Search

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.

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.

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.

Background Successful clinical outcomes of faecal microbiota transplantation (FMT) for recurrent Clostridium difficile infection have been reported in humans and a marmoset. However, it has been unclear whether oral FMT was effective for the treatment of C. difficile-associated diarrhoea in dogs. Case presentation An 8-month-old, intact male French bulldog was presented with a 4-month history of intermittent large bowel diarrhoea. Physical and clinical examinations did not identify any specific causes for diarrhoea. Real-time PCR analysis and immunochromatography detected C. difficile antigen and toxin A&B genes and proteins in a faecal sample. Based on these findings, diarrhoea in the dog was considered to be induced by C. difficile-associated colitis. The dog was treated with oral FMT, in which a faecal solution obtained from a healthy beagle was orally administered to the subject. Stool consistency and frequency and faecal blood and mucus became normal 2–3 days after oral FMT, and real-time PCR analysis and immunochromatography was negative for C. difficile antigen and toxin A&B genes and proteins. No adverse events were observed. Conclusion The present case report demonstrated that oral FMT was an effective treatment for C. difficile-associated diarrhoea in a dog. The findings in this report provide a rationale to evaluate clinical efficacy of oral FMT for other gastrointestinal diseases in dogs.

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 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.

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.

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.

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.

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.

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.

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.

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.

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.

Aquaporins (AQPs) function as water channels in many types of cells involved in fluid transport. More than 10 isoforms have been identified, and these are differentially expressed in many types of mammalian cells in the body. Six AQPs (AQP0, AQP1, AQP3, AQP4, AQP5, and AQP9) have been identified in the eyes of humans and/or rodents. The unique permeability characteristics and distribution of AQPs indicate their diverse roles in the regulation of water homeostasis in the eye. The aim of this study was to investigate the localisation of AQPs in normal canine eyes, with AQP0 protein expressed in the crystalline lens and retina. Although AQP1 mRNA was detected in various areas of the canine eye, its protein expression was limited to the cornea, iris and ciliary body. AQP4 was identified in the iris, retina and optic nerve. AQP3 and AQP5 were found in the cornea and conjunctiva, and their expression was particularly high in the limbus. AQP3 and AQP5 were present in the nictitating membrane indicating that they play a role in water transport within the membrane. The observations suggested that several subtypes of the AQP family are involved in the regulation of water homeostasis in the canine eye.

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.

It is essential to develop a technique to culture purified skin-derived mast cells (SMCs) to facilitate immunological research on allergic diseases in dogs. This study was performed to develop an efficient culture system for canine SMCs and to characterize the cells in comparison to canine bone marrow-derived mast cells (BMMCs). Enzymatically digested skin biopsy samples were cultivated in serum-free AIM-V medium supplemented with recombinant canine stem cell factor. Three to five weeks after the initiation of culture, mast cells were collected by a magnetic activated cell separation system using anti-c-Kit antibody. The collected cells were composed of a uniform population showing morphological characteristics of mast cells with a round or oval nucleus and abundant toluidine blue-positive metachromatic granules in the cytoplasm. The results of flow cytometric analysis for the presence of cell membrane c-Kit and Fc epsilon receptor I (FcepsilonRI) indicated that approximately 90% of the cells were mast cells. The cytoplasmic granules were positive for both tryptase and chymase. Apparent dose-dependent degranulation was induced by antibody-mediated cross-linking of immunoglobulin E (IgE) bound to the cells. These cytological and immunological characteristics observed in SMCs were mostly similar to those observed in BMMCs; however, IgE-mediated degranulation was significantly lower in SMCs than BMMCs. The culture system for canine SMCs developed in this study would be useful in understanding the pathophysiology and developing anti-allergic therapeutics in canine allergic dermatitis.

Much is known regarding participations of mast cells with innate and acquired immunity by secreting various cytokines and chemical mediators. However, details of mast cell biology still remain unclear. In this study, we successfully established a novel growth factor-independent mast cell line (MPT-1) derived from canine mast cell tumor. MPT-1 cells manifested factor-independent proliferation as floating cells containing a large amount of histamine, as well as chymase-like dog mast cell protease 3, in cytosolic granules. Particularly, MPT-1 cells expressed high-affinity IgE receptors (FcepsilonRI) and wild-type c-kit receptors. Degranulation of MPT-1 cells was induced not only by stimulation with calcium ionophore but also by cross-linkage of the surface IgE. Given that MPT-1 is the first mast cell line with FcepsilonRI which has no c-kit mutations, MPT-1 cells may provide great contribution for investigation of IgE-mediated activation mechanisms of mast cells, leading to development of effective treatment for allergic disorders.

IgE-reactive beef components were examined by an immunoblot analysis using a serum from a dog with food hypersensitivity against beef. The immunoblot analysis revealed a distinct band at approximately 66 kDa and a faint band at approximately 50 kDa. The immunoblot analysis for serum IgE reactivity to bovine serum albumin (BSA) also revealed a positive band at 66 kDa. Serum IgE reactivity to the 66-kDa protein of beef was diminished by pre-incubating the serum sample with BSA. Furthermore, a positive reaction to BSA was detected in intradermal testing in the dog. These results clearly indicated that BSA was an IgE-reactive beef component in the dog with food hypersensitivity against beef.

Summary Background Since dogs frequently develop allergic diseases, similar to those in humans, dogs represent a possible animal model for allergy in humans. In human atopic dermatitis (AD), CC chemokine receptor 4 (CCR4) has been shown to play an important role in the development of allergic inflammation of AD; however, the association between allergic reaction and CCR4 is not well understood in dogs. Objective To examine CCR4 expression in peripheral blood CD4+ cells in dogs that had AD and were experimentally sensitized with Japanese cedar pollen. Materials and methods Peripheral blood mononuclear cells (PBMCs) were isolated from 17 dogs with AD. The proportion of CCR4+ cells in peripheral blood CD4+ cells (CCR4/CD4) was evaluated by flow cytometry and compared with that in 10 healthy dogs. Similarly, in dogs that were experimentally sensitized to Japanese cedar pollen antigen, the proportion of CCR4/CD4 was examined pre- and post-sensitization. Results The proportion of CCR4/CD4 in dogs with AD was 40.3±3.3%, which was significantly higher than that in normal dogs (23.6±4.3%) (P

Activation-induced cytidine deaminase (AID) is essential for class switch recombination, somatic hypermutation, and gene conversion of immunoglobulin gene. In the present study, canine AID cDNA was cloned from the lymph node of a healthy dog by RT-PCR with rapid amplification of cDNA ends (RACE) method. The canine AID cDNA was 1,377 bp in length, and contained the entire open reading frame encoding 198 amino acids which had 94.9%, 94.4%, and 89.9% homology with human, mouse, and chicken homologues, respectively. Canine AID mRNA was expressed in thymus, lung, spleen, kidney, small intestine, lymph node, and tonsil of a healthy dog, similar to humans.

Allergic reactions after vaccination are considered as an important practical problem in dogs; however, their immunological mechanism has not been well understood. The present study was designed to investigate the relationship between IgE reactivity to the vaccines and immediate-type allergic reactions after vaccination in dogs. Sera from 10 dogs that developed immediate-type allergic reactions such as circulatory collapse, cyanosis, dyspnea, facial edema, and vomiting within 1h after vaccination with non-rabies monovalent or combined vaccines and sera from 50 dogs that did not develop allergic reactions after vaccination were collected. Serum IgE reactivity to the injected vaccines was measured by fluorometric ELISA using a mouse monoclonal anti-dog IgE antibody. Then, IgE reactivity to fetal calf serum (FCS) and stabilizer proteins (gelatin, casein, and peptone) included in the vaccines was measured in sera that had high levels of IgE to the vaccines. Levels of serum specific IgE to the vaccines in dogs with immediate-type allergic reactions (59-4173 fluorescence units [FU], mean +/- S.D.: 992.5 +/- 1181.9 FU) were significantly higher than those in control dogs (38-192 FU, 92.4 +/- 43.3 FU) (P < 0.001). Of the eight dogs that developed immediate-type allergic reactions and had high levels of serum specific IgE to the vaccines, seven had specific IgE directed to FCS. The IgE reactivity to the vaccines in sera from these dogs was almost completely inhibited by FCS. The other one dog had serum IgE directed to gelatin and casein included in the vaccine as stabilizers. The results obtained in this study suggest that immediate-type allergic reactions after vaccination in dogs were induced by type I hypersensitivity mediated by IgE directed to vaccine components. In addition, FCS, gelatin, and casein included in vaccines could be the causative allergens that induced immediate-type allergic reactions after vaccination in dogs.

A dog with Japanese cedar (Cryptomeria japonica, CJ) pollinosis had oral allergy syndrome (OAS) after ingesting fresh tomato. The dog showed specific IgE to both CJ and tomato allergens. As a negative control, twenty dogs without atopic dermatitis that had no exposure to tomato and no specific IgE to CJ allergen were used. They had no specific IgE to tomato allergen. Furthermore, IgE cross-reactivity was observed between CJ and tomato allergens in the dog. We found that OAS induced by tomato exists in the dog and there is a relationship between CJ and tomato allergens.

ALLERGIC reactions, including anaphylaxis, have been observed in dogs after vaccination (Brooks 1991, Greene 1998). Anaphylaxis is the most severe and life-threatening adverse event after vaccination. It is a systemic reaction of immediate type I hypersensitivity caused by allergen-specific immunoglobulin E, which causes the release of various mediators from mast cells and basophils (Greene 1998). In a previous retrospective study of 311 dogs in Japan with adverse reactions after vaccination, 46 of the dogs showed anaphylaxis, and seven of the 46 cases of anaphylaxis resulted in death (Ohmori and others 2002). Although allergic reactions, including anaphylaxis, after vaccination in dogs are a problem in small animal practice, little is known about them. The aim of this study was to obtain epidemiological information regarding allergic reactions after vaccination in dogs. Information on 85 dogs that had showed suspected allergic reactions within 24 hours after non-rabies vaccine injections was collected from 40 private small animal veterinary practitioners in Japan between January 2001 and July 2002; information on one to eight dogs (mean 2·1 dogs) was obtained from each practice. For the purposes of the study, the suspected allergic reactions were defined as clinical signs associated with type I hypersensitivity, such as hypotensive shock, dyspnoea, facial oedema, pruritus, weakness and diarrhoea, occurring after vaccination, as described previously by Greene (1998). The information on the 85 dogs comprised their history, the types of vaccine used, the history of previous vaccination, the clinical signs, and the time of onset of clinical signs after vaccination; the dogs were classified into three groups based on their clinical signs. Group 1 consisted of dogs with predominantly cardiovascular and/or respiratory signs, group 2 comprised those with predominantly dermatological signs, and group 3 consisted of dogs showing cardiovascular/respiratory and dermatological signs simultaneously. Of the 85 dogs, 83 were purebred and two were crossbred; there were 31 miniature dachshunds, seven shih tzus, six Maltese, six pugs, four labrador retrievers, four papillons, four Yorkshire terriers, three beagles, three miniature schnauzers, three Shetland sheepdogs, three toy poodles, two chihuahuas, two golden retrievers, two Welsh corgis and one akita, one Bernese mountain dog and one pomeranian. The dogs’ ages ranged from two months to 16 years; 43 were aged up to one year, 39 were over one year old, and the age of three of them was not clear. There were 42 males and 43 females. The following four types of vaccines are commercially available in Japan: a monovalent live parvovirus vaccine (type 1); monovalent inactivated parvovirus or Leptospira vaccines (type 2); combined live vaccines composed of canine parvovirus, distemper virus, adenovirus type 2 and/or parainfluenza virus (type 3); and combined live and inactivated vaccines composed of live canine parvovirus, distemper virus, adenovirus type 2, parainfluenza virus and/or coronavirus vaccines, and inactivated coronavirus and/or Leptospira vaccines (type 4). Of the 85 dogs studied, clinical signs of suspected allergic reactions were observed in two recipients of type 1 vaccine, 28 recipients of type 3 vaccines and 53 recipients of type 4 vaccines; no dogs had been injected with type 2 vaccines. Information on the types of vaccine used in two dogs was not obtained. Of the 85 dogs, 24 were classified into group 1: they showed predominant cardiovascular/respiratory signs consistent with anaphylaxis, such as circulatory collapse, cyanosis, bradycardia, hypotension, hypothermia, dyspnoea and/or tachypnoea. Of these 24 dogs, five showed concurrent gastrointestinal signs such as vomiting and/or diarrhoea. In addition, one dog, a seven-year-old male miniature dachshund, died of anaphylactic shock after vaccination. Fifty-nine of the 85 dogs showed dermatological signs such as facial oedema, erythema, pruritus and/or urticaria, and were classified into group 2; 55 of these dogs showed facial oedema, which was the most common dermatological sign. Of the 59 dogs in group 2, 11 dogs also showed concurrent gastrointestinal signs. Two of the 85 dogs showed cardiovascular/respiratory and dermatological signs at the same time (group 3), without concurrent gastrointestinal signs. The cardiovascular and/or respiratory signs in the 24 dogs in group 1 were observed within 60 minutes of vaccination, whereas the dermatological signs in the 59 dogs in group 2 appeared within 60 minutes in 22 dogs, but appeared from one to 24 hours after vaccination in the other 37 dogs (Table 1). Concurrent cardiovascular/respiratory and dermatological signs in the two dogs of group 3 were observed within 60 minutes after vaccination (Table 1). The results suggest that the cardiovascular/respiratory signs could have been caused by an immediate-type reaction, and the dermatological signs could have consisted of both immediateand non-immediate-type reactions, similar to the allergic reactions observed in human beings after vaccination (Kumagai and others 1997, Ohsaki and others 1999). Of the 85 dogs studied, 24 had received one vaccine injection, and 40 had received two or more vaccine injections, before the last vaccination which had provoked the suspected allergic reactions. Unexpectedly, 16 dogs had not received any vaccine injections before the vaccination which induced the reaction. In the other five dogs, the number of previous vaccinations was unknown. The 16 dogs with suspected allergic reactions after the first vaccination may have already been sensitised to some allergens included in the vaccines before the vaccination. The nature of such allergens in dogs is unclear, but may relate to the use of gelatin or bovine serum in the vaccines, as has been suggested in human beings (Bonin and others 1973, Erdos and others 1975, Kelso and others 1993, Sakaguchi and others 1995). It is also possible that anaphylactoid reactions induced the clinical signs in these 16 dogs, without sensitisation to allergens in the vaccines. In the present study, it was not possible to calculate the incidence of suspected allergic reactions because the total number of dogs that had received vaccination at the 40 veterinary practices was not obtained. Further studies, including the gathering of such information, will be necessary to invesShort Communications