Osamu Negi

Evaluation of epidermal nerve density and opioid receptor levels in psoriatic itch.

Background  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.

Topically applied semaphorin 3A ointment inhibits scratching behavior and improves skin inflammation in NC/Nga mice with atopic dermatitis

BACKGROUND Epidermal hyperinnervation in atopic dermatitis (AD) is activated directly by various external stimuli, causing enhanced itching. Nerve density is regulated by the nerve repulsion factor semaphorin 3A (Sema3A), along with nerve elongation factors. OBJECTIVE To investigate the effects of Sema3A ointment in the NC/Nga mouse model of AD. METHODS An AD-like phenotype was induced by repeated application of Dermatophagoides farinae body (Dfb) ointment to the dorsal skin of NC/Nga mice. Vaseline, heparinoid, betamethasone, tacrolimus and recombinant Sema3A ointments were applied to the lesional skin once a day for 4 days. Transepidermal water loss (TEWL) was measured before and after each treatment. We also scored the degree of dermatitis and recorded videos to observe scratching behavior. Subsequently, we collected skin samples from these mice for histological analyses. RESULTS Topical application of Sema3A, betamethasone and tacrolimus ointments significantly inhibited scratching behavior and improved dermatitis scores in Dfb-treated mice compared with control mice, whereas vaseline and heparinoid had no effects. A significant improvement of TEWL was observed only in Sema3A ointment-treated mice. Moreover, Sema3A ointment reduced the densities of PGP9.5- and substance P-immunoreactive nerve fibers in the epidermis and the numbers of inflammatory cells, such as CD4 immunoreactive T cells and eosinophils, and improved acanthosis in the Dfb-treated mice compared with controls. CONCLUSION Sem3A ointment may have therapeutic efficacy in patients with pruritus and dermatitis of AD.

Topical application of emollients prevents dry skin-inducible intraepidermal nerve growth in acetone-treated mice

Abstract In common dermatoses, such as atopic dermatitis (AD), a decline in skin barrier function often accompanies an increased severity of clinical symptomatology, including pruritus [1]. Skin barrier disruption alters epidermal innervation and increases nerve density in the skin [2]. These findings are indicative of increases in sensory receptors responsive to exogenous trigger factors, suggesting that hyperinnervation is partly responsible for intense itch sensations [2]. Therefore, the abnormal innervation associated with skin barrier dysfunction such as dry skin has been considered as a target of antipruritic therapy. Moreover, recent studies have demonstrated that epidermal innervation is probably regulated by a fine balance of nerve elongation factors (e.g., nerve growth factor (NGF), amphiregulin, gelatinase) [2] and nerve repulsion factors (e.g., semaphorin 3A (Sema3A), anosmin-1) [2,3]. Although many people use emollients daily to alleviate symptoms of clinically and subjectively dry skin [4], the effects of emollients on nerve fiber density and nerve growth activity in dry skin remain unclear. We therefore examined the anti-nerve growth effects of petrolatum and heparinoid cream in the epidermis of acetone-treated mice, an animal model of acute dry skin [5].

Keratinocyte-derived anosmin-1, an extracellular glycoprotein encoded by the X-linked Kallmann syndrome gene, is involved in modulation of epidermal nerve density in atopic dermatitis

BACKGROUND Epidermal nerve density is increased in atopic dermatitis (AD), suggesting that the hyperinnervation is partly responsible for abnormal itch perception. It is probably controlled by axonal guidance molecules produced by keratinocytes. An extracellular matrix glycoprotein anosmin-1 encoded by KAL1 has chemoattractive or chemorepulsive effects on different neuronal types. OBJECTIVE This study was performed to investigate the roles of anosmin-1 in skin innervation. METHODS Rat dorsal root ganglion (DRG) neurones were cultured in conditioned medium from control or KAL1-overexpressing cells for neurite outgrowth assay. KAL1 expression in cultured epidermal keratinocytes or human skin was examined by quantitative RT-PCR (qRT-PCR). Anosmin-1 distribution in normal and atopic skin was examined immunohistochemically. The effects of calcium concentrations and cytokines on KAL1 expression in cultured normal human epidermal keratinocytes (NHEK) were analysed by qRT-PCR. RESULTS Neurite outgrowth in cultured DRG neurones was inhibited by conditioned medium from KAL1-overexpressing cells, while it was rescued by addition of recombinant fibroblast growth factor receptor 1 for capturing anosmin-1. KAL1 transcripts were expressed in cultured keratinocytes or in normal skin. Anosmin-1 was strongly expressed in the basal cell layer of normal skin, but decreased in atopic skin, concomitant with increases of epidermal nerve fibres. KAL1 expression was downregulated during keratinocyte differentiation. The expression was also upregulated by interleukin-4 (IL-4), IL-13 or transforming growth factor (TGF)-beta1. TGF-beta1 acted synergistically with IL-13 to enhance KAL1 expression, while interferon-gamma inhibited its expression. CONCLUSION Anosmin-1 produced by epidermal keratinocytes in response to calcium concentrations or cytokines may modulate epidermal nerve density in AD.

Histamine H4 Receptor Antagonists Ineffective against Itch and Skin Inflammation in Atopic Dermatitis Mouse Model

TO THE EDITOR Histamine is the best known pruritogen in humans and the most commonly used experimental itch-causing substance. It induces increased itch responses in the lesional skin of atopic dermatitis (AD) patients compared with normal skin (Ikoma et al., 2006). However, histamine H1 receptor (H1R) antagonists frequently fail to relieve the itch in AD patients as well as it does in patients with systemic diseases such as kidney and liver diseases. The lack of amelioration by high-potency H1R antagonists of different types in patients with itch suggests that other systems are involved (Ikoma et al., 2006; Ständer and Weisshaar, 2012). Involvement of histamine H4 receptor (H4R) in histamine-evoked itch in animal models has been reported (Dunford et al., 2007; Thurmond et al., 2008). However, the therapeutic efficacy of H4R antagonists on the H1R antagonistresistant itch in AD is poorly understood. We therefore examined the therapeutic effects of H4R antagonists on itch and skin inflammation in AD using NC/Nga mice, a mouse model of AD that has been previously described (Tanaka et al., 2012). Male NC/Nga mice (Charles River Japan, Yokohama, Japan), 10 weeks old, were maintained in clean condition. All animal procedures were approved by the institutional Animal Care and Use Committee of Juntendo University Graduate School of Medicine. It is generally accepted worldwide that AD patients are highly sensitized to house dust mite allergens (Sanda et al., 1992); and that house dust mite Dermatophagoides farinae body (Dfb) and feces are wellknown major environmental allergens (Matsuoka et al., 1995). We used a Dfb ointment-induced AD-like mouse model (Dfb-NC/Nga) to evaluate the therapeutic efficacy of H4R antagonists against itch-related behavior (scratching) and dermatitis in a mouse model of AD. Dermatitis was induced by application of Dfb ointment (Biostir, Kobe, Japan) twice a week for 3 weeks as described (Yamamoto et al., 2009). Severity of skin lesion was graded according to the criteria as described (Matsuda et al., 1997). Animals that received repeated application of Dfb ointment to their skin (Figure 1a) showed higher dermatitis scores than controls after 3 weeks (data not shown). After the induction, transepidermal water loss was measured using a Tewameter TM210 (Courage and Khazawa, Cologne, Germany) and scratching behavior was observed for 2 hours using a MicroAct (Neuroscience, Tokyo, Japan) as described (Inagaki et al., 2003). Dfb-NC/Nga mice showed significant loss of transepidermal water and more scratching bouts (data not shown). We examined effects of H4R antagonists, JNJ7777120 and JNJ28307474, on dermatitis and scratching behavior in Dfb-NC/Nga mice. In mice, antagonist JNJ28307474 shows a longer plasma half-life than JNJ7777120 (Thurmod et al., unpublished observations). Mice that scored over 5 for dermatitis severity were treated by either intraperitoneal injection with a vehicle (20% dimethylsulphoxide and 80% 2-hydroxypropyl-b-cyclodextrin in saline) or H4R antagonists (10 or 30 mg kg ) three times per week for 3 weeks (Figure 1a). Dermatitis score was assessed after each Dfb application, and the data were expressed as fold change values over score of dermatitis before H4R antagonist treatment (baseline) in each group. No significant amelioration of dermatitis followed treatment by either of these H4R antagonists (Figure 1b and c). In addition, scratching behavior was recorded before and after H4R antagonist treatment (# shown in Figure 1a). The data were expressed as fold change values over number of scratching bouts before the treatment (baseline) in each group. Behavior analyses revealed neither treatment inhibited scratching behavior (Figure 1d and e). Moreover, the fold change value of scratching bouts significantly increased by treatment of 30 mg kg 1 JNJ28307474 (Figure 1e). Treatment with JNJ7777120 or JNJ28307474 had no effect on locomotion activity (Kamo et al., unpublished observations). In this study, we found that treatment with H4R antagonist (JNJ7777120 or Accepted article preview online 20 August 2013; published online 19 September 2013 Abbreviations: AD, atopic dermatitis;; Dfb, Dermatophagoides farinae body; H1R, histamine H1 receptor; H4R, histamine H4 receptor A Kamo et al. Effects of H4R Antagonist on Dfb-AD Model

Successful treatment of three cases of generalized pustular psoriasis with granulocyte and monocyte adsorption apheresis.

Generalized pustular psoriasis (GPP) is a rare form of psoriasis characterized by the presence of variable numbers of sterile pustules appearing in erythematous and scaly lesions, which are associated with moderate to severe constitutional symptoms. It can be life‐threatening especially in the elderly; therefore, medical care must be performed in rapid succession of treatment especially in refractory cases. We have performed granulocyte and monocyte adsorption apheresis (GCAP) on three GPP cases associated with several systemic and laboratory findings. As a result, the edema, erythema and numbers of sterile pustules on the skin lesions were reduced dramatically in all three patients after the first sessions of GCAP therapy. The sizes of the psoriatic lesions were reduced in all three patients following a weekly GCAP treatment for 5 consecutive weeks. Psoriasis area and severity index on discharge had improved in all three patients. No serious adverse effects were observed for up to at least 8 months after treatment. We therefore considered GCAP as one effective alternative to currently existing therapies, especially for recalcitrant cases of GPP.

Efficacy of an emollient containing diethylene glycol/dilinoleic acid copolymer for the treatment of dry skin and pruritus in patients with senile xerosis

Pruritus frequently reduces quality of life (QOL) in patients with senile xerosis. This study investigated the moisturizing and antipruritic effects of a topical emollient containing a diethylene glycol/dilinoleic acid copolymer (D/DC) in patients with pruritic senile xerosis.

Erratum to “Topical application of emollients prevents dry skin-inducible intraepidermal nerve growth in acetone-treated mice” [J. Dermatol. Sci. 62 (2011) 64–66]

Erratum to ‘‘Topical application of emollients prevents dry skin-inducible intraepidermal nerve growth in acetone-treated mice’’ [J. Dermatol. Sci. 62 (2011) 64–66] Atsuko Kamo , Mitsutoshi Tominaga , Osamu Negi , Suhandy Tengara , Hideoki Ogawa , Kenji Takamori * a Institute for Environmental and Gender Specific Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Urayasu, Chiba 279-0021, Japan Department of Dermatology, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba 279-0021, Japan

Monitoring of immunoglobulin A antibodies to epidermal and tissue transglutaminases over an 18-month period in a Japanese patient with dermatitis herpetiformis

Dear Editor, Dermatitis herpetiformis (DH) is a subtype of autoimmune bullous diseases and is considered as the cutaneous expression of a gluten-sensitive enteropathy (GSE), which is indistinguishable from celiac disease. DH is relatively common in Caucasian populations, but it is very rare in the Japanese. Also, several differences between Caucasian and Japanese DH have been reported. Japanese DH shows a high frequency of fibrillar immunoglobulin A (IgA) deposition in the papillary dermis, rarely associates with GSE and has no human leukocyte antigen (HLA) DQ2/DQ8 haplotype. Additionally, in contrast to high sensitivity (60–80%) and specificity (90–100%) of IgA antiepidermal transglutaminase (eTG) antibodies in Caucasian DH, IgA antibodies to both eTG and tissue transglutaminase (tTG) are infrequently detected in Japanese DH. A 26-year-old Japanese man was referred to our hospital with a 3-week history of pruritic erythema, papules and vesicles on the face, trunk and extremities (Fig. 1a,b). There was no history of GSE. Histological examination from a chest lesion revealed a neutrophilic infiltrate in the subepidermal blister formation (Fig. S1). Direct immunofluorescence (IF) showed granular IgA deposition in the papillary dermis (Fig. S2). Indirect IF studies were negative. HLA haplotypes were A24, A33, B60, B44, DR12 and DR13. The patient was diagnosed with DH based on these findings. Immunoglobulin A anti-eTG and anti-tTG antibodies in the patient sera were monitored over an 18-month period. At the first visit, IgA anti-eTG and anti-tTG antibodies were positive (145 and 35 AU/mL, respectively; cut-off, <22) (Fig. 1f). Four weeks after administration of dapsone 75 mg/day, no new skin lesions developed (Fig. 1c), and only IgA anti-eTG antibodies decreased to 103.42 AU/mL. Thereafter, dapsone was tapered and discontinued in 6 months, when only pigmented lesions remained (Fig. 1d). At this time, IgA antibodies to both eTG and tTG decreased to 84.13 and 29.84 AU/mL, respectively. After dapsone was discontinued, IgA anti-eTG antibodies remained positive but stable. In contrast, IgA antitTG antibodies decreased to the normal range in 12 months.