Increases in serum carbonylated protein levels of dogs with hypercortisolism.

Protein carbonylation is an irreversible and degenerative modification that can be used to evaluate oxidative stress caused by glucocorticoids. In this study, we focused on protein carbonylation in dogs with hypercortisolism (HC). Sera samples were collected from 14 dogs diagnosed with HC and treated with trilostane, 12 dogs with inflammatory diseases (disease control group), and eight clinically healthy dogs. When the carbonylated protein levels were detected by the immunoblot analysis, one band of approximately 40 kDa was predominantly increased in the dogs with HC. The band was identified as haptoglobin using the liquid chromatography tandem mass spectrometry method. Furthermore, haptoglobin immune reactivity was higher in the dogs with HC. Although the average protein carbonylation level of the HC group was not significantly different from that of the other groups, the carbonylation level was significantly higher for the poorly controlled HC cases than for the well-controlled HC group. Additionally, the primary culture of canine hepatocytes was used to clarify the direct effect of glucocorticoids on protein carbonylation in dog livers. Both the carbonylated protein and haptoglobin clearly increased after 72 h. These findings suggest that haptoglobin and its carbonylated form are increased with canine HC, and that the protein carbonylation ratio and/or haptoglobin level could be related to disease management. These factors could be useful as biomarkers for an oxidative stress reaction, at least in the liver, and for treatment monitoring of HC.

ErbB2 Copy Number Aberration in Canine Urothelial Carcinoma Detected by a Digital Polymerase Chain Reaction Assay.

Urothelial carcinoma (UC) is the most common tumor affecting the urinary bladder of dogs. Protein overexpression of ErbB2 (the canine homolog of HER2) has been observed in dogs with UC. However, no study regarding ErbB2 copy number aberration (CNA) is reported in dogs with UC. In this study, a digital PCR assay for detecting CNA of canine ErbB2 was developed. DNA samples were isolated from 83 formalin-fixed, paraffin-embedded urinary bladder tissues (36 UC, 8 polypoid cystitis, and 39 normal) and 94 urinary sediments (54 UC, 30 nonneoplastic, and 10 normal). The copy number of canine chromosome 8 (CFA8) was used as a control. In the urinary bladder tissues, ErbB2 CNA was detected in 12 of 36 (33%) UC, 2 of 8 (25%) polypoid cystitis, and 0 of 39 (0%) normal controls. In the urinary sediments, ErbB2 CNA was also detected in 19 of 54 (35%) UC; however, no ErbB2 CNA was detected in nonneoplastic diseases or normal controls. The sensitivity and specificity of ErbB2 CNA in urinary sediment for the detection of UC were 35% and 100%, respectively. There was a positive correlation between the copy number ratios of ErbB2 to CFA8 in the urinary bladder tissues and urinary sediments. Our findings indicate that the digital PCR assay of urinary sediments may be a useful, noninvasive method for detecting ErbB2 CNA in dogs with UC.

Assessment of HER2 Expression in Canine Urothelial Carcinoma of the Urinary Bladder.

Canine urothelial carcinoma (UC) has a poor prognosis and high metastatic rate. Human epidermal growth factor receptor 2 (HER2), a receptor tyrosine kinase involved in cell proliferation and differentiation regulation, has been attracting interest as a therapeutic target molecule for human breast cancer. This study investigated expression of the canine homolog of HER2 (ERBB2) in canine UC, and its association with clinical factors. Since it has been controversial whether commercial anti-human HER2 antibody (Dako A0485) correctly recognizes the canine homolog of HER2, an application of the antibody using a canine UC cell line was validated first. By Western blot, a single band at the appropriate size for canine HER2 (185 kDa) was recognized. Immunohistochemistry for HER2 was performed on 23 samples of UC, 8 samples of polypoid cystitis, and 8 samples of normal urinary bladder, and the results were scored as either 0, 1+, 2+, or 3+ with reference to the evaluation method for human UC. Intense membranous HER2 immunoreactivity was frequently observed in neoplastic cells, especially in grade 2 UC. Minor HER2 expression was found in the epithelial cells of polypoid cystitis and normal bladder. The incidence of HER2 positivity (scores of 2+ or 3+) was 14 of 23 (60.9%) in UC, 3 of 8 (37.5%) in polypoid cystitis, and 0 of 8 (0%) in normal bladder. There was no significant correlation between HER2 positivity and clinical factors. While increased HER2 expression was observed in a subset of urothelial carcinomas, further mechanistic studies are needed to determine its role in the pathogenesis and targeted therapy of this cancer.

Comprehensive gene expression analysis of canine invasive urothelial bladder carcinoma by RNA-Seq.

BACKGROUND: Invasive urothelial carcinoma (iUC) is a major cause of death in humans, and approximately 165,000 individuals succumb to this cancer annually worldwide. Comparative oncology using relevant animal models is necessary to improve our understanding of progression, diagnosis, and treatment of iUC. Companion canines are a preferred animal model of iUC due to spontaneous tumor development and similarity to human disease in terms of histopathology, metastatic behavior, and treatment response. However, the comprehensive molecular characterization of canine iUC is not well documented. In this study, we performed transcriptome analysis of tissue samples from canine iUC and normal bladders using an RNA sequencing (RNA-Seq) approach to identify key molecular pathways in canine iUC. METHODS: Total RNA was extracted from bladder tissues of 11 dogs with iUC and five healthy dogs, and RNA-Seq was conducted. Ingenuity Pathway Analysis (IPA) was used to assign differentially expressed genes to known upstream regulators and functional networks. RESULTS: Differential gene expression analysis of the RNA-Seq data revealed 2531 differentially expressed genes, comprising 1007 upregulated and 1524 downregulated genes, in canine iUC. IPA revealed that the most activated upstream regulator was PTGER2 (encoding the prostaglandin E2 receptor EP2), which is consistent with the therapeutic efficiency of cyclooxygenase inhibitors in canine iUC. Similar to human iUC, canine iUC exhibited upregulated ERBB2 and downregulated TP53 pathways. Biological functions associated with cancer, cell proliferation, and leukocyte migration were predicted to be activated, while muscle functions were predicted to be inhibited, indicating muscle-invasive tumor property. CONCLUSIONS: Our data confirmed similarities in gene expression patterns between canine and human iUC and identified potential therapeutic targets (PTGER2, ERBB2, CCND1, Vegf, and EGFR), suggesting the value of naturally occurring canine iUC as a relevant animal model for human iUC.

Neuronal ceroid lipofuscinosis in Border Collie dogs in Japan: clinical and molecular epidemiological study (2000-2011).

Neuronal ceroid lipofuscinosis (NCL) is an inherited, neurodegenerative lysosomal disease that causes premature death. The present study describes the clinical and molecular epidemiologic findings of NCL in Border Collies in Japan for 12 years, between 2000 and 2011. The number of affected dogs was surveyed, and their clinical characteristics were analyzed. In 4 kennels with affected dogs, the dogs were genotyped. The genetic relationships of all affected dogs and carriers identified were analyzed. The survey revealed 27 affected dogs, but there was a decreasing trend at the end of the study period. The clinical characteristics of these affected dogs were updated in detail. The genotyping survey demonstrated a high mutant allele frequency in examined kennels (34.8%). The pedigree analysis demonstrated that all affected dogs and carriers in Japan are related to some presumptive carriers imported from Oceania and having a common ancestor. The current high prevalence in Japan might be due to an overuse of these carriers by breeders without any knowledge of the disease. For NCL control and prevention, it is necessary to examine all breeding dogs, especially in kennels with a high prevalence. Such endeavors will reduce NCL prevalence and may already be contributing to the recent decreasing trend in Japan.

Clinical assessment of testosterone analogues for urethral sphincter mechanism incompetence in ten spayed female dogs.

Urethral sphincter mechanism incompetence (USMI) is a common cause of urinary incontinence in dogs. Although estrogen is often prescribed for the medical therapy of USMI for spayed female dogs, they are known to have limited effectiveness and potential adverse effects. In castrated male dogs with USMI, testosterone reagents have been attempted besides estrogen. In this study, the effect of testosterone drugs, mainly methyltestosterone, on spayed female dogs with USMI was retrospectively evaluated. Ten spayed female dogs with USMI were included. Diagnosis of USMI was based on the results of the dogs' medical history, clinical signs, and no abnormalities in physical examinations, urinalysis, ultrasonography, X-ray imaging, and neurological examinations. Methyltestosterone was administered at doses of 0.32-1.27 mg/kg BW p.o. semel in die (sid.) to twice a week. Nine of the ten dogs had good or excellent responses 2 to 4 weeks after the start of treatment. The minimum effective dose was 0.32 mg/kg/day. Although no severe adverse symptoms occurred in any dog, a mild increase in alanine aminotransferase was temporally observed at doses of 1.0 and 1.1 mg/kg/day in the two dogs. After dose reduction or withdrawal, two of eight dogs had recurrence of urinary incontinence. Resumption of testosterone treatment clearly improved the symptoms in the two dogs. These results indicate that testosterone reagents might be an option for treating USMI in spayed female dogs as well.

Inflammatory myopathy with severe tongue atrophy in Pembroke Welsh Corgi dogs.

A disease characterized by tongue and facial muscle atrophy has been recognized sporadically among Pembroke Welsh Corgi (PWC) dogs in Japan. The present study describes the pathologic findings of this canine syndrome. Histopathologic examinations were performed in 2 dogs, including a case of muscular biopsy. Identification and characterization of autoantibodies were attempted by fluorescent antibody test (FAT) and Western blot (WB) by using sera from 7 PWC dogs with typical clinical features, 6 PWC dogs with other clinical signs, and 2 from other breeds with polymyositis. Clinically, the 7 affected PWC dogs exhibited dysphagia with severe tongue atrophy, facial muscular atrophy, and occasional walking difficulty. Histopathologic examinations of the 2 dogs with clinical symptoms revealed moderate to severe inflammatory lesions characterized by lymphohistiocytic infiltration and muscular atrophy in the tongue and/or femoral muscles. The tongue lesions were very severe and accompanied by diffuse fatty infiltration. There were no major lesions in the nervous tissues examined. By FAT, an autoantibody against the cross striation of skeletal muscle was detected in sera from 5 affected PWC dogs. By using WB analysis, the autoantibodies recognized a 42-kDa molecule in striated muscle but not in the nervous tissues. All of the findings indicated that the unique disease of PWC dogs might be generalized inflammatory myopathy, whereas the detailed etiology concerning the dominant involvement of tongue muscles and the role of the autoantibody in the canine disease remain to be clarified.

Evaluation of an automated point-of-care test system for measuring thrombin-antithrombin complex in dogs.

OBJECTIVE: To evaluate the utility of the chemiluminescent enzyme immunoassay (CLEIA) method for point-of-care (POC) measurement of canine plasma thrombin-antithrombin complex (TAT) concentration. ASSESSMENT AND MAIN RESULTS: Plasma TAT concentration was measured in 54 healthy dogs and in 72 dogs with various diseases. A significant correlation was found between TAT concentration measured by CLEIA and that measured by an ELISA that was previously used in dogs. The upper limit of the reference value of TAT concentrations measured by CLEIA was determined to be 0.2 ng/mL based on the TAT concentration in 54 healthy dogs. TAT concentrations exceeded the reference interval in a portion of dogs when a hypercoagulable state may be present. CONCLUSIONS: Canine plasma TAT concentrations measured using CLEIA were correlated with that measured using ELISA. Hence, a POC testing instrument may be used for early detection of activation of thrombin generation in emergency and critical care settings.

Antioxidant, free radical-scavenging, and NF-kappaB-inhibitory activities of phytosteryl ferulates: structure-activity studies.

Some of the pharmacological properties of phytosteryl ferulates may be linked to their antioxidant potential. In this study, 2,2-diphenyl-1-picrylhydrazyl (DPPH), electron spin resonance (ESR), and thiobarbituric acid-reactive substances (TBARS) assays demonstrated that phytosteryl ferulates such as cycloartenyl ferulate (CAF), 24-methylenecycloartanyl ferulate (24-mCAF), and beta-sitosteryl ferulate (beta-SF) and ferulic acid (FA) each exerted strong free radical scavenging and antioxidation of lipid membrane, which were comparable to alpha-tocopherol. However, the sterol moiety alone, such as cycloartenol (CA), had neither activity. Since, the reactive oxygen species (ROS) production in the cell complex defense mechanism cannot be ruled out with the cell free system, we measured ROS production in NIH 3T3 fibroblast cells induced by H(2)O(2). CAF and ethyl ferulate (eFA) greatly decreased the ROS level in this system. CA also significantly inhibited the ROS level, suggesting that CA could inhibit ROS production in living cells. Besides these, CAF, 24-mCAF, beta-SF, as well as eFA and CA, all these chemicals significantly inhibited the NF-kappaB activity as analyzed by measuring translocation of NF-kappaB p65 in LPS-stimulated RAW 264.7 macrophages. These observations revealed that phytosteryl ferulates are responsible for the antioxidant and anti-inflammatory activity via ROS scavenging and inhibition of ROS production.

Serial examinations of anti-GFAP autoantibodies in cerebrospinal fluids in canine necrotizing meningoencephalitis.

Canine necrotizing meningoencephalitis (NME) is characterized by autoantibodies against glial fibrillary acidic protein (GFAP) in cerebrospinal fluids (CSFs). To clarify the time-course changes in autoantibodies, serial examinations were conducted in three dogs with NME (two Pugs and a Pomeranian) that were treated by immunosuppressive therapy. The Pugs retained high autoantibody titers throughout the observation periods (146 and 813 days) and died with neurological signs. On the other hand, the Pomeranian switched from being positive for autoantibody to negative after day 580, and its NME seemed to be in clinical remission until death on day 1238. Therefore, the anti-GFAP autoantibodies can be detected over time in canine NME even during immunosuppressive therapies. However, the autoantibodies can also disappear within a certain period after onset.

A novel sandwich enzyme-linked immunosorbent assay for feline insulin.

A novel sandwich enzyme-linked immunosorbent assay (ELISA) was established to determine the serum insulin concentrations in domestic cats. By using a solid-phase mouse anti-bovine insulin monoclonal antibody and a peroxidase-conjugated guinea pig anti-rat insulin polyclonal antibody, feline serum insulin concentrations in the range of 0.1 to 3.6 ng/ml could be measured. The intraassay CV and interassay CV were less than 6% and less than 10%, respectively. The present insulin assay will strongly help studies on feline diabetes mellitus.

CCR4 Blockade Depletes Regulatory T Cells and Prolongs Survival in a Canine Model of Bladder Cancer.

Regulatory T-cell (Treg) infiltration can be targeted as a cancer immunotherapy. Here, we describe therapeutic efficacy of this strategy in a canine model of bladder cancer. We used dogs with naturally occurring bladder cancer to study the molecular mechanism of Treg infiltration into bladder cancer tissues and the effect of anti-Treg treatment. Tumor-infiltrating Tregs were evaluated by immunohistochemistry, and their association with prognosis was examined in dogs with bladder cancer. The molecular mechanism of Treg infiltration was explored by RNA sequencing and protein analyses. Murine xenograft experiments and canine studies were used to explore the therapeutic potential of anti-Treg treatment for bladder cancer. We found that tumor-infiltrating Tregs were associated with poor prognosis in dogs bearing spontaneous bladder cancer. Treg infiltration was caused by interaction between the tumor-producing chemokine CCL17 and the receptor CCR4 expressed on Tregs. CCR4 blockade inhibited tumor growth and Treg infiltration into the tissues in a xenograft mouse model. Dogs with spontaneous bladder cancer responded to anti-CCR4 treatment with improved survival and low incidence of clinically relevant toxicities. In human patients with bladder cancer, immunohistochemistry showed that tumor-infiltrating Tregs expressed CCR4. Thus, anti-CCR4 treatment may be a rational approach to test in clinical trials for human patients with bladder cancer.

Sphingosine-1-phosphate (S1P) signaling regulates the production of intestinal IgA and its potential role in the pathogenesis of canine inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a common gastrointestinal disease in dogs. Decreased production of intestinal immunoglobulin A (IgA) has been suggested as a possible pathogenesis in a subset of canine IBD; however, the underlying cause remains unclear. Sphingosine-1-phosphate (S1P) is a lipid mediator that regulates intestinal IgA production by controlling lymphocyte trafficking in mice. The objectives of this study were to clarify the role of S1P in IgA production in dogs and to evaluate the expression of S1P-related molecules in dogs with IBD. First, an S1P receptor antagonist was administrated to five healthy dogs. The S1P receptor antagonist significantly decreased the IgA concentration in sera and feces but did not affect the IgG concentration. Moreover, the immunoreactivity of intestinal IgA was significantly decreased by S1P signal blockade. These results indicate that S1P signaling specifically regulates the intestinal IgA production in dogs. Subsequently, the intestinal S1P concentration and the expression of S1P-related molecules were measured in dogs with IBD and healthy dogs. The intestinal concentration of S1P was significantly lower in dogs with IBD than in healthy dogs. In addition, the gene expression levels of S1P receptor (S1P1) and S1P synthase (SK1) were significantly lower in dogs with IBD than in healthy dogs. Taken together, these observations suggest that decreased S1P production, likely caused by a lower expression of S1P synthetase, leads to attenuation of S1P/S1P1 signaling pathway and the production of intestinal IgA in dogs with IBD.

Impaired expression of excitatory amino acid transporter 2 (EAAT2) and glutamate homeostasis in canine necrotizing meningoencephalitis.

To clarify the involvement of excitatory and inhibitory amino acids in canine necrotizing meningoencephalitis (NME), glutamate, aspartate, taurine and gamma-aminobutylic acid (GABA) were determined in the cerebrospinal fluids (CSF) from eight NME cases and ten healthy controls. NME dogs exhibited significantly higher concentrations of glutamate and aspartate than those in controls (p<0.001 and p<0.001, respectively), while there was no difference in taurine or GABA between the two groups. When fetal canine astrocytes were cultured for 24 hr in the presence of NME-CSF, supernatant concentrations of glutamate, aspartate and taurine were significantly elevated. Simultaneously, expression of excitatory amino acid transporter 2 (EAAT2) mRNA was significantly reduced in the astrocytes without change in EAAT1 mRNA. Hence, reduced expression of EAAT2 and impaired glutamate homeostasis may contribute to the pathogenesis of NME.

In vitro differentiation of canine celiac adipose tissue-derived stromal cells into neuronal cells.

To investigate in vitro differentiation of canine adipose tissue-derived stromal cells (ATSCs) into neuronal cells, ATSCs from celiac adipose tissue in clinically healthy beagle dogs were treated with 100 muM dibutyryl cyclic adenosine monophosphate (dbcAMP) and 125 muM isobuthylmethylxanthine (IBMX). ATSCs were morphologically changed into differentiated ATSCs from spindle-shaped cells to neuron-like cells with numerous processes after the treatment. Expression of neuron-specific enolase (NSE) as an early neuron specific marker protein was detected in both ATSCs and differentiated ATSCs, however diachronic increase of NSE expression was observed in differentiated ATSCs after the treatment with dbcAMP/IBMX. In addition, neurofilament-68 (NF-68) as an early to mature neuron specific marker protein was weakly expressed in differentiated ATSCs. Neuron specific glutamate and glucose transporter (EAAC1 and GLUT-3, respectively) mRNAs were strongly expressed in differentiated ATSCs compared with those in ATSCs, although glia specific glutamate transporter mRNA (GLT-1) was also detected in differentiated ATSCs. ATSCs can differentiate into early to mature neuronal cells and are candidate cells for autologous nerve regeneration therapy, although additional research is needed to examine functional characteristics of differentiated ATSCs.

Generation of monoclonal antibody against canine neural-cell adhesion molecule.

A monoclonal antibody, K9BYU, was generated using Escherichia coli recombinant extracellular domain of canine neural-cell adhesion molecule (N-CAM) as an antigen. Immunoreactivity of K9BYU to insect cell recombinant canine N-CAM was demonstrated by Western blotting using Sf9 insect cells transfected with the canine N-CAM gene. In Western blotting against canine brain tissue, K9BYU detected three isoforms of N-CAM that correspond to three major isoforms of human and mouse N-CAM (N-CAM-120, -140, and -180). From these results, K9BYU was considered to be a useful tool for research of canine N-CAM.

Decreased plasma amino acid concentrations in cats with chronic gastrointestinal diseases and their possible contribution in the inflammatory response.

In humans, plasma amino acids (AAs) levels are used as dynamic nutritional markers. Moreover, some AAs are associated with chronic inflammation. In this study, we analyzed plasma AA profiles in cats with chronic gastrointestinal (GI) diseases. Eight healthy controls (HCs) and 12 client-owned cats with chronic GI diseases including chronic enteritis (n=8) and neoplasms (n=4) were recruited. Plasma albumin, total protein, and 22 AAs (11 essential and 11 non-essential AAs) levels were estimated. There was no significant difference in plasma albumin and total protein concentrations between the cats with chronic GI diseases and HCs. The plasma concentrations of 7 essential AAs (arginine, histidine, lysine, methionine, phenylalanine, taurine, and tryptophan) and 7 non-essential AAs (asparagine, aspartic acid, glutamic acid, glycine, hydroxyproline, proline, and serine) were significantly decreased in the cats with chronic GI diseases (P<0.05). Moreover, plasma histidine and tryptophan levels were inversely correlated with severity of symptoms (histidine: rs=-0.7781, P<0.005; tryptophan: rs=-0.6040, P<0.05). To examine the contribution of altered AAs levels in the inflammatory response, feline macrophages were stimulated by lipopolysaccharides (LPS) with or without histidine, and the expression of interleukin-8 (IL-8) mRNA was quantified. The expression of IL-8 mRNA was significantly increased in the LPS-stimulated feline macrophages (P<0.05). Histidine almost suppressed the LPS-induced IL-8 expression in the feline macrophages (P<0.05). Our findings suggest that plasma AAs levels are more sensitive nutritional markers than albumin and total protein levels in cats with chronic GI diseases. There is a possibility that the decrease of histidine levels in cats with GI diseases is associated with chronic inflammation.

Anti-tumour effect of lapatinib in canine transitional cell carcinoma cell lines.

Transitional cell carcinoma (TCC) accounts for >90% of canine malignant tumours occurring in urinary bladder, and the prognosis is poor. Our previous study, using RNA sequencing, showed that human epidermal growth factor 2 (HER2) was the most activated upstream regulator related to carcinogenesis in canine TCC. The aim of this study was to examine the anti-tumour effect of lapatinib, a tyrosine kinase inhibitor of HER2, on canine TCC cell lines in vitro and in vivo. Five canine TCC cell lines (TCCUB, Love, Sora, LCTCC, and MCTCC) were used. Western blotting showed that HER2 protein expression was observed in all of the canine TCC cell lines. Lapatinib inhibited phosphorylation of HER2 and cell growth in a dose-dependent manner. Cell cycle analyses using flow cytometry showed that lapatinib significantly increased the sub-G1 and G0 /G1 phase fractions and significantly decreased the S and G2 /M phase fractions in the cell lines (Sora and TCCUB). For the in vivo experiments, the canine TCC cells (Sora) were subcutaneously injected into nude mice. Six days after inoculation, lapatinib (100 mg/kg) or vehicle was administered daily via intraperitoneal administration for 14 days. Tumour volume was significantly smaller in the lapatinib group compared with the vehicle control group. Histologically, lapatinib significantly increased necrotic areas in the tumour tissues. These findings suggest that lapatinib exerts anti-tumour effects on canine TCC cells by inhibiting HER2 signalling and inducing cell cycle arrest.

Multiple acquired portosystemic shunts secondary to primary hypoplasia of the portal vein in a cat.

A 6-year 5-month-old spayed female Scottish Fold cat presented with a one-month history of gait abnormalities, increased salivation, and decreased activity. A blood test showed hyperammonemia and increased serum bile acids. Imaging tests revealed multiple shunt vessels indicating acquired portosystemic shunt. Histopathologic analysis of liver biopsy showed features consistent with liver hypoperfusion, such as a barely recognizable portal vein, increased numbers of small arterioles, and diffuse vacuolar degeneration of hepatocytes. These findings supported the diagnosis of primary hypoplasia of the portal vein/microvascular dysplasia, (PHPV/MVD). To our knowledge, this is the first case of feline PHPV/MVD that developed multiple acquired portosystemic shunts and presented with hepatic encephalopathy.

Autoantibodies against glial fibrillary acidic protein (GFAP) in cerebrospinal fluids from Pug dogs with necrotizing meningoencephalitis.

Cerebrospinal fluids (CSFs) from 9 Pug dogs with necrotizing meningoencephalitis (NME: Pug dog encephalitis) were examined to identify the antigens for anti-astrocyte autoantibodies. Each CSF exhibited a positive reaction to the cytoplasm of cultured canine astrocytes by an indirect fluorescent antibody test. In an immunoblotting analysis on normal canine brain proteins, eight of 9 CSFs showed a common band of 52 kDa, corresponding to glial fibrillary acidic protein (GFAP), and all of 9 CSFs reacted with purified bovine GFAP. From these results, GFAP is one of the common autoantigens in Pug dogs with NME. On the other hand, the reactivity of CSFs to chymotrypsin-digested bovine GFAP fragments were variable among dogs, indicating that the antibodies in the CSFs recognized different epitopes on GFAP.