Noriko Komitsu

Low-intensity pulsed ultrasound activates the phosphatidylinositol 3 kinase/Akt pathway and stimulates the growth of chondrocytes in three-dimensional cultures: a basic science study

IntroductionThe effect of low-intensity pulsed ultrasound (LIPUS) on cell growth was examined in three-dimensional-cultured chondrocytes with a collagen sponge. To elucidate the mechanisms underlying the mechanical activation of chondrocytes, intracellular signaling pathways through the Ras/mitogen-activated protein kinase (MAPK) and the integrin/phosphatidylinositol 3 kinase (PI3K)/Akt pathways as well as proteins involved in proliferation of chondrocytes were examined in LIPUS-treated chondrocytes.MethodsArticular cartilage tissue was obtained from the metatarso-phalangeal joints of freshly sacrificed pigs. Isolated chondrocytes mixed with collagen gel and culture medium composites were added to type-I collagen honeycomb sponges. Experimental cells were cultured with daily 20-minute exposures to LIPUS. The chondrocytes proliferated and a collagenous matrix was formed on the surface of the sponge. Cell counting, histological examinations, immunohistochemical analyses and western blotting analysis were performed.ResultsThe rate of chondrocyte proliferation was slightly but significantly higher in the LIPUS group in comparison with the control group during the 2-week culture period. Western blot analysis showed intense staining of type-IX collagen, cyclin B1 and cyclin D1, phosphorylated focal adhesion kinase, and phosphorylated Akt in the LIPUS group in comparison with the control group. No differences were detected, however, in the MAPK, phosphorylated MAPK and type-II collagen levels.ConclusionLIPUS promoted the proliferation of cultured chondrocytes and the production of type-IX collagen in a three-dimensional culture using a collagen sponge. In addition, the anabolic LIPUS signal transduction to the nucleus via the integrin/phosphatidylinositol 3-OH kinase/Akt pathway rather than the integrin/MAPK pathway was generally associated with cell proliferation.

Decreased Expression of Caveolin-1 Contributes to the Pathogenesis of Psoriasiform Dermatitis in Mice

Psoriasis is a chronic inflammatory skin disease characterized by excessive proliferation and abnormal keratinocyte development, in which T helper type 17 cells and signal transducer and activator of transcription 3 (STAT3) activation have pivotal roles. Moreover, caveolin-1 (CAV-1) has been implicated in the regulation of signal transduction, and aberrant CAV-1 expression is involved in a variety of diseases. However, whether CAV-1 is involved in psoriasis is unknown. Here we examined CAV-1 expression in the psoriatic epidermis and investigated its role in the pathogenesis of psoriasis. CAV-1 was markedly reduced in lesional epidermis of psoriasis patients. CAV1 silencing in keratinocytes in vitro revealed significant activation of STAT3, leading to increased expression of keratin 16 and several cytokine/chemokines, such as IL-6, C-X-C chemokine ligand 8 (CXCL8), CXCL9, and C-C chemokine ligand 20. In addition, psoriasis-related cytokines, including tumor necrosis factor-α (TNF-α), decreased CAV-1 expression in keratinocytes. Finally, administration of CAV-1 scaffolding domain peptide in a murine model of psoriasis-like skin inflammation induced by imiquimod improved the skin phenotype and reduced epidermal thickness and infiltrating cell counts. Furthermore, expression of TNF-α, IL-17A, and IL-23 was significantly suppressed by this treatment. Collectively, our study indicated that CAV-1 participates in the pathogenesis of psoriasis by regulating the STAT3 pathway and cytokine networks.

Elevation of serum squamous cell carcinoma antigen 2 in patients with psoriasis: associations with disease severity and response to the treatment†

Squamous cell carcinoma antigen (SCCA) belongs to the ovalbumin–serpin family and is a known tumour marker. Expression of SCCA is upregulated in the serum and skin of patients with psoriasis.

The serum level of HMGB1 (high mobility group box 1 protein) is preferentially high in drug‐induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms

denominator of TEN development. A single or multiplier effect by idiosyncratic, dose-related or drug-interactive reactions of phytochemicals or contaminants might be involved in the development of TEN in these patients. The objective evaluation by the Naranjo adverse drug reaction (ADR) probability scale calculated a possible ADR by the herbal remedy in cases 1 and 3 and a probable cause in case 2. In all cases, the TEN-specific algorithm for epidermal necrolysis (ALDEN) confirmed a possible cause of herbal remedies in TEN developement.

Pro-fibrotic phenotype of human skin fibroblasts induced by periostin via modulating TGF-β signaling

BACKGROUND Periostin is a matricellular protein that belongs to a class of extracellular matrix (ECM)-related molecules defined by their ability to modulate cell-matrix interactions. We previously reported an elevated level of circulating periostin in patients with systemic sclerosis (SSc) and its association with the severity of skin sclerosis. OBJECTIVE To examine the role of periostin in transforming growth factor (TGF)-β signaling involved in fibrosis. METHODS Levels of periostin were examined in skin and lung fibroblasts obtained from SSc patients. Levels of ECM proteins and pro-fibrotic factors were evaluated in periostin-expressing human skin fibroblasts in the presence or absence of TGF-β. Effects of periostin on the Smad proteins were also evaluated following stimulation with TGF-β by immunoblotting, immunofluorescence staining, and RNA interference. RESULTS Periostin was strongly expressed in skin and lung fibroblasts from SSc patients. Although recombinant periostin alone did not affect ECM protein levels, TGF-β and recombinant periostin treatment or periostin overexpression in skin fibroblasts significantly enhanced the production of ECM proteins. Overexpression of periostin in the presence of TGF-β also augmented expressions of α-smooth muscle actin and early growth response-1 but decreased the level and activity of matrix metalloproteinase 1. Interestingly, the level of Smad 7, a TGF-β-inducible inhibitor of TGF-β signaling, was reduced in periostin-expressing fibroblasts but increased in periostin-silenced fibroblasts. In addition, Smad 7 reduction induced by periostin was partially inhibited in integrin αV-silenced fibroblasts. CONCLUSION Periostin contributes to fibrosis by enhancing TGF-β signaling via Smad 7 inhibition, which may lead to ECM deposition and periostin generation.

Serum levels of squamous cell carcinoma antigens 1 and 2 reflect disease severity and clinical type of atopic dermatitis in adult patients

BACKGROUND Recent studies have indicated that serum levels of squamous cell carcinoma antigen (SCCA) 1 and 2 induced by type 2 cytokines such as IL-4 and IL-13, are increased in patients with atopic dermatitis (AD). However, no clinical studies have analyzed serum levels of SCCA2 in larger series of AD patients or their association with various clinical characteristics. This study was performed to clarify whether serum levels of SCCA2 are associated with disease severity and clinical phenotypes of adult AD patients. METHODS An enzyme-linked immunosorbent assay was performed to examine serum SCCA2 levels in 240 adult patients with AD and 25 healthy controls in this study. Serum SCCA2 levels were analyzed with clinical characteristics and laboratory parameters including thymus and activation-regulated chemokine (TARC), lactate dehydrogenase (LDH), blood eosinophils, total IgE, and specific IgE (Japanese cedar pollen, Dermatophagoides farina, Candida, malassezia, Staphylococcal enterotoxin B). Expression of SCCA2 in AD eruption was examined by immunohistochemistry. The effect of treatment on serum SCCA2 was also assessed. RESULTS Serum SCCA2 level showed a positive correlation with disease severity, levels of TARC, LDH, eosinophil counts, and IgE levels. Robust expression of SCCA2 was detected in the supra basal keratinocytes in the epidermis of AD patients. Serial measurements of serum SCCA2 revealed decreased levels of SCCA2 after treatment for AD. CONCLUSIONS Serum SCCA2 levels reflected disease severity and clinical type of AD. Serum SCCA2 may thus be a relevant biomarker for AD.

Reduction of interleukin-10 production by B cells in intractable toxic epidermal necrolysis.

Several interleukin (IL)‐10 producing B‐cell subsets have been identified recently. However, few studies have examined the role of them in toxic epidermal necrolysis (TEN). We describe a 41‐year‐old woman with TEN who had B‐cell lymphoma and a history of treatments including B‐cell depletion therapy. Her re‐epithelization was still ongoing after 7 months, despite treatments. To investigate her immune system, we compared cytokine and chemokine production from B cells and non‐B cells isolated from the patient and another non‐lymphoma TEN patient. IL‐10 production from B cells decreased in the patient compared with the control TEN‐only patient. Cytokine and chemokine levels from non‐B cells involved in inflammation were elevated in the patient compared with the control patient. In conclusion, this study demonstrates that IL‐10 from B cells as well as regulatory T cells is critical in the pathogenesis of TEN, and that B‐cell dysfunction based on B‐cell lymphoma and B‐cell depletion therapy may be involved in the intractability of TEN.