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ABSTRACT: Dissolved organic matter (DOM) concentrations in a fringing coral reef were measured for both carbon and nitrogen with the
analytical technique of high-temperature catalytic oxidation. Because of high precision of the analytical system, not only
the concentrations of dissolved organic carbon and nitrogen (DOC and DON, respectively) but the C:N ratio was also determined
from the distribution of DOC and DON concentrations. The observed concentrations of DOC and DON ranged 57–76 and 3.8–5.6μmoll−1, respectively. The C:N ratios of the DOM that was produced on the reef flat were very similar between seagrass- and coral-dominated
areas; the C:N ratio was 10 on average. The C:N ratio of DOM was significantly higher than that of particulate organic matter
(POM) that was produced on the reef flat. Production rates of DOC were measured on the reef flat during stagnant periods and
accounted for 3–7% of the net primary production, depending on the sampling site. The production rate of DON was estimated
to be 10–30% of the net uptake of dissolved inorganic N in the reef community. Considering that the DOM and POM concentrations
were not correlated with each other, a major source of the reef-derived DOM may be the benthic community and not POM such
as phytoplankton. It was concluded that a widely distributed benthic community in the coral reef released C-rich DOM to the
overlying seawater, conserving N in the community.
KeywordsDOM–POM–Coral reef–C:N ratio–Primary production
Coral Reefs 04/2012; 30(2):533-541. · 3.88 Impact Factor
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ABSTRACT: Changes in gene expression in CD3+ T cells associated with disease progression in systemic lupus erythematosus (SLE) patients were determined. The genes related to SLE disease-related activities were identified and their gene regulatory networks were investigated. Analyses of gene expression were performed by both DNA microarray and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The expression of certain genes including interferon (IFN) regulatory factor (IRF)-related genes, such as IFN-regulated, -related, and -signature genes was increased in the active phase of SLE. Pathway network analyses suggested that these IRF-related genes are regulated through the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. JAK/STAT pathway-mediated regulation of IRF-related genes may have an important role in the disease activity of SLE. Inhibitors of JAK/STAT cascade may be useful as therapeutic agents.
Lupus 10/2011; 20(12):1231-9. · 2.34 Impact Factor
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ABSTRACT: Psoriasis is a complex, multifactorial inflammatory skin disease with genetic and environmental interactions. Patients with psoriasis exhibit erythematous plaques with itch, but the mechanisms of psoriatic itch are poorly understood.
This study was performed to investigate epidermal nerve density and opioid receptor levels in psoriatic skin with or without itch.
Twenty-four patients with psoriasis aged between 39 and 82 years were included in this study. The number of epidermal nerve fibres, the levels of semaphorin 3A (Sema3A) and the expression patterns of μ- and κ-opioid systems were examined immunohistologically in skin biopsies from psoriatic patients with or without itch and healthy volunteers as controls.
The number of epidermal nerve fibres tended to increase in approximately 40% of psoriatic patients with itch compared with healthy controls, while such intraepidermal nerves were not observed in other itchy patients. In comparison with healthy controls, Sema3A levels also tended to decrease in the epidermis of psoriatic patients with itch. However, no relationship was found between nerve density and Sema3A levels in the epidermis of psoriatic patients with itch. The levels of μ-opioid receptor and β-endorphin in the epidermis were the same in healthy controls and psoriatic patients with or without itch. The levels of κ-opioid receptor and dynorphin A were significantly decreased in the epidermis of psoriatic patients with itch compared with healthy controls.
Based on Sema3A levels in the epidermis, epidermal opioid systems, rather than hyperinnervation, may be involved in the pathogenesis of psoriatic itch.
British Journal of Dermatology 04/2011; 165(2):277-84. · 3.67 Impact Factor
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Y Niwa,
D P Potaczek,
S Kanada,
A Takagi,
N Shimokawa,
T Ito,
K Mitsuishi,
Y Okubo,
M Tajima,
A Hobo,
W Ng,
R Tsuboi,
S Ikeda, H Ogawa,
K Okumura,
C Nishiyama
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ABSTRACT: Two promoter polymorphisms of the high-affinity IgE receptor alpha-subunit (FcepsilonRIalpha) gene (FCER1A), -66T>C (rs2251746) and -315C>T (rs2427827), were analysed in Japanese atopic dermatitis subjects. Patients with the -315CT/TT genotype tended to have higher total serum IgE levels, while the proportion of -315CT/TT genotype or the -315T allele was significantly higher in those with highly elevated total serum IgE concentrations.
International Journal of Immunogenetics 02/2010; 37(2):139-41. · 1.29 Impact Factor
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ABSTRACT: Epidermal hyperinnervation occurs in dermatoses with intractable pruritus, such as atopic dermatitis, suggesting that the hyperinnervation is partly responsible for abnormal itch perception.
To investigate the mechanisms of penetration of sensory nerve fibres into the basement membrane of the skin.
A rat dorsal root ganglion neurone culture system consisting of Matrigel and a Boyden chamber containing a nerve growth factor (NGF) concentration gradient was used. In some experiments, matrix metalloproteinase (MMP) blockers and semaphorin 3A (Sema3A) were added to the culture system. Matrigel-coated membranes were stained with anti-Tau antibody, and the number of nerve fibres that crossed the membrane was counted. Expression of MMPs in the cultured neurones was examined at mRNA and protein levels by quantitative reverse transcription-polymerase chain reaction and immunocytochemistry, respectively. The activity was also examined by zymography.
Nerve fibres penetrated into Matrigel in the presence of an NGF concentration gradient, which was dose-dependently inhibited by GM6001, a broad-spectrum MMP inhibitor. Transcripts for MMP2, but not MMP9, were increased in the cultured neurones, and the penetration was dose-dependently inhibited by MMP-2 blockers. MMP-2 and its activity were partially localized on the NGF-responsive growth cones. NGF also upregulated pro-MMP-2 activation molecules in the cultured neurones. Sema3A stimulation showed the opposite effects on these NGF-dependent events. Interestingly, MMP2 expression was modulated by extracellular matrix (ECM) substrates for this enzyme.
Membrane-associated MMP-2 contributes to penetration of nerve fibres into Matrigel through modulation by axonal guidance molecules and/or ECM. These findings provide insight for understanding the development of intractable pruritus involving epidermal nerve density.
British Journal of Dermatology 11/2009; 161(5):1028-37. · 3.67 Impact Factor
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D P Potaczek,
Q-H Wang,
M Sanak,
T Tokura,
H Matsuda,
S Dziedzina,
N Nakano,
M Hara, H Ogawa,
A Szczeklik,
K Okumura,
C Nishiyama
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ABSTRACT: Low-affinity IgE receptor gene (FCER2) rs3760687 polymorphism was found to be associated with differential binding affinity of transcription factors Sp1 and Sp3 leading to altered transcriptional activity. Haplotypic interaction of functional FCER2 polymorphisms (rs28364072, rs2228137 and rs3760687) might potentially provide a background for genotype-phenotype associations previously observed for some rather non-functional FCER2 variants.
Tissue Antigens 10/2009; 74(6):534-8. · 2.59 Impact Factor
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ABSTRACT: Neurotropin (NTP), a biological extract from rabbit skin inoculated with vaccinia virus, is an effective analgesic and anti-allergic agent, and has antipruritic effects in various dermatoses including eczema, dermatitis and urticaria. In patients receiving haemodialysis who have pruritus, NTP appears to exert its antipruritic effect by lowering the plasma levels of substance P (SP), but its underlying mechanisms are not fully understood.
To investigate the antipruritic mechanisms of NTP.
The effects of NTP on capsaicin-induced SP release from neonatal rat dorsal root ganglion (DRG) neurones were assessed by measuring SP concentrations in culture media by a competitive ELISA. The effects of NTP on nerve growth factor (NGF)-induced neurite outgrowth were assessed by measuring the length of the longest process of cultured DRG neurones. The neuronal cytotoxicity of NTP was determined using a methylthiazole tetrazolium cytotoxicity assay.
NTP dose-dependently inhibited capsaicin-induced release of SP from cultured DRG neurones, whereas NTP alone had no effect on SP release. Moreover, NTP dose-dependently inhibited NGF-induced neurite outgrowth in cultured DRG neurones. NTP had no observable cytotoxicity.
These results suggest that NTP exerts its antipruritic effects by inhibiting both SP release and neurite outgrowth of cutaneous sensory nerves.
Clinical and Experimental Dermatology 10/2009; 35(1):73-7. · 1.20 Impact Factor
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ABSTRACT: Human IL-12B gene on chromosome 5q31 encodes the common p40 subunit of IL-12 and IL-23. IL-12 is known to play critical roles in the generation of T-helper type 1 (TH(1)) cells, whereas IL-23 is involved in maintenance and/or population expansion of TH(17) cells. Although several reports suggested an association between a polymorphism (-6415CTCTAA/GC) in IL-12B and asthma, the molecular mechanism how this polymorphism is involved in allergic inflammation is still unclear.
The transcription activity was analysed by reporter assay. A transcription factor binding to -6415 polymorphic site was identified by electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assay. The amount of cytokines produced from peripheral monocytes were determined by ELISA.
Reporter assay showed that the transcription activity of the GC allele was higher than that of the CTCTAA allele. A transcription factor Sp1 bound to the region including the GC allele with a higher affinity than that of the CTCTAA allele in EMSA. In vivo binding of Sp1 to IL-12B gene carrying -6415GC was confirmed by ChIP assay. Overexpression of Sp1 up-regulated transcription activity of promoter carrying GC allele sequence, whereas the CTCTAA promoter was not affected by Sp1. We examined the correlation between -6415CTCTA/GC polymorphism and production of cytokine IL-12/23p40, IL-12p70, and IL-23 on peripheral blood monocytes, and monocytes with the GC/GC allele exhibited significantly higher expression of IL-12p70 protein than those with the CTCTAA/CTCTAA allele (P=0.009).
The -6415 polymorphism is involved in cytokine production potential by affecting Sp1-mediated transcription activity.
Clinical & Experimental Allergy 01/2009; 39(2):228-35. · 5.03 Impact Factor
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ABSTRACT: The skin has evolved an epithelial defence mechanism which is characterized by antimicrobial peptides that inactivate various microorganisms and exhibit stimulatory activities bridging innate and adaptive immunity. Dermcidin (DCD) is a newly isolated antimicrobial peptide produced by the eccrine sweat glands in the skin. Recently, the DCD peptides DCD-1 and DCD-1L have been shown to display in vitro microbicidal activities against bacteria and viruses.
Because some skin-derived antimicrobial peptides activate keratinocytes, we investigated whether DCD-1L would also trigger keratinocyte activation.
Normal human keratinocytes were used in this study. The ability of DCD-1L to induce the production of cytokines/chemokines by keratinocytes was determined by enzyme-linked immunosorbent assay, and various inhibitors were used to investigate the stimulatory mechanism of DCD-1L. Mitogen-activated protein kinase (MAPK) phosphorylation and NF-kappaB activation were analysed by Western blotting.
DCD-1L stimulated keratinocytes to generate cytokines and chemokines including tumour necrosis factor-alpha, interleukin-8 (CXCL8), interferon-inducible protein 10 (CXCL10) and macrophage inflammatory protein-3alpha (CCL20). To determine the molecular mechanism involved, we showed that DCD-1L-mediated cytokine/chemokine production was controlled by both G-protein and MAPK pathways, as evidenced by the inhibitory effects of pertussis toxin and specific inhibitors for p38 and ERK, but not for JNK, on DCD-1L-induced keratinocyte activation. Furthermore, we confirmed that DCD-1L could induce phosphorylation of p38 and ERK, and noticeably upregulated NF-kappaB activation.
Taken together, the new activity of DCD-1L to stimulate the production of cytokines/chemokines by keratinocytes provides novel evidence for the implication of DCD, beyond its microbicidal ability, in skin immunity.
British Journal of Dermatology 12/2008; 160(2):243-9. · 3.67 Impact Factor
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ABSTRACT: Two FCER1A gene proximal promoter polymorphisms, -344C > T and -95T > C, both associated with total serum IgE and/or allergic disorders in Caucasians and East Asians, were shown to influence the gene expression in additive manner. In face of the rarity of other proximal promoter variants in Caucasians or their lack in East Asians, future investigations of the FCER1A locus in these ethnic groups should probably focus on three common haplotypes of the common -344C > T and -95T > C polymorphisms.
International Journal of Immunogenetics 09/2008; 35(4-5):339-40. · 1.29 Impact Factor
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Allergy 06/2008; 63(5):626-7. · 6.27 Impact Factor
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ABSTRACT: Psoriasis is characterized by epidermal infiltration of neutrophils that destroy invading microorganisms via a potent antimicrobial arsenal of oxidants and antimicrobial agents. In contrast to atopic dermatitis, psoriasis exhibits low levels of skin infections due to the presence of antimicrobial agents, including cathelicidin LL-37. LL-37 kills a broad spectrum of microbes, and activates neutrophil chemotaxis.
To determine whether or not LL-37 could regulate additional neutrophil functions such as production of cytokines/chemokines, reactive oxygen species and release of neutrophil antimicrobial peptides.
Human peripheral blood neutrophils were used in this study. The production of interleukin (IL)-8 and release of alpha-defensins were analysed by enzyme-linked immunosorbent assay, and real-time polymerase chain reaction (PCR) was used to quantify alpha-defensin gene expression. Phosphorylation of mitogen-activated protein kinase (MAPK) was determined by Western blotting. The generation of reactive oxygen species was examined using flow cytometry, and intracellular Ca(2+) mobilization was measured using a calcium assay kit.
LL-37 enhanced the production of IL-8 under the control of MAPK p38 and extracellular signal regulated kinase (ERK), as evidenced by the inhibitory effects of p38 and ERK1/2 inhibitors on LL-37-mediated IL-8 production. Furthermore, LL-37 induced phosphorylation of p38 and ERK. We also revealed that LL-37 stimulated the generation of reactive oxygen species dose- and time-dependently, most probably via NADPH oxidase activation and intracellular Ca(2+) mobilization. Finally, LL-37 induced both mRNA expression and protein release of alpha-defensins, known as human neutrophil peptide 1-3.
Taken together, we suggest that in addition to its microbicidal properties, LL-37 may contribute to innate immunity by enhancing neutrophil host defence functions at inflammation and/or infection sites.
British Journal of Dermatology 01/2008; 157(6):1124-31. · 3.67 Impact Factor
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ABSTRACT: The hair cycle is regulated by various molecules, among which FGF-5 has been shown to promote the transition from anagen to catagen. The FGFR-1, a trans-membrane receptor of FGF-5 with tyrosine kinase activity, is localized in the follicular papilla of hair follicles.
In order to apply the antisense oligonucleotides targeting FGFR-1 as a treatment for baldness, we examined the effect of the oligonucleotides on hair follicle growth in a serum-free organ culture system.
Vibrissal hair follicles from C3H/He mice were cultured in the presence of a reagent at 31 degrees C in 95% O(2)-5% CO(2) for 72 h. A 20-mer antisense nucleotide and its randomly arranged counterpart were prepared by predicting the effective target site of FGFR-1 mRNA. Cellular activity in the hair bulb was estimated by measuring the fluorescence intensity (FI) of the medium after incubation with AlamarBlue dye.
The addition of 30 microM of the phosphorothioate form of antisense oligonucleotide (A1561TS) to the media increased the FI by 30%, whereas the control produced no detectable change. This effect was reproducible dose-dependent with maximal stimulation at 30 microM. Incorporation of the oligonucleotide into the follicular papilla was histologically confirmed by incubation with FITC-labeled phosphorothioate oligonucleotides, and the intact morphological structure of the hair bulb was maintained intact after a 72-h incubation.
These results suggest the clinical utility of antisense nucleotide targeting FGFR-1 as a treatment for baldness.
International Journal of Dermatology 04/2007; 46(3):259-63. · 1.14 Impact Factor
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ABSTRACT: Recent studies on epigenetics, including the methylation of DNA and the enzymes regulating methylation, seem likely to contribute to understanding the pathogenesis of autoimmune diseases such as systemic lupus erythematosus (SLE). In fact, the relationship between DNA methylation and SLE has long been the subject of investigation. To obtain a deeper understanding of the role of DNA methylation in the onset of SLE, we reviewed the findings reported in the literature and our own data about DNA methylation and SLE. Various studies have indicated the possible importance of DNA methylation, especially hypomethylation, in the aetiology of SLE. Epigenetic studies may provide clues for elucidating the pathogenesis of SLE and for developing new strategies to treat this disease.
Clinical and Experimental Medicine 11/2006; 6(3):99-106. · 1.58 Impact Factor
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ABSTRACT: We report a 6-day-old Japanese girl showing generalized erythroderma accompanied by yellowish, exfoliative scaling that was accentuated on the face and scalp. Histological analysis showed psoriasiform dermatitis with acanthotic epidermis and premature shedding of the stratum corneum. Measurement of trypsin-like hydrolytic activity in SC showed six-fold greater activity compared with age-matched controls. DNA analysis revealed two mutations, 375delAT and 966insC, in exons 5 and 11, respectively, of the SPINK5 gene. Although at 4 weeks the child was still too young to display characteristic hair abnormalities or atopic diathesis, we diagnosed Netherton syndrome based on enzyme assay and DNA analysis.
Clinical and Experimental Dermatology 10/2006; 31(5):677-80. · 1.20 Impact Factor
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Journal of Dermatological Science 08/2006; 43(1):57-9. · 3.72 Impact Factor
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British Journal of Dermatology 07/2006; 131(4):585 - 586. · 3.67 Impact Factor
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ABSTRACT: Although it is thought that both Th1- and Th2-type inflammations are involved in the pathogenesis of atopic dermatitis (AD), it is controversial which immune response is more involved in regulating the clinical severity of AD. We recently found that the squamous cell carcinoma antigens 1 (SCCA1) and SCCA2 are novel biomarkers of bronchial asthma, downstream of IL-4 and IL-13.
We examined whether SCCA1 and SCCA2 could also serve as biomarkers of AD, reflecting its Th2-type immune responses, and whether the expression level of SCCA was correlated with clinical severity of AD.
We compared the expression of SCCA1 and SCCA2 at the mRNA and protein levels in both involved and uninvolved skin of AD patients and in normal control skin. We next analysed induction of SCCA by IL-4 or IL-13 in keratinocytes. Finally, we compared the serum level of SCCA with laboratory parameters reflecting Th2-type inflammation and clinical severity in AD patients.
SCCA1 and SCCA2 were highly expressed in involved skin of AD patients, compared with their uninvolved skin, at both mRNA and protein levels. SCCA protein was dominantly expressed in suprabasal keratinocytes in the epidermis of AD patients. Either IL-4 or IL-13, but not IFN-gamma or TNF, induced production of SCCA in keratinocytes. These result suggest that SCCA is induced in AD skin, probably due to direct actions of IL-4 and/or IL-13 on keratinocytes. Serum levels of SCCA were well correlated with eosinophil numbers and serum lactate dehydrogenase levels, and weakly with serum IgE levels, in AD patients. Furthermore, serum levels of SCCA were strongly correlated with clinical severity.
Th2-type inflammation dominantly regulates the clinical severity of AD, and SCCA is a relevant biomarker of AD, reflecting both Th2-type inflammation and clinical severity.
Clinical & Experimental Allergy 11/2005; 35(10):1327-33. · 5.03 Impact Factor
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ABSTRACT: We report a 6-month-old Japanese boy showing ichthyosis linearis circumflexa localized on the palms and soles. He showed bamboo hairs and aminoaciduria, and was positive for cow's milk and egg IgE antibodies by radioallergosorbent tests. Trypsin-like hydrolytic activity in the patient's lesional stratum corneum showed an activity seven times higher than that in age-matched controls. DNA analysis showed that the patient harboured the compound heterozygous mutations R790X and 1220+1 G-->C in the SPINK5 gene, compatible with the diagnosis of Netherton syndrome (NS). As the genotype/phenotype correlations in NS have not yet been fully clarified, the position of the premature termination codon in the SPINK5 gene may contribute to explain such a mild form of NS in our patient.
British Journal of Dermatology 09/2005; 153(3):661-3. · 3.67 Impact Factor
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ABSTRACT: CDK5 is a member of proline-directed serine/threonine kinases. Although its cDNA was originally cloned as a homologue to those for the other members of the cyclin-dependent kinase (CDK) family, CDK5 has been shown to function differently from other CDKs. CDK5 is activated by non-cyclin partners, p35 and p39, and important during brain development by influencing adhesion, migration and differentiation of neurones.
We sought to investigate the expression and functions of CDK5 in human keratinocytes.
Expression of CDK5/p35, interaction of CDK5/p35 with adhesion molecules, and its roles in cell-cell and cell-matrix adhesion were studied by reverse transcriptase-polymerase chain reaction, immunoblotting and aggregation/adhesion assays in primary cultured normal human keratinocytes from infant foreskins and a human keratinocyte HaCaT cell line. Localization of CDK5 and p35 in normal human epidermis and psoriatic epidermis was studied by immunohistochemistry.
Both CDK5 and p35 were expressed in primary cultured keratinocytes, HaCaT cells and normal human epidermis. Roscovitine, an inhibitor of CDK5, enhanced Ca2+-dependent (cadherin-dependent) aggregation of HaCaT cells whereas it inhibited adhesion of HaCaT cells to fibronectin associated with reduced active states of beta1 integrin. Interestingly, psoriatic skin showed reduced CDK5 and p35 expression in the lower half of the epidermis, which might be associated with decreased amount of activated beta1 integrin in the epidermis of psoriatic skin.
CDK5/p35 may be involved in cell-cell and cell-matrix adhesion in human keratinocytes by differently regulating cadherins and integrins. Furthermore, reduced expression of CDK5/p35 in the epidermis might be involved in the pathogenesis of psoriasis.
British Journal of Dermatology 08/2005; 153(1):37-45. · 3.67 Impact Factor
