Masaki Ibe

Asahikawa Medical University, Asahikawa, Hokkaido, Japan

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Publications (8)22.6 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Psoriasis is a chronic inflammatory skin disease, which has been increasing during the last 50 years in Japan. The aim of the present study is to analyze psoriatic patients registered from 1983-2007 in Asahikawa Medical College Hospital, which is located in the northern part of Japan. A total of 607 cases were registered at the first inspection in the Department of Dermatology, Asahikawa Medical College. Men (403 cases, 66.4%) were predominant over women (204 cases, 33.6%). The clinical types of psoriasis were psoriasis vulgaris (91.5%), guttate psoriasis (4.2%), psoriasis arthropathica (2.8%), psoriatic erythroderma (0.6%), generalized pustular psoriasis (0.6%), localized pustular psoriasis (0.15%) and infantile psoriasis (0.15%). Topical corticosteroids (78.1%) and vitamin D3 (18.1%) products were the main previous topical agents. Previous systemic treatments included etretinate (7.7%), cyclosporine (1.5%) and methotrexate (0.3%). Use of topical vitamin D3 and cyclosporine therapies have been gradually increasing during the past 25 years. Regarding the previous phototherapy, topical psoralen and ultraviolet A therapy (PUVA) (4.9%) was predominant over ultraviolet B (0.9%), and systemic PUVA (0.7%). Use of ultraviolet B phototherapy has been increasing during the past 5 years. The results are essentially similar to those of a survey of psoriasis in Japan from 1982-2001. Although the incidence of psoriasis might be higher in Hokkaido Prefecture, there is essentially no variation in the disease profile of psoriatic patients.
    The Journal of Dermatology 12/2009; 36(12):632-7. · 1.77 Impact Factor
  • Journal of Dermatological Science 05/2008; 50(1):73-5. · 3.52 Impact Factor
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    ABSTRACT: Cystatin A is a cysteine proteinase inhibitor abundantly expressed in keratinocytes. Although cystatin A is one of the cornified cell envelope constituents and expressed in the upper epidermis, its precise function is still unknown. Ultraviolet B irradiation (UVB) induces apoptosis accompanied with the activation of cysteine proteinases, caspases. We investigated the effect of cystatin A on UVB-induced apoptosis of keratinocytes. We assessed the caspase activities and apoptotic cell numbers induced by UVB ittadiation in cystatin A gene transfected keratinocytes. UVB-induced pro-caspase 3 cleavage and caspase 3 activation were suppressed in cystatin A expression vector-transfected SV40-transformed human keratinocytes (SVHK). Furthermore, the transfected SVHK cells were resistant to UVB-induced apoptosis. In contrast neither caspase 8 nor caspase 9 activities were affected by UVB irradiation in cystatin A-transfected SVHK cells. The effects were also observed in cystatin A expression adenovirus vector-transfected cultured normal human keratinocytes (NHK). Conversely knockdown of cystatin A by si-RNA induced marked apoptosis of NHK cells following UVB irradiation accompanied with increased caspase 3 activity. In order to confirm the antiapoptotic effect of cystatin A in vivo UVB irradiation was performed on cystatin A transgenic mice (cystatin A-tg). The epidermis from cystatin A-tg was resistant to UVB-induced apoptosis compared to control mice epidermis. These results indicate that cystatin A suppresses UVB-induced apoptosis of keratinocytes by the inhibition of caspase 3 activation.
    Journal of Dermatological Science 07/2007; 46(3):179-87. · 3.52 Impact Factor
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    ABSTRACT: Recent study revealed that photodynamic therapy (PDT) with a novel photosensitizer (ATX-S10(Na)) shows more potent effects for various skin diseases than ALA-PDT. The effect of ATX-S10(Na)-PDT on dermal fibroblasts is still unknown. Using dermal fibroblasts derived from normal and scleroderma patients, and mouse skin in vivo, we compared the effects of ATX-S10(Na)-PDT and ALA-PDT. Fibroblasts from normal, scleroderma patients or mice skin were treated with ATX-S10(Na)-PDT or ALA-PDT. After the PDT treatments, the expression of matrix metalloproteinases (MMPs) Tissue inhibitors of metalloproteinases (TIMPs) and collagen synthesis was assayed using ELISA and reverse transcription-PCR (RT-PCR). The expression of MMP-1 and MMP-3 was slightly decreased and collagen I mRNA was significantly increased in scleroderma fibroblasts compared with normal fibroblasts. Both ATX-S10(Na)-PDT and ALA-PDT increased the expression of MMP-1 and MMP-3 in protein and mRNA levels in both normal and scleroderma fibroblasts with more potent effect by ATX-S10(N)-PDT. Collagen I synthesis was markedly decreased by ATX-S10(Na)-PDT and by ALA-PDT again with more potent effect by ATX-S10(Na)-PDT in both normal and scleroderma fibroblasts. In mice skin the effect of PDT for MMPs and collagen I was also detected and the effect was more potent in ATX-S10(Na)-PDT. In contrast, MMP-2, TIMP-1, TIMP-2, and collagen III expression was not affected by the ATX-S10(Na)-PDT or ALA-PDT treatment. ATX-S10(Na)-PDT is more potent modulator for dermal matrix components than ALA-PDT and might be useful for scleroderma patients.
    Archives for Dermatological Research 12/2006; 298(6):257-63. · 2.71 Impact Factor
  • International Journal of Dermatology 04/2005; 44(3):260-2. · 1.34 Impact Factor
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    ABSTRACT: The active form of vitamin D(3), 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D3), regulates proliferation and differentiation of keratinocytes. Cystatin A, a cysteine proteinase inhibitor, is a cornified cell envelope constituent and a differentiation marker of keratinocytes. In the present study, we examined the effect of 1,25(OH)(2)D3 on the expression of cystatin A of cultured normal human keratinocytes (NHK). 1,25(OH)(2)D3 suppressed NHK proliferation in a dose-dependent manner with the maximal effect at 1x10(-7) M. It also stimulated cystatin A promoter activity and its expression with similar dose effects. The increased cystatin A was detected by 24 h and the effect was accompanied by the suppression of ERK activity. Cystatin A promoter activity was not affected by cotransfection of vitamin D(3) receptor or retinoid X receptor. Further analyses disclosed that the 12- o-tetradecanoylphorbol-13-acetate (TPA)-responsive element (TRE), T2 (-272 to -278), in cystatin A promoter is critical for the regulation by 1,25(OH)(2)D3. Transfection of the dominant-negative form of ERK adenovirus (Ad-dnERK) increased cystatin A promoter activity and its expression, which was markedly augmented by 1,25(OH)(2)D3 treatment. Transfection of the dominant-active form of Raf-1 (Ad-daRaf-1) or MEK1 (Ad-daMEK1) inhibited 1,25(OH)(2)D3-dependent cystatin A promoter activity and its expression. Consistent with these results, the MEK1 inhibitor, PD98059, further augmented 1,25(OH)(2)D3-induced cystatin A promoter activity and its expression. The present study demonstrated that the 1,25(OH)(2)D3-responsive element in the cystatin A gene is identical to the TRE, T2 (-272 to -278), and that the suppression of Raf-1/MEK1/ERK1,2 signaling pathway increases cystatin A expression of NHK.
    Archives for Dermatological Research 07/2003; 295(2):80-7. · 2.71 Impact Factor
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    ABSTRACT: The active vitamin D3 regulates proliferation and differentiation of epidermal keratinocytes. Recently topical vitamin D3, tacalcitol, calcipotriol, and maxacalcitol are widely used for psoriasis. To examine the effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on cultured normal keratinocytes (NHK) and compared its effect with those of various vitamin D3 analogues. Cell proliferation of NHK cells was analyzed by MTS, BrdU and 3H-thymidine incorporation. The expression of involucrin, transglutaminase 1, keratin 5 and keratin 1 was investigated by western blot and PCR amplification and quantitative assay. Furthermore, we performed cornified cell envelope (CE) formation assay. 1,25(OH)2D3, tacalcitol, calcipotriol, and maxacalcitol decreased NHK cell proliferation in a concentration-dependent manner and the maximal effect was observed at 10(-7) M. There was no significant difference in the anti-proliferative effect among the active vitamin D3 analogues. The expression of involucrin and transglutaminase 1 were induced by 1,25(OH)2D3 and its analogues in mRNA and protein levels. CE formation was also induced by 1,25(OH)2D3 and its analogues. There was no significant difference in the potency among these chemicals. Keratin 5 and 1 expression was not altered by these active vitamin D3 analogues. The present study demonstrated that active vitamin D3 analogues, tacalcitol, calcipotriol, and maxacalcitol, suppress keratinocyte proliferation and induce differentiation with similar potency.
    Journal of Dermatological Science 03/2003; 31(1):21-8. · 3.52 Impact Factor
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    ABSTRACT: Psoriatic skin shows markedly increased keratinocyte proliferation and altered differentiation with various abnormal signalling pathways. In the present study, we investigated the expression of mitogen-activated protein kinases in psoriatic skin. Immunohistochemical study showed increased extracellular regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) expression in the nuclei of involved epidermis. Western blot analyses confirmed the increased active phospho-ERK and phospho-JNK expression in the involved epidermis. In contrast, expression pattern of p38 was not different between the involved and uninvolved epidermis, which was confirmed by western blot analysis. These results indicate that psoriatic epidermis shows selective activation of ERK and JNK, which might be related to hyperproliferation and abnormal differentiation of psoriatic epidermis.
    Journal of Dermatological Science 12/2002; 30(2):94-9. · 3.52 Impact Factor