Unique mouse monoclonal antibodies reactive with maturation-related epitopes on type VII collagen.

In this study, we generated a new set of monoclonal antibodies (mAbs) to bovine and human type VII collagen (COL7) by immunizing mice with bovine cornea-derived basement membrane zone (BMZ) fraction. The four mAbs, tentatively named as COL7-like mAbs, showed speckled subepidermal staining in addition to linear BMZ staining of normal human skin and bovine cornea, a characteristic immunofluorescence feature of COL7, but showed no reactivity with COL7 by in vitro biochemical analyses. Taking advantage of the phenomenon that COL7-like mAbs did not react with mouse BMZ, we compared immunofluorescence reactivity between wild-type and COL7-rescued humanized mice and found that COL7-like mAbs reacted with BMZ of COL7-rescued humanized mice. In ELISAs, COL7-like mAbs reacted with intact triple-helical mammalian recombinant protein (RP) of COL7 but not with bacterial RP. Furthermore, COL7-like mAbs did not react with COL7 within either cultured DJM-1 cells or basal cells of skin of a bullous dermolysis of the newborn patient. These results confirmed that COL7-like mAbs reacted with human and bovine COL7. The epitopes for COL7-like mAbs were considered to be present only on mature COL7 after secretion from keratinocytes and deposition to BMZ and to be easily destroyed during immunoblotting procedure. Additional studies indicated association of the speckled subepidermal staining with both type IV collagen and elastin. These unique anti-COL7 mAbs should be useful in studies of both normal and diseased conditions, particularly dystrophic epidermolysis bullosa, which produces only immature COL7.

Various peroxisome proliferator-activated receptor (PPAR)-γ agonists differently induce differentiation of cultured human keratinocytes.

Peroxisome proliferator-activated receptors (PPARs) are potentially useful for the treatment of skin diseases, because they stimulate keratinocyte differentiation, exert anti-inflammatory effects and improve barrier function. We examined five PPAR-γ agonists, including four thiazolidinediones (ciglitazone, troglitazone, rosiglitazone and pioglitazone) and an angiotensin-II receptor blocker (telmisartan), for their ability to upregulate filaggrin and loricrin expression at both mRNA and protein levels in cultured normal human keratinocytes (NHKs). Troglitazone, rosiglitazone, pioglitazone and telmisartan significantly increased filaggrin expression at both mRNA and protein levels in calcium-induced differentiated NHKs. Rosiglitazone and pioglitazone, but not troglitazone nor telmisartan, also significantly increased loricrin expression at both mRNA and protein levels in differentiated NHKs. These effects were not found in undifferentiated NHKs nor differentiated NHKs treated with ciglitazone. This study revealed differential effects of various PPAR-γ agonists on epidermal differentiation, and the most potent of those are rosiglitazone and pioglitazone.

Distinct protein expression and activity of transglutaminases found in different epidermal tumors.

We investigated protein expression and in situ activity of transglutaminases (TGs) in normal skin and various epidermal neoplasms. In normal skin, TG1 protein expression and TG activity were found at keratinocyte cell membranes in upper epidermis and granular layer, respectively. In seborrhoeic keratosis, TG1 protein was expressed evenly throughout tumors, while TG activity increased in gradient fashion from lower tumor area to cornified layer. In squamous cell carcinoma, TG1 protein was expressed at inner side of cell membranes, whereas TG activity was found in cytoplasm predominantly at horn pearls. In basal cell carcinoma, weak TG activity was found in cytoplasm of all tumor cells without the presence of TG1 protein. Immunoblotting and in situ activity assays using specific substrate peptides confirmed that TG2, but not TG1, contributed to the TG activity. These results suggested that different expression and activation of TGs may contribute to characteristics of the skin tumors.

B-cell activating factor detected on both naïve and memory B cells in bullous pemphigoid.

B-cell activating factor (BAFF), an important immune regulatory cytokine, is involved in development of autoimmune diseases. Although BAFF is expressed in various cells, including dendritic cells (DCs) and monocytes, BAFF expression on B cells has not been well documented. In the present study, BAFF molecules on DCs and naïve and memory B cells in autoimmune bullous diseases, including pemphigus vulgaris, pemphigus foliaceus and bullous pemphigoid (BP), were analysed by flow cytometry. Compared with healthy controls (HC), BAFF expression on naïve and memory B cells increased significantly in BP. No difference in BAFF receptor expression in naïve and memory B cells was shown among all study groups. Furthermore, BAFF expression in both naïve and memory B cells of BP, but not HC, was detected by confocal microscopic analysis. These results implied that BAFF expressed by B cells may play a pathogenic role in autoimmune bullous diseases, particularly BP.

How do keratinizing disorders and blistering disorders overlap?

Inherited keratinizing disorders are caused by mutations in the genes encoding cornified cell envelope proteins, enzymes and their inhibitors, adhesion molecules, cytoskeletal proteins and others in the epidermis. These molecules are known to regulate differentiation, proliferation and cell adhesions. Intriguingly, some keratinizing disorders show blistering skin lesions, while some inherited blistering disorders show abnormal keratinization. Therefore, hereditary keratinizing and blistering diseases are closely related and show overlapping genetic backgrounds. In this review, we overviewed keratinizing and blistering disorders in terms of overlapping of the two disease groups. Gene mutations in desmosomal components cause striate keratoderma, Naxos disease, epidermolytic palmoplantar keratoderma and plakophilin deficiency, which first show skin fragility and blisters and later hyperkeratosis. Gene mutations in hemidesmosomal components cause various forms of epidermolysis bullosa, some of which show hyperkeratosis on the nails, palms and soles, in addition to blister formation. Diseases with gene mutations in calcium pump proteins are Darier disease and Hailey-Hailey disease, which show clinicopathological overlaps and develop both keratinizing and blistering skin lesions. Finally, gene mutations in epidermal keratins cause epidermolysis bullosa simplex, epidermolytic ichthyosis, superficial epidermolytic ichthyosis, epidermolytic palmoplantar keratoderma and pachyonychia congenita/focal palmoplantar keratoderma, which show thickening of the palms and soles with underlying blister formation. In general, responsible proteins for diseases developing both keratinizing and blistering conditions are adhesion molecules, calcium pump proteins and keratins, but not connexins, cornified cell envelop proteins, enzymes or inhibitors. It is still unknown how particular keratinizing diseases develop blisters and vice versa.

Mizoribine treatment for antihistamine-resistant chronic autoimmune urticaria.

Chronic autoimmune urticaria is routinely diagnosed using an autologous serum skin test. Mizoribine is a newly developed immunosuppressive agent that has low toxicity. The pharmacological effects of mizoribine are similar to those of another purine biosynthesis inhibitor, mycophenolate mofetil. A 57-year-old woman presented with recurrent wheals and was insufficiently managed with administration of antihistamines, antileukotrienes, oral corticosteroids, and cyclosporine. She was positive in the autologous serum skin test. Oral mizoribine therapy was started as a combination therapy with prednisolone. The patient achieved a dramatic improvement in symptoms and complete resolution of the urticaria a few days after adding mizoribine to her treatment. The prednisolone was tapered after the start of mizoribine treatment. Her symptoms did not flare up, and no side effects were observed. In vitro basophil histamine release assays suggested that she might have anti-IgE autoantibody-type histamine release activity. We believe that mizoribine has a therapeutic role in some patients with chronic autoimmune urticaria and may be useful for treatment of cases not responsive to classical therapy. We suggest that mizoribine might help to reduce anti-IgE autoantibody acting on the surface of basophils in chronic autoimmune urticaria.

Oral zinc therapy for zinc deficiency-related telogen effluvium.

Zinc is crucial for maintaining human body homeostasis and is one of the major components of hormones, signal molecules, and enzymes. Zinc deficiency is caused by insufficient uptake of zinc from food, or caused by malabsorption syndromes, increased gastrointestinal and urinary losses, and administration of various medications. In order to test whether oral zinc administration can successfully improve zinc deficiency-related alopecia, we treated five patients with zinc deficiency-related telogen effluvium with oral zinc administration in the form of polaprezinc (Promac®). In all patients, hair loss was cured or improved. The administration of zinc for zinc deficiency-related alopecia may recover appropriate activities of metalloenzymes, hedgehog signaling, and immunomodulation, all of which are required for normal control of hair growth cycle.

Anti-laminin gamma-1 pemphigoid.

Anti-p200 pemphigoid has been characterized by autoantibodies to an unidentified 200-kDa protein (p200) of the dermal-epidermal junction. The objective of this study was to identify p200. We performed 2D gel electrophoresis of dermal extracts and immunoblotting with patients' sera, followed by MS analysis of a unique protein band. The protein band corresponded to laminin gamma1. Anti-laminin gamma1 mAb reacted with the anti-p200 immunoprecipitates by immunoblotting. Sera from 32 patients with anti-p200 pemphigoid showed 90% reactivity to the recombinant products of laminin gamma1. None of the healthy control sera reacted with laminin gamma1. By immunoblotting, reactivity of a patient's serum with p200 was competitively inhibited by adding anti-laminin gamma1 C-terminus mAb. Purified anti-p200 IgG also inhibited the reactivity of this mAb to dermal laminin gamma1. Most laminin gamma1-positive sera showed reactivity with recombinant laminin gamma1 C-terminal E8 fragment. Reactivity of patients' sera and purified IgG to dermal laminin gamma1 was higher than reactivity to blood vessel laminin gamma1 under reducing conditions. These results suggest that laminin gamma1 is the autoantigen for patients with anti-p200 pemphigoid. The autoantibodies may specifically recognize dermal laminin gamma1 with unique posttranslational modifications. The epitope is localized to the 246 C-terminal amino acids within the coiled-coil domain. The 9 C-terminal residues are known to be critically involved in laminin recognition by integrins.

Low-dose cyclosporin improves the health-related quality of life in Japanese psoriasis patients dissatisfied with topical corticosteroid monotherapy.

Psoriasis greatly impacts the health-related quality of life of patients, including any dermatological conditions that are listed in the dermatology life quality index (DLQI). We investigated the relationships between DLQI and the degree of patient satisfaction using questionnaires among psoriasis patients treated only with topical corticosteroids. Patients who were dissatisfied with topical corticosteroids alone and agreed to receive cyclosporin were given low-dose oral cyclosporin. We assessed changes of the DLQI and the psoriasis area and severity index (PASI) scores in patients dissatisfied with treatment during the period of cyclosporin addition. Of 32 enrolled patients, 17 reported dissatisfaction with the current treatment of topical corticosteroids alone. There was a significantly positive correlation between the degree of patient satisfaction questionnaires and the DLQI of these 32 patients. Among the 17 dissatisfied patients, 12 patients agreed to receive additional cyclosporin therapy and five did not. The 12 patients who started on cyclosporin had a significantly lower PASI after 12 weeks than they did at baseline. The DLQI improved significantly after 12 weeks in the cyclosporin-treated patients. The 12 patients who agreed to receive cyclosporin showed a significantly lower DLQI at 12 weeks compared to the five patients who declined the addition of cyclosporin to their treatment. Assessing the degree of patient satisfaction with therapy using a questionnaire could be useful for improving clinical interventions in psoriasis patients. Low-dose oral cyclosporin could be effective in patients who are dissatisfied with topical corticosteroid treatment alone.

Lesional Th17 cells and regulatory T cells in bullous pemphigoid.

Th17 cells play crucial roles in the pathogenesis of autoimmune diseases. We previously reported that Th17 cells are recruited to the lesional skin in pemphigus vulgaris (PV) and pemphigus foliaceus (PF). The aim of this study was to evaluate lesional Th17 cells and Treg cells in bullous pemphigoid (BP). Correlations between these cells and disease severity of BP were also evaluated. Immunohistochemical studies showed that both IL-17+ and Foxp3+ cells were present in higher numbers in BP lesions, compared with control skin. IL-17/CD4 ratio in BP was significantly higher than that in PF. Foxp3/CD4 ratio in BP was significantly less than that in either PV or PF. There were no obvious correlations between these cells and disease severity of BP. This study suggests that, compared with pemphigus, BP shows more Th17 cell-related inflammation and less Treg-related regulation.

Successful treatment with mycophenolate mofetil of four Japanese patients with pemphigus vulgaris.

Mycophenolate mofetil has been used as an immunosuppressive agent to prevent acute rejection in kidney transplantation since the early 1990s. There are several reports that mycophenolate mofetil is effective in autoimmune bullous diseases including pemphigus vulgaris in combination with high doses of systemic corticosteroids or as a monotherapy. In Japan, however, there are few reports of pemphigus vulgaris treated with mycophenolate mofetil. The present study showed that mycophenolate mofetil treatment combined with systemic corticosteroid was successful in four Japanese patients with pemphigus vulgaris who were refractory to therapies including systemic corticosteroids, plasmapheresis, and oral immunosuppressives. For Japanese and European patients, mycophenolate mofetil may be an excellent therapy in a combination with systemic corticosteroid for refractory patients with pemphigus vulgaris.

Isolation of All CD44 Transcripts in Human Epidermis and Regulation of Their Expression by Various Agents.

CD44, a cell surface proteoglycan, is involved in many biological events. CD44 transcripts undergo complex alternative splicing, resulting in many functionally distinct isoforms. To date, however, the nature of these isoforms in human epidermis has not been adequately determined. In this study, we isolated all CD44 transcripts from normal human epidermis, and studied how their expressions are regulated. By RT-PCR, we found that a number of different CD44 transcripts were expressed in human epidermis, and we obtained all these transcripts from DNA bands in agarose and acrylamide gels by cloning. Detailed sequence analysis revealed 18 CD44 transcripts, 3 of which were novel. Next, we examined effects of 10 different agents on the expression of CD44 transcripts in cultured human keratinocytes, and found that several agents, particularly epidermal growth factor, hydrogen peroxide, phorbol 12-myristate 13-acetate, retinoic acid, calcium and fetal calf serum differently regulated their expressions in various patterns. Furthermore, normal and malignant keratinocytes were found to produce different CD44 transcripts upon serum stimulation and subsequent starvation, suggesting that specific CD44 isoforms are involved in tumorigenesis via different CD44-mediated biological pathways.

Shikonin Promotes Skin Cell Proliferation and Inhibits Nuclear Factor-κB Translocation via Proteasome Inhibition In Vitro.

BACKGROUND: Shikonin is a major active chemical component extracted from Lithospermi Radix, an effective traditional herb in various types of wound healing. Shikonin can accelerate granulomatous tissue formation by the rat cotton pellet method and induce neovascularization in granulomatous tissue. The purpose of the study was to investigate its mechanism of action in human skin cells. METHODS: MTS assay was used to measure cell growth. The collagen type I (COL1 ) mRNA expression and procollagen type I C-peptide (PIP) production were detected by real-time quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Immunofluorescence and western blot analyses were carried out to investigate nuclear factor-κB (NF-κB) signaling pathway. Cell-based proteasome activity assay was used to determine proteasome activity. RESULTS: In this study, we found that 10 µmol/L shikonin stimulated the growth of normal human keratinocytes and 1 µmol/L shikonin promoted growth of human dermal fibroblasts. However, shikonin did not directly induce COL1 mRNA expression and PIP production in dermal fibroblasts in vitro. In addition, 1 µmol/L shikonin inhibited translocation of NF-κB p65 from cytoplasm to nucleus induced by tumor necrosis factor-α stimulation in dermal fibroblasts. Furthermore, shikonin inhibited chymotrypsin-like activity of proteasome and was associated with accumulation of phosphorylated inhibitor κB-α in dermal fibroblasts. CONCLUSIONS: These results suggested that shikonin may promote wound healing via its cell growth promoting activity and suppress skin inflammation via inhibitory activity on proteasome. Thus, shikonin may be a potential therapeutic reagent both in wound healing and inflammatory skin diseases.

Nodular morphea (NM): report of a case of concurrent NM and morphea profunda associated with limited type systemic sclerosis, and overview and definition for NM.

Morphea consists of various variants, including nodular morphea (NM), keloidal morphea (KM) and morphea profunda (MP). NM and KM are used synonymously. We present a 67-year-old Japanese female, the first case of limited type systemic sclerosis (SSc), developing both NM and MP. The NM and MP lesions on the lower legs were partly continuous, and showed histopathological features of morphea but not of keloid or scar. Pregabalin relieved severe lesional pain. Our literature review of all NM/KM cases indicated that some cases had merely keloid or scar, and, therefore, we first propose to abandon the term KM and use only the term NM for this condition to avoid confusion. We also propose making the diagnosis of NM only in cases showing histopathological features characteristic of SSc or morphea, which should facilitate the establishment of this entity. Our literature review also indicated that NM is closely associated with SSc, while the standard classification for morphea, which does not refer to NM/KM, probably due to ambiguity of this entity, suggests that morphea is rarely associated with SSc. Therefore, NM should be included as a distinct and unique subset in the classification of morphea when the disease entity of NM is established. Establishment of the disease entity of NM may change the general consensus of the rare association of morphea with SSc.

An attempt to develop mouse model for anti-laminin γ1 pemphigoid.

BACKGROUND: We recently reported that the autoantibodies of anti-p200 pemphigoid sera react with laminin γ1 and renamed this entity as anti-laminin γ1 pemphigoid. However, it has not been clarified whether the anti-laminin γ1 autoantibodies, particularly those to the C-terminal integrin binding site, affect the dermoepidermal junction and cause subepidermal blisters. OBJECTIVE: The aim of this study was to develop animal models for anti-laminin γ1 pemphigoid. METHODS: We attempted to produce two mouse models for anti-laminin γ1 pemphigoid; (1) a passive transfer model: injection of rabbit IgG to shorter bacterial recombinant protein of the murine laminin γ1 C-terminal 107 amino acids, and (2) an active disease model: direct immunization to mice with this recombinant protein. RESULTS: Immunoblotting revealed that 70% of patient sera reacted with the shorter recombinant protein of human laminin γ1 C-terminus. In the passive transfer model, rabbit IgG to the murine laminin γ1 C-terminus was deposited, without C3 deposition, at the epidermal basement membrane zone. In contrast, in the active disease model, direct immunofluorescence of mouse skin sections showed no deposition of either murine IgG or C3. Blister formation was not seen in either model both phenotypically and histopathologically. CONCLUSION: In the two different mouse animal models for anti-laminin γ1 pemphigoid, although rabbit IgG to the recombinant laminin γ1 C-terminus bound to the epidermal basement membrane zone in passive transfer model, no obvious blister formation was seen. To reproduce skin lesions in mouse models for anti-laminin γ1 pemphigoid, further improvement should be needed.

Morphological changes of the hair roots in alopecia areata: a scanning electron microscopic study.

Alopecia areata is a chronic inflammatory condition causing non-scarring patchy hair loss. Diagnosis of alopecia areata is made by clinical observations, hair pluck test and dermoscopic signs. However, because differentiation from other alopecia diseases is occasionally difficult, an invasive diagnostic method using a punch biopsy is performed. In this study, to develop a reliable, less invasive diagnostic method for alopecia areata, we performed scanning electron microscopy of the hair roots of alopecia areata patients. This study identified four patterns of hair morphology specific to alopecia areata: (I) long tapering structure with no accumulation of scales; (II) club-shaped hair root with fine scales; (III) proximal accumulation of scales; and (IV) sharp tapering of the proximal end of hair. On the basis of these results, we can distinguish alopecia areata by scanning electron microscopic observation of the proximal end of the hair shafts.

Anti-α-2-macroglobulin-like-1 autoantibodies are detected frequently and may be pathogenic in paraneoplastic pemphigus.

Paraneoplastic pemphigus (PNP) shows autoantibodies mainly to plakin and desmosomal cadherin family proteins. We have recently identified alpha-2-macroglobulin-like-1 (A2ML1), a broad range protease inhibitor, as a unique PNP antigen. In this study, we tested a large number of PNP sera by various methods. Forty (69.0%) of 58 PNP sera recognized A2ML1 recombinant protein expressed in COS7 cells by immunofluorescence (IF) and/or immunoprecipitation (IP)/immunoblotting (IB). IP/IB showed higher sensitivity than IF. In addition, 22 (37.9%) PNP sera reacted with A2ML1 by IB of cultured normal human keratinocytes (NHKs) under non-reducing conditions. Statistical analyses using various clinical and immunological data showed that the presence of anti-A2ML1 autoantibodies was associated with early disease onset and absence of ocular lesions. Next, to investigate the pathogenic role of anti-A2ML1 antibody, we performed additional functional studies. Addition of anti-A2ML1 polyclonal antibody to culture media decreased NHK cell adhesion examined by dissociation assay, and increased plasmin activity detected by casein zymography, suggesting that anti-A2ML1 antibody may decrease NHK cell adhesion through plasmin activation by inhibition of A2ML1. This study demonstrates that autoantibodies to A2ML1 are frequently and specifically detected and may have a pathogenic role in PNP.

Interaction of plectin and intermediate filaments.

BACKGROUND: Plectin, a member of the plakin family proteins, is a high molecular weight protein that is ubiquitously expressed. It acts as a cytolinker for the three major components of the cyotoskeleton, namely actin microfilaments, microtubules and intermediate filaments. OBJECTIVE: The aim of our experiments was to identify new binding sites for intermediate filaments on plectin and to specify these sites. METHODS: We introduced truncated forms of plectin into several cell lines and observe interaction between plectin and intermediate filaments. RESULTS: We found that a linker region in the COOH-terminal end of plectin was required for the association of the protein with intermediate filaments. In addition, we also demonstrated that a serine residue at position 4645 of plectin may have a role on binding of plectin to intermediate filaments. CONCLUSION: A linker region in the COOH-terminal end and serine residue at position 4645 may be important for the binding of plectin to intermediate filaments.