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Inflammasomes play a pivotal role in gastrointestinal homeostasis and inflammation. However, it remains elusive whether the nucleotide-binding oligomerization domain-like receptor (NLR) family inflammasomes, such as NLR family pyrin domain-containing (NLRP) 3, NLRP6, and NLRP12, are involved in the pathogenesis of canine chronic enteropathy (CE), which includes antibiotic-responsive enteropathy (ARE), food-responsive enteropathy (FRE), immunosuppressant-responsive enteropathy (IRE), and non-responsive enteropathy (NRE). Thus, we measured mRNA expression of NLRP3, NLRP6, and NLRP12 in the intestinal mucosa of 35 dogs with CE (ARE, four dogs; FRE, 11 dogs; IRE and NRE, 20 dogs) and seven healthy dogs. As per real-time PCR analysis, significant increases in mRNA expression of NLRP3 and NLRP12 were noted in the colonic but not in the duodenal mucosa of dogs with FRE compared to healthy dogs. These findings suggested that the NLRP3 and NLRP12 inflammasomes might contribute to the development of colitis in dogs with FRE.

A 7-year 6-month-old, castrated male Shiba dog presented with a 1-month history of lethargy, anorexia, vomiting, and frequent watery diarrhea. Weight loss, hypoalbuminemia, anemia, and leukocytosis were detected at the first visit. The dog was diagnosed with non-responsive enteropathy (NRE) based on clinical and histopathological examinations. Since the dog did not respond to the immunosuppressive drugs, fecal microbiota transplantation (FMT) was performed during the treatment with chlorambucil. A single endoscopic FMT into the cecum and colon drastically recovered clinical signs and clinicopathological abnormalities and corrected dysbiosis in the dog. No recurrence or adverse events were observed. The present case report suggests that FMT, possibly together with chlorambucil, might be a treatment option for NRE in Shiba dogs that have poorer prognosis compared with other dog breeds.

The molecular clock network in mast cells has been shown to be a factor responsible for circadian regulation of allergic inflammation. PF670462 is a selective inhibitor of casein kinase 1δ and e (CK1δ/e) that control the posttranslational modification of clock proteins. The aims of this study were to evaluate the effects of PF670462 on gene and protein expression of FceRI, the high-affinity IgE receptor, in canine mast cells and on IgE-mediated immediate-type cutaneous reactions in dogs. PF670462 decreased mRNA expression of FceRIα and β, but not γ, and protein expression of FceRI in a canine mast cell line. Furthermore, PF670462 suppressed IgE-mediated immediate-type cutaneous erythema in dogs. These findings indicate that CK1δ/e function as regulators for FceRI expression and IgE-mediated cutaneous reactions in dogs.

Vincristine, one of the anti-cancer drugs used in veterinary practice, has adverse hematological and gastrointestinal effects in dogs. Juzen-taiho-to is a traditional Chinese medicine used for patients with anorexia in human medicine. However, the protective effects of Juzen-taiho-to against anti-cancer drug-induced toxicity in dogs have not been investigated. We therefore examined whether the administration of Juzen-taiho-to to dogs affects gastric motility, and vincristine-induced gastrointestinal and hematological toxicity. The study was composed of three trials. In the first trial, Juzen-taiho-to (450 mg/kg/day) was orally administered to five dogs. In the second and third trials, vincristine (0.75 mg/m2) was intravenously administered to each dog in the absence or presence of Juzen-taiho-to (450 mg/kg/day). During these trials, gastric motility and blood parameters were assessed. Juzen-taiho-to increased gastric motility and improved vincristine-induced gastrointestinal, but not hematological, adverse effects in dogs. This study suggested that Juzen-taiho-to may be applicable for gastrointestinal care in dogs receiving chemotherapy.

House dust mite (HDM) is an environmental allergen ubiquitously present indoors, causing allergic inflammation in dogs. However, it is unclear whether HDM allergens can be detected in the gastrointestinal (GI) tract of dogs. In addition, although expression of interleukin (IL)-1β is increased in the intestinal mucosa of dogs with chronic enteropathy (CE), the role of HDM allergens in the production of IL-1β has not been evaluated. The objectives of this study were to determine the presence of HDM allergens in the GI tract of dogs and to elucidate the effect of HDM on IL-1β expression in canine macrophages. HDM allergen, Dermatophagoides pteronyssinus (Der p) 1, was quantified in the gastric and duodenal fluids and the duodenal and colonic mucosae of dogs with CE and healthy laboratory dogs, and faeces of dogs with CE, healthy laboratory dogs and healthy client-owned dogs. Gene expression and protein levels of IL-1β were measured in HDM-stimulated canine peripheral macrophages from healthy laboratory dogs. Der p 1 was detected in the gastric and duodenal fluids of dogs with CE and healthy laboratory dogs, and faeces of all dogs examined. Der p 1 levels in the duodenal and colonic mucosae were significantly higher in dogs with CE than in healthy laboratory dogs. HDM increased both gene expression and protein levels of IL-1β in canine macrophages. These findings demonstrate the presence of HDM allergens in the GI tract of dogs and the possible involvement of HDM allergens in the pathogenesis of CE by promoting IL-1β expression in macrophages.

An entire, female, mixed-breed cat of unknown age was presented with a 6-week history of lethargy, anorexia and vomiting There was an increase in the number of white blood cells in the blood, including neutrophils and eosinophils;moderate anaemia;ascites;and possible mesenteric peritonitis Exploratory laparotomy revealed firm, multifocal small nodules in the mesentery As the nodules were surgically unresectable, they were biopsied Histologically, the nodules were composed of thin trabeculae of dense collagen fibres mixed with plump fibroblasts and numerous eosinophils, consistent with feline gastrointestinal eosinophilic sclerosing fibroplasia Bacteria were not detected on histological examination of the nodules and cytology of the ascites Remission of disease occurred following treatment with prednisolone and ciclosporin A for 22 days and antibiotics for 40 days After remission, ciclosporin A was administered for 236 days and then discontinued Eosinophilia also resolved after treatment with ciclosporin A The cat is still alive and in good condition on day 689 This report describes what may be an atypical case of feline gastrointestinal eosinophilic sclerosing fibroplasia, lacking involvement of the gastrointestinal tract, and was apparently cured by treatment that involved ciclosporin A Copyright © 2019 British Small Animal Veterinary Association

Background Mucosal imbalance of interleukin (IL)-1β and IL-1 receptor antagonist (Ra) has been reported in the duodenal mucosa of dogs with inflammatory bowel disease (IBD). However, the imbalance in the colonic mucosa and its role in duodenitis and colitis in IBD of dogs remain unclear. Objectives To measure the expression of IL-1β and IL-1Ra proteins in the colonic mucosa of dogs with IBD, and to determine the effect of IL-1β on expression of occludin (ocln) mRNA, a tight junction component, in the duodenal and colonic mucosa of dogs with IBD. Animals Twelve dogs with IBD and 6 healthy dogs. Methods IL-1β and IL-1 Ra proteins in the colonic mucosa were quantified by ELISA in 7 of the 12 dogs with IBD. Expression of ocln mRNA in the duodenal and colonic mucosa was examined in the 12 dogs by real-time PCR. Results The ratio of IL-1β to IL-1Ra in the colonic mucosa was significantly higher in dogs with IBD than in healthy dogs. The ex vivo experiment determined that IL-1β suppressed expression of ocln mRNA in the colonic mucosa, but not in the duodenal mucosa, of healthy dogs. Expression of ocln mRNA in the colonic mucosa, but not in the duodenal mucosa, was significantly lower in dogs with IBD than in healthy dogs. Conclusions and clinical importance A relative increase in IL-1β may attenuate ocln expression, leading to intestinal barrier dysfunction and promotion of intestinal inflammation in the colonic mucosa, but not in the duodenal mucosa, of dogs with IBD.

A genital ulcer can be associated with sexually transmitted infections, such as syphilis and herpes, and sexually transmitted organisms, such as Chlamydia trachomatis. We report a case of scrotal ulcer caused by Staphylococcus aureus clone USA300 in a 56-year-old man living with human immunodeficiency virus in Osaka, Japan. It is important to enhance the awareness and surveillance regarding the potential of spread of this organism in the community of men who have sex with men in this district.

The involvement of interleukin (IL)-33 produced by keratinocytes has been suggested in the pathogenesis of canine atopic dermatitis (cAD). House dust mite (HDM)-derived proteases induce the production of various cytokines and chemokines in keratinocytes via protease-activated receptor-2 (PAR-2); however, their effects on IL-33 mRNA expression in canine keratinocytes have not been determined.To clarify whether HDM-derived proteases induce IL-33 mRNA expression in canine keratinocytes via PAR-2.Expression of IL-33 mRNA was quantified by real-time PCR in a cell line of canine progenitor epidermal keratinocytes (CPEK) stimulated with Dermatophagoides farinae (Der f) whole body extract, Der f pre-treated with cysteine protease and serine protease inhibitors, and trypsin. Trypsin and Der f-mediated IL-33 mRNA expression also was measured in CPEK cells treated with a PAR-2 antagonist.Der f enhanced IL-33 mRNA expression in CPEK cells in incubation time- and dose-dependent manners. Der f pre-treated with a serine protease inhibitor, and not a cysteine protease inhibitor, abrogated an increase in IL-33 mRNA expression in CPEK cells. Trypsin also enhanced IL-33 mRNA expression in CPEK cells. Trypsin-mediated IL-33 mRNA expression was completely abolished by a PAR-2 antagonist, while Der f-mediated IL-33 mRNA expression was partially and significantly diminished by it.Der f-derived serine protease upregulated IL-33 mRNA expression in CPEK cells at least in part via PAR-2. These findings suggest that HDM may be involved in the development ofL’implication de l’interleukine (IL)-33 produite par les kératinocytes a été suggérée dans la pathogénie de la dermatite atopique canine (cAD). Les protéases dérivées des acariens de poussière de maison (HDM) induisent la production de cytokines et chimiokines variées dans les kératinocytes via PAR-2 (protease-activated receptor-2) ; cependant, leurs effets sur l’expression d’ARNm IL-33 des kératinocytes canins n’ont pas été déterminés. HYPOTHÈSES/OBJECTIFS: Clarifier si les protéases dérivées d’HDM induisent l’expression d’IL-33 au sein des kératinocytes canins via PAR-2. MATÉRIELS ET MÉTHODES: L’expression d’ ARNm d’IL-33 a été quantifiée par PCR en temps réel dans une lignée cellulaire de CPEK (canine progenitor epidermal keratinocytes) stimulée par extrait de corps entier de Dermatophagoides farinae (Der f), Der F prétraité avec inhibiteurs de cystéine protéase et serine protéase, et Der F pré-traité avec trypsine. L’expression de trypsine et Der f médiée par l’expression d’ARNm d’IL-33 a aussi été mesurée dans les cellules CPEK traitées avec antagoniste de PAR-2. RÉSULTATS: L’expression d’ARNm IL-33 a été augmentée par Der f dans les cellules CPEK en incubation de manière temps et dose dépendante. Der f pré traité par inhibiteur de serine protéase et par inhibiteur de cystéine protéase, a supprimé l’augmentation de l’expression d’ARNm IL-33 au sein des cellules CPEK. L’expression d’ARNm d’IL-33 médiée par la trypsine était complémentent supprimée par antagoniste de PAR-2, alors que l’expression d’ARNm IL-33 médiée par Der f était partiellement et significativement diminuée.La serine protéase dérivée de Der f augmente l’expression d’ARNm d’IL-33 dans les cellules CPEK au moins en partie via PAR-2. Ces données suggèrent que HDM peut être impliquée dans le développement de CAD en augmentant l’expression d’ARNm IL-33 dans les kératinocytes.INTRODUCCIÓN: Se ha sugerido la participación de la interleuquina (IL) -33 producida por los queratinocitos en la patogenia de la dermatitis atópica canina (cAD). Las proteasas derivadas de ácaros del polvo doméstico (HDM) inducen la producción de diversas citoquinas y quimioquinas en los queratinocitos a través del receptor 2 activado por proteasa (PAR-2); sin embargo, no se han determinado sus efectos sobre la expresión de RNAm de IL-33 en queratinocitos caninos. HIPÓTESIS/OBJETIVO: aclarar si las proteasas derivadas de HDM inducen la expresión de RNAm de IL-33 en queratinocitos caninos a través de PAR-2. MÉTODOS Y MATERIALES: se cuantificó la expresión de RNAm de IL-33 mediante PCR a tiempo real en una línea celular de progenitores de queratinocitos epidérmicos caninos (CPEK) estimulados con extracto de cuerpo entero de Dermatophagoides farinae (Der f), Der F pretratado con cisteína proteasa e inhibidores de serina proteasa, y Der F pretratado con tripsina. La expresión de RNAm de IL-33 mediada por tripsina y Der f también se midió en células CPEK tratadas con un antagonista de PAR-2. RESULTADOS: Der f aumentó la expresión de RNAm de IL-33 en células CPEK en forma dependientes del tiempo de incubación y de la dosis. El pretratamiento de Der f con un inhibidor de serina proteasa, y no con un inhibidor de cisteína proteasa, anuló el aumento en la expresión de RNAm de IL-33 en células CPEK. La tripsina también incrementó la expresión de RNAm de IL-33 en células CPEK. La expresión de RNAm de IL-33 mediada por tripsina fue completamente abolida por un antagonista de PAR-2, mientras que la expresión de RNAm de IL-33 mediada por Der f disminuyó parcial y significativamente. CONCLUSIONES Y RELEVANCIA CLÍNICA: la serina proteasa derivada de Der f incrementó la expresión de RNAm de IL-33 en células CPEK al menos en parte a través de PAR-2. Estos hallazgos sugieren que HDM puede estar involucrado en el desarrollo de cAD al aumentar la expresión de RNAm de IL-33 en queratinocitos.Eine Beteiligung von Interleukin (IL)-31, welches von Keratinozyten produziert wird, an der Pathogenese der atopischen Dermatitis des Hundes (cAD), wird vermutet. Proteasen aus Hausstaubmilben (HDM) induzieren die Produktion verschiedener Zytokine und Chemokine in Keratinozyten über den Protease-Activated Rezeptor-2 (PAR-2); ihre Auswirkungen auf eine IL-33 mRNA Exprimierung in caninen Keratinozyten wurde bisher nicht bestimmt.Eine Abklärung, ob Proteasen aus HDM eine IL-33 mRNA Exprimierung in caninen Keratinozyten über PAR-2 induzieren.Die Exprimierung von IL-33 mRNA wurde mittels Real-Time PCR in einer Zelllinie von caninen epidermalen Keratinozyten Vorläuferzellen (CPEK) quantifiziert, die mittels Dermatophagoides farinae (Der f) Ganzkörperextrakt, mit Der F vorbehandelt mit Cystein Protease und Serin Protease Inhibitoren, und Der F vorbehandelt mit Trypsin stimuliert worden waren. Trypsin und Der f-mediierte IL-33 mRNA Exprimierung wurde auch in CPEK Zellen, die mit einem PAR-2 Antagonisten behandelt worden waren, gemessen.Der f verstärkte die IL-33 mRNA Exprimierung in CPEK Zellen Inkubationszeit- und Dosisabhängig. Der f vorbehandelt mit Serin Proteaseinhibitor, und nicht mit einem Cystein Proteaseinhibitor, verhinderte eine Zunahme an IL-33 mRNA Exprimierung in CPEK Zellen. Trypsin mediierte IL-33 mRNA Exprimierung wurde durch einen PAR-2 Antagonisten völlig verhindert, während Der f-mediierte IL-33 mRNA Exprimierung teilweise und signifikant dadurch vermindert wurde.Der f-stammend aus Serinprotease regelte IL-33 mRNA Exprimierung in CPEK Zellen zumindest teilweise über PAR-2 hoch. Diese Ergebnisse weisen darauf hin, dass HDM bei der Entwicklung von CAD durch Zunahme von IL-33 mRNA Exprimierung in Keratinozyten eine Rolle spielen könnten.背景: 犬アトピー性皮膚炎 (cAD) の発症には、ケラチノサイトで産生されるインターロイキン (IL)-33の関与が示唆されている。ハウスダストマイト (HDM) 由来プロテアーゼは、プロテアーゼ活性化受容体-2(PAR-2) を介してケラチノサイトで様々なサイトカインやケモカインの産生を誘導するが、犬のケラチノサイトにおけるIL-33 mRNAの発現に対する影響は明らかにされていない。 仮説・目的: 本研究の目的は、HDM 由来プロテアーゼが PAR-2 を介して犬のケラチノサイトにおける IL-33 mRNA の発現を誘導するかどうかを明らかにすることであった。 材料・方法: Dermatophagoides farinae(Der f) の全抽出物、システインプロテアーゼ阻害剤およびセリンプロテアーゼ阻害剤で前処理したDer F、トリプシンで前処理したDer Fで刺激した犬の前駆表皮角化細胞 (CPEK) において、IL-33 mRNAの発現をリアルタイムPCR法で定量した。PAR-2アンタゴニストで処理したCPEK細胞においても、トリプシンおよびDer fを介したIL-33 mRNAの発現を測定した。 結果: Der fはCPEK細胞のIL-33 mRNAの発現を、インキュベーション時間および用量に依存して促進した。Der fは、システインプロテアーゼ阻害剤ではなく、セリンプロテアーゼ阻害剤で前処理することにより、CPEK細胞におけるIL-33 mRNAの発現増加を無効にした。トリプシンもCPEK細胞におけるIL-33 mRNAの発現を促進した。トリプシンを介したIL-33 mRNAの発現はPAR-2アンタゴニストによって完全に消失したが、Der fを介したIL-33 mRNAの発現はPAR-2アンタゴニストによって部分的かつ有意に減少した。 結論と臨床的妥当性: Der f由来セリンプロテアーゼは、少なくとも部分的にはPAR-2を介してCPEK細胞のIL-33 mRNA発現を上昇させた。これらの知見は、HDMがケラチノサイトにおけるIL-33 mRNAの発現を増加させることにより、CADの発症に関与している可能性を示唆している。.背景: 角质细胞产生的白介素(IL)-33参与了犬特应性皮炎(cAD)的发病机制。屋尘螨(HDM)衍生的蛋白酶通过蛋白酶激活受体-2(PAR-2)诱导角质细胞产生各种细胞因子和趋化因子; 然而, 尚未确定其对犬角质细胞中IL-33 mRNA表达的影响。 假设/目的: 阐明HDM衍生的蛋白酶是否通过PAR-2诱导犬角质细胞表达IL-33 mRNA。 方法和材料: 用粉尘螨(Der f)全身提取物、用半胱氨酸蛋白酶和丝氨酸蛋白酶抑制剂预处理的Der f, 以及用胰蛋白酶预处理的Der f刺激的犬祖细胞表皮角质细胞(CPEK)的细胞系, 并通过实时PCR定量IL-33 mRNA的表达。在用PAR-2拮抗剂处理的CPEK细胞中也测定了胰蛋白酶和Der f介导的IL-33 mRNA表达。 结果: Der f以孵育时间和剂量依赖性方式增强CPEK细胞中IL-33 mRNA的表达。用丝氨酸蛋白酶抑制剂而不是半胱氨酸蛋白酶抑制剂预处理的Der f可消除CPEK细胞中IL-33 mRNA表达的增加。胰蛋白酶还可增强CPEK细胞中IL-33 mRNA的表达。PAR-2拮抗剂可完全消除胰蛋白酶介导的IL-33 mRNA表达, 而Der f介导的IL-33 mRNA表达可部分显著减弱。 结论和临床相关性: Der f衍生的丝氨酸蛋白酶至少部分通过PAR-2上调CPEK细胞中IL-33 mRNA的表达。这些发现提示HDM可能通过增加角质细胞中IL-33 mRNA的表达参与CAD的发生。.O envolvimento da interleucina (IL) -33 produzido por queratinócitos tem sido sugerido na patogênese da dermatite atópica canina (CAD). As proteases derivadas de ácaros da poeira doméstica (HDM) induz a produção de várias citocinas e quimiocinas por queratinócitos via receptor-2 ativado por protease (PAR-2); Entretanto, seus efeitos sobre a expressão de IL-33 mRNA em queratinócitos caninos não foram determinados. HIPÓTESE/OBJETIVO: Esclarecer se as proteases derivadas HDM induzem a expressão de IL-33 mRNA em keratinócitos caninos via par-2. MÉTODOS E MATERIAIS: Expressão do IL-33 RNAm foi quantificada por PCR em tempo real em uma linha celular de queratinócitos epidérmicos de progenitores caninos (CPEK) estimulada com extrato de Dermatophagoides farinae (Der F) inteiro, Der F pré-tratado com inibidores de protease cisteína e protease de serina e Der F pré-tratado com tripsina. A expressão de tripsina e de IL-33 mRNA mediadas por Der F também foram medidas em células CPEK tratadas com um antagonista PAR-2.Der F fortaleceu a expressão de IL-33 mRNA em células CPEK dependente do tempo de incubação e da dose. Der F pré-tratado com um inibidor de protease de serina, e não um inibidor de protease da cisteína, gerou um aumento na expressão de IL-33 mRNA em células CPEK. A tripsina também exacerbou a expressão de IL-33 mRNA em células CPEK. A expressão de IL-33 mRNA mediada por tripsina foi completamente interrompida por um antagonista de PAR-2, enquanto a expressão de IL-33 mRNA mediada por Der F foi significativamente e parcialmente diminuída por ela. CONCLUSÕES E RELEVÂNCIA CLÍNICA: As serina proteases derivadas de Der F regularam a expressão de IL-33 mRNA em células do CPEK via PAR-2 ao menos em parcialmente. Essas descobertas sugerem que o HDM pode estar envolvido no desenvolvimento da DAC aumentando a expressão de IL-33 mRNA em queratinócitos.

It remains unclear whether epithelial cell-derived cytokines, including interleukin (IL)-25, IL-33 and thymic stromal lymphopoietin (TSLP), contribute to development of canine chronic enteropathy (CE), which includes antibiotic-responsive enteropathy (ARE), food-responsive enteropathy (FRE) and inflammatory bowel disease (IBD). In the present study, we examined mRNA expression of il-25, il-33 and tslp in the duodenal and colonic mucosae of dogs with ARE, FRE and IBD. Real-time PCR analysis revealed that mRNA expression of il-33 was significantly lower in the duodenum in dogs with FRE than in healthy dogs. The results suggest that epithelial cell-derived cytokines may not be an inducer of Th2-type immunity in the gut of dogs with CE, and decreased expression of IL-33 may be involved in induction of FRE. Further studies are required to clarify roles of epithelial cell-derived cytokines, especially IL-33, in the pathogenesis of canine CE.

OBJECTIVE To characterize platelet-activating factor (PAF)–induced edema and erythema in the skin of dogs and compare those reactions with histamine-induced cutaneous reactions. ANIMALS 6 healthy Beagles. PROCEDURES Experiments were performed at ≥ 2-week intervals. Each dog received ID injections (5 μg/site) of PAF C16, PAF C18, lyso-PAF, and histamine. Edema (mean diameter) and erythema scores (none, mild, moderate, or severe) were assessed 30 minutes after the injections. Dogs received ID injections of PAF and histamine each with various concentrations of WEB 2086 (PAF receptor antagonist) or underwent ID testing with PAF and histamine before and 3 hours after oral administration of cetirizine hydrochloride or prednisolone (at 2 doses each). RESULTS ID injections of PAF C16 and PAF C18, but not lyso-PAF, induced comparable levels of edema and erythema. The PAF-induced edema and erythema peaked at 30 minutes and lasted for 6 hours after the injection; histamine-induced edema and erythema peaked at 30 minutes and lasted for 3 hours after the injection. Edema sizes and erythema scores were significantly smaller and lower, respectively, for PAF than for histamine. The WEB 2086 inhibited PAF-induced but not histamine-induced edema and erythema. Cetirizine slightly, but significantly, repressed PAF-induced edema and erythema as well as histamine-induced cutaneous reactions. Prednisolone suppressed both PAF-induced and histamine-induced edema and erythema. CONCLUSIONS AND CLINICAL RELEVANCE In canine skin, the duration of PAF-induced inflammation was longer than that of histamine-induced inflammation. The PAF- and histamine-induced cutaneous reactions were effectively suppressed by oral administration of prednisolone. The importance of PAF in dogs with anaphylaxis and allergic disorders warrants further investigation.

There have been limited reports on the prevalence of adverse food reactions among dogs suffering from chronic enteropathy (CE) in Japan. We examined the prevalence and histological features of food-responsive enteropathy (FRE) in a total of 32 dogs with history of CE. Fourteen of 18 cases (56.2%) diagnosed as FRE had lymphocytic-plasmacytic enteritis or eosinophilic enteritis by histopathological examination. Characteristic histopathological changes indicating FRE were not identified in 18 cases, though 4 cases did not show any abnormalities. Results collected from this study provided important information that can help to change the way dogs with CE are treated in the future.

A time-of-day-dependent variation in IgE-mediated passive systemic anaphylaxis was previously reported in ICR mice. In the present study, we investigated time-of-day-dependent variations in IgE-, histamine-, and platelet-activating factor (PAF)-mediated systemic anaphylaxis in C57BL/6, BALB/c, and NC/Nga mice at 9:00 h and 21:00 h, and evaluated the potential influence of glucocorticoids (GCs) on these variations. We found significant time-of-day-dependent variations in IgE-mediated systemic anaphylaxis in C57BL/6 mice, and in histamine- and PAF-mediated systemic anaphylaxis in BALB/c mice. Significant daily variations in IgE-, histamine-, and PAF-mediated systemic anaphylaxis were not observed in NC/Nga mice. Pretreatment with dexamethasone and adrenalectomy abolished the daily variations in IgE-mediated systemic anaphylaxis in C57BL/6 mice and in PAF-mediated systemic anaphylaxis in BALB/c mice, suggesting that GCs from adrenal glands are pivotal in regulating these variations. In contrast, pretreatment with dexamethasone and adrenalectomy did not abolish the daily variation in histamine-mediated systemic anaphylaxis in BALB/c mice, suggesting that GC-independent and adrenal gland-independent mechanisms are important for the variation. The present study demonstrated that time-of-day-dependent variations in systemic anaphylaxis differed among inbred mouse strains and with anaphylaxis-inducing substances. Thus, mouse strains, time of experiment, and anaphylaxis-inducing substances used must be considered to obtain appropriate experimental results.

A 9-year-old, spayed female Chihuahua was presented with a 1-week history of lethargy and anorexia. Abdominal ultrasonography and computed tomography found bilateral adrenal masses without metastasis. Serum cortisol levels that were sampled before and after an adrenocorticotropic hormone stimulation test were within reference ranges. Lethargy and anorexia completely resolved after short-term fluid therapy; the clinical signs did not occur for approximately 8 months until her sudden death. A postmortem examination revealed bilateral adrenocortical carcinomas and liver metastasis. Primary adrenocortical carcinomas developed in the dog met the definition of bilateral incidental adrenal gland masses (IAGMs). This is the first case report to demonstrate based on histological identification that adrenocortical carcinomas cause bilateral IAGMs in dogs.

In the current study, molecular, biological, and antigenic analyses were performed to characterize Border disease virus (BDV) strain FNK2012-1 isolated from a pig in 2012 in Japan. The complete genome comprises 12,327 nucleotides (nt), including a large open reading frame of 11,685 nt. Phylogenetic analysis revealed that FNK2012-1 was clustered into BDV genotype 1 with ovine strains. FNK2012-1 grew in porcine, bovine, and ovine primary cells and cell lines, but grew better in bovine and ovine cells than in porcine cells. Specific pathogen–free pigs inoculated with FNK2012-1 did not show any clinical signs. Noninoculated contact control pigs also did not show clinical signs and did not seroconvert. The results suggest that FNK2012-1 may be of ruminant origin and is poorly adapted to pigs. Such observations can provide important insights into evidence for infection and transmission of BDV, which may be of ruminant origin, among pigs.

To gain further insight into the genomic features of bovine viral diarrhea virus 1 (BVDV-1) subgenotypes, we sequenced the complete genome of BVDV-1n Shitara/02/06 and BVDV-1o IS26NCP/01. The complete genome of Shitara/02/06 and IS26NCP/01 shared 77.7 to 79.3% and 78.0 to 85.7% sequence identities with other BVDV-1 subgenotype strains, respectively.

To detect allergen-specific IgE in dogs with allergic diseases, we developed a recombinant canine high affinity IgE receptor α chain (FcεRIα)-based IgE detection system. Using the recombinant protein of canine FcεRIα expressed by an Escherichia coli expression system, we could detect house dust mite (Dermatophagoides farinae) allergen-specific IgE in sera from dogs naturally and experimentally sensitized to this allergen with ELISA and western blotting. The IgE binding activity of recombinant canine FcεRIα on ELISA was impaired by heat treatment of these sera. The specificity of this recombinant canine FcεRIα-based IgE detection system was confirmed by inhibition assays with canine IgE. The recombinant canine FcεRIα-based IgE detection system established in this study offers an alternative tool to measure allergen-specific IgE in dogs.

Mast cells are one of the major producers of prostaglandins (PGs). The final metabolite of PGs 15-deoxy-delta-12,14-PGJ2(15-deoxy-delta PGJ2) is the endogenous ligand of the peroxisome proliferator-activated receptor (PPAR) γ. PPARγ modulates adipocyte differentiation; therefore, we attempted to investigate whether PGs derived from mast cells influenced on adipogenesis. We found the increase of mast cell numbers in fat tissue of obese mice fed with a high-fat diet allowed us to speculate contributions of mast cells to adipogenesis. Mast cell-mediated induction of adipogenesis was evaluated by using 3T3 L1 cells. Supernatants obtained from mast cells stimulated with calcium ionophore or the high-glucose condition contained 15-deoxy-delta PGJ2and induced adipogenesis of 3T3 L1 cells. Agonistic activity of PGJ2from the supernatants on PPARγ was confirmed by a reporter gene assay. Culture medium collected from calcium ionophore-stimulated bone marrow-derived cultured mast cells (BMCMC) activated PPAR-responsive element in NIH3T3 fibroblasts, and the specific inhibitor of PPARγ canceled the activation. Contribution of mast cells to obesity was evaluated by using mast cell-deficient mice fed with a Western diet. Weight gain of mast cell-deficient mice during high-fat feeding was impaired compared with their littermate wild-type mice; on the other hand, transplantation of bone marrow-derived cultured mast cells to mast cell-deficient mice restored the weight gain by intake of a high-fat diet. In this study, we clearly demonstrated that mast cells produced PGs in response to the high-glucose condition and induced adipocyte differentiation and possibly obesity. This is the first study that provides evidence for a novel role of mast cells in adipogenesis via PPARγ activation.

Basophils mediate many of their biological functions by producing IL-4. However, it is unknown how the Il4 gene is regulated in basophils. Here, we report that CCAAT/enhancer-binding protein α (C/EBPα), a major myeloid transcription factor, was highly expressed in basophils. We show that C/EBPα selectively activated Il4 promoter-luciferase reporter gene transcription in response to IgE cross-linking, but C/EBPα did not activate other known Th2 or mast cell enhancers. We found that the PI3K pathway and calcineurin were essential in C/EBPα-driven Il4 promoter-luciferase gene transcription. Our mutation analyses revealed that C/EBPα drove Il4 promoter-luciferase activity depending on its DNA binding domain. Mutation of the C/EBPα-binding site in the Il4 promoter region abolished C/EBPα-driven Il4 promoter-luciferase activity. Our results further showed that a mutation in nuclear factor of activated T cells (NFAT)-binding sites in the Il4 promoter also negated C/EBPα-driven Il4 promoter-luciferase activity. Our study demonstrates that C/EBPα, in cooperation with NFAT, directly regulates Il4 gene transcription.

Lymphoid neoplasms including lymphoma and leukemia are one of the most life-threatening disorders in dogs. Many lymphoid malignancies are well-treated with glucocorticoid (GC); however, GC resistance sometimes develops and its mechanism remains uncertain. Since constitutive activation of nuclear factor-κB (NF-κB) has been reported to play roles in lymphoid malignancies, we examined whether inhibition of NF-κB activity with a synthetic inhibitor IMD-0354 affected GC sensitivity of canine neoplastic lymphoid cells, CL-1 and GL-1. Dexamethasone failed to inhibit proliferation of these cells, in which low expression of glucocorticoid receptors (GR) was identified. In the presence of IMD-0354, GR expressions in CL-1 and GL-1 were increased, consequently dexamethasone inhibited their proliferation. These results indicated that GR expression might be down-regulated by spontaneous activation of NF-κB, resulting in GC resistance. Taken together, interference of NF-κB activity may have the synergistic effect in combination chemotherapy with GC for treatment against lymphoid malignancies.

Ultrapure soft water (UPSW) is water in which calcium and magnesium ions have been replaced with sodium ions using a cation-exchange resin. We recently demonstrated that washing with soap and UPSW reduced the clinical severity of dermatitis and improved the skin barrier function in NC/NgaTnd mice, a murine model for human atopic dermatitis. The purpose of this pilot study was to evaluate the efficacy of shampoo treatment with UPSW for dogs with pruritus. Eleven dogs with pruritus were randomly assigned to two groups depending on whether they received weekly shampoo treatment with UPSW or tap water for 4 weeks. After a washout period, the treatment protocol was switched such that each dog received both treatments. The pre-treatment and post-treatment values of the following were compared: pruritus scores assessed by the owners; dermatitis scores recorded by an investigator; and transepidermal water loss (TEWL). Shampoo treatment with UPSW significantly decreased pruritus and dermatitis scores in the dogs, whereas shampoo treatment with tap water did not. In addition, shampoo treatment with UPSW, but not with tap water, significantly reduced TEWL in the dogs. Adverse events due to the treatment were not observed in the dogs. Furthermore, we found that topical application of UPSW for barrier-disrupted skin caused by tape stripping in healthy dogs decreased TEWL more rapidly than topical application of tap water. Our findings suggest that shampoo treatment with UPSW promotes skin barrier recovery and thus could be considered as a possible therapeutic option in the management of pruritus and dermatitis in dogs.

There has been a need for improvement of the elimination diet used for diagnosis of adverse food reaction (AFR) in dogs. Recently, a novel elimination diet composed of a mixture of amino acids and potatoes was developed. We evaluated the efficacy of the elimination diet for diagnosis of AFR in dogs. Twenty dogs that were suspected to have allergic dermatitis were enrolled in a 2-month food elimination trial using the diet. Before and after the trial, the clinical symptoms were evaluated based on the change in canine atopic dermatitis extent and severity index (CADESI), pruritus score and medication score. Of the 20 dogs, 15 completed the food elimination trial. The remaining 5 dogs were removed from the trial because of diet unpalatability, skin disease progression or diarrhea. On the basis of evaluation of the clinical scores, we observed that the clinical symptoms improved in 11 of the 15 dogs that completed the food elimination trial. Provocative challenge was performed in 10 of the 11 dogs that showed improvement in their clinical symptoms. Of the 10 dogs, 7 were diagnosed as having AFR against food ingredients such as pork, beef, chicken and wheat because their skin symptoms reappeared after intake of these ingredients. The results of the food elimination trial and the provocative challenge indicated the usefulness of the novel elimination diet for diagnosis of AFR.

Prevalence of allergies has increased during the last two decades. Alteration of the gut microbiota composition is thought to play a crucial role in development of atopic diseases. Oral administration of probiotics has been reported to treat and/or prevent symptoms of atopic diseases in infants, but the results are still controversial. We investigated the potential efficacy of dietary interventions by a probiotic strain on prevention and treatment of atopic dermatitis (AD) in a human-like AD model, NC/NgaTnd mice by perinatal administration. Pregnant NC/NgaTnd mice were orally treated with the probiotic strain Lactobacillus rhamnosus CGMCC 1.3724 (LPR), which was followed by treatment of pups until 12 weeks of age. LPR-treated mice exhibited significant lower clinical symptoms of dermatitis, reduced scratching frequency, lower levels of plasma total Immunoglobulin E and higher levels of interferon-gamma in skin biopsies, compared with untreated mice. The protective effect was also observed when mice started to be treated at weaning time (5 weeks of age) even with limited supplementation period of 2 weeks. However, treatment of mice with the probiotic starting 1 week after the onset of the disease (8 weeks of age) had limited effects. The usefulness of LPR for primary prevention of AD was supported.

Recent work has established important roles for basophils in regulating immune responses. To exert their biological functions, basophils need to be expanded to critical numbers. However, the mechanisms underlying basophil expansion remain unclear. In this study, we established that IL-3 played an important role in the rapid and specific expansion of basophils. We found that the IL-3 complex (IL-3 plus anti-IL-3 Ab) greatly facilitated the differentiation of GMPs into basophil lineage-restricted progenitors (BaPs) but not into eosinophil lineage-restricted progenitors or mast cells in the bone marrow. We also found that the IL-3 complex treatment resulted in ∼4-fold increase in the number of basophil/mast cell progenitors (BMCPs) in the spleen. IL-3-driven basophil expansion depended on STAT5 signaling. We showed that GMPs but not common myeloid progenitors expressed low levels of IL-3 receptor. IL-3 receptor expression was dramatically up-regulated in BaPs but not eosinophil lineage-restricted progenitors. Approximately 38% of BMCPs expressed the IL-3Rα-chain. The up-regulated IL-3 receptor expression was not affected by IL-3 or STAT5. Our findings demonstrate that IL-3 induced specific expansion of basophils by directing GMPs to differentiate into BaPs in the bone marrow and by increasing the number of BMCPs in the spleen.

Gain-of-function mutations in the proto-oncogene c-kit have been considered the molecular mechanism of neoplastic proliferation of mast cells. However, the importance of c-kit gene mutations is not well evaluated in canine mast cell tumors (MCTs). In the present study, we established and characterized a mast cell line, HRMC, derived from a dog with MCT. We also examined c-kit mutations in HRMC cells and assessed an inhibitory effect of a tyrosine kinase inhibitor, STI571, on HRMC cells. HRMC cells had cytoplasmic metachromatic granules, chymase and tryptase, and expressed both KIT and FcepsilonRI on the cell surface. HRMC cells contained histamine and released beta-hexosaminidase through FcepsilonRI cross-linking and calcium ionophore stimulation. Nucleotide sequence analysis demonstrated no mutations in an open reading frame of c-kit cDNA and genomic DNA of the juxtamembrane domain of c-kit in HRMC cells. STI571 did not show any inhibitory effects on the proliferation of HRMC cells. These findings clearly demonstrated the existence of c-kit mutations-independent neoplastic canine mast cell proliferation. The growth factor-independent mast cell line established in this study might be valuable to explore novel mechanisms of c-kit mutations-independent neoplastic proliferation of mast cells in dogs.

Naive CD4(+) T cells were reported to produce small amounts of IL-4 in vitro, which are implicated to be sufficient to initiate T(h)2 response in vivo. However, IL-4-producing naive CD4(+) T cells are difficult to study in vivo because they are present in low numbers shortly after the first antigen exposure. Here, we used IL-4/green fluorescence protein (GFP) reporter mice (G4 mice) to track the initial response of CD4(+) IL-4-producing cells. We first established a flow cytometry method to estimate the number of GFP(+) cells. We demonstrated the effectiveness of this method by showing that the responding CD4(+)GFP(+) cells exhibited an activated phenotype, possessed the capacity to express IL-5 and IL-13, but not IFN-gamma mRNA, and showed enhanced levels of GATA3 and c-maf mRNA expression. More importantly, we showed that the cell lines derived from FACS-sorted CD4(+)GFP(+) cells were antigen specific. By using this newly established method, we showed that the majority of responding GFP(+) cells were CD4(+) T cells. Our study provides direct ex vivo evidence to show that a small percent of CD4(+) T cells that have no previous experience of antigenic stimulation might produce IL-4 to initiate T(h)2 response.

We previously demonstrated the presence of IgE directed to fetal calf serum (FCS) in the sera from dogs that developed allergic reactions after vaccination. In this study, by an immunoblot analysis, we investigated the IgE-reactive components of FCS using sera from 16 dogs that exhibited allergic reactions after vaccination. The immunoblot analysis revealed that several FCS proteins of approximately 25-, 50-, 66-, 75-, 120-, and 175-kDa strongly reacted with IgE in the sera from dogs that showed post-vaccination allergic reactions. The 66-kDa band was detected in the sera from 14 of the 16 dog serum samples analyzed in the immunoblot analysis for FCS, and it was speculated to be albumin based on its molecular weight; however, serum IgE reactivity to bovine serum albumin could be detected in only four of the 14 dog samples. These findings demonstrated that a variety of FCS components including albumin could function as allergens in dogs that developed allergic reactions after vaccination.

The objectives of this study were to determine daily variation in intradermal reactivity to histamine in dogs and to evaluate a potential influence of glucocorticoids on reactivity. Wheal sizes formed after intradermal injections of histamine were measured every 6 h during a single 24 h period in six healthy dogs. To determine whether glucocorticoids were implicated in daily variation, intradermal reactivity to histamine was evaluated at 9:00 h and at 21:00 h during a single day in dogs that received oral prednisolone (a synthetic glucocorticoid) or oral trilostane (an inhibitor of endogenous glucocorticoid synthesis). Finally, the time required for the histamine reaction to diminish after an intravenous injection of hydrocortisone was also assessed. A significant time-of-day-dependent variation in intradermal reactivity to histamine was detected in dogs, with a larger wheal size observed at 9:00 h than at 21:00 h. Administration of prednisolone or trilostane disrupted this variation. Intradermal reactivity to histamine was significantly reduced 6 h after an intravenous injection of hydrocortisone. These results suggest that glucocorticoid secretion from the adrenal glands could be involved in the regulation of daily variation in histamine-mediated reactions in dogs.

A canine highly similar to retinoic acid receptor alpha (canine HS-RARa) cDNA was isolated from the spleen tissue. A database search and the alignment revealed that the canine cDNA was most similar to highly similar type of human RARa and was named canine HS-RARa. The expression of the genes encoding RARa in the dog was the highest in the testis and moderate in the blood, lymph node, mammary gland, pancreas, salivary gland, spleen, thyroid gland, tonsil and uterus. The nucleotide sequence encoded the 462-amino acid containing the conserved sequence motif of RARa. Though the amino acid sequences were well-conserved among species, some unique arrangements were observed within each class. In the phylogenetic analysis, each species separated according to their class. In the branch of mammals, the dog is in the cluster of humans, mice and western wild mice. However, hamsters and rats formed another branch.

The receptors for endothelin (ET) family, ETA and ETB, were molecularly cloned and the expression of ETA and ETB as well as preproendothelin-1 (PPET-1, precursor of ET-1) was examined in normal canine tissues by RT-PCR. The entire open reading frames of the canine ETA and ETB were shown to encode 427 and 442 amino acid residues, respectively, showing from 87.4 to 97.3% sequence similarity to human, mouse, and rat counterparts. ETA and ETB mRNAs were ubiquitously expressed in a variety of canine tissues in this study and PPET-1 mRNA was detected in the tissues except for heart and liver. It was speculated that ET could play an important role in physiological events in most of the organs.

Thymus and activation-regulated chemokine (TARC) is a member of CC chemokine and plays an essential role in recruitment of CC chemokine receptor 4 positive Th2 cells to allergic lesion. To investigate the association of TARC in allergic inflammation of cats, a TARC cDNA was cloned from feline thymus by RT-PCR with 3' rapid amplification of cDNA ends (RACE) method. The feline TARC clone contained a full length open reading frame encoding 99 amino acids which shared 80.8%, 72.5%, 65.6% and 67.8% homology with dog, human, mouse and rat homologues, respectively. Expression of TARC mRNA was detected not only in thymus but also in spleen, lung, lymph node, kidney, small intestine, colon and skin of the normal cat tissues examined. Furthermore, it was found that TARC mRNA was strongly expressed in lesional skin of cats with eosinophilic plaque. The present results demonstrated that TARC might be involved in the pathogenesis of eosinophilic plaque in cats.

Scratching and skin barrier dysfunctions are pivotal features and therapeutic targets of atopic dermatitis (AD); however, time-of-day-dependent variations of these characteristics remain unclear. NC/Tnd mice have been shown to exhibit severe scratching behavior and skin barrier disruption together with the development of spontaneous atopic dermatitis when they are raised under air-uncontrolled environment. In the present study, time-of-day-dependent variations of scratching behavior and transepidermal water loss (TEWL) were evaluated in NC/Tnd mice that developed moderate to severe AD. Analysis of the mice for 24 hr revealed that scratching frequency and duration were increased from in the afternoon to the nocturnal period when locomotor activity was low, and scratching behavior was decreased in the morning. The highest scratching frequency and duration were 3.8- and 4.1-fold increases in the lowest scratching frequency and duration, respectively. In addition, TEWL on the dorsal skin lesion was decreased in the diurnal period, while that was increased in the nocturnal period. The highest TEWL was a 1.3-fold increase in the lowest TEWL. Significant daily variations were detected in scratching frequency and duration and TEWL. These results indicate that NC/Tnd mice are an appropriate mouse model to investigate time-of-day-dependent variations of scratching behavior and skin barrier dysfunctions associated with AD.

DNA immunization induces systemic humoral and cellular immune responses to the antigen encoded by cDNA in a plasmid DNA. In the present study, a plasmid DNA encoding cDNA of beta-galactosidase (beta-gal), pCAGGS-lacZ, was inoculated intramuscularly to a healthy dog in order to evaluate location and duration of the gene expression. On day 7, the plasmid DNA was found by PCR in the muscle where the plasmid was injected. Furthermore, beta-gal expression was detected in the same muscle sample by beta-gal staining. However, the plasmid DNA was not detected in any samples collected on days 14, 21 and 28. The present results suggest that duration of the gene expression of beta-gal by the plasmid DNA is limited in the muscle in dogs and an efficacy for a gene expression should be evaluated depending on the gene inserted in the plasmid DNA for immunotherapy.

Contribution of SCF auto-production to neoplastic growth of mast cells. Mastocytosis is a disease accompanied by the abnormal expansion and accumulation of mast cells. Although the D816V mutation is detected in most cases of systemic mastocytosis, the mutation is rarely observed in other forms of mastocytosis, such as cutaneous mastocytosis and mast cell leukemia/sarcoma, for which the mechanism of tumorigenesis remains unknown. In this study, we demonstrated a novel mechanism of mast cell tumorigenesis via SCF autocrine/paracrine release. SCF was highly expressed in a WT KIT-expressing HRMC line, contributing to the phosphorylation of KIT. Neutralization of external SCF using a neutralizing antibody or suppression of SCF production by RNA interference inhibited the growth of HRMC cells, indicating the essential role of SCF in cell proliferation. To the best of our knowledge, this is the first report to determine the significant contribution of SCF autoproduction to neoplastic proliferation of mast cells. These results indicate the possibility that targeting SCF production may become a novel treatment for mast cell malignancies.

Circadian rhythms have a periodicity of approximately 24h and, in mammals, are regulated by clock genes. In this study, expression profiles of clock genes (per1, per2, clock, bmal1 and cry1) were investigated over a single 24h period by real-time PCR in peripheral blood mononuclear cells (PBMCs) of healthy dogs and canine PBMCs treated in vitro and in vivo with glucocorticoids. Only per1 mRNA exhibited daily rhythms in canine PBMCs. Canine PBMCs cultured with dexamethasone in vitro had dose- and time-dependent increases in per1 mRNA expression. Intravenous injection of dexamethasone increased expression of per1 in canine PBMCs in vivo. Rhythmic expression of per1 in PBMCs could be used as a molecular marker for monitoring circadian rhythms and the effects of drugs on clock genes in dogs.

Background Effects of probiotics on the prevention of atopic diseases have been proposed recently. Although we have already reported the suppressive effects of the probiotic, ImmuBalance™, on a mouse model for peanuts allergy, its influence on atopic diseases remains unclear. Objective Potential efficacy of ImmuBalance™, which is the fermented soy product, on treatment of atopic dermatitis (AD) was investigated using a mouse model for human AD, NC/Tnd mice. Methods For in vivo study, ImmuBalance containing chow or a control diet were fed to NC/Tnd mice with moderate dermatitis for 2 weeks. Topical application of FK506 ointment was used as a positive control. Clinical skin severity scores, scratching behaviors, trans-epidermal water loss (TEWL), and histological features were analyzed. For in vitro study, suppressive effect of ImmuBalance™ on nerve growth factor (NGF)-activated neurite outgrowth of PC12 cells was examined. Results Clinical skin severity scores of the mice fed with ImmuBalance containing chow were gradually reduced as well as the mice treated with FK506. Feeding with ImmuBalance completely inhibited the increase in scratching behavior of NC/Tnd mice. The value of TEWL of NC/Tnd mice fed with ImmuBalance was significantly decreased. In addition, histological examination revealed that application of ImmuBalance decreased the number of PGP9.5-positive neuronal fibers in the lesional skin. When ImmuBalance extract was added to the culture, NGF-activated neurite outgrowth of PC12 cells was diminished through the inhibition of the phosphatidylinositol 3-kinase phosphorylation. Conclusion ImmuBalance could exhibit favorable alterations on AD symptoms, particularly through down regulation of the itch sensation.

Adverse reactions to vaccines were examined in 311 canine cases reported to the Ministry of Agriculture, Forestry and Fisheries in Japan during the period of 6 years from April of 1994 to March of 2000, and classified according to their clinical symptoms. There were 27 cases of adverse reactions to rabies virus vaccines. Gastrointestinal symptoms were the most frequently observed (26%), followed by respiratory and/or cardiovascular symptoms (22%) and dermatologic symptoms (11%). There were 284 cases of adverse reactions to non-rabies monovalent vaccines and mixed vaccines. Dermatologic symptoms were the most frequently observed (53%), followed by gastrointestinal symptoms (16%) and respiratory and/or cardiovascular symptoms (14%). Of the total 311 cases, 11 (3.5%) died of adverse reactions to vaccines.

Aims Intermittent claudication (IC) is one of the serious symptoms of peripheral arterial disease (PAD) and is characterized by pain in the legs or buttocks that worsens with exercise and subsides with rest. The concept of ‘therapeutic angiogenesis’ for PAD has been widely proposed; however, the methodology, including cell transplantation, is still unclear. In this study, we examined the clinical efficacy of silencing the int6 gene, which encodes a protein that stabilizes hypoxia-inducible factor (HIF)-2α, on angiogenesis in PAD. Methods and results An animal model for IC was established in Sprague–Dawley rats by external iliac artery ligation and evaluated by quantitative analysis of gait disturbance. Next, we explored the therapeutic effects of int6 siRNA injected into the adductor magnus muscle on IC. Recovery of hindlimb function occurred in the early stages after int6 siRNA injection. The number of blood vessels showed an obvious increase in the int6 siRNA-treated muscles. Angiography revealed the recovery of peripheral circulation at the affected sites. Early up-regulation of HIF-2α and other angiogenic factors, including basic fibroblast growth factor and hepatocyte growth factor, was also apparent in the int6 siRNA-treated sites. We also confirmed the up-regulation of HIF-2α and its translocation to the nucleus in the int6 siRNA-injected muscle. Conclusion A single injection of int6 siRNA promoted angiogenesis via up-regulation of HIF-2α-related angiogenic factors in the muscles of the affected hindlimb and reduced gait disturbance. The int6 gene may be a novel therapeutic target for the treatment of IC in patients with PAD.