Publications by authors named "Ayako Aoki"

19 Publications

  • Page 1 of 1

Comparative analysis of microRNA expression profiles in the colons of specific pathogen-free mice and germ-free mice.

Biosci Biotechnol Biochem 2021 Jul;85(8):1869-1872

Department of Food and Nutrition, Faculty of Human Sciences and Design, Japan Women's University, Bunkyo-ku, Tokyo, Japan.

MicroRNAs play an important role in microbiota-host crosstalk. In this study, we compared microRNA expression in whole colons of specific pathogen-free mice and germ-free mice. Forty-eight microRNAs were differentially expressed by more than 2-fold. Gene ontology analysis of the predicted mRNA targets revealed that the majority of the most significant gene ontology terms were related to GTPases and nerves.
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http://dx.doi.org/10.1093/bbb/zbab112DOI Listing
July 2021

Heme Oxygenase-1 in Patients With Interstitial Lung Disease: A Review of the Clinical Evidence.

Am J Med Sci 2021 08 13;362(2):122-129. Epub 2021 Feb 13.

Department of Pulmonology, Yokohama City University Graduate School of Medicine, 4-57 Fukuura, Kanazawa-ku, Yokohama City, 236-0024, Japan.

The clinical course and rate of progression of interstitial lung disease (ILD) are extremely variable among patients. For the purpose of monitoring disease activity, ILD diagnosis, and predicting disease prognosis, there are various biomarkers, including symptoms, physiological, radiological, and pathological findings, and peripheral blood and bronchoalveolar lavage fluid results. Of these, blood biomarkers such as sialylated carbohydrate antigen, surfactant proteins-A and -D, CC-chemokine ligand 18, matrix metalloprotease-1 and -7, CA19-9, and CA125 have been previously proposed. In the future, heme oxygenase-1 (HO-1) may also become a candidate ILD biomarker; it is a 32-kDa heat shock protein converting heme to carbon monoxide, biliverdin/bilirubin, and free iron to play a role in the pulmonary cytoprotective reaction in response to various stimuli. Recent research suggests that HO-1 can increase in lung tissues of patients with ILD, reflecting anti-inflammatory M2 macrophage activation, and the measurement of HO-1 levels in peripheral blood can be useful for evaluating the severity of lung damage in ILD and for predicting subsequent fibrosis formation.
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http://dx.doi.org/10.1016/j.amjms.2021.02.009DOI Listing
August 2021

Additional Efficacy of Macrolide for Patients With Acute Deterioration of Interstitial Lung Disease Requiring Corticosteroid Pulse Therapy.

Am J Ther 2021 Jan 7. Epub 2021 Jan 7.

Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Japan Department of Biostatistics, Yokohama City University School of Medicine, Yokohama, Japan Respiratory Disease Center, Yokohama City University Medical Center, Yokohama, Japan.

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http://dx.doi.org/10.1097/MJT.0000000000001321DOI Listing
January 2021

Serum heme oxygenase-1 measurement is useful for evaluating disease activity and outcomes in patients with acute respiratory distress syndrome and acute exacerbation of interstitial lung disease.

BMC Pulm Med 2020 Nov 25;20(1):310. Epub 2020 Nov 25.

Department of Pulmonology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama City, 236-0004, Japan.

Background: Oxidative stress plays an important role in acute lung injury, which is associated with the development and progression of acute respiratory failure. Here, we investigated whether the degree of oxidative stress as indicated by serum heme oxygenase-1 (HO-1) is clinically useful for predicting prognosis among the patients with acute respiratory distress syndrome (ARDS) and acute exacerbation of interstitial lung disease (AE-ILD).

Methods: Serum HO-1 levels of newly diagnosed or untreated ARDS and AE-ILD patients were measured at diagnosis. Relationships between serum HO-1 and other clinical parameters and 1 and 3-month mortality were evaluated.

Results: Fifty-five patients including 22 of ARDS and 33 of AE-ILD were assessed. Serum HO-1 level at diagnosis was significantly higher in ARDS patients than AE-ILD patients (87.8 ± 60.0 ng/mL vs. 52.5 ± 36.3 ng/mL, P <  0.001). Serum HO-1 correlated with serum total bilirubin (R = 0.454, P <  0.001) and serum LDH (R = 0.500, P <  0.001). In both patients with ARDS and AE-ILDs, serum HO-1 level tended to decrease from diagnosis to 2 weeks after diagnosis, however, did not normalized. Composite parameters including serum HO-1, age, sex, and partial pressure of oxygen in arterial blood/fraction of inspired oxygen (P/F) ratio for prediction of 3-month mortality showed a higher AUC (ARDS: 0.925, AE-ILDs: 0.892) than did AUCs of a single predictor or combination of two or three predictors.

Conclusion: Oxidative stress assessed by serum HO-1 is persistently high among enrolled patients for 2 weeks after diagnosis. Also, serum HO-1 levels at the diagnosis combined with age, sex, and P/F ratio could be clinically useful for predicting 3-month mortality in both ARDS and AE-ILD patients.
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http://dx.doi.org/10.1186/s12890-020-01341-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7687749PMC
November 2020

Clinical utility of a composite scoring system including Charlson Comorbidity Index score in patients with interstitial lung disease.

J Thorac Dis 2020 Oct;12(10):5774-5782

Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.

Background: Prognostic factors have yet to be established for patients with interstitial lung disease (ILD). We aimed to clarify whether the Charlson Comorbidity Index score (CCIS) could help predict disease prognosis in patients with ILD.

Methods: Among ILD patients treated between April 2013 and April 2017, we retrospectively assessed the relationship between baseline clinical parameters including age, sex, CCIS, ILD diagnosis, pulmonary function test results, and 3-year ILD-related events including cause-specific death and first acute exacerbation (AE).

Results: We assessed 180 patients (mean age, 74 years), all of whom underwent pulmonary function testing including percentage predicted diffusion capacity for carbon monoxide (%D). Underlying pathologies included idiopathic pulmonary fibrosis (IPF) in 57 cases, idiopathic nonspecific interstitial pneumonia (iNSIP) and collagen vascular disease-related interstitial pneumonia in 117 cases, and chronic hypersensitivity pneumonia (CHP) in 6 cases. A composite scoring system comprising IPF diagnosis, CCIS, and %D provided a favorable C-index (0.825) for predicting 3-year ILD-related events. The nomogram for 3-year prognosis revealed the largest contributions from CCIS, %D and IPF diagnosis.

Conclusions: This composite scoring system accounting for IPF diagnosis, CCIS, and %D could provide a useful tool for predicting prognosis in relatively mild ILD patients tolerated to pulmonary diffusion capacity testing.
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http://dx.doi.org/10.21037/jtd-20-1302DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7656418PMC
October 2020

Antibody-Based Receptor Targeting Using an Fc-Binding Peptide-Dodecaborate Conjugate and Macropinocytosis Induction for Boron Neutron Capture Therapy.

ACS Omega 2020 Sep 2;5(36):22731-22738. Epub 2020 Sep 2.

Research Center of BNCT, Osaka Prefecture University, 1-2, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570, Japan.

Boron neutron capture therapy (BNCT) is a radiation method used for cancer therapy. Cellular uptake of boron-10 (B) atoms induces cancer cell death by the generation of alpha particles and recoiling lithium-7 (Li) nuclei when the cells are irradiated with low-energy thermal neutrons. Current BNCT technology shows effective therapeutic benefits in refractory cancers such as brain tumors and head and neck cancers. However, improvements to cancer targeting and the cellular uptake efficacy of the boron compounds and the expansion of the diseases treatable by BNCT are highly desirable. In this research, we aimed to develop an antibody-based drug delivery method for BNCT through the use of the Z33 peptide, which shows specific recognition of and interaction with the Fc domain of human IgG, for on-demand receptor targeting. In addition, we determined with an assay that macropinocytosis induction during antibody-based drug delivery is crucial for the biological activity of BNCT.
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http://dx.doi.org/10.1021/acsomega.0c01377DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7495456PMC
September 2020

Unusual lung involvements of invasive mucinous adenocarcinoma with chylothorax.

Thorac Cancer 2020 11 18;11(11):3407-3408. Epub 2020 Sep 18.

Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.

A 77-year-old man who had a persistent productive cough for one month was admitted to our hospital. Chest computed tomography (CT) revealed subpleural nodular opacities, irregular pleural thickening with bilateral basal predominance, and a small right pleural effusion. Aspirated fluid was exudative and had the appearance of chylothorax without malignant cells. Surgical lung biopsy specimen showed focal proliferation of neoplastic epithelial cells with lepidic-predominant pattern and abundant mucus in the alveolar spaces, consistent with invasive mucinous adenocarcinoma (IMA). The results of PD-L1 expression and the EGFR, ALK, ROS1, and BRAF mutation status analyzed by next generation sequencer were all negative. IMA should be considered in the differential diagnosis of subpleural micronodular opacities accompanied by pleural effusion (chylothorax) on chest CT. KEY POINTS: Significant findings of the study This case showed subpleural micronodular opacities and chylothorax as unusual chest computed tomography (CT) patterns for invasive mucinous adenocarcinoma (IMA). What this study adds Invasive mucinous adenocarcinoma (IMA) should be considered in the differential diagnosis of subpleural micronodular opacities accompanied by pleural effusion on chest CT.
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http://dx.doi.org/10.1111/1759-7714.13665DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7605987PMC
November 2020

Afatinib + bevacizumab combination therapy in EGFR-mutant NSCLC patients with osimertinib resistance: Protocol of an open-label, phase II, multicenter, single-arm trial.

Thorac Cancer 2020 08 3;11(8):2125-2129. Epub 2020 Jun 3.

Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.

Introduction: As most patients with epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) develop progressive disease after treatment with osimertinib, it is important to develop more effective treatment options. Afatinib has been shown to be more effective in in vitro studies than osimertinib when used in cancer cell lines containing some specific EGFR mutations. Therefore, afatinib may be an effective solution, especially when used in combination with an anti-VEGF agent such as bevacizumab.

Methods: A phase II multicenter, open-label, single-arm trial has been initiated to evaluate the efficacy and safety of afatinib and bevacizumab combination as salvage therapy for EGFR-mutated lung cancer in patients previously treated with osimertinib. The primary endpoint will be the objective response rate (ORR) and secondary endpoints are progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and adverse events (AEs).

Discussion: A previous study indicated that afatinib inhibits lung cancer cells with specific EGFR mutations more effectively than other EGFR-TKIs such as osimertinib. Therefore, we expect that combination therapy using afatinib and bevacizumab will be effective in patients previously treated with osimertinib (registration no. jRCTs031190077).
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http://dx.doi.org/10.1111/1759-7714.13503DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7396380PMC
August 2020

Diffuse alveolar hemorrhage complicating acute exacerbation of IPF.

Respir Med Case Rep 2020 7;29:101022. Epub 2020 Feb 7.

Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.

An 83-year-old man with a history of interstitial lung disease (ILD) presented with a 1-week history of progressive dyspnea. Computed tomography of the chest revealed right lung-predominant, diffuse, ground glass opacities superimposed upon reticular opacities. Despite methylprednisolone pulse therapy under a diagnosis of acute exacerbation (AE) of ILD, lung involvement and renal dysfunction worsened and disseminated intravascular coagulation developed. The patient died on day 5 of hospitalization. Pathological examination at autopsy revealed diffuse alveolar hemorrhage (DAH) superimposed upon organizing diffuse alveolar damage and usual interstitial pneumonia. We reached a final diagnosis of DAH-predominant AE of idiopathic pulmonary fibrosis (IPF). Abundant expression of the oxidative stress marker hemeoxygenase-1 (HO-1) was observed in alveolar macrophages. These suggest that HO-1 expression in the lungs may offer a useful biomarker for this atypical histological subtype of AE of IPF.
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http://dx.doi.org/10.1016/j.rmcr.2020.101022DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7016274PMC
February 2020

An NRAS mutation in primary malignant melanoma of the lung: a case report.

Diagn Pathol 2020 Feb 7;15(1):11. Epub 2020 Feb 7.

Department of Pathology, Yokohama City University Hospital, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.

Background: Primary malignant melanoma of the lung (PML) is extremely rare. No precursor lesions of PML have been identified, and little is known about the genetic mutations associated with the disease. Typically, 15-20% of malignant melanomas possess NRAS gene mutations, but no cases of NRAS-mutated PML have been reported in the English literature. We present a case of PML involving an NRAS mutation.

Case Presentation: Clinical summary A 74-year-old Japanese female presented with worsening dyspnea and was admitted to hospital. Computed tomography (CT) revealed a right lung (S10) mass and pleural dissemination. Cytology of the pleural effusion in the right lung was performed, and malignant melanoma or clear cell sarcoma was suspected. A dermatological examination and gallium scintigraphy were conducted to determine the primary tumor site, but no suspicious lesions, expect for the right lung mass, were found. After admission, CT showed complicating bilateral pneumonia, and an antibiotic drug was administered, but the pleural effusion got worse. About 2 weeks later, the patient died of respiratory failure and cardiac arrest. An autopsy was performed to determine the histological diagnosis. Autopsy findings A 26x15x20-mm black and pale yellow mass was found in the right lower lobe. Many disseminated nodules were found in the right lobe. The tumor had invaded the right diaphragm. Subcarinal lymph node metastasis was also detected. Immunohistochemically, the tumor cells exhibited positivity for S-100 and HMB45 staining. The patient was diagnosed with malignant melanoma. Sanger sequencing of the tumor detected an NRAS mutation.

Conclusions: We found an NRAS D54N mutation in PML, which has not been reported previously anywhere in the world. Previous reports indicated that most cases of PML can be classified into the triple-wild-type, but BRAF mutation status was only analyzed in a few cases. We should analyze the mutation patterns of PML to determine whether any subtypes other than the triple-wild-type exist. PML might be a form of de novo cancer.
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http://dx.doi.org/10.1186/s13000-020-0928-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7006422PMC
February 2020

Reproducibility of the T-SPOT.TB test for screening Mycobacterium tuberculosis infection in Japan.

J Infect Chemother 2020 Feb 5;26(2):194-198. Epub 2019 Sep 5.

Department of Pulmonology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.

Objectives: The interferon-gamma release assay (IGRA) is useful for diagnosing Mycobacterium tuberculosis infections, especially in countries where Bacille Calmette-Guérin vaccinations are performed. However, reproducibility of the IGRA is unclear, as recent data suggest high IGRA conversion and reversion rates in serial tests among healthcare workers. This longitudinal study aimed to evaluate reproducibility of T-SPOT.TB for screening M. tuberculosis infections in Japan.

Methods: Results of T-SPOT.TB tests performed between April 2014 and March 2016 at two hospitals in Yokohama, Japan, where the incidence of tuberculosis was 18.0 per 100,000 population in 2014, were analyzed.

Results: In total, 3890 T-SPOT.TB tests were included. Overall, positive and negative test rates were 8.4% and 87.6%, respectively. Among 373 serial tests within two years, conversion and reversion rates were only 1.1% and 12.5%, respectively. Almost all patients who were initially negative (98.9%) remained so. There was no statistically significant difference between the outcomes observed at the two hospitals.

Conclusions: The conversion rate of T-SPOT.TB in Japan is as low as that recently reported in other countries where the incidence of tuberculosis is low. These data indicate that T-SPOT.TB is a reproducible tuberculosis screening tool at local hospitals in areas with a moderate incidence of tuberculosis.
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http://dx.doi.org/10.1016/j.jiac.2019.08.006DOI Listing
February 2020

Arginine-rich cell-penetrating peptide-modified extracellular vesicles for active macropinocytosis induction and efficient intracellular delivery.

Sci Rep 2017 05 16;7(1):1991. Epub 2017 May 16.

Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan.

Extracellular vesicles (EVs) including exosomes have been shown to play crucial roles in cell-to-cell communication because of their ability to carry biofunctional molecules (e.g., microRNAs and enzymes). EVs also have pharmaceutical advantages and are highly anticipated to be a next-generation intracellular delivery tool. Here, we demonstrate an experimental technique that uses arginine-rich cell-penetrating peptide (CPP)-modified EVs to induce active macropinocytosis for effective cellular EV uptake. Modification of arginine-rich CPPs on the EV membrane resulted in the activation of the macropinocytosis pathway, and the number of arginine residues in the peptide sequences affected the cellular EV uptake efficiency. Consequently, the ribosome-inactivating protein saporin-encapsulated EVs modified with hexadeca-arginine (R16) peptide effectively attained anti-cancer activity.
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http://dx.doi.org/10.1038/s41598-017-02014-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5434003PMC
May 2017

Receptor-mediated endocytosis of macromolecules and strategy to enhance their transport in alveolar epithelial cells.

Expert Opin Drug Deliv 2015 May 12;12(5):813-25. Epub 2014 Dec 12.

Hiroshima University, Graduate School of Biomedical and Health Sciences, Department of Pharmaceutics and Therapeutics , 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan +81 82 257 5315 ; +81 82 257 5319 ;

Introduction: Pulmonary delivery is an attractive administration route for therapeutic proteins and peptides. In this context, endocytosis/transcytosis at the distal lung epithelial barrier is an important process in the pulmonary absorption of therapeutic macromolecules. The alveolar epithelium is comprised of type I and type II cells. Understanding the transport mechanisms in these cells is essential for the development of efficient pulmonary delivery systems of therapeutic macromolecules.

Areas Covered: Endocytic pathways for albumin and insulin in alveolar epithelial cells and possible receptors for the endocytosis are discussed. Strategies to enhance the endocytosis and pulmonary absorption of macromolecules are also discussed, by focusing on the effects of cationic poly(amino acid)s.

Expert Opinion: Although the surface area occupied by type II cells in alveoli is much smaller than that covered by type I cells, type II cells may significantly contribute to the endocytosis/transcytosis of macromolecules such as albumin. Identification of the receptors involved in the cellular uptake of each macromolecule is prerequisite for the understanding and regulation of its transport into and across alveolar epithelial cells. Establishment of novel in-vitro culture cell models of type I and type II cells would be a great help for the future advance of this research field.
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http://dx.doi.org/10.1517/17425247.2015.992778DOI Listing
May 2015

Evaluation of feedback interventions for improving the quality assurance of cancer screening in Japan: study design and report of the baseline survey.

Jpn J Clin Oncol 2012 Feb 22;42(2):96-104. Epub 2011 Dec 22.

Screening Research Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.

Objective: The importance of quality assurance in cancer screening has recently gained increasing attention in Japan. To evaluate and improve quality, checklists and process indicators have been developed. To explore effective methods of enhancing quality in cancer screening, we started a randomized control study of the methods of evaluation and feedback for cancer control from 2009 to 2014.

Methods: We randomly assigned 1270 municipal governments, equivalent to 71% of all Japanese municipal governments that performed screening programs, into three groups. The high-intensity intervention groups (n = 425) were individually evaluated using both checklist performance and process indicator values, while the low-intensity intervention groups (n= 421) were individually evaluated on the basis of only checklist performance. The control group (n = 424) received only a basic report that included the national average of checklist performance scores. We repeated the survey for each municipality's quality assurance activity performance using checklists and process indicators.

Results: In this paper, we report our study design and the result of the baseline survey. The checklist adherence rates were especially low in the checklist elements related to invitation of individuals, detailed monitoring of process indicators such as cancer detection rates according to screening histories and appropriate selection of screening facilities. Screening rate and percentage of examinees who underwent detailed examination tended to be lower for large cities when compared with smaller cities for all cancer sites.

Conclusions: The performance of the Japanese cancer screening program in 2009 was identified for the first time.
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http://dx.doi.org/10.1093/jjco/hyr185DOI Listing
February 2012

Evaluation and revision of checklists for screening facilities and municipal governmental programs for gastric cancer and colorectal cancer screening in Japan.

Jpn J Clin Oncol 2010 Nov 9;40(11):1021-30. Epub 2010 Jun 9.

Department of Public Health/Health Policy, University of Tokyo, Tokyo, Japan.

Objective: To evaluate the appropriateness of current checklists created by a governmental committee to assess screening programs run by municipal governments and service provider facilities for gastric and colorectal cancer, and to accumulate expert opinions to provide insights aimed at the next revision.

Methods: We convened an expert panel that consisted of physicians nominated by regional offices of the Japanese Society for Gastrointestinal Cancer Screening and radiology technicians nominated by the technician chapter of the society. The panel rated the appropriateness of each checklist item on a scale of 1-9 (1, extremely inappropriate; 9, extremely appropriate) twice, between which they had a face-to-face discussion meeting. During the process they were allowed to propose modifications and additions to the items.

Results: In the first round of rating, the panelists rated all 57 and 56 checklists items for gastric and colorectal cancer, respectively, as appropriate based on an acceptance rule determined a priori. During the process of the face-to-face discussion, however, the panel proposed modifications to 23 (40%) and 22 (39%) items, respectively, and the addition of 27 new items each. After integrating overlapping items and rating again for appropriateness, 66 and 64 items, respectively, were accepted as the revised checklist set.

Conclusions: The expert panel considered current checklists for colorectal and gastric cancer-screening programs and facilities to be suitable. Their proposals for a new set of checklist items will help further improve the checklists.
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http://dx.doi.org/10.1093/jjco/hyq091DOI Listing
November 2010

Repression of nascent strand elongation by deregulated Cdt1 during DNA replication in Xenopus egg extracts.

Mol Biol Cell 2009 Feb 8;20(3):937-47. Epub 2008 Dec 8.

Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, 980-8578, Japan.

Excess Cdt1 reportedly induces rereplication of chromatin in cultured cells and Xenopus egg extracts, suggesting that the regulation of Cdt1 activity by cell cycle-dependent proteolysis and expression of the Cdt1 inhibitor geminin is crucial for the inhibition of chromosomal overreplication between S phase and metaphase. We analyzed the consequences of excess Cdt1 for DNA replication and found that increased Cdt1 activity inhibited the elongation of nascent strands in Xenopus egg extracts. In Cdt1-supplemented extracts, overreplication was remarkably induced by the further addition of the Cdt1-binding domain of geminin (Gem79-130), which lacks licensing inhibitor activity. Further analyses indicated that fully active geminin, as well as Gem79-130, restored nascent strand elongation in Cdt1-supplemented extracts even after the Cdt1-induced stalling of replication fork elongation had been established. Our results demonstrate an unforeseen, negative role for Cdt1 in elongation and suggest that its function in the control of replication should be redefined. We propose a novel surveillance mechanism in which Cdt1 blocks nascent chain elongation after detecting illegitimate activation of the licensing system.
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http://dx.doi.org/10.1091/mbc.e08-06-0613DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2633378PMC
February 2009

Bloom helicase and DNA topoisomerase IIIalpha are involved in the dissolution of sister chromatids.

Mol Cell Biol 2006 Aug;26(16):6299-307

Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai 980-8578, Japan.

Bloom's syndrome (BS) is an autosomal disorder characterized by predisposition to a wide variety of cancers. The gene product whose mutation leads to BS is the RecQ family helicase BLM, which forms a complex with DNA topoisomerase IIIalpha (Top3alpha). However, the physiological relevance of the interaction between BLM and Top3alpha within the cell remains unclear. We show here that Top3alpha depletion causes accumulation of cells in G2 phase, enlargement of nuclei, and chromosome gaps and breaks that occur at the same position in sister chromatids. The transition from metaphase to anaphase is also inhibited. All of these phenomena except cell lethality are suppressed by BLM gene disruption. Taken together with the biochemical properties of BLM and Top3alpha, these data indicate that BLM and Top3alpha execute the dissolution of sister chromatids.
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http://dx.doi.org/10.1128/MCB.00702-06DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1592785PMC
August 2006

Molecular cloning and characterization of a novel soybean gene encoding a leucine-zipper-like protein induced to salt stress.

Gene 2005 Aug;356:135-45

Laboratory of Biochemistry and Molecular Biology, Department of Applied Biological Resource Sciences, School of Agriculture, Ibaraki University, Chuo-3-21-1, Ami-machi, Inashiki-gun, Ibaraki 300-0393, Japan.

To understand molecular responses to salt stress in soybean (Glycine max [L.] Merr.), we identified 106 salt-inducible soybean genes that expressed differentially at 72 h after 100 mM NaCl treatment using the cDNA-amplified fragment length polymorphism (AFLP) method. The genes were designated as G. max Transcript-Derived Fragments (GmTDFs). Among these genes, we characterized a soybean gene GmTDF-5 that encoded an unknown protein of 367 amino acids. The GmTDF-5 protein was a putative cytosolic protein with two leucine-zipper motifs at the N-terminal and was calculated as 40.7 kDa. Southern blot analysis indicated that GmTDF-5 presents as an intron-less single gene on soybean genome and possibly distributes narrowly throughout the higher plants. By 100 mM NaCl treatment, the gene expression of GmTDF-5 was induced in the stem and lower-expanded leaf, and the amount of mRNA increased 5.1- and 2.0-fold up to 72 h, respectively. Interestingly, GmTDF-5 expression in the upper-leaf appeared dramatically with 10.0-fold increase at 72 h after the salt stress, but not until 48 h. Hyperosmotic pressure (mannitol treatment) and dehydration also caused the increases similar to NaCl treatment in the levels of GmTDF-5 expression. These results suggest that GmTDF-5 might be a novel cytosolic leucine-zipper-like protein functioning in mature organs of soybean shoot against water-potential changes.
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http://dx.doi.org/10.1016/j.gene.2005.04.014DOI Listing
August 2005

A novel transgenic chimaeric mouse system for the rapid functional evaluation of genes encoding secreted proteins.

Nucleic Acids Res 2005 May 24;33(9):e85. Epub 2005 May 24.

Pharmaceutical Research Laboratory, Pharmaceutical Division, Kirin Brewery Co. Ltd. 3 Miyahara-cho, Takasaki-shi, Gunma 370-1295, Japan.

A major challenge of the post-genomic era is the functional characterization of anonymous open reading frames (ORFs) identified by the Human Genome Project. In this context, there is a strong requirement for the development of technologies that enhance our ability to analyze gene functions at the level of the whole organism. Here, we describe a rapid and efficient procedure to generate transgenic chimaeric mice that continuously secrete a foreign protein into the systemic circulation. The transgene units were inserted into the genomic site adjacent to the endogenous immunoglobulin (Ig) kappa locus by homologous recombination, using a modified mouse embryonic stem (ES) cell line that exhibits a high frequency of homologous recombination at the Igkappa region. The resultant ES clones were injected into embryos derived from a B-cell-deficient host strain, thus producing chimaerism-independent, B-cell-specific transgene expression. This feature of the system eliminates the time-consuming breeding typically implemented in standard transgenic strategies and allows for evaluating the effect of ectopic transgene expression directly in the resulting chimaeric mice. To demonstrate the utility of this system we showed high-level protein expression in the sera and severe phenotypes in human EPO (hEPO) and murine thrombopoietin (mTPO) transgenic chimaeras.
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http://dx.doi.org/10.1093/nar/gni083DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1140086PMC
May 2005
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