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Biomedical subjects

Hiroshi Shimizu

Publications and source records attributed to Hiroshi Shimizu.

At least 19 recordsLinked to original sources
PubMed2007

Small-diameter porous poly (epsilon-caprolactone) films enhance adhesion and growth of human cultured epidermal keratinocyte and dermal fibroblast cells.

Autologous keratinocyte grafts provide clinical benefit by rapidly covering wounded areas, but they are fragile. We therefore developed biocompatible hexagonal-packed porous films with uniform, circular pore sizes to support human keratinocytes and fibroblasts. Cells were cultured on these porous poly (epsilon-calprolactone) films with pore sizes ranging from novel ultra-small 3 microm to 20 microm. These were compared with flat (pore-less) films. Cell growth rates, adhesion, migration, and ultrastructural morphology were examined. Human keratinocytes and fibroblasts attached to all films. Furthermore, small-pore (3-5 microm) films showed the highest levels of cell adhesion and survival and prevented migration into the pores and opposing film surface. Keratinocyte migration over small-pore film surface was inhibited. Keratinocytes optimally attached to 3-microm-pore films due to a combination of greater pore numbers (porosity), a greater circumference of the pore edge per unit surface area, and greater frequency of flat surface areas for attachment, allowing better cell-substrate and cell-cell attachment and growth. The 3-microm pore size allowed cell-cell communication, together with diffusion of soluble nutrients and factors from the culture medium or wound substrate. These characteristics are considered important in developing grafts for use in the treatment of human skin wounds.

Biocompatible Materials↗
PubMed2006

DNA-based prenatal diagnosis of harlequin ichthyosis and characterization of ABCA12 mutation consequences.

Until the identification of ABCA12 as the causative gene, prenatal diagnosis (PD) for harlequin ichthyosis (HI) had been performed by electron microscopic observation of fetal skin biopsy samples. We report the first case of HI DNA-based PD. Direct sequence analysis of ABCA12 revealed that the deceased proband was a compound heterozygote for two novel mutations. The maternal nonsense mutation p.Ser1249Term likely leads to nonsense-mediated messenger RNA decay. The paternal mutation c.7436G>A affects the last codon of exon 50 and was expected to be a splice site mutation. For their third pregnancy, the parents requested PD. Direct sequence analysis of fetal genomic DNA from amniotic fluid cells at 17 weeks gestation revealed the fetus was a compound heterozygote for both mutations. The parents requested the pregnancy to be terminated. Analysis of ABCA12 transcripts of cultured keratinocytes from the abortus showed the presence of six abnormally spliced products from the allele carrying the splice site mutation. Four of them lead to premature termination codons whereas the two others produced shortened proteins missing 21 and 31 amino acids from the second ATP-binding cassette. This report provides evidence for residual ABCA12 expression in HI, and demonstrates the efficiency of early DNA-based PD of HI.

ATP-Binding Cassette Transporters↗
PubMed2006

Macrophage migration inhibitory factor in zinc-allergic systemic contact dermatitis.

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine whose expression has been found to be critical to the generation of the antigen-specific immune response. Recent studies suggested that MIF plays a role in the initiation and maintenance of allergic disease. The aim of this study was to investigate whether MIF is involved in the pathogenesis of zinc-allergic systemic contact dermatitis. A 49-year-old Japanese woman developed facial edema, blepharedema and pruritic edematous erythema with papules over the entire body. Based of the results of a metal patch test, drug lymphocyte stimulating test and drug challenge test, diagnosis of zinc-allergic systemic contact dermatitis was made. Serum MIF and TNF-alpha levels of the patient, 20 healthy controls and other 6 patients who showed positive reaction to metal patch test were measured by an ELISA. Moreover we examined MIF production of peripheral blood mononuclear cells (PBMCs) from our patient, 3 healthy controls and other 2 patients who showed positive reaction to metal patch test at various metal concentrations. The patient's serum showed high MIF and TNF-alpha levels compared to healthy controls and other metal allergy patients. Furthermore, zinc stimulation of patient's PBMC showed higher MIF and TNF-alpha secretion compared with healthy subjects. The MIF content of 2 patients with other metal allergy was not significantly increased after metal stimulation. Our data suggest that zinc in the peripheral blood of zinc-allergic patients induce PBMCs to produce increased MIF levels, which could lead to systemic contact dermatitis.

Cells, Cultured↗
PubMed2006

Induction of therapeutically relevant cytotoxic T lymphocytes in humans by percutaneous peptide immunization.

Percutaneous peptide immunization (PPI) is a simple and noninvasive immunization approach to induce potent CTL responses by peptide delivery via skin with the stratum corneum removed. After such a barrier disruption in human skin, epidermal Langerhans cells, although functionally matured through the up-regulation of HLA expression and costimulatory molecules, were found to emigrate with a reduced number of dendrites. CD8(+) populations binding to MHC-peptide tetramers/pentamers and producing IFN-gamma appeared in the blood after PPI with HLA class I-restricted antigenic peptides. PPI with melanoma-associated peptides reduced the lesion size and suppressed further development of tumors in four of seven patients with advanced melanoma. These beneficial effects were accompanied by the generation of circulating CTLs with in vitro cytolytic activity and extensive infiltration of tetramer/pentamer-binding cells into regressing lesions. PPI elicited neither local nor systemic toxicity or autoimmunity, except for vitiligo, in patients with melanoma. Therefore, PPI represents a novel therapeutic intervention for cancer in the clinical setting.

Administration, Cutaneous↗
PubMed2006

N-linked neutral oligosaccharides in the stratum corneum of normal and ichthyotic skin.

N-Glycan oligosaccharides are thought to play multiple, important roles in a variety of biological events. However, N-glycan profiles in the stratum corneum of human skin have not yet been studied in detail. To clarify the N-glycan profiles in the stratum corneum of normal and ichthyotic epidermis, N-glycan profiles were studied by high-performance liquid chromatography using normal human epidermal samples and scales from hyperkeratotic skin of ichthyosis patients. Chromatograms of patient scale samples showed unique alterations in three peaks eluted at 15.8, 18.8 and 26.9 min. The N-glycan profiles were significantly altered in ichthyotic hyperkeratotic skin compared with normal non-hyperkeratotic controls. These findings indicate the reduction of N-acetylglucosaminyltransferase II and fucosyltransferase 8 activities. Alteration of N-glycan structures in hyperkeratotic skin suggests the biological role of N-glycans in keratinization.

Chromatography, High Pressure Liquid↗
PubMed2006

Dietary glucosylceramide improves skin barrier function in hairless mice.

BACKGROUND: Sphingolipids are known to play an important role in both water retention and epidermal permeability barrier function in mammalian stratum corneum. However, little is known about the effects on epidermal function of orally administered sphingolipids. OBJECTIVE: We examined the effect of dietary glucosylceramide (GluCer) on the maintenance and recovery of epidermal barrier function. METHODS: Hairless mice were fed a particular diet (HR-AD) for 4 weeks to induce chronic skin perturbation. Subsequently, a normal diet supplemented with GluCer (from rice bran and germ) was provided for the next 4 weeks. Transepidermal water loss (TEWL) and stratum corneum flexibility were measured throughout this recovery phase. Additional hairless mice were fed a diet with or without a maize-extracted GluCer supplement for 5 weeks, then their skin was acutely perturbed with repeated tape-stripping, and the TEWL was measured. RESULTS: Although skin functions were generally lower following chronic perturbation, in GluCer-fed mice the TEWL was significantly reduced at 2 weeks and the stratum corneum flexibility was increased at 3 weeks compared to controls. Following acute barrier perturbation by tape-stripping, mice an HR-AD fed a GluCer diet exhibited enhanced recovery compared with the control diet group. CONCLUSION: These results demonstrate that in hairless mice skin barrier functions impaired by chronic or acute perturbations were improved by dietary GluCer. The oral administration of GluCer may be useful for the preservation and recovery of epidermal barrier functions an HR-AD.

Adhesives↗
PubMed2006

Polymorphisms in the muscarinic receptor 1 gene confer susceptibility to asthma in Japanese subjects.

RATIONALE: The human cholinergic receptor muscarinic-1 (CHRM1) is widely distributed in the lungs. In patients with asthma, CHRM1 may be involved in airway constriction, airway epithelial cell proliferation, and airway inflammation. The CHRM1 gene is located on chromosome 11q13, which is one of the candidate loci for asthma and atopy. OBJECTIVES: To determine the role of the CHRM1 gene polymorphisms in asthma. METHODS: We studied nine single-nucleotide polymorphisms (-18379G > A, -9697C > T, -6965T > C, -4953A > G, +267A > C, +1353C > T, +3970C > G, +5418C > G, and +5455G > T) in a case-control study using 326 patients with asthma and 333 healthy control subjects. We also examined functional consequences of the -9697C > T and -4953A > G polymorphisms at the regulatory region using an mRNA reporter assay. MEASUREMENTS AND MAIN RESULTS: Two common single-nucleotide polymorphisms (-9697C > T and -4953A > G) were associated with asthma. The odds ratio for the TT homozygotes at the -9697C > T polymorphism was 0.29 compared with the CC homozygotes (95% confidence interval, 0.12-0.73; p = 0.008), and the odds ratio for the GG homozygotes at the -4953A > G polymorphism was 1.86 compared with the AA homozygotes (95% confidence interval, 1.04-3.34; p = 0.038). Haplotype analysis showed that the -9697T/-6965T/-4953A haplotype was associated with a lower risk of asthma (p = 0.00055) and the -9697C/-6965T/-4953G haplotype was associated with an increased risk of asthma (p = 0.020). The -9697T/-4953A haplotype was also associated with lower luciferase activity in vitro compared with the -9697C/-4953G haplotype. CONCLUSIONS: This study, together with an in vitro functional study, suggests that the CHRM1 gene is an important susceptibility locus for asthma on chromosome11q13.

Adolescent↗
PubMed2006

CTACK/CCL27 accelerates skin regeneration via accumulation of bone marrow-derived keratinocytes.

Recent studies have suggested that bone marrow (BM) cells transdifferentiate to regenerate a variety of cellular lineages. Due to the relatively small population of BM-derived cells in each organ, it is still controversial whether these BM-derived cells are really present in sufficient numbers for effective function. Conversely, it is speculated that chemokine/chemokine receptor interactions mediate this migration of the tissue-specific precursor cells from BM into the target tissue. Here, we show that cutaneous T-cell attracting chemokine (CTACK)/CCL27 is the major regulator involved in the migration of keratinocyte precursor cells from BM into skin. By screening various chemokine expression patterns, we demonstrated that CTACK is constitutively expressed in normal skin and upregulated in wounds and that approximately 20% of CD34(+) BM cells expressed CCR10, the ligand for CTACK. Intradermal injection of CTACK/CCL27 into the periphery of skin wounds significantly enhanced BM-derived keratinocyte (BMDK) migration, and CTACK/CCL27 neutralizing antibody inhibited this BMDK migration. Furthermore, increased BMDK migration caused by CTACK/CCL27 significantly accelerated the wound-healing process without any influence over either angiogenesis or keratinocyte proliferation. These results provide direct evidence that recruitment of BM keratinocyte precursor cells to the skin is regulated by specific chemokine/chemokine receptor interactions, making possible the development of new regenerative therapeutic strategies.

Animals↗
PubMed2006

Speciation of sulfate in size-fractionated aerosol particles using sulfur K-edge X-ray absorption near-edge structure.

X-ray absorption near-edge structure (XANES) at sulfur K-edge was used to determine the sulfate species present in size-fractionated aerosol particles based on the postedge structure after the main absorption peak in the XANES region. A comparison of the XANES spectra of reference sulfate materials and aerosol samples collected in Tsukuba in Japan clearly showed that (NH4)2SO4 was the main sulfur species in particles with a smaller diameter and CaSO4 x 2H2O (gypsum) was the main sulfur species in particles with a larger diameter. A simulation of the XANES spectra by reference materials allows us to obtain the quantitative mixing ratios of the different sulfate species present in the aerosol samples. The presence of minor sulfur species other than (NH4)2SO4 and gypsum at the surface of mineral aerosols is suggested in our simulations and by a surface-sensitive conversion electron/He-ion yield XANES. In the absence of a contribution from a large dust event, the mole concentration of gypsum in the mineral aerosol fraction (particle diameter > 1 microm) determined by XANES is similar to that of Ca which is determined independently using ion chromatography. This shows that the Ca and sulfate in the mineral aerosols are present only as gypsum. Considering that calcite is the main Ca mineral in the original material arising from an arid and semiarid area in China, it is strongly suggested that gypsum is formed in aerosol during its long-range transportation by a reaction between calcite and sulfate ions.

Absorptiometry, Photon↗
PubMed2006

Simultaneous control of apparent extract and volatile compounds concentrations in low-malt beer fermentation.

Volatile compounds cause undesirable flavor when their concentrations exceed threshold values in beer fermentation. The objective of this study is to develop a system for controlling apparent extract concentration, which indicates the fermentation degree and which should be decreased below a targeted value at a fixed time under a constraint of tolerable amounts of volatile compounds. In beer fermentation, even though the production of volatile compounds is suppressed by maintaining a low fermentation temperature, a low temperature causes a delay in the control of apparent extract concentration. Volatile compound concentration was estimated on-line, and the simulation of apparent extract consumption and volatile compound production was performed. To formulate various beer tastes and conserve energy for attemperation, optimal temperature profiles were determined using a genetic algorithm (GA). The developed feedback control of the brewing temperature profile was successfully applied, and apparent extract and volatile compound concentrations at a fixed time reached their target concentrations. Additionally, the control technique developed in this study enables us to brew a wide variety of beers with different tastes.

Acids↗
PubMed2006

Targeted skipping of a single exon harboring a premature termination codon mutation: implications and potential for gene correction therapy for selective dystrophic epidermolysis bullosa patients.

This study examined the feasibility of antisense oligoribonucleotide (AON) therapy for dystrophic epidermolysis bullosa (DEB). AON was designed to induce skipping of a targeted exon containing a premature termination codon mutation, resulting in restoration of the open reading frame. We targeted exon 70 of COL7A1, as a recurrent mutation 5818delC in Japanese DEB patients was localized to exon 70. We found that one AON induced effective skipping of normal exon 70 containing 16 amino acids. Attachment and migration analyses showed that recombinant collagen without contribution of exon 70 was similar in effect to normal type VII collagen. Next, we synthesized mutation-specific AON by deleting cytosine at 5818. Introduction of this AON into DEB keratinocytes harboring 5818delC showed that the AON induced skipping of exon 70 in the abnormal 5818delC allele. Furthermore, 6.2% of DEB keratinocytes started to express type VII collagen in vitro after application of the mutation-specific AON. Injection of the AON into rat model grafted with DEB keratinocytes and fibroblasts induced a low amount of type VII collagen expression. We conclude that skipping of targeted exons using mutation-specific AON may show potential for future gene therapy for DEB patients.

Animals↗
PubMed2006

Compound heterozygous mutations including a de novo missense mutation in ABCA12 led to a case of harlequin ichthyosis with moderate clinical severity.

Harlequin ichthyosis (HI) is one of the most devastating genodermatoses. Recently, ABCA12 mutations were identified as the cause of HI. A newborn Japanese male demonstrated the typical features of HI. The patient was treated with oral etretinate and his general condition has been good (now aged 1.5 years). This patient with moderate clinical severity was compound heterozygous for a novel de novo missense mutation 1160G > A (S387N) in exon 10 and a maternal deletion mutation 4158_4160delTAC (T1387del) in exon 28 of ABCA12. T1387del was a deletion of a highly conserved threonine residue within the first adenosine 5' triphosphate-binding domain and is thought to seriously affect the function of the ABCA12 protein. Conversely, the residue 387 is located outside the known active sites of ABCA12 and S387N is predicted not to lead to a serious functional deficiency in ABCA12. Electron microscopy revealed abnormal lamellar granules in the granular layer cells and a moderate number of lipid vacuoles in the cornified cells. Disturbed glucosylceramide transport was confirmed in the cultured keratinocytes from the patient. No de novo mutation in ABCA12 has yet been reported either in HI or lamellar ichthyosis. The present case suggested that a de novo ABCA12 mutation might underlie HI.

ATP-Binding Cassette Transporters↗
PubMed2006

Presence of circulating CCR10+ T cells and elevated serum CTACK/CCL27 in the early stage of mycosis fungoides.

PURPOSE: Mycosis fungoides (MF), a common type of cutaneous T cell lymphoma with an indolent clinical course, has the characteristic that malignant T cell clones are recruited into the skin from the early disease stages. The mechanisms of recruitment have been suggested from our knowledge of various chemokine-chemokine receptor interactions. Recently, CCR10 and CTACK/CCL27 were proposed to play a role in the recruitment of other types of cutaneous T cell lymphoma. We examined the expression of CCR10 in peripheral blood and serum CTACK/CCL27 levels in patients with MF. EXPERIMENTAL DESIGN: Eighteen patients with MF, six patients with atopic dermatitis, and nine healthy volunteers were enrolled in our investigation. We investigated the differences in CCR10+ CD4+ expression in peripheral blood mononuclear cells by flow cytometry. Serum CTACK/CCL27 levels were determined using a CTACK/CCL27 ELISA assay kit. RESULTS: The number of circulating CCR10+ CD4+ cells was significantly higher in MF peripheral blood than in controls, even during the early stages. In lesional MF skin, infiltrating tumor cells also showed extensive expression of CCR10. The serum level of CTACK/CCL27 was higher in patients with MF than normal controls, but no statistical difference was found compared with atopic dermatitis patients. CONCLUSIONS: CCR10-CTACK/CCL27 interactions between circulating T cells and keratinocytes would seem to play an important role in the pathophysiology of MF from the early disease stages.

Adult↗
PubMed2006

COL7A1 mutation G2037E causes epidermal retention of type VII collagen.

COL7A1 glycine substitution (GS) mutations result in dominant and recessive dystrophic epidermolysis bullosa (DDEB and RDEB). Here, we report a DDEB family in which retention of type VII collagen by epidermal keratinocytes was observed for a female proband. Mutational analysis detected a GS mutation, G2037E, in the proband and her affected father. To demonstrate direct association of G2037E and type VII collagen retention we introduced this mutated COL7A1 gene into cultured keratinocytes using retroviral methods. This mutation was dominant, so we transferred a 1:1 mixture of wild-type (unaffected) and G2037E-mutated COL7A1, together, in addition to the unaffected gene or the mutated gene alone. The increase in type VII collagen cytoplasmic staining in the G2037E/wild transfectant cell samples was compared with that for control/wild-type cells. Intracellular collagen VII staining in the G2037E (alone)-transfected cells was even stronger than for the G2037E/wild transfection sample. These results indicate that the G2037E COL7A1 mutation leads to increased epidermal retention of type VII collagen in vivo, and also suggests that homozygotes carrying this dominant GS mutation may have more severe phenotypes than heterozygotes. This study furthers our understanding of GS COL7A1 mutations in DEB.

Collagen Type VII↗