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result(s) for
"Kato, Atsushi"
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Regulatory mechanism of a heat-activated retrotransposon by DDR complex in Arabidopsis thaliana
2022
The RNA-directed DNA methylation (RdDM) pathway plays an essential role in the transposon silencing mechanism; the DDR complex, consisting of DRD1, DMS3, and RDM1, is an essential component of the RdDM pathway. ONSEN , identified in Arabidopsis , is a retrotransposon activated by heat stress at 37°C; however, studies on the regulation of ONSEN are limited. In this study, we analyzed the regulation of ONSEN activity by the DDR complex in Arabidopsis . We elucidated that loss of any component of the DDR complex increased ONSEN transcript levels. Transgenerational transposition of ONSEN was observed in the DDR-complex mutants treated with heat stress for 48 h. Furthermore, the DDR complex components DRD1, DMS3, and RDM1 played independent roles in suppressing ONSEN transcription and transposition. Moreover, we found that the duration of heat stress affects ONSEN activity. Therefore, the results of this study provide new insights into the retrotransposon regulatory mechanisms of the DDR complex in the RdDM pathway.
Journal Article
Epidemiological Review of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) in Japan: From Discovery and Spread to Economic Losses and Future Prospects
by
Sugiura, Katsuaki
,
Kato, Atsushi
,
Tsutsumi, Nobuyuki
in
Abortion
,
Animal diseases
,
Biosecurity
2025
Porcine reproductive and respiratory syndrome virus (PRRSV) poses a significant economic challenge to Japan’s swine industry. This review synthesizes the epidemiological evolution of PRRSV in Japan by examining the available scientific literature from its initial Type 2 isolation in 1993 to recent events. Endemic Type 2 strains, initially dominated by Cluster III (Lineage 4), have diversified significantly. This diversification was marked by key events including the emergence of vaccine-associated Cluster II (Lineage 5) and incursions of virulent Cluster IV/Lineage 1F (MN184A-like) strains and Type 1 virus around 2008. By 2018–2020, Clusters II and IV predominated nationwide, a trend strongly linked to widespread modified live virus (MLV) vaccination. The recent detection of the globally significant NADC34-like (Lineage 1A) strain underscores ongoing foreign incursion risks. Current MLV vaccines face challenges, including safety concerns and limited cross-protection against diverse field strains. Consequently, effective control requires integrated strategies, comprising optimized vaccination, stringent biosecurity, advanced molecular surveillance, improved diagnostics, and coordinated regional control programs guided by systematic herd classification and stakeholder partnerships. The development of next-generation vaccines and sustained multi-stakeholder collaboration are critical for mitigating the impact of PRRSV in Japan.
Journal Article
Cytokines in Chronic Rhinosinusitis. Role in Eosinophilia and Aspirin-exacerbated Respiratory Disease
by
Stevens, Whitney W.
,
Fujieda, Shigeharu
,
Carter, Roderick G.
in
Adult
,
Aged
,
Asthma, Aspirin-Induced - immunology
2015
Abstract
Rationale
The mechanisms that underlie the pathogenesis of chronic rhinosinusitis without nasal polyps (CRSsNP), chronic rhinosinusitis with nasal polyps (CRSwNP), and aspirin-exacerbated respiratory disease (AERD) are not clear.
Objectives
To first evaluate the inflammatory profiles of CRSsNP and CRSwNP tissues and then to investigate whether clinical differences observed between CRSwNP and AERD are in part secondary to differences in inflammatory mediator expression within nasal polyp (NP) tissues.
Methods
Expression levels of numerous inflammatory mediators were determined by quantitative real-time polymerase chain reaction, ELISA, and multiplex immunoassay.
Measurements and Main Results
CRSwNP NP had increased levels of type 2 mediators, including IL-5 (P < 0.001), IL-13 (P < 0.001), eotaxin-2 (P < 0.001), and monocyte chemoattractant protein (MCP)-4 (P < 0.01), compared with sinonasal tissue from subjects with CRSsNP and control subjects. Expression of IFN-γ messenger RNA or protein was low and not different among the chronic rhinosinusitis subtypes examined. Compared with CRSwNP, AERD NP had elevated protein levels of eosinophil cationic protein (ECP) (P < 0.001), granulocyte–macrophage colony–stimulating factor (GM-CSF) (P < 0.01), and MCP-1 (P = 0.01), as well as decreased gene expression of tissue plasminogen activator (tPA) (P = 0.02). Despite the higher eosinophilia in AERD, there was no associated increase in type 2 mediator protein levels observed.
Conclusions
CRSwNP was characterized by a predominant type 2 inflammatory environment, whereas CRSsNP did not reflect a classic type 1 milieu, as has been suggested previously. AERD can be distinguished from CRSwNP by elevated ECP levels, but this enhanced eosinophilia is not associated with elevations in traditional type 2 inflammatory mediators associated with eosinophil proliferation and recruitment. However, other factors, including GM-CSF, MCP-1, and tPA, may be important contributors to AERD pathogenesis.
Journal Article
Borylated 5-Membered Ring Iminosugars: Synthesis and Biological Evaluation for Glycosidase Inhibition and Anticancer Properties for Application in Boron Neutron Capture Therapy (BNCT)—Part 2
2025
Background: The synthesis and biological investigation of pyrrolidine (L-gulo) iminosugars bearing an organic boron pharmacophore in ortho and meta positions of an N-benzyl group is reported. This paper completes the structure–activity relationship data for this novel family of boron-bearing iminosugars. These can establish reversible intramolecular interactions via dative bonding from nucleophilic amino acid side chains to the empty p-orbital of the boron atom. Methods: Inhibitory activities against two panels of glycosidases and cancer cell lines were investigated to ascertain structure–activity relationship profiles for these novel iminosugar drug leads. Results: These iminosugars display selective, moderate-to-weak inhibitions (IC50s = 116–617 μM) of β-D-galactosidase (bovine liver), and indications of inhibition of β-D-glucosidases (almond, bovine liver) (IC50s = 633 and 710 μM) and α-D-glucosidases (rice, yeast, rat intestinal maltase) (IC50s = 106–784 μM). The boronic acid group emerges as a useful pharmacophore for management of lysosomal storage disorders via the chaperone-mediated therapy approach. The cancer assays revealed that the A2780 ovarian carcinoma cell line is selectively inhibited by all compounds screened and the MIA-Pa-Ca2 pancreatic carcinoma cell line is selectively inhibited by most compounds. Growth inhibition and GI50 values were most potent for the meta 7 side-product. Conclusions: Beyond the cancer cell line inhibition and dose-response capabilities, the real therapeutic potential of these borylated drugs lies in their switch on/switch off activation under boron neutron capture therapy (BNCT) radiotherapeutic conditions, thus providing an important area of application for borylated monosaccharides.
Journal Article
Borylated Five-Membered Ring Iminosugars: Synthesis, Spectroscopic Analysis, and Biological Evaluation for Glycosidase Inhibition and Anticancer Properties for Application in Boron Neutron Capture Therapy (BNCT)—Part 1
by
Yoshimura, Kosuke
,
Bartholomew, Barbara
,
Yamamoto, Suzuka
in
Acids
,
Alkaloids
,
Antimitotic agents
2025
Background/Objectives: This article reports pyrrolidine iminosugars of L-gulose absolute stereochemical configuration that are functionalised via N-alkylation to bear boronate ester and boronic acid pharmacophores. Inclusion of boron pharmacophores has been shown to reduce toxicity profiles of drugs and can expand the range of interactions between drugs and target enzymes. Methods: The synthetic development, detailed spectroscopic analysis, and biological investigation against glycosidase enzymes and cancer cell lines of these novel five-membered ring iminosugars are reported. Results: This family of iminosugars displays selective, moderate-to-weak inhibition (IC50s = 133–501 μM) of β-d-galactosidase (bovine liver) and emerging inhibition of β-d-glucosidases (almond) and (bovine liver). The boronic acid pharmacophore may be suitable for the management of lysosomal storage disorders to support the restoration of biological activity of mutant enzymes via the chaperone-mediated therapy approach. From a structure–activity perspective, the cancer screening revealed slight growth inhibition in a panel of cancer cell lines, with A2780 ovarian carcinoma cells showing the strongest response across all compounds. Beyond the growth inhibition capabilities, the real therapeutic potential of these borylated drugs lies in their switch-on/switch-off activation under BNCT radiotherapeutic conditions. Conclusions: This is an important novel family of drug leads capable of interacting with drug targets via intermolecular and intramolecular interactions, changing shape and electronics. Introduction of organic boron atoms to organic molecules presents significant synthetic and purification challenges, as well as analysis of the equilibria that arise in aqueous systems. We provide a methodology to achieve all this and introduce boron pharmacophores onto carbohydrate scaffolds in a systematic manner to facilitate a more widespread adoption of boron pharmacophores.
Journal Article
Derivation of pancreatic acinar cell carcinoma cell line HS‐1 as a patient‐derived tumor organoid
by
Maru, Yoshiaki
,
Fukayama, Masashi
,
Tsujimoto, Akiko
in
acinar cell carcinoma
,
Animals
,
Bile ducts
2023
Acinar cell carcinoma (ACC) of the pancreas is a malignant tumor of the exocrine cell lineage with a poor prognosis. Due to its rare incidence and technical difficulties, few authentic human cell lines are currently available, hampering detailed investigations of ACC. Therefore, we applied the organoid culture technique to various types of specimens, such as bile, biopsy, and resected tumor, obtained from a single ACC patient. Despite the initial propagation, none of these organoids achieved long‐term proliferation or tolerated cryopreservation, confirming the challenging nature of establishing ACC cell lines. Nevertheless, the biopsy‐derived early passage organoid developed subcutaneous tumors in immunodeficient mice. The xenograft tumor histologically resembled the original tumor and gave rise to infinitely propagating organoids with solid features and high levels of trypsin secretion. Moreover, the organoid stained positive for carboxylic ester hydrolase, a specific ACC marker, but negative for the duct cell marker CD133 and the endocrine lineage marker synaptophysin. Hence, we concluded the derivation of a novel ACC cell line of the pure exocrine lineage, designated HS‐1. Genomic analysis revealed extensive copy number alterations and mutations in EP400 in the original tumor, which were enriched in primary organoids. HS‐1 displayed homozygous deletion of CDKN2A, which might underlie xenograft formation from organoids. Although resistant to standard cytotoxic agents, the cell line was highly sensitive to the proteasome inhibitor bortezomib, as revealed by an in vitro drug screen and in vivo validation. In summary, we document a novel ACC cell line, which could be useful for ACC studies in the future. By combining the organoid culture and xenograft formation, a novel cell line HS‐1 was eventually established from a biopsy of acinar cell carcinoma (ACC), a rare subtype of pancreatic cancer, for the first time as an organoid. HS‐1 is positive for carboxylic ester hydrolase (CEH), a highly specific acinar cell marker, and secretes trypsin abundantly, but is negative for the duct cell marker CD133, thereby retaining the features of acinar cells and the original tumor. HS‐1 harbors a missense mutation in EP400 and a 30‐Mb deletion encompassing CDKN2A. Drug screening identified the proteasome inhibitor bortezomib as a potential ACC therapeutic. This cell line will be useful for further ACC studies.
Journal Article
Fibroblast growth factor 19 expression correlates with tumor progression and poorer prognosis of hepatocellular carcinoma
by
Okamura, Daiki
,
Kimura, Fumio
,
Otsuka, Masayuki
in
Aged
,
Apoptosis - drug effects
,
Biomedical and Life Sciences
2012
Background
Although fibroblast growth factor 19 (FGF19) can promote liver carcinogenesis in mice, its involvement in human hepatocellular carcinoma (HCC) has not been well investigated. FGF19, a member of the FGF family, has unique specificity for its receptor FGFR4. This study aimed to clarify the involvement of FGF19 in the development of HCC.
Methods
We investigated human FGF19 and FGFR4 expression in 40 hepatocellular carcinoma specimens using quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) analysis and immunohistochemistry. Moreover, we examined the expression and the distribution of FGF19 and FGFR4 in 5 hepatocellular carcinoma cell lines (HepG2, HuH7, HLE, HLF, and JHH7) using RT-PCR and immunohistochemistry. To test the role of the FGF19/FGFR4 system in tumor progression, we used recombinant FGF19 protein and small interfering RNA (siRNA) of
FGF19
and
FGFR4
to regulate their concentrations.
Results
We found that FGF19 was significantly overexpressed in HCCs as compared with corresponding noncancerous liver tissue (
P
< 0.05). Univariate and multivariate analyses revealed that the tumor
FGF19
mRNA expression was an independent prognostic factor for overall and disease-free survival. Moreover, we found that the FGF19 recombinant protein could increase the proliferation (
P
< 0.01,
n
= 12) and invasion (
P
< 0.01,
n
= 6) capabilities of human hepatocellular carcinoma cell lines and inhibited their apoptosis (
P
< 0.01,
n
= 12). Inversely, decreasing
FGF19
and
FGFR4
expression by siRNA significantly inhibited proliferation and increased apoptosis in JHH7 cells (
P
< 0.01,
n
= 12). The postoperative serum FGF19 levels in HCC patients was significantly lower than the preoperative levels (
P
< 0.01,
n
= 29).
Conclusions
FGF19 is critically involved in the development of HCCs. Targeting FGF19 inhibition is an attractive potential therapeutic strategy for HCC.
Journal Article
Sporadic Outbreaks of Avian Infectious Bronchitis Viruses Highly Similar to the S95 Live Attenuated Vaccine Strain in Japan: A Comparative Study of Ten Field Isolates and S95
by
Tsutsumi, Nobuyuki
,
Oguro, Shiori
,
Ohmori, Takashi
in
Attenuated vaccines
,
Attenuation
,
avian
2025
Background: As infectious bronchitis virus (IBV) strains similar to the IBV S95 live attenuated vaccine strain have been occasionally detected in poultry farms in Japan, we investigated the suspicion that outbreaks of the disease were related to the S95 vaccine. Methods: We isolated ten S95 vaccine-like strains, classified in the JP-I genotype of S1, the VIb (Y-4) genogroup of S2, and the GI-18 lineage, from IBV-affected chickens in Japan between 2020 and 2024. The whole-genome sequence and adaptation to embryonated chicken eggs were investigated. We developed a method for distinguishing the S95 vaccine strain from S95-like wild-type strains using specific primer sets having either the S95 vaccine or S95 parent-specific nucleotide at the 3′ termini of primers on the ORF2 gene. Results: Nine of ten S95 vaccine-like strains lacked identical mutations to the ORF1ab, ORF2, and ORF5a genes that the S95 vaccine strain acquired during attenuation. The remaining S95-like strain, B3389, had identical mutations to the S95 vaccine strain in the ORF1ab and ORF5a genes. The B3389 strain, however, had strain-specific nucleotides that were not found in the S95 vaccine or S95 parent strains, and produced fewer embryonated egg-adapted phenotypes than the S95 vaccine strain. Conclusions: The ten S95-like strains appear not to have emerged from the S95 vaccine strain. Instead, sporadic outbreaks of S95 vaccine-like IBV strains in Japan were indicated. A method for distinguishing and excluding the S95-like wild-type strains as suspected revertants of the S95 vaccine may be utilized for comprehensive IBV surveillance to facilitate development of a vaccination strategy.
Journal Article
Novel Antigenic Variant Infectious Bursal Disease Virus Outbreaks in Japan from 2014 to 2023 and Characterization of an Isolate from Chicken
by
Takahashi, Mari
,
Kato, Atsushi
,
Tsutsumi, Nobuyuki
in
Amino acids
,
Animals
,
Antigenic determinants
2024
Novel antigenic variant strains of the infectious bursal disease virus (IBDV) classified into genogroup A2d have been found in the western part of Japan since 2017. Novel antigenic variant IBDVs now occur in higher frequencies in poultry houses and have been detected in the eastern part of Japan, indicating the spread of IBDVs despite the usual IBDV vaccination. We isolated a novel antigenic variant IBDV, designated as the B2977CE2C3 strain. The B2977CE2C3 strain had two genogroup A2d specific amino acids—lysine and isoleucine, at 221 and 252 aa—along with the other genogroup A2 common amino acids in the projection domains of the VP2 protein corresponding to the virus-neutralizing epitopes and viral pathogenicity. Experimental infection of the B2977CE2C3 strain did not produce any apparent clinical signs in the specific-pathogen-free chickens during the observation period (21 days), but atrophy of the bursa of Fabricius (BF) was apparent. The mean BF to the body weight ratio was 0.35 in negative control chickens at 21 days post-infection (pi) but 0.06 in the B2977CE2C3 infected group. An extremely high copy number of the IBDV genome (>108 copies/µL) was observed in the BF at 3 days pi, while a high copy number of the IBDV genome (>106 copies/µL) was observed in the thymus, spleen cecal tonsil, and bone marrow even though macroscopic lesions were not apparent in these organs.
Journal Article
Clinical and endocrine features of orthostatic intolerance detected in patients with long COVID
2024
Orthostatic intolerance (OI) is a key symptom of long COVID; however, the pathophysiology remains unknown. Among 688 long COVID patients who visited our clinic during the period from February 2021 to April 2023, 86 patients who were suspected of having OI and who underwent an active standing test (ST) were investigated to elucidate the clinical characteristics of OI in patients with long COVID. Of the 86 patients, 33 patients (38%) were ST-positive. Nausea and tachycardia in daily life were frequent complaints in the ST-positive group. The increase in heart rate (HR) during the ST was significantly greater during a 10-min period after standing in the ST-positive group (+ 30 bpm) than in the ST-negative group (+ 16 bpm). The initial increase in diastolic blood pressure (DBP) just after standing was significantly greater in the ST-positive group (+ 14 mmHg) than in the ST-negative group (+ 9 mmHg). Serum cortisol levels in the ST-positive patients aged over 20 years were higher and growth hormone levels in the patients under 20 years of age were lower than those in the ST-negative group. Autonomous nervous symptoms, transient DBP rise with increasing HR after standing, and endocrine dysfunctions are helpful for detecting OI related to long COVID.
Journal Article