Caffeine is a major biologically active constituent in coffee and tea. Because caffeine has been reported to inhibit carcinogenesis in UVB-exposed mice, the cancer-preventing effect of caffeine has attracted considerable attention. In the present study, the effect of caffeine in quiescent (G0 phase) cells was investigated. Pretreatment with caffeine suppressed cell proliferation in a dose-dependent manner 36 h after addition of fetal bovine serum as a cell growth stimulator. Analysis by flow cytometry showed that caffeine suppressed cell cycle progression at the G0/G1 phase, i.e., 18 h after addition of fetal bovine serum, the percentages of cells in G0/G1 phase in 1 mM caffeine-treated cells and in caffeine-untreated cells were 61.7 and 29.0, respectively. The percentage of cells in G0/G1 phase at 0 h was 75.5. Caffeine inhibited phosphorylation of retinoblastoma protein at Ser780 and Ser807/Ser811, the sites where retinoblastoma protein has been reported to be phosphorylated by cyclin-dependent kinase 4 (cdk4). Furthermore, caffeine inhibited the activation of the cyclin D1-cdk4 complex in a dose-dependent manner. However this compound did not directly inhibit the activity of this complex. In addition, caffeine did not affect p16INK4 or p27Kip1 protein levels, but inhibited the phosphorylation of protein kinase B (Akt) and glycogen synthase kinase 3beta. Our results showed that caffeine suppressed the progression of quiescent cells into the cell cycle. The inhibitory mechanism may be due to the inhibition of cell growth signal-induced activation of cdk4, which may be involved in the inhibition of carcinogenesis in vivo.

Animals↗
PubMed2004

Molecular biology of pyridine nucleotide and nicotine biosynthesis.

Nicotinamide adenine dinucleotide (NAD) is a ubiquitous coenzyme in oxidation-reduction reactions. Recent animal and fungal studies show that it also plays important roles in transcriptional regulation, longevity, and age-associated diseases. NAD is synthesized de novo from aspartic acid in E. coli or from tryptophan in animals, by way of quinolinic acid. Although the number of biochemical studies on NAD is very limited, a bioinformatic search of genome databases suggests that Arabidopsis (dicots) synthesizes NAD from aspartic acid whereas rice (monocots) may utilize both aspartate and tryptophan as starting amino acids. The salvage pathway recycles the breakdown products of NAD metabolism. In tobacco, an intermediate in the de novo NAD synthetic pathway supplies the pyridine ring moiety of nicotine alkaloids. Gene expression studies in tobacco suggest that part of the NAD pathway is coordinately regulated with nicotine biosynthesis.

Animals↗