Publications by authors named "Ryoji Yamaguchi"

73 Publications

Pseudorabies virus infection in hunting dogs in Oita, Japan: Report from a prefecture free from Aujeszky's disease in domestic pigs.

J Vet Med Sci 2021 Apr 15;83(4):680-684. Epub 2021 Feb 15.

Centre for Animal Disease Control, University of Miyazaki, 1-1 Gakuen Kibanadai-nishi, Miyazaki 889-2192, Japan.

We isolated two pseudorabies virus (PRV) isolates (designated OT-1 and OT-2) from two hunting dogs exhibiting neurological manifestations after eating the flesh of wild boar hunted in Oita prefecture, Kyushu Island, Japan. The isolates corresponded to a previously reported PRV (MY-1 strain) isolated from a hunting dog in neighboring Miyazaki prefecture, and it clustered into genotype II based on the glycoprotein C sequence. Our results suggest that this common PRV strain may have been maintained in wild boars on Kyushu Island even though domestic pigs in this area have attained an Aujeszky's disease-free status.
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http://dx.doi.org/10.1292/jvms.20-0450DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8111351PMC
April 2021

Suppurative necrotizing bronchopneumonia caused by Nocardia cyriacigeorgica infection in a stranded striped dolphin (Stenella coeruleoalba) in Japan.

J Vet Med Sci 2021 Jan 11;83(1):146-150. Epub 2020 Dec 11.

Laboratory of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Nishi 1-1, Gakuen-Kibana, Miyazaki 889-2192, Japan.

On a coastline in Miyazaki Prefecture, Japan, a wild subadult female striped dolphin was found dead. Necropsy revealed poor nutritional status and bilateral pneumonia, which was histologically diagnosed as severe suppurative necrotizing bronchopneumonia. Special staining detected numerous intralesional filamentous, branching bacteria, which was identified as Nocardia cyriacigeorgica by sequencing of 16S ribosomal RNA and gyrB genes. Other main histological findings included lymphoid depletion in the spleen and superficial cervical and pulmonary lymph nodes. Suppurative nocardiosis without a granulomatous reaction is uncommon, and it is assumed its pathogenesis was related to the host's immune status. This paper discusses the variable inflammatory response to nocardiosis and describes the first case of N. cyriacigeorgica infection in a wild striped dolphin in Japan.
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http://dx.doi.org/10.1292/jvms.20-0234DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7870406PMC
January 2021

Pathological investigation and viral antigen distribution of emerging African swine fever in Vietnam.

Transbound Emerg Dis 2020 Sep 26. Epub 2020 Sep 26.

Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki City, Japan.

African swine fever (ASF) is emerging in Vietnam and poses a continuing severe threat to the swine industry. A histopathological study of clinical samples collected during the May to July 2019 outbreak of ASF was performed to determine the characteristic lesions. We analysed samples from eight ASFV-infected farms. Histopathological results revealed the characteristic lesions of the acute to the subacute clinical form of ASF. Immunohistochemical results showed ASFV viral antigen distribution in mononuclear cells/macrophage in various organs, hepatocytes and renal tubular epithelium. Molecular analysis of partial capsid protein 72 gene revealed that ASFV strain from the eight separate outbreaks belonged to genotype II.
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http://dx.doi.org/10.1111/tbed.13851DOI Listing
September 2020

Bursa atrophy at 28 days old caused by variant infectious bursal disease virus has a negative economic impact on broiler farms in Japan.

Avian Pathol 2021 Feb 10;50(1):6-17. Epub 2020 Dec 10.

Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.

Infectious bursal disease (IBD), caused by IBD virus (IBDV), is highly contagious, immunosuppressive and causes a negative economic impact on poultry industry. IBDV-vaccinated broiler farms at south Kyushu, Japan had a bursa-to-bodyweight ratio (BB ratio) reduction at 28 days (d) old, followed by high mortality 30 d later. We analysed the influence of the IBDV on atrophy of the bursa of fabricius (BF) and the subsequent mortality after 30 d. Ten broilers were sampled at each timepoint from the farm with high mortality at 21, 25, 28 and 35 d. A second flock from the same farm was sampled at 14, 21, 25, 28, 35 and 42 d. IBDV was detected in BF samples at 25, 28 and 35 d and at 21, 25, 28 and 35 d in the first and second flocks, respectively, using immunohistochemical staining and RT-PCR. IBDV isolates from both flocks were closely related to the China KM523643 strain. Histopathology and TUNEL assay indicated apoptosis, severe lymphoid depletion, vacuoles within follicles, lymphoid follicle atrophy and fibrosis in the BF. We observed 75% of the polyserositis and 10% of the airsacculitis at 30 D in dead broilers. The antigenic variant IBDV infection was appeared to be the main influencing factor on BF atrophy and BB ratio reduction in the broilers. High mortality in the broilers after 30 d could be due to secondary infection. The disease caused by IBDV had a negative economic impact in the farm. New variant IBDV caused bursa atrophy and reduced BB ratio in 28-day-old broilers. After vIBDV had infected broilers, at 21 days old they became immunosuppressed. High mortality at 30 days old in broilers was due to secondary infection. New vIBDV has a negative economic impact on broiler farms in Japan.
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http://dx.doi.org/10.1080/03079457.2020.1822989DOI Listing
February 2021

Pathology of the outbreak of subgenotype 2.5 classical swine fever virus in northern Vietnam.

Vet Med Sci 2021 01 11;7(1):164-174. Epub 2020 Aug 11.

Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.

Classical swine fever (CSF) is an endemic disease in southeastern Asia and is one of the most important swine diseases in Vietnam. This study was conducted to characterize the pathology of natural cases of CSF in northern Vietnam in 2018 and their genetic prevalence. A total of 10 representative pigs were collected from four provinces (Hung Yen, Ha Noi, Quang Ninh and Thai Binh) during five outbreaks and examined pathologically. The gross and histopathological findings showed the disease was expressed as the acute or the subacute to chronic form of CSF, depending on the age of the animals. The most consistently observed lesions associated with infection by the classical swine fever virus (CSFV) included lymphoid depletions in tonsils, lymph node and spleen; histiocytic hyperplasia in spleen; cerebral haemorrhage; perivascular cuffing in the brain; renal erythrodiapedesis; urothelial vacuolation and degeneration and interstitial pneumonia. The immunohistochemical findings showed a ubiquitous CSFV antigen mainly in the monocytes/macrophages and in the epithelial and endothelial cells in various organs. CSFV neurotropism was also found in the small neurons of the cerebrum and the ganglia of the myenteric plexus. Analysis of the full-length envelope protein (E2) genome sequence showed that all strains were genetically clustered into subgenotype 2.5, sharing a nucleotide identity of 94.0%-100.00%. Based on the results of this study, the strain was categorized as a moderately virulent CSFV.
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http://dx.doi.org/10.1002/vms3.339DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7840204PMC
January 2021

Development of anti-human CADM1 monoclonal antibodies as a potential therapy for adult T-cell leukemia/lymphoma.

Int J Hematol 2020 Oct 12;112(4):496-503. Epub 2020 Jul 12.

Division of Tumor and Cellular Biochemistry, Department of Medical Sciences, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan.

Adult T-cell leukemia/lymphoma (ATLL) is a highly invasive and refractory T-cell malignancy, with poor prognosis. We previously identified that cell adhesion molecule 1 (CADM1) is overexpressed consistently in ATLL cells, and that CADM1 expression increases the adhesion capacity of ATLL cells to endothelial cells and promotes the organ invasion of ATLL cells in a xenograft mouse model. In this study, we first show that newly developed several anti-human CADM1 antibodies, which were complete human IgG antibodies generated by phage display method, specifically recognize CADM1 on ATLL cells. Although most of the CADM1 antibodies did not have a direct cytotoxic effect against CADM1-positive ATLL cells, clone 089-084 exhibited weak but significant antibody-dependent cell-mediated cytotoxic activity. Moreover, clone 103-189 effectively inhibits the interaction between endothelial cells and CADM1-positive ATLL cells. Furthermore, in mice bearing intra-splenic transplantation of EL4 mouse lymphoma cells expressing CADM1, the treatment of 103-189 significantly suppressed the organ invasion of CADM1-positive EL4 cells, resulting in improved survival time of mice. Therefore, since the anti-CADM1 antibody may be useful for the suppression of organ invasion in ATLL patients, combination use of the anti-CADM1 antibody with chemotherapy drugs could be beneficial for the efficient elimination of ATLL cells.
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http://dx.doi.org/10.1007/s12185-020-02939-1DOI Listing
October 2020

New tropisms of porcine epidemic diarrhoea virus (PEDV) in pigs naturally coinfected by variants bearing large deletions in the spike (S) protein and PEDVs possessing an intact S protein.

Transbound Emerg Dis 2020 Nov 3;67(6):2589-2601. Epub 2020 Jun 3.

Laboratory of Veterinary Pathology, Department of Veterinary, Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki, Japan.

We previously reported the coinfection of novel porcine epidemic diarrhoea virus (PEDV) variants bearing large deletions in the S protein and PEDVs possessing an intact S protein (S-intact PEDV) in domestic pigs in Japan. The variants were frequently observed in pig farms with persistent or recurrent infection. To elucidate the role of the variants in persistent infections and their tropism properties, we genetically characterized and immunohistochemically detected PEDVs collected in primary and recurrent outbreaks in two persistently infected farms. Our results revealed coinfection of the PEDV variants bearing a 214-amino acid deletion in the S protein and S-intact PEDVs in the lungs of the naturally infected pigs. New tropisms of PEDV, including epithelial cells and submucosal glands of the airway tract, epithelial cells of the bile duct, and monocytes/macrophages were identified. The findings elucidate the mechanism of PEDV infection, epidemiology and pattern changes in the disease.
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http://dx.doi.org/10.1111/tbed.13607DOI Listing
November 2020

Severe Degenerative Changes in Cryptorchid Testes in Japanese Black Cattle.

Vet Pathol 2020 05 25;57(3):418-426. Epub 2020 Feb 25.

Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.

This is a histopathologic and endocrinologic study of 6 calves diagnosed with cryptorchidism. Cases 1-3 were diagnosed as resembling testicular regression syndrome. In cases 1 and 2, the extracted tissue was a small, firm, gray-white mass, and there was lack of obvious testicular tissue in case 3. Histopathologically, the excised tissue in cases 1-3 was a fibrotic testicular remnant with inflammation, mineralization, hemosiderin-laden macrophages or lipofuscin-laden macrophages, and lack of germ cells and interstitial endocrine cells. These findings were compared with cases 4-6, which were diagnosed as testicular hypoplasia due to cryptorchidism. These cases had small but otherwise grossly unremarkable intra-abdominal testicular tissue and histologically had a few germ cells and sustentacular cells with arrested spermatogenesis and an increase in interstitial endocrine cells. Cases 1-3 had more severe degenerative changes compared with cases 4-6. In case 2, the average diameter of the seminiferous tubules was much smaller than in cases 4-6, and there were few tubule cross sections. Anti-Müllerian hormone (214 pg/ml) was detected in the plasma of case 2. Based on the macroscopic and histopathologic findings as well as endocrinologic profiles, the testicular degeneration in cases 1-3 was considered similar to that of testicular regression syndrome. In this condition, it is thought that a normally developing intra-abdominal testis undergoes degeneration due to heat or a vascular disorder such as torsion.
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http://dx.doi.org/10.1177/0300985820906891DOI Listing
May 2020

Development of indirect enzyme-linked immunosorbent assay for detection of porcine epidemic diarrhea virus specific antibodies (IgG) in serum of naturally infected pigs.

BMC Vet Res 2019 Nov 12;15(1):409. Epub 2019 Nov 12.

Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-Nishi, Miyazaki, 889-2192, Japan.

Background: Porcine epidemic diarrhea virus (PEDV) infection is a highly contagious infectious disease causing watery diarrhea, vomiting, dehydration and high mortality rate in newborn piglets. PEDV infection can cause high economic losses in pig industry. In Japan, a PEDV outbreak occurred with high mortality from 2013 to 2015. Even though until now, PEDV infection occurs sporadically. For the control and monitoring of PEDV infection, not only symptomatic pigs, but also asymptomatic pigs should be identified. The objective of this study is to develop and optimize novel indirect ELISA as a simple, rapid, sensitive and specific method for the detection of anti-PEDV antibodies and evaluate the efficacy of the assay as a diagnostic method for PED.

Results: One hundred sixty-two serum samples, consisting of 81 neutralization test (NT) positive and 81 NT negative sera, were applied to the assay. Indirect ELISA test based on whole virus antigen (NK94P6 strain) derived from Vero cell culture was evaluated by receiver operating characteristic (ROC) analysis with neutralization test (NT) as a reference method, and cut-off value was determined as 0.320 with sensitivity and specificity of 92.6 and 90.1%, respectively. The area under curve (AUC) was 0.949, indicating excellent accuracy of indirect ELISA test. There was significant positive correlation between indirect ELISA and neutralization test (R = 0.815, P < 0.05). Furthermore, the kappa statics showed the excellent agreement between these two tests (kappa value = 0.815). In addition, the sensitivity and specificity of preserved plates with different periods (1 day, 2 weeks, 1, 2, 3, 4, 5 and 6 months) after drying antigen coated plates were 100% and 80-100%, respectively.

Conclusions: The developed indirect ELISA test in our study would be useful as a reliable test for serological survey and disease control of PEDV infection, and our pre-antigen coated ELISA plates can be preserved at 4 °C until at least 6 months.
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http://dx.doi.org/10.1186/s12917-019-2123-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6852973PMC
November 2019

Overexpression of a virus-like particle influenza vaccine in Eri silkworm pupae, using Autographa californica nuclear polyhedrosis virus and host-range expansion.

Arch Virol 2018 Oct 19;163(10):2787-2797. Epub 2018 Jul 19.

The Institute of Biological Resources, 893-2, Nakayama, Nago, Okinawa, 905-0004, Japan.

Ecological investigations of silkworms have revealed that Eri silkworms (Samia cynthia ricini) possess useful morphological and ecological characteristics for virus-like particle (VLP) production, namely non-seasonal breeding, longer lengths, and heavier weights than Bombyx mori silkworms. Furthermore, when vector DNA from Bombyx mori nuclear polyhedrosis virus (BmNPV), which is unable to replicate in Sf9 cells from Eri silkworms, was replaced with the Autographa californica nuclear polyhedrosis virus (AcNPV) vector, three improved AcNPV influenza virus recombinants capable of replication in Sf9 cells were obtained. Although VLP antigens produced previously in silkworms were not evaluated individually, the present recombinant Fukushima (FkH5) and Anhui (AnH7) VLP antigens were detected in tissue fluids and fat bodies of Eri silkworms. Here, we aimed to determine the function of the AcNPV vector and P143 gene by expressing recombinants in Sf9 cells and eri silkworm pupae. The FkH5 recombinant produced high yields of haemagglutinin (HA)-positive VLPs, showing a mean HA titre of 1.2 million. Similarly, high production of H7 HA VLPs was observed in the fat bodies of eri silkworm pupae. Antigenic analysis and electron microscopy examination of Eri-silkworm-produced H5 HA VLPs showed characteristic antigenicity and morphology similar to those of the influenza virus. Although FkH5 recombinants possessing the AcNPV vector did not replicate in Bm-N cells, the introduction of the helicase p143 gene from BmNPV resulted in their production in Bm-N and Sf9 cells.
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http://dx.doi.org/10.1007/s00705-018-3941-4DOI Listing
October 2018

Development of a Japanese encephalitis virus genotype V virus-like particle vaccine in silkworms.

J Gen Virol 2018 07 7;99(7):897-907. Epub 2018 Jun 7.

The Institute of Biological Resources, Okinawa, Japan.

To counter the spread of multiple Japanese encephalitis virus (JEV) variants harboured in alternative host species and highly neurotoxic variants with new antigenicity, such as genotype V (Muar), methods for developing more effective and low-cost vaccines against a variety of epidemic JEV strains are required. Here, we successfully synthesized large amounts of a Muar virus-like particle (MVLP) vaccine for JEV in silkworm pupae by using a Bombyx mori nuclear polyhedrosis virus recombinant consisting of JEV codon-optimized envelope (E) DNA. In particular, histopathological examination suggested that MVLP was efficiently synthesized in body fat tissues as well as epithelial cells. Quantitative analysis indicated that one silkworm pupa produced 724.8 µg of E protein in the MVLP vaccine. Electron microscopic examination of purified MVLP vaccine defined a typical MVLP morphological structure. Detailed MVLP antigen assessment by immune-electron microscopy revealed that the majority of MVLPs were covered with approximately 10 nm projections. Boosted immunization with MVLP antigens in mice and rabbits tended to show improved plaque inhibition potency against homologous Muar and heterologous Nakayama, but less potency to Beijing-1 strains. Notably, mixed immune rabbit antisera against Nakayama and Muar VLP antigens led to an increase in the low antibody reaction to Beijing-1. Additionally, a stopgap divalent JEV vaccine consisting of MVLP and Nakayama VLP and its immune mouse serum significantly increased plaque inhibition titre against Muar, Nakayama and Beijing-1 strains. These findings suggested that low-cost MVLP vaccines prepared in silkworm pupae are suitable for providing simultaneous protection of individuals in developing countries against various JEV strains.
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http://dx.doi.org/10.1099/jgv.0.001081DOI Listing
July 2018

Development of pooled testing system for porcine epidemic diarrhoea using real-time fluorescent reverse-transcription loop-mediated isothermal amplification assay.

BMC Vet Res 2018 May 29;14(1):172. Epub 2018 May 29.

Animal Infectious Disease and Prevention, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.

Background: Porcine epidemic diarrhoea (PED) is an emerging disease in pigs that causes massive economic losses in the swine industry, with high mortality in suckling piglets. Early identification of PED virus (PEDV)-infected herd through surveillance or monitoring strategies is necessary for mass control of PED. However, a common working diagnosis system involves identifying PEDV-infected animals individually, which is a costly and time-consuming approach. Given the above information, the thrusts of this study were to develop a real-time fluorescent reverse transcription loop-mediated isothermal amplification (RtF-RT-LAMP) assay and establish a pooled testing system using faecal sample to identify PEDV-infected herd.

Results: In this study, we developed an accurate, rapid, cost-effective, and simple RtF- RT-LAMP assay for detecting the PEDV genome targeting M gene. The pooled testing system using the RtF-RT-LAMP assay was optimized such that a pool of at least 15 individual faecal samples could be analysed.

Conclusions: The developed RtF-RT-LAMP assay in our study could support the design and implementation of large-scaled epidemiological surveys as well as active surveillance and monitoring programs for effective control of PED.
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http://dx.doi.org/10.1186/s12917-018-1498-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5975689PMC
May 2018

The HDAC Inhibitor, SAHA, Prevents Colonic Inflammation by Suppressing Pro-inflammatory Cytokines and Chemokines in DSS-induced Colitis.

Acta Histochem Cytochem 2018 Feb 21;51(1):33-40. Epub 2018 Feb 21.

Department of Anatomy, Histochemistry and Cell Biology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.

Inflammatory bowel disease (IBD) is an inflammatory disorder of the gastrointestinal tract that is caused by multiple factors, including dysfunction of the immune system and genetic and epigenetic alterations. Aberrant epigenetic regulation, especially histone acetylation, was found in biopsies from IBD patients and mouse models of colitis, suggesting that an epigenetic treatment approach may be useful for IBD therapy. Therefore, we investigated the effects of the histone deacetylase (HDAC) inhibitor, suberoylanilide hydroxamic acid (SAHA), in a mouse model of dextran sulfate sodium (DSS)-induced colitis. C57BL/6 mice were treated with 1.5% DSS for 5 days and/or SAHA (25 mg/kg BW/day) for 26 days. Levels of mRNA for the pro-inflammatory cytokines, interleukin (IL)-6 and tumor necrosis factor (TNF)-α, and the chemokines, Ccl2, were examined by qRT-PCR. CD11b, a marker of dendritic cells, macrophages, and monocytes, as well as Ccl2 expression, were examined by immunohistochemistry. IL-6, TNF-α, and Ccl2 gene expression peaked on day 5 in DSS-treated mouse colon, whereas SAHA treatment significantly decreased pro-inflammatory gene expression. Ccl2 protein expression resembled Ccl2 gene expression results. Moreover, localization of CD11b showed that migratory inflammatory cells were dramatically decreased by SAHA treatment compared to DSS-treated mouse colon. Thus, we conclude that the HDAC inhibitor, SAHA, attenuates inflammatory changes in DSS-induced colitis by suppressing local secretion of pro-inflammatory cytokines and chemokines and also by suppressing mobilization and accumulation of inflammatory cells.
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http://dx.doi.org/10.1267/ahc.17033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5880801PMC
February 2018

Molecular characterization of US-like and Asian non-S INDEL strains of porcine epidemic diarrhea virus (PEDV) that circulated in Japan during 2013-2016 and PEDVs collected from recurrent outbreaks.

BMC Vet Res 2018 Mar 14;14(1):96. Epub 2018 Mar 14.

Department of Veterinary Medicine, Faculty of Agriculture, University of Miyazaki, Gakuen-kibanadai-nishi-1-1, Miyazaki, 889-2192, Japan.

Background: Since late 2013, porcine epidemic diarrhea virus (PEDV) has reemerged in Japan and caused severe economic losses to the swine industry. Although PEDV vaccines have been used widely, the disease has swept rapidly across the county, and is commonly observed in PED-vaccinated farms, and has recurred in domestic herds. To better understand PEDVs responsible for the reemerging outbreaks in Japan, full-length spike (S), membrane (M), and nucleocapsid (N) genes of 45 PEDVs collected in Japan during 2013-2016, were sequenced and analyzed.

Results: Phylogenetic analysis based on S gene sequences revealed that all the recent field PEDVs were genetically distinct from the classical Japanese strains, and were classified into three genotypes: North American (NA), S INDEL, and Asian non-S INDEL. Our data suggested a possibility that multiple parental PEDV strains were introduced into Japan from abroad at the same time or similar times. The newly identified Japanese strains showed the closest relationship to the US strains. Two sublineages of Japanese strains circulating in Japan were similar to two sublineages identified in the US, suggesting common ancestors for these strains. In comparison with two vaccine strains used in Japan, the field strains had various changes in epitope regions, glycosylation sites, and phosphorylation sites. These substitutions, particularly observed in epitope regions of the S (521, 553, 568, and 570), M (5), and N (123, 252, and 255) proteins, may have affected antigenicity and vaccine efficacy, resulting in an unsuccessful PEDV control. Sequence comparisons between PEDVs collected from primary and secondary outbreaks in three herds revealed that the disease has developed to an endemic stage in which PEDV could persist for nearly two years in the herds or local regions, causing subsequent epidemics.

Conclusions: These results elucidate the genetic characteristics, origin, and molecular epidemiology of PEDVs circulating in Japan, as well as the PEDV strains causing recurrent outbreaks. This study provides a better insight into the PEDVs responsible for recent outbreaks in Japan, and could potentially help to develop measures for controlling and preventing the disease.
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http://dx.doi.org/10.1186/s12917-018-1409-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5852955PMC
March 2018

Two types of deposits, hyaline droplets and eosinophilic bodies, associated with α-globulin accumulation in the rat kidney.

J Toxicol Pathol 2017 Oct 8;30(4):275-282. Epub 2017 Jul 8.

Pathology Department, Kumamoto Laboratory, Nonclinical Research Center, LSI Medience Corporation, 1285 Kurisaki-machi, Uto, Kumamoto 869-0425, Japan.

Alpha-globulin is an adult male rat-specific protein that accumulates spontaneously or inductively in the renal proximal tubular epithelium and forms microscopically observable deposits, which are generally referred to as "hyaline droplets," whereas a specific type of deposits is referred to as "eosinophilic bodies" by Japanese toxicologic pathologists. We compared hyaline droplets and eosinophilic bodies using special stains including immunostaining for α-globulin and lysosome-associated membrane protein in spontaneously occurring and -limonene-induced cases. Eosinophilic bodies appeared simultaneously and increased in parallel with the hyaline droplets in the induced case. In both of the spontaneous and induced cases, hyaline droplets and eosinophilic bodies were associated with α-globulin and lysosomes, although there were differences in the forms and staining properties that probably reflected the purity or density of α-globulin. According to the results, it is not necessary for eosinophilic bodies to be strictly distinguished from hyaline droplets, and it is reasonable to identify eosinophilic bodies as hyaline droplets in α-globulin nephropathy in routine toxicity studies, as they have been recognized to be a sequence of changes associated with accumulation of α-globulin.
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http://dx.doi.org/10.1293/tox.2017-0023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5660949PMC
October 2017

Development of a Japanese encephalitis virus-like particle vaccine in silkworms using codon-optimised prM and envelope genes.

Heliyon 2017 Apr 11;3(4):e00286. Epub 2017 Apr 11.

The Institute of Biological Resources, 893-2, Nakayama, Nago-shi, Okinawa 905-0004, Japan.

We have successfully prepared a Japanese encephalitis virus (JEV) - Nakayama virus like particle (NVLP) vaccine using synthetic codon-optimized prM and E genes. The expression of the recombinant JEV Nakayama-BmNPV (JEV-NNPV) virus was determined in infected silkworm Bm-N cells by fluorescence and Western blot analysis. The recombinant was inoculated into silkworm pupae and the yield of Nakayama VLP (NVLP) reached a peak in the homogenates after 3 days. Additionally, in the peptide analysis of infected pupae homogenate, it appeared approximately 300-500 μg E protein/pupa were produced. When purified the above eluates on the discontinuous sucrose density gradient centrifugation, NVLP showed a strong hemagglutination (HA) activity by using chicken red blood cell in phosphate-buffered saline (PBS) free from Mg and Ca ions. The immune antisera against NVLP strain could efficiently neutralize the plaque formation of Nakayama, Beijing-1 and Muar strains, showing tendency of much higher reaction with heterologous Muar strain than homologous Nakayama strain. Our findings suggest that the JEV-NVLP may be useful for JEV epidemic control in many endemic areas of Asian countries as a widely effective and less expensive JE vaccine.
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http://dx.doi.org/10.1016/j.heliyon.2017.e00286DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5390689PMC
April 2017

Experimental induction of chicken amyloid A amyloidosis in white layer chickens by inoculation with inactivated vaccines.

Avian Pathol 2017 Oct 15;46(5):497-505. Epub 2017 May 15.

a Department of Veterinary Pathology, Faculty of Agriculture , University of Miyazaki , Miyazaki , Japan.

We investigated the amyloidogenic potential of inactivated vaccines and the localized production of serum amyloid A (SAA) at the injection site in white layer chickens. Hens in the treated group were injected intramuscularly three times with high doses of inactivated oil-emulsion Salmonella Enteritidis vaccine and multivalent viral and bacterial inactivated oil-emulsion vaccines at two-week intervals. Chickens in the control group did not receive any inoculum. In the treated group, emaciation and granulomas were present, while several chickens died between 4 and 6 weeks after the first injection. Hepatomegaly was seen at necropsy, and the liver parenchyma showed inconsistent discolouration with patchy green to yellowish-brown areas, or sometimes red-brown areas with haemorrhage. Amyloid deposition in the liver, spleen, duodenum, and at injection sites was demonstrated using haematoxylin and eosin staining, Congo red, and immunohistochemistry. The incidence of chicken amyloid A (AA) amyloidosis was 47% (28 of 60) in the treated group. In addition, RT-PCR was used to identify chicken SAA mRNA expression in the liver and at the injection sites. Furthermore, SAA mRNA was detected by in situ hybridization in fibroblasts at the injection sites, and also in hepatocytes. We believe that this is the first report of the experimental induction of systemic AA amyloidosis in white layer chickens following repeated inoculation with inactivated vaccines without the administration of amyloid fibrils or other amyloid-enhancing factors.
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http://dx.doi.org/10.1080/03079457.2017.1321103DOI Listing
October 2017

Expression of canine distemper virus receptor nectin-4 in the central nervous system of dogs.

Sci Rep 2017 03 23;7(1):349. Epub 2017 Mar 23.

Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki, 889-2192, Japan.

Canine distemper virus (CDV) exhibits lymphotropic, epitheliotropic, and neurotropic nature, and causes a severe systemic infection in susceptible animals. Initially, signaling lymphocyte activation molecule (SLAM) expressed on immune cells has been identified as a crucial cellular receptor for CDV. Currently, nectin-4 expressed in epithelia has been shown to be another receptor for CDV. Our previous study demonstrated that neurons express nectin-4 and are infected with CDV. In this study, we investigated the distribution pattern of nectin-4 in various cell types in the canine central nervous system and showed its relation to CDV infection to further clarify the pathology of disease. Histopathological, immunohistochemical and immunofluorescent analyses were done using formalin-fixed paraffin-embedded tissues of CDV-infected dogs. Dual staining of nectin-4 and CDV antigen or nectin-4 and brain cell markers was performed. Nectin-4 was detected in ependymal cells, epithelia of choroid plexus, meningeal cells, neurons, granular cells, and Purkinje's cells. CDV antigens were detected in these nectin-4-positive cells, further suggesting contribution of nectin-4 for the CDV neurovirulence. On the other hand, astrocytes did not express nectin-4, although they were frequently infected with CDV. Since astrocytes are negative for SLAM expression, they must express an unidentified CDV receptor, which also contributes to CDV neurovirulence.
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http://dx.doi.org/10.1038/s41598-017-00375-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5428276PMC
March 2017

An atypical case of recurrent carotid body carcinoma in a young adult dog: Histopathological, immunohistochemical and electron microscopic study.

J Vet Med Sci 2017 Apr 27;79(4):714-718. Epub 2017 Feb 27.

Laboratory of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Gakuen-kibanadai-nishi-1-1, Miyazaki 889-2192, Japan.

A 3.5-year-old female Chihuahua was presented with complaint of neck pain, intermittent cough and dysphagia. Physical examination and diagnostic imaging of neck region revealed a solid and highly vascularized mass involving the retropharyngeal region. Histologically, the mass showed an atypical zellballen pattern which comprised of high density of type I chief cells with high nuclear cytoplasmic ratio and separated by delicate fibrovascular stroma. Immunoreactivity for neuroendocrine markers was diffusely positive in cytoplasm of tumor cells. Disseminated tumor emboli in external jugular vein were detected 6 months after initial surgery. An electron microscopic study revealed numerous electron-dense intracytoplasmic neurosecretory granules. Based on these findings, carotid body carcinoma was diagnosed.
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http://dx.doi.org/10.1292/jvms.16-0501DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5402192PMC
April 2017

Loss of NDRG2 Expression Confers Oral Squamous Cell Carcinoma with Enhanced Metastatic Potential.

Cancer Res 2017 05 16;77(9):2363-2374. Epub 2017 Feb 16.

Division of Tumor and Cellular Biochemistry, Department of Medical Sciences, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.

Loss of the tumor suppressor NDRG2 has been implicated in the development of oral squamous cell carcinoma (OSCC), acting by modulating PI3K/AKT-mediated dephosphorylation of PTEN at S380/S382/T383 (STT). Here, we show that the majority of OSCC tumors with lymph node metastasis, a major prognostic factor, exhibit high levels of phosphorylated AKT-S473 and PTEN-STT and low levels of NDRG2 expression. In -deficient mice, which develop a wide range of tumors, we developed a model of OSCC by treatment with the tobacco surrogate 4-nitroquinoline-1-oxide (4-NQO). In this model, both the number and size of OSCC tumors were increased significantly by deficiency, which also increased invasion of cervical lymph nodes. 4-NQO treatment of human OSCC cell lines exhibiting low NDRG2 expression induced epithelial-mesenchymal transition via activation of NF-κB signaling. Conversely, ectopic expression of NDRG2 reversed the EMT phenotype and inhibited NF-κB signaling via suppression of PTEN-STT and AKT-S473 phosphorylation. Our results show how NDRG2 expression serves as a critical determinant of the invasive and metastatic capacity of OSCC. .
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http://dx.doi.org/10.1158/0008-5472.CAN-16-2114DOI Listing
May 2017

Novel Porcine Epidemic Diarrhea Virus (PEDV) Variants with Large Deletions in the Spike (S) Gene Coexist with PEDV Strains Possessing an Intact S Gene in Domestic Pigs in Japan: A New Disease Situation.

PLoS One 2017 17;12(1):e0170126. Epub 2017 Jan 17.

Laboratory of Veterinary Pathology, Department of Veterinary, Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki, Japan.

Since late 2013, after an absence of seven years, outbreaks of porcine epidemic diarrhea virus (PEDV) infection have reemerged and swept rapidly across Japan, resulting in significant economic losses. In this study, we report the emergence, mixed infection, and genetic characterization of 15 novel field PEDV variants with large genomic deletions. The sizes of deletion varied between 582 nt (194 aa) and 648 nt (216 aa) at positions 28-714 (10-238) on the S gene (protein). Among 17 PEDV samples isolated from individual pigs, all of them contained at least two distinct genotypes with large genomic deletions, and 94.1% of them were found to consist of strains with an intact S gene. These variants were found in eight primary and nine recurrent outbreaks, and they might be associated with persistent PEDV infection in the farms. Full-length S and ORF3 genes of eight variants derived from 2 samples were characterized. This is the first report of mixed infections caused by various genotypes of PEDV and would be important for the studies of viral isolation, pathogenesis, and molecular epidemiology of the disease.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0170126PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5241010PMC
August 2017

Histopathological changes in the pancreas of cattle with abdominal fat necrosis.

J Vet Med Sci 2017 Jan 30;79(1):52-59. Epub 2016 Oct 30.

Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, 5200, Kihara, Kiyotake, Miyazaki 889-1692, Japan.

The association between pancreatic disorder and abdominal fat necrosis in cattle remains unclear. The pancreases of 29 slaughtered cattle with or without fat necrosis were collected to investigate pathological changes. Japanese Black (JB) cattle were classified into the FN group (with abdominal fat necrosis; n=9) and N group (without fat necrosis; n=5). The pancreases were also collected from 15 Holstein Friesian (HF) cows. All JB cattle showed high body condition scores. Regarding the pathological findings, fatty pancreas which involves adipocyte infiltration into the pancreas and fat necrosis (saponification) were observed in 25 and 27 cases, respectively. Immunohistochemical staining with anti-Iba-1 antibody showed large numbers of macrophages surrounding the saponified fat in the pancreas. CD3-positive T cells were significantly more common in the pancreas of both the FN and N groups compared with the HF group (P<0.05). Furthermore, fibrosis in the pancreas exhibited a correlative tendency with the formation of necrotic fat mass in the peritoneal cavity (P<0.1). These results indicate that obesity leads to increased severity of pancreatic disorder, including fatty pancreas and pancreatitis. The pathological lesions in the pancreas may play a key role in abdominal fat necrosis through the inflammatory process.
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http://dx.doi.org/10.1292/jvms.16-0282DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5282410PMC
January 2017

US-like isolates of porcine epidemic diarrhea virus from Japanese outbreaks between 2013 and 2014.

Springerplus 2015 2;4:756. Epub 2015 Dec 2.

Laboratory of Veterinary Pathology, Department of Veterinary, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-Nishi, Miyazaki, 889-2192 Japan.

Since late 2013, outbreaks of porcine epidemic diarrhea virus (PEDV) have reemerged in Japan. In the present study, we observed a high detection rate of PEDV, with 72.5 % (148/204) of diarrhea samples (suckling, weaned, and sows) and 88.5 % (77/87) of farms experiencing acute diarrhea found to be positive for PEDV by reverse transcription PCR. Sequencing and phylogenic analyses of the partial spike gene and ORF3 of PEDV demonstrated that all prevailing Japanese PEDV isolates belonged to novel genotypes that differed from previously reported strains and the two PEDV vaccine strains currently being used in Japan. Sequence and phylogenetic analysis revealed prevailing PEDV isolates in Japan had the greatest genetic similarity to US isolates and were not vaccine-related. Unlike vaccine strains, all prevailing field PEDV isolates in Japan were found to have a number of amino acid differences in the neutralizing epitope domain, COE, which may affect antigenicity and vaccine efficacy. The present study indicates recent PEDV isolates may have been introduced into Japan from overseas and highlights the urgent requirement of novel vaccines for controlling PEDV outbreaks in Japan.
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http://dx.doi.org/10.1186/s40064-015-1552-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4668244PMC
December 2015

A case report of suspected hepatopulmonary syndrome secondary to ductal plate malformation with chronic active hepatitis in a dog.

J Vet Med Sci 2016 Mar 30;78(3):493-7. Epub 2015 Nov 30.

Veterinary Teaching Hospital, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen Kibanadai-nishi, Miyazaki 889-2192, Japan.

Hepatopulmonary syndrome (HPS) is a respiratory complication of hepatic disease, that is well recognized in humans and defined by the presence of 1) liver disease, 2) hypoxemia and/or high alveolar-arterial oxygen gradient (AaDO2) and 3) intrapulmonary vasodilatation. The present report describes a similar case of HPS in a dog. A six-month-old Papillon was diagnosed with ductal plate malformation with chronic active hepatitis and showed progressive increases in AaDO2 over the course of the following six months. The presence of intrapulmonary vasodilatation was confirmed by agitated saline contrast transthoracic echocardiography. Also, the absence of congenital cardiac defect was confirmed by transthoracic echocardiography. From these results, we suspected that this dog had HPS. This is the first description of suspected canine HPS.
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http://dx.doi.org/10.1292/jvms.15-0425DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4829524PMC
March 2016

Enhanced detection of Porcine reproductive and respiratory syndrome virus in fixed tissues by in situ hybridization following tyramide signal amplification.

J Vet Diagn Invest 2015 May 8;27(3):326-31. Epub 2015 Apr 8.

Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan (Trang, Hirai, Fuke, Toyama, Yamaguchi)Departments of Veterinary Public Health (Trang, Ngan) Faculty of Veterinary Medicine, Hanoi University of Agriculture, Hanoi, VietnamVeterinary Pathology (Lan), Faculty of Veterinary Medicine, Hanoi University of Agriculture, Hanoi, Vietnam.

This study evaluated the sensitivity of biotinyl-tyramide-based in situ hybridization (TISH) method by comparison with chromogenic in situ hybridization (CISH) and immunohistochemical staining (IHC) methods. This study also determined the effect of fixative and fixation time on the detection of Porcine reproductive and respiratory syndrome virus (PRRSV) in paraffin-embedded tissues. Lung samples were fixed in 4% paraformaldehyde (PFA) or 10% neutral buffered formalin (NBF) for various times before paraffin embedding. Of 30 paraffin-embedded lung samples, fixed for 1 day in 4% PFA or 10% NBF, 18 (60%) were positive for PRRSV by nested reverse transcription polymerase chain reaction (nRT-PCR). All 18 lung samples (100%) also were positive for PRRSV by TISH, but only 10 of these 18 specimens (56%) were positive for PRRSV by IHC and CISH. We demonstrated that TISH can detect PRRSV RNA in paraffin-embedded tissues after up to 90 days of fixation. PRRSV nucleic acids and antigens were better preserved in 4% PFA than in 10% NBF. Compared with CISH and IHC testing methods, TISH appeared to be more sensitive for the detection of PRRSV in paraffin-embedded tissues.
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http://dx.doi.org/10.1177/1040638715579260DOI Listing
May 2015

Foot-and-mouth disease in Asiatic black bears (Ursus thibetanus).

J Vet Diagn Invest 2014 Sep 18;26(5):705-13. Epub 2014 Aug 18.

Vietnam Bear Rescue Centre, Animals Asia Foundation, Tam Dao National Park, Vinh Phuc, Vietnam (Officer, Weegenaar)Key Laboratory of Veterinary Biotechnology and Department of Veterinary Pathology, Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Ha Noi, Vietnam (Nguyen Thi Lan, Nguyen Thi Hoa)PREDICT Program, Wildlife Conservation Society, Ha Noi, Vietnam (Wicker)Animals Asia Foundation, Sheung Wan, Hong Kong (Robinson)Department of Veterinary Pathology, University of Miyazaki, Japan (Ryoji)Laboratory of Pathology, Faculty of Veterinary Medicine, Aristotle University, Thessalonica, Greece (Loukopoulos)California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, University of California-Davis, San Bernardino, CA (Loukopoulos).

Foot-and-mouth disease (FMD) is a highly contagious, debilitating, and globally significant viral disease typically affecting cloven-hoofed hosts. The diagnosis of FMD in bears in Vietnam is described. The current study describes a confirmed case of FMD in a bear species, and the clinical signs compatible with FMD in a Malayan sun bear. Thirteen Asiatic black bears (Ursus thibetanus) and 1 Malayan sun bear (Helarctos malayanus) were apparently affected. In August 2011, an adult bear became lethargic, and developed footpad vesicles. Over 15 days, 14 out of 17 bears developed similar signs; the remaining 3 co-housed bears and another 57 resident bears did not. All affected bears developed vesicles on all footpads, and most were lethargic for 24-48 hr. Nasal and oral lesions were noted in 6 and 3 cases, respectively. Within 1 month, all looked normal. Foot-and-mouth disease virus (FMDV) was detected by reverse transcription polymerase chain reaction, classified as serotype O, and isolated by virus isolation techniques. Phylogenetic analysis demonstrated clustering of 3 bear isolates, in a branch distinct from other FMDV type O isolates. The outbreak likely occurred due to indirect contact with livestock, and was facilitated by the high density of captive bears. It showed that Asiatic black bears are capable of contracting FMDV and developing clinical disease, and that the virus spreads easily between bears in close contact.
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http://dx.doi.org/10.1177/1040638714547256DOI Listing
September 2014

Detection of porcine reproductive and respiratory syndrome virus in oral fluid from naturally infected pigs in a breeding herd.

J Vet Sci 2014 2;15(3):361-7. Epub 2014 Apr 2.

Department of Veterinary Pathology, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan.

The objectives of the present study were to evaluate the anatomic localization of porcine reproductive and respiratory syndrome virus (PRRSV) in naturally infected pigs and to determine whether oral fluid could be used to detect the virus in infected animals. Two sows, seven 2-month-old grower pigs, and 70 6-month-old gilts were included in this study. PRRSV in sera and oral fluid were identified by nested reverse transcription PCR (nRT-PCR) while lung, tonsil, and tissue associated with oral cavity were subjected to nRT-PCR, immunohistochemistry, and in situ hybridization. In sows, PRRSV was identified in oral fluid and tonsils. PRRSV was also detected in oral fluid, tonsils, salivary glands, oral mucosa, and lungs of all seven grower pigs. However, viremia was observed in only two grower pigs. Double staining revealed that PRRSV was distributed in macrophages within and adjacent to the tonsillar crypt epithelium. In gilts, the North American type PRRSV field strain was detected 3 to 8 weeks after introducing these animals onto the farm. These results confirm previous findings that PRRSV primarily replicates in tonsils and is then shed into oral fluid. Therefore, oral fluid sampling may be effective for the surveillance of PRRSV in breeding herds.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4178137PMC
http://dx.doi.org/10.4142/jvs.2014.15.3.361DOI Listing
January 2016

Loss of NDRG2 expression activates PI3K-AKT signalling via PTEN phosphorylation in ATLL and other cancers.

Nat Commun 2014 Feb 26;5:3393. Epub 2014 Feb 26.

Division of Tumor and Cellular Biochemistry, Department of Medical Sciences, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan.

Constitutive phosphatidylinositol 3-kinase (PI3K)-AKT activation has a causal role in adult T-cell leukaemia-lymphoma (ATLL) and other cancers. ATLL cells do not harbour genetic alterations in PTEN and PI3KCA but express high levels of PTEN that is highly phosphorylated at its C-terminal tail. Here we report a mechanism for the N-myc downstream-regulated gene 2 (NDRG2)-dependent regulation of PTEN phosphatase activity via the dephosphorylation of PTEN at the Ser380, Thr382 and Thr383 cluster within the C-terminal tail. We show that NDRG2 is a PTEN-binding protein that recruits protein phosphatase 2A (PP2A) to PTEN. The expression of NDRG2 is frequently downregulated in ATLL, resulting in enhanced phosphorylation of PTEN at the Ser380/Thr382/Thr383 cluster and enhanced activation of the PI3K-AKT pathway. Given the high incidence of T-cell lymphoma and other cancers in NDRG2-deficient mice, PI3K-AKT activation via enhanced PTEN phosphorylation may be critical for the development of cancer.
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http://dx.doi.org/10.1038/ncomms4393DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3948061PMC
February 2014

Structure-activity relationship study of BACE1 inhibitors possessing a chelidonic or 2,6-pyridinedicarboxylic scaffold at the P(2) position.

Bioorg Med Chem Lett 2014 Jan 8;24(2):618-23. Epub 2013 Dec 8.

Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Minatojima, Chuo-ku, Kobe 650-8586, Japan; Center for Frontier Research in Medicinal Science, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8412, Japan; Laboratory of Peptide Science, Nagahama Institute of Bio-Science and Technology, Tamura-cho, Nagahama 526-0829, Japan.

We have previously reported potent substrate-based pentapeptidic BACE1 inhibitors possessing a hydroxymethylcarbonyl isostere as a substrate transition-state mimic. While these inhibitors exhibited potent activities in enzymatic and cellular assays (KMI-429 in particular inhibited Aβ production in vivo), these inhibitors contained some natural amino acids that seemed to be required to improve enzymatic stability in vivo and permeability across the blood-brain barrier, so as to be practical drug. Recently, we synthesized non-peptidic and small-sized BACE1 inhibitors possessing a heterocyclic scaffold at the P2 position. Herein we report the SAR study of BACE1 inhibitors possessing this heterocyclic scaffold, a chelidonic or 2,6-pyridinedicarboxylic moiety.
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http://dx.doi.org/10.1016/j.bmcl.2013.12.007DOI Listing
January 2014

The V protein of canine distemper virus is required for virus replication in human epithelial cells.

PLoS One 2013 17;8(12):e82343. Epub 2013 Dec 17.

Department of Virology 3, National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan.

Canine distemper virus (CDV) becomes able to use human receptors through a single amino acid substitution in the H protein. In addition, CDV strains possessing an intact C protein replicate well in human epithelial H358 cells. The present study showed that CDV strain 007Lm, which was isolated from lymph node tissue of a dog with distemper, failed to replicate in H358 cells, although it possessed an intact C protein. Sequence analyses suggested that a cysteine-to-tyrosine substitution at position 267 of the V protein caused this growth defect. Analyses using H358 cells constitutively expressing the CDV V protein showed that the V protein with a cysteine, but not that with a tyrosine, at this position effectively blocked the interferon-stimulated signal transduction pathway, and supported virus replication of 007Lm in H358 cells. Thus, the V protein as well as the C protein appears to be functional and essential for CDV replication in human epithelial cells.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0082343PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3866114PMC
September 2014