72 results on '"Suzuki, Atsushi"'
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2. High pressure-processed foods in Japan and the world
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Suzuki, Atsushi, primary
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- 2002
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3. Understanding the pressure effects on postmortem muscle
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Suzuki, Atsushi, primary, Kim, Ken, additional, and Ikeuchi, Yoshihide, additional
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- 1996
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4. Defects in muscle-cytoskeleton interaction in diseased states
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Ozawa, Eijiro, primary and Suzuki, Atsushi, additional
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- 1996
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5. Effect of high pressure treatment on proteolytic system in meat
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Homma, Noriyuki, primary, Ikeuchi, Yoshihide, additional, and Suzuki, Atsushi, additional
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- 1996
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6. Transgenerational acclimation to acidified seawater and gene expression patterns in a sea urchin.
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Iguchi A, Gibu K, Yorifuji M, Nishijima M, Suzuki A, Ono T, Matsumoto Y, Inoue M, Fujii M, Muraoka D, Fujita Y, and Takami H
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- Animals, Hydrogen-Ion Concentration, Larva genetics, Gene Expression, Japan, Seawater, Acclimatization, Sea Urchins genetics, Sea Urchins physiology
- Abstract
Transgenerational responses of susceptible calcifying organisms to progressive ocean acidification are an important issue in reducing uncertainty of future predictions. In this study, a two-generation rearing experiment was conducted using mature Mesocentrotus nudus, a major edible sea urchin that occurs along the coasts of northern Japan. Morphological observations and comprehensive gene expression analysis (RNA-seq) of resulting larvae were performed to examine transgenerational acclimation to acidified seawater. Two generations of rearing experiments showed that larvae derived from parents acclimated to acidified seawater tended to have higher survival and show less reduction in body size when exposed to acidified seawater of the same pH, suggesting that a positive carry-over effect occurred. RNA-seq analysis showed that gene expression patterns of larvae originated from both acclimated and non-acclimated parents to acidified seawater tended to be different than control condition, and the gene expression pattern of larvae originated from acclimated parents was substantially different than that of larvae of non-acclimated and control parents., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
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- 2024
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7. Potential microemboli formation risk and its management during the heated saline-enhanced radiofrequency needle-tip catheter ablation.
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Suzuki A, Lehmann HI, Konishi H, Wang S, Hohmann S, Rettman ME, Newman LK, Parker KD, Curley MG, and Packer DL
- Abstract
Background: The potential risk of embolic events during ablation in the left ventricle (LV) with a heated saline-enhanced radiofrequency (SERF) needle-tip ablation catheter has not been characterized., Objective: This study aimed to investigate the formation of microemboli or other untoward events during SERF ablation., Methods: Ninety-three radiofrequency (RF) ablation procedures were performed in the LV of 14 pigs by using a SERF catheter (35 W, 70 seconds, and 60°C; normal or degassed saline [NS or DS] irrigation with a flow rate of 10 mL/min) vs a standard irrigated-tip radiofrequency (S-RF) catheter (30 or 50 W, 30 seconds, and 17 mL/min). Microbubble formation was graded on the basis of intracardiac echocardiography. Microbubbles, microembolic signals, and microparticles were monitored using our established model., Results: There was no significant difference in microbubble volume among SERF-NS, SERF-DS, and S-RF 30 W with "grade 1" intracardiac echocardiography microbubbles (median and 25th-75th percentiles 0.201 [0.011-3.13], 0.455 [0.06-2.66], and 0.004 μL [0.00-0.16 μL], respectively). There was no significant difference in microembolic signals among SERF-NS, SERF-DS, and S-RF 30 W with grade 1 bubbles (n = 8.0 ± 5.8, n = 7.6 ± 4.2, and n = 6.1 ± 6.1, respectively). Both SERF-NS and SERF-DS created larger lesions than did both S-RF 30 W and S-RF 50 W deliveries (mean 1241.5 ± 658.6, 1497.7 ± 893.4, 75.0 ± 24.8, and 184.0 ± 93.8 mm
3 ; P < .001). There was no significant difference in microparticle incidence among groups (P = .675). No evidence of embolic events was found in the brain and other organs at the histology assessment., Conclusion: In the setting of SERF ablation, significantly large LV lesions can be created without any increment in embolic microbubble or particle events. Grade 1 microbubble is related to the efficacy and safety., Competing Interests: Disclosures Dr Packer reported receiving grants from the National Institutes of Health (NIH)/National Heart, Lung, and Blood Institute, St. Jude Medical and St. Jude Memorial Foundation, Biosense Webster, Medtronic, and Boston Scientific during the conduct of the study and receiving grants from Abbott, Biosense Webster, Boston Scientific, CardioFocus, Medtronic, St. Jude Medical, CardioInsight, the NIH, Siemens, Thermedical, Endosense, Robertson Foundation, and Hansen Medical. He reported serving on the advisory board without compensation for Abbott, Biosense Webster, Boston Scientific, CardioFocus, Medtronic, St. Jude Medical, Spectrum Dynamics, Siemens, Thermedical, Johnson & Johnson, and SigNum Preemptive Healthcare; speaking with honorarium from Biotronik and MediaSphere Medical; and receiving royalties from Wiley, Oxford, and St. Jude Medical. Dr Packer and Mayo Clinic jointly have equity in a privately held company, External Beam Ablation Medical Devices (outside the submitted work). In addition, Dr Packer has mapping technologies with royalties paid. Dr Hohmann was funded by the Deutsche Forschungsgemeinschaft (DFG [German Research Foundation]; project no. 380200397). The other authors report no potential conflicts of interest., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)- Published
- 2024
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8. Whole transcriptome analysis of demersal fish eggs reveals complex responses to ocean deoxygenation and acidification.
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Iguchi A, Hayashi M, Yorifuji M, Nishijima M, Gibu K, Kunishima T, Bell T, Suzuki A, and Ono T
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- Animals, Hydrogen-Ion Concentration, Fishes metabolism, Aquatic Organisms metabolism, Gene Expression Profiling, Oxygen metabolism, Carbon Dioxide analysis, Climate Change, Oceans and Seas, Seawater, Ecosystem
- Abstract
Ocean acidification and deoxygenation co-occur in marine environments, causing deterioration of marine ecosystems. However, effects of compound stresses on marine organisms and their physiological coping mechanisms are largely unknown. Here, we show how high pCO
2 and low dissolved oxygen (DO) cause transcriptomic changes in eggs of a demersal fish (Sillago japonica), which are fully exposed to such stresses in natural environment. Overall gene expression was affected more strongly by low DO than by high pCO2 . Enrichment analysis detected significant stress responses such as glycolytic processes in response to low DO. Increased expression of a group of glycolytic genes under low DO conditions is presumably because oxygen depletion disables the electron transfer pathway, complementing ATP production in the glycolytic pathway. Contrary to expectations, apparent mitigation of gene expression changes was dominant under combined stress conditions, and may represent an innate fish adaptive trait for severe environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2024
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9. Preliminary study on the acute effects of hydrogen sulfide on Amphipoda (Lysianassoidea; Pseudorchomene sp. and Anonyx sp.) collected from deep-sea floors in the Sea of Japan.
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Ishida H, Mukai R, Ikeuchi E, Kise H, Nishijima M, Iguchi A, Suzuki A, and Suzumura M
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- Humans, Animals, Japan, Toxicity Tests, Geologic Sediments, Hydrogen Sulfide toxicity, Amphipoda
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To study the environmental impact of the assessment technologies for the development of shallow methane hydrate zones in the Sea of Japan, deep-sea amphipods (Pseudorchomene sp. and Anonyx sp.) were collected from a depth of approximately 1000 m and were tested for H
2 S toxicity. At 0.57 mg L-1 H2 S, all specimens of Pseudorchomene sp. were dead after 96 h, whereas all individuals survived at 0.18 mg L-1 . Moreover, Anonyx sp. had a survival rate of 17 % after 96 h at 0.24 mg L-1 . A similar toxicity test was conducted with the coastal amphipod Merita sp., a detritivore, and all individuals died within 24 h at 0.15 mg L-1 . These results suggested that compared with coastal detritivorous amphipods, deep-sea detritivorous amphipods, which also live near biomats with sediment H2 S concentrations exceeding 10 mg L-1 , showed a higher tolerance to H2 S., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2023
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10. Actin cytoskeletal reorganization is involved in hyperosmotic stress-induced autophagy in tubular epithelial cells.
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Miyano T, Suzuki A, and Sakamoto N
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- Rats, Animals, Autophagy, Cytoskeleton, Microtubules, Actins metabolism, Epithelial Cells metabolism
- Abstract
Tubular epithelial cells are routinely exposed to severe changes in osmolarity. Although the autophagic activity of cells is an indispensable process to maintain cellular homeostasis and respond to stressors, the effect of hyperosmotic stress on autophagic activity in tubular epithelial cells remains unknown. The aim of this study was to determine the effect of hyperosmotic stress on autophagy in rat kidney tubular epithelial cells focusing on the role of actin and microtubule cytoskeletons. Normal rat kidney (NRK)-52E cells exposed to mannitol-induced hyperosmotic stress. As a result, NRK-52E cells showed elevated protein levels of the autophagosome marker LC3-II, indicating enhancement of the autophagic flux. Hyperosmotic stress also transiently decreased cell volume and caused the reorganization of actin and microtubule cytoskeletal structures in NRK-52E cells. The inhibition of the actin cytoskeleton reorganization by cytochalasin D impaired the increase in the levels of LC3-II; however, disassembly of the microtubules following treatment with nocodazole did not affect the increase. These results indicate that hyperosmotic stress can induce autophagy mediated by the reorganization of the actin cytoskeleton in tubular epithelial cells., Competing Interests: Declaration of competing interest T. Miyano, A. Suzuki, and N. Sakamoto declare that they have no conflicts of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)
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- 2023
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11. Zbtb21 is required for the anterior-posterior patterning of neural tissue in the early Xenopus embryo.
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Takebayashi-Suzuki K, Uchida M, and Suzuki A
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- Animals, Ectoderm, Embryo, Nonmammalian, Wnt Signaling Pathway, Xenopus laevis, Body Patterning genetics, Gene Expression Regulation, Developmental, Xenopus Proteins genetics, Xenopus Proteins metabolism
- Abstract
The vertebrate body is organized along the dorsal-ventral (DV) and anterior-posterior (AP) axes by the BMP and Wnt pathways, respectively. We previously reported that Xenopus Zbtb14 promotes dorsalization (neural induction) of ectoderm by inhibiting BMP signaling and also posteriorizes neural tissue by activating Wnt signaling, thereby coordinating the patterning of the DV and AP axes during early development. Although it has been reported that human ZBTB21 binds to ZBTB14 and is involved in gene expression in cultured mammalian cells, the function of Zbtb21 in early embryonic development remains unknown. Here, we show that Xenopus Zbtb21 plays an essential role in AP axis formation in the early Xenopus embryo. zbtb21 and zbtb14 are co-expressed in the dorsal region of embryos during gastrulation. Simultaneous overexpression of Zbtb21 and Zbtb14 in ectodermal explants enhances the neural-inducing activity of Zbtb14. Moreover, knockdown experiments showed that Zbtb21 is required for the formation of posterior neural tissue and the suppression of anterior neural development. Collectively, these results suggest that in cooperation with Zbtb14, Zbtb21 has a crucial function in AP patterning during early Xenopus embryogenesis., Competing Interests: Declaration of competing interest To the best of our knowledge, the named authors have no conflict of interest, financial or otherwise., (Copyright © 2022 Elsevier Inc. All rights reserved.)
- Published
- 2022
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12. Interstitial lung diseases.
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Wijsenbeek M, Suzuki A, and Maher TM
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- Dyspnea etiology, Exercise Tolerance, Humans, Lung, Quality of Life, Lung Diseases, Interstitial diagnosis, Lung Diseases, Interstitial epidemiology, Lung Diseases, Interstitial etiology, Pulmonary Fibrosis complications, Pulmonary Fibrosis etiology
- Abstract
Over 200 interstitial lung diseases, from ultra rare to relatively common, are recognised. Most interstitial lung diseases are characterised by inflammation or fibrosis within the interstitial space, the primary consequence of which is impaired gas exchange, resulting in breathlessness, diminished exercise tolerance, and decreased quality of life. Outcomes vary considerably for each of the different interstitial lung diseases. In some conditions, spontaneous reversibility or stabilisation can occur, but unfortunately in many people with interstitial lung disease, especially in those manifesting progressive pulmonary fibrosis, respiratory failure and death are a sad reality. Over the past 3 years, the field of interstitial lung disease has had important advances, with the approval of drugs to treat systemic sclerosis-associated interstitial lung disease, interstitial lung disease-associated pulmonary hypertension, and different forms of progressive pulmonary fibrosis. This Seminar provides an update on epidemiology, pathogenesis, presentation, diagnosis, disease course, and management of the interstitial lung diseases that are most frequently encountered in clinical practice. Furthermore, we describe how developments have led to a shift in the classification and treatment of interstitial lung diseases that exhibit progressive pulmonary fibrosis and summarise the latest practice-changing guidelines. We conclude with an outline of controversies, uncertainties, and future directions., Competing Interests: Declaration of interests MW reports grants from The Netherlands Organisation for Health Research and Development, The Dutch Lung Foundation, Boehringer Ingelheim, The Dutch Pulmonary Fibrosis Patient Association, The Thorax Foundation Erasmus MC, and Sarcoidosis.nl; consulting fees from Boehringer Ingelheim, Hoffman la Roche, Galapagos, Bristol Myers Squibb, Galecto, PureTech Health, Kinevant Sciences, Molecure, Respivant, Nerretherapeutics, Horizontherapeutics, and CLS Behring; lecture fees from Boehringer Ingelheim, Hoffman la Roche, and Novartis; travel support from Boehringer Ingelheim, Hoffman la Roche, and Galapagos; and participation in data safety monitoring boards for Savara and Galapagos. All grants and fees were paid to her institution. AS reports lecture fees from Boehringer Ingelheim and GSK. TMM reports a grant from GSK paid to his institution; consulting fees from Boehringer Ingelheim, Roche, Galapagos, Bristol Myers Squibb, AstraZeneca, GSK, IQVIA, Pliant, Therevance, Galecto, Blade Therapeutics, Respivant, and Fibrogen; lecture honoraria from Boehringer Ingelheim, Roche, and Galapagos; travel support from Boehringer Ingelheim and Roche; and participation in data safety monitoring boards for Blade Therapeutics, Fibrogen, IQVIA, and Bergen Biosciences., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
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- 2022
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13. Calcium influx through TRPV4 channels involve in hyperosmotic stress-induced epithelial-mesenchymal transition in tubular epithelial cells.
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Miyano T, Suzuki A, and Sakamoto N
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- Animals, Cadherins metabolism, Calcium metabolism, Epithelial Cells metabolism, Rats, TRPV Cation Channels metabolism, Epithelial-Mesenchymal Transition, Transient Receptor Potential Channels metabolism
- Abstract
The epithelial-mesenchymal transition (EMT) is a biological process that occurs in the pathogenesis of kidney diseases in which injured tubular epithelial cells transform into myofibroblasts. We previously showed that mannitol-mediated hyperosmotic stress induces EMT of tubular epithelial cells. Although Ca
2+ signaling is essential for the induction of EMT in tubular epithelial cells, the role of specific calcium channels is unknown. In this study, we assessed the transient receptor potential vanilloid 4 (TRPV4)-mediated Ca2+ influx in the hyperosmolarity-induced EMT. The Fluo-4 assay was used to examine the effect of hyperosmotic stress on the intracellular Ca2+ level of normal rat kidney (NRK)-52E cells. Expression of a mesenchymal marker α-smooth muscle actin (α-SMA) and an epithelial marker E-cadherin was also observed by fluorescence microscopy. The hyperosmotic stress caused a transient increase in intracellular Ca2+ concentration as well as a decrease in E-cadherin and an increase in α-SMA expressions in tubular epithelial cells, indicating the induction of EMT. A TRPV4 channel antagonist inhibited hyperosmotic stress-induced Ca2+ influx and the EMT, whereas, a TRPV4 channel agonist increased Ca2+ influx and EMT induction in tubular epithelial cells without the hyperosmotic stress. These findings suggest that Ca2+ influx through TRPV4 channels contributes to the hyperosmotic stress-induced EMT of tubular epithelial cells., Competing Interests: Declaration of competing interest T. Miyano, A. Suzuki, and N. Sakamoto declare that they have no conflicts of interest., (Copyright © 2022 Elsevier Inc. All rights reserved.)- Published
- 2022
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14. The prognostic value of the COPD Assessment Test in fibrotic interstitial lung disease.
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Matsuda T, Kondoh Y, Furukawa T, Suzuki A, Takei R, Sasano H, Yamano Y, Yokoyama T, Kataoka K, and Kimura T
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- Humans, Lung diagnostic imaging, Male, Prognosis, Retrospective Studies, Idiopathic Pulmonary Fibrosis diagnosis, Lung Diseases, Interstitial diagnosis, Pulmonary Disease, Chronic Obstructive diagnosis
- Abstract
Background: The COPD Assessment Test (CAT) has been studied as a measure of health status in idiopathic pulmonary fibrosis (IPF) and interstitial lung disease associated with connective tissue disease. However, its prognostic value is unknown. The present study explored the association between CAT score and mortality in fibrotic interstitial lung disease (FILD), including IPF and other forms of ILD., Methods: We retrospectively analyzed 501 consecutive patients with FILD who underwent clinical assessment, including pulmonary function test and CAT. The association between CAT score and 3-year mortality was assessed using Cox proportional hazard analysis, Kaplan-Meier plots, and the log-rank test for trend. To handle missing data, the imputed method was used., Results: The patients' median age was 68 years, and 320 were male (63.9%). Regarding CAT severity, 203 patients had a low impact level (score <10), 195 had a medium level (10-20), 80 had a high level (21-30), and 23 had a very high level (31-40). During the 3-year study period, 118 patients died. After adjusting for age, sex, forced vital capacity, diffusion capacity for carbon monoxide, IPF diagnosis, and usual interstitial pneumonia pattern on high-resolution computed tomography, the CAT score was significantly associated with 3-year mortality (hazard ratio in increments of 10 points: 1.458, 95% confidence interval 1.161-1.830; p < 0.001). In addition, patients with high and very high impact levels had twofold and threefold higher mortality risk than those with low levels, respectively., Conclusion: The CAT has prognostic value in FILD., (Copyright © 2021. Published by Elsevier B.V.)
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- 2022
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15. TAK-653, an AMPA receptor potentiator with minimal agonistic activity, produces an antidepressant-like effect with a favorable safety profile in rats.
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Hara H, Suzuki A, Kunugi A, Tajima Y, Yamada R, and Kimura H
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- Animals, Brain-Derived Neurotrophic Factor metabolism, Depressive Disorder, Major metabolism, Depressive Disorder, Treatment-Resistant drug therapy, Excitatory Amino Acid Antagonists pharmacology, Humans, Ketamine pharmacology, Male, Neurons metabolism, Prefrontal Cortex metabolism, Rats, Rats, Sprague-Dawley, Receptors, N-Methyl-D-Aspartate antagonists & inhibitors, Ribosomal Protein S6 Kinases, 70-kDa metabolism, TOR Serine-Threonine Kinases metabolism, Thiadiazines chemistry, Antidepressive Agents pharmacology, Depressive Disorder, Major drug therapy, Receptors, AMPA metabolism, Thiadiazines pharmacology
- Abstract
The N-methyl-d-aspartate receptor antagonist, ketamine, exhibits rapid and sustained antidepressant activity in patients with treatment-resistant depression (TRD), but its use is associated with psychotomimetic side effects. Evidence has suggested that the activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors followed by activation of the mechanistic target of rapamycin (mTOR) signaling pathway and production of brain derived neurotrophic factor (BDNF) protein may underlie the antidepressant efficacy of ketamine. In this study, we characterized the antidepressant-like effects of TAK-653, a novel AMPA receptor potentiator with virtually no agonistic activity. In rat primary cortical neurons, TAK-653 significantly increased phosphorylated and activated forms of mTOR and p70S6 kinase and their upstream regulators Akt and extracellular signal-regulated kinase (ERK). TAK-653 also significantly increased BDNF protein levels in rat primary cortical neurons. Ketamine at 30 mg/kg, i.p. produced antidepressant-like effects in the reduction of submissive behavior model (RSBM) in rats. Ketamine's antidepressant-like effect was blocked by pretreatment with the AMPA receptor antagonist NBQX at 10 mg/kg, i.p., indicating the essential role of AMPA receptor activation in the antidepressant-like effect of ketamine. Consistent with this finding, a sub-chronic administration of TAK-653 for 6 days produced significant antidepressant-like effect in the rat RSBM. Unlike ketamine, however, TAK-653 did not induce a hyperlocomotor response in rats, which is a behavioral index associated with psychotomimetic side effects in humans. TAK-653 may be a promising drug for the treatment of major depressive disorders including TRD with the potential for an improved safety profile compared with ketamine., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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16. The Effect of Pirfenidone on the Prescription of Antibiotics and Antitussive Drugs in Patients With Idiopathic Pulmonary Fibrosis: A Post Hoc Exploratory Analysis of Phase III Clinical Trial.
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Suzuki A, Sakaguchi H, Sakamoto K, Ebina M, Azuma A, Ogura T, Taguchi Y, Suga M, Takahashi H, Sugiyama Y, Kudoh S, Nukiwa T, Miyazawa S, and Kondoh Y
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- Aged, Disease Progression, Female, Humans, Male, Middle Aged, Treatment Outcome, Anti-Bacterial Agents therapeutic use, Antifibrotic Agents therapeutic use, Antitussive Agents therapeutic use, Idiopathic Pulmonary Fibrosis drug therapy, Polypharmacy, Pyridones therapeutic use
- Published
- 2021
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17. The dual-specificity protein kinase Clk3 is essential for Xenopus neural development.
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Virgirinia RP, Nakamura M, Takebayashi-Suzuki K, Fatchiyah F, and Suzuki A
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- Animals, Ectoderm embryology, Ectoderm metabolism, Embryo, Nonmammalian embryology, Embryo, Nonmammalian metabolism, Gene Expression Regulation, Developmental, Xenopus genetics, Neurogenesis, Protein Serine-Threonine Kinases genetics, Protein-Tyrosine Kinases genetics, Xenopus embryology, Xenopus Proteins genetics
- Abstract
During vertebrate development, the formation of the central nervous system (CNS) is initiated by neural induction and patterning of the embryonic ectoderm. We previously reported that Cdc2-like kinase 2 (Clk2) promotes neural development in Xenopus embryos by regulating morphogen signaling. However, the functions of other Clk family members and their roles in early embryonic development remain unknown. Here, we show that in addition to Clk2, Clk1 and Clk3 play a role in the formation of neural tissue in Xenopus. clk1 and clk3 are co-expressed in the developing neural tissue during early Xenopus embryogenesis. We found that overexpression of clk1 and clk3 increases the expression of neural marker genes in ectodermal explants. Furthermore, knockdown experiments showed that clk3 is required for the formation of neural tissues. These results suggest that Xenopus Clk3 plays an essential role in promoting neural development during early embryogenesis., Competing Interests: Declaration of competing interest To the best of our knowledge, the named authors have no conflict of interest, financial or otherwise., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2021
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18. TGF-β1 signaling is essential for tissue regeneration in the Xenopus tadpole tail.
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Nakamura M, Yoshida H, Moriyama Y, Kawakita I, Wlizla M, Takebayashi-Suzuki K, Horb ME, and Suzuki A
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- Animals, Cell Proliferation, Signal Transduction, Smad2 Protein metabolism, Smad3 Protein metabolism, Xenopus, Xenopus Proteins metabolism, Larva metabolism, Transforming Growth Factor beta1 metabolism
- Abstract
Amphibians such as Xenopus tropicalis exhibit a remarkable capacity for tissue regeneration after traumatic injury. Although transforming growth factor-β (TGF-β) receptor signaling is known to be essential for tissue regeneration in fish and amphibians, the role of TGF-β ligands in this process is not well understood. Here, we show that inhibition of TGF-β1 function prevents tail regeneration in Xenopus tropicalis tadpoles. We found that expression of tgfb1 is present before tail amputation and is sustained throughout the regeneration process. CRISPR-mediated knock-out (KO) of tgfb1 retards tail regeneration; the phenotype of tgfb1 KO tadpoles can be rescued by injection of tgfb1 mRNA. Cell proliferation, a critical event for the success of tissue regeneration, is downregulated in tgfb1 KO tadpoles. In addition, tgfb1 KO reduces the expression of phosphorylated Smad2/3 (pSmad2/3) which is important for TGF-β signal-mediated cell proliferation. Collectively, our results show that TGF-β1 regulates cell proliferation through the activation of Smad2/3. We therefore propose that TGF-β1 plays a critical role in TGF-β receptor-dependent tadpole tail regeneration in Xenopus., Competing Interests: Declaration of competing interest To the best of our knowledge, the named authors have no conflict of interest, financial or otherwise., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2021
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19. Impact of myocardial fiber orientation on lesions created by a novel heated saline-enhanced radiofrequency needle-tip catheter: An MRI lesion validation study.
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Suzuki A, Lehmann HI, Wang S, Monahan KH, Parker KD, Rettmann ME, Curley MG, and Packer DL
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- Animals, Disease Models, Animal, Dogs, Equipment Design, Feasibility Studies, Tachycardia, Ventricular diagnosis, Tachycardia, Ventricular physiopathology, Catheter Ablation instrumentation, Magnetic Resonance Imaging, Cine methods, Myocardium pathology, Tachycardia, Ventricular surgery
- Abstract
Background: Irrigated needle catheter ablation is efficacious for creation of transmural lesions in the left ventricle (LV). However, interdependence of needle orientation and myocardial fiber orientation and the resulting influence on lesion creation remain unclear., Objective: The purpose of this study was to investigate the impact of myocardial fiber orientation on reproducibility and controllability of lesion creation in LV myocardium using a heated saline-enhanced radiofrequency (SERF) needle-tip catheter system., Methods: Eleven dogs underwent catheter ablation using this novel catheter. Ablative lesions were created using different power and ablation times (15-50 W; application 25-120 seconds; 60°C irrigation saline at 10 mL/min). Hearts were explanted, and lesions were evaluated using 3-T cardiac magnetic resonance (CMR), gross pathologic, and histologic investigations., Results: Forty-three of 57 lesions (75.4%) were transmural, and lesion depth reached approximately 90% of LV wall thickness. Lesion volume in both gross pathology and ex vivo CMR showed a positive linear correlation with power × radiofrequency (RF) time index (r = 0.637, P <.001; and r = 0.786, P <.001, respectively). Maximum width (circumferential direction of LV) and maximum length (long-axis direction) of all lesions were distributed in the middle layer of LV where myocardium runs circumferentially. Paired-sample t-test showed maximum lesion width was significantly greater than maximum lesion length by both CMR and gross pathologic evaluation (26.1 ± 9.6 mm vs 17.2 ± 6.7 mm, P <.001; and 22.5 ± 7.7 mm vs 18.6 ± 5.9 mm, P <.001, respectively)., Conclusion: This catheter showed feasibility in creating transmural LV lesions. Power × RF time index was strongly correlated with lesion volume and predicted lesion size. More importantly, SERF lesions extended along the myocardial fiber orientation., (Copyright © 2020 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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20. Geochemical distribution of heavy metal elements and potential ecological risk assessment of Matsushima Bay sediments during 2012-2016.
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Ota Y, Suzuki A, Yamaoka K, Nagao M, Tanaka Y, Irizuki T, Fujiwara O, Yoshioka K, Kawagata S, Kawano S, and Nishimura O
- Abstract
Heavy metal pollution of marine sediments has attracted a great deal of attention because of its persistence, bioaccumulation, and toxicity. To evaluate the effects of mega-tsunami, anthropogenic activities, and redox conditions on heavy metal accumulation in coastal areas, sediments from Matsushima Bay, Miyagi Prefecture, Japan, were sampled to test variations in heavy metal spatial distribution on the bay floor during 4 years following the 2011 Tohoku Earthquake tsunami. Cluster analysis and principal component analysis were performed to assess the influencing factors and potential sources of heavy metal enrichment in the sediments of the bay. Additionally, the sediment enrichment levels of heavy metals were assessed on the basis of the enrichment factor (EF). The results of multivariate statistical analyses showed that the Ti, Fe, V, Pb, and Zn contents in Matsushima Bay sediments, which were transported mainly from Sendai Bay, depended on the mud content. The value of EF < 2 for Fe, V, Pb, and Zn indicated that these elements were not enriched. The value of EF > 7 for Cu suggested that the contamination levels in western Matsushima Bay were moderate to severe in every sampling year from 2012 to 2016 by anthropogenic activities. From the values of EF > 5 for U and Mo during 2012 and 2014, the severe enrichment of both elements in these periods may be explained by contamination with 2011 tsunami deposits; the improvement in 2015-2016 suggests that there was recovery of the tsunami-affected sediment composition to its original state. The values of EF > 3 for Mn and As indicated moderate to severe contamination with these heavy metals in the bay mouth area during 2015. This was likely explained by more oxic bottom conditions in the mouth of Matsushima Bay during that year., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2021
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21. Catheter-free ablation of infarct scar through proton beam therapy: Tissue effects in a porcine model.
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Hohmann S, Deisher AJ, Konishi H, Rettmann ME, Suzuki A, Merrell KW, Kruse JJ, Fitzgerald ST, Newman LK, Parker KD, Monahan KH, Foote RL, Herman MG, and Packer DL
- Subjects
- Animals, Disease Models, Animal, Dose-Response Relationship, Radiation, Magnetic Resonance Imaging, Cine, Myocardial Infarction diagnosis, Swine, Tachycardia, Ventricular diagnosis, Tachycardia, Ventricular etiology, Treatment Outcome, Ablation Techniques methods, Myocardial Infarction complications, Myocardium pathology, Proton Therapy methods, Tachycardia, Ventricular radiotherapy
- Abstract
Background: Scar-related ventricular arrhythmias are common after myocardial infarction. Catheter ablation can improve prognosis, but the procedure is invasive and results are not always satisfactory. Noninvasive, catheter-free ablation using ionizing radiation has recently gained interest among electrophysiologists, but the tissue effects and physiological outcome have not been fully characterized., Objective: The purpose of this study was to investigate the structural effects of cardiac scanned pencil beam proton therapy on infarct scar, the time course of imaging biomarkers, arrhythmias, and cardiac function in a porcine model., Methods: Fourteen infarcted swine underwent proton beam treatment of the scar (40 or 30 Gy) and were followed for up to 30 weeks. Magnetic resonance imaging was performed every 4 weeks., Results: Treated scar areas showed a significantly lower fraction of surviving myocytes at 30 weeks compared to untreated scar (30.1% ± 18.5% and 59.9% ± 10.1% in treated and untreated infarct, respectively), indicating scar homogenization. Four animals died suddenly during follow-up, all from documented monomorphic ventricular tachycardia. Cardiac function remained stable over the course of the study. Distinct imaging morphologies corresponded to certain tissue dose ranges and time points., Conclusion: Radioablation of cardiac infarct scar leads to significant homogenization of the scar, replicating the histologic effects of radiofrequency ablation. These changes correspond to distinct imaging morphologies on delayed contrast-enhanced cardiac magnetic resonance imaging, enabling noninvasive confirmation of tissue ablation effects The present study is the first to thoroughly investigate the structural effects of cardiac proton beam therapy in infarcted myocardium., (Copyright © 2020 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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22. Biophysical properties, efficacy, and lesion characteristics of a new linear cryoablation catheter in a canine model.
- Author
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Suzuki A, Lehmann HI, Wang S, Parker KD, Rettmann ME, Monahan KH, and Packer DL
- Subjects
- Animals, Disease Models, Animal, Dogs, Tachycardia, Ectopic Atrial physiopathology, Ablation Techniques methods, Cryosurgery methods, Electrocardiography, Heart Conduction System physiopathology, Pulmonary Veins surgery, Tachycardia, Ectopic Atrial surgery
- Abstract
Background: The cryoballoon (CB) catheter is an established tool for pulmonary vein isolation (PVI), but its use is limited for that purpose., Objective: The purpose of this study was to investigate the biophysical properties of a newly developed linear cryoablation catheter for creation of linear ablation lesions in an in vivo model., Methods: Twenty-nine dogs (14 acutely ablated, 15 chronically followed) underwent cryoablation using the linear cryoablation catheter. Regions of interest included the cavotricuspid isthmus (CTI), mitral isthmus (MI), left atrial (LA) roof, and LA posterior wall in an acute study. Cryoablations for CTI and MI were performed in 14 atrial fibrillation animals after PVI and followed over 1 month in the chronic study. Tissue temperature during cryoablation was monitored using implanted thermocouples in the regions of interest. Gross and microscopic pathologic characteristics of the lesions were assessed., Results: In acute animals, lesion length (transmurality) was CTI 34 ± 4 mm (89% ± 11%); MI 29 ± 4 mm (90% ± 13%); LA roof 19 ± 3 mm (90% ± 8%); and LA posterior wall 19 ± 2 mm (81% ± 13%), with 1 or 2 freezes. Chronic bidirectional block was achieved in 13 of 14 CTI (93%) and 10 of 14 MI (71%) ablations after 1-month follow-up and was consistent with lesion continuity and transmurality upon pathology. The lowest tissue temperature correlated well with the closest distance to the linear cryocatheter (r = 0.688; P <.001)., Conclusion: This linear cryocatheter created continuous and transmural linear lesions with "single-shot" cryoenergy application and has the potential for clinical use in the setting of various arrhythmias., (Copyright © 2020 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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23. Changes in characteristics and outcomes in Japanese patients with heart failure from the 2000s to the 2010s: The HIJ-HF cohorts.
- Author
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Suzuki A, Shiga T, Kawashiro N, and Hagiwara N
- Subjects
- Aged, Aged, 80 and over, Female, Hospitalization, Humans, Japan epidemiology, Male, Middle Aged, Survival Rate, Ventricular Function, Left, Heart Failure mortality, Heart Failure physiopathology
- Abstract
Background: The number of hospitalized patients with heart failure (HF) is increasing as a result of the increase in the elderly population in Japan. We evaluated changes in the characteristics and outcomes of HF patients hospitalized in the 2000s to the 2010s and discharged alive based on left ventricular ejection fraction (LVEF)., Methods: Pooled patient data were obtained from The Heart Institute of Japan Heart Failure studies (HIJ-HF I: 2001-2 and HIJ-HF II: 2013-4). We studied patients discharged alive from pooled data based on LVEF < 40% (HFrEF), 40-49% (HFmrEF), and ≥50% (HFpEF). The primary outcome was death from any cause, and the secondary outcomes were cardiac death and rehospitalization due to worsened HF., Results: The proportion of HFpEF increased (35%-43%, p < 0.01), and the median ages of patients with HFmrEF (72-76 years, p < 0.01) or HFpEF (72-80 years, p < 0.01) increased from HIJ-HF I to HIJ-HF II. The use of angiotensin II receptor blockers, beta-blockers, statins, amiodarone, and erythropoietin increased, but nitrate and digoxin usage decreased. The adjusted survival rate and cardiac death-free rate were not significantly different between the 2000s and 2010s in any LVEF group, and the incidence of rehospitalization due to worsened HF was reduced in patients discharged alive from HIJ-HF I to HIJ-HF II [HFrEF: hazard ratio (HR) 0.67, 95% confidence interval (CI) 0.51-0.89; HFmrEF: HR 0.89, 95% CI 0.68-1.16; and HFpEF: HR 0.77, 95% CI 0.61-0.97] with no significant interaction by LVEF groups., Conclusion: Our study demonstrated that age, the proportion of HFpEF, and guideline-recommended drug therapy use increased among hospitalized Japanese HF patients from the 2000s to the 2010s. The adjusted survival rate was not improved in any LVEF group, although the incidence of rehospitalization due to worsened HF was reduced., (Copyright © 2020 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2020
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24. Induction of Steatohepatitis and Liver Tumorigenesis by Enforced Snail Expression in Hepatocytes.
- Author
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Miura S and Suzuki A
- Subjects
- Animals, Bile Acids and Salts metabolism, Carcinogenesis genetics, Carcinogenesis pathology, Disease Models, Animal, Epithelial-Mesenchymal Transition physiology, Fatty Liver genetics, Fatty Liver pathology, Gene Expression Regulation, Neoplastic, Hepatocytes pathology, Liver Neoplasms genetics, Liver Neoplasms pathology, Mice, Mice, Transgenic, Snail Family Transcription Factors genetics, Carcinogenesis metabolism, Fatty Liver metabolism, Hepatocytes metabolism, Liver Neoplasms metabolism, Snail Family Transcription Factors metabolism
- Abstract
Snail is a transcription factor that regulates many cellular events involved in development, homeostasis, and disease. In hepatocellular carcinoma (HCC), Snail induces epithelial-to-mesenchymal transition that confers invasive properties on tumor cells during HCC progression and malignancy. Snail activation observed in HCC mouse models suggests its involvement not only in progression, but also onset of HCC. However, it remains unclear whether Snail directly contributes to HCC initiation or whether it supports HCC initiation promoted by other oncogenes. In this study, we generated mouse models for liver-specific and hepatocyte-specific overexpression of Snail to show the independent roles of Snail in liver homeostasis and disease. Enforced Snail expression resulted in liver and hepatocyte enlargement, inflammatory cell infiltration in the liver, lipid accumulation in hepatocytes, substantial increases in serum alanine aminotransferase and bile acids, yellow discoloration of tissues caused by bilirubin accumulation, and liver tumorigenesis. Snail overexpression suppressed mRNA expression of the tight junction components claudins and occludin and that of proteins associated with bile acid metabolism, leading to disruption of the biliary canaliculus formed among hepatocytes and excretion of abnormal amounts of unusual bile acids from hepatocytes. In conclusion, enforced Snail expression in hepatocytes is sufficient for induction of steatohepatitis and liver tumorigenesis through disruption of the biliary canaliculus and bile acid homeostasis in the liver., (Copyright © 2020 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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25. Novel compound heterozygous MCOLN1 mutations identified in a Japanese girl with severe developmental delay and thin corpus callosum.
- Author
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Yamaguchi N, Ban K, Suzuki A, Nakamura Y, Kato K, Muramatsu H, Okuno Y, Hattori A, Kaname T, Takahashi Y, and Saitoh S
- Subjects
- Child, Preschool, Developmental Disabilities etiology, Female, Humans, Japan, Mucolipidoses complications, Corpus Callosum pathology, Developmental Disabilities genetics, Mucolipidoses genetics, Transient Receptor Potential Channels genetics
- Abstract
Mucolipidosis type IV (MLIV) is a rare lysosomal storage disorder causing severe psychomotor developmental delay and progressive visual impairment. MLIV is an autosomal recessive disease caused by mutations in MCOLN1, which encodes for mucolipin-1. Here, we report a case of a 4-year-old Japanese girl with severe intellectual disability and motor deficits. Brain magnetic resonance imaging showed signal abnormalities in the white matter and thinning of the corpus callosum. Whole-exome sequencing was performed on the proband and her parents, and novel compound heterozygous mutations at c.936_938del (p.Phe313del) and c.1503dupC (p.Ile502Hisfs*106) in MCOLN1 (NM_020533.2) were identified in the proband. Additional biochemical examinations revealed elevated serum gastrin level and iron deficiency anemia, leading to the diagnosis of MLIV. More reports of such pathogenic mutations are expected to broaden the understanding of the channel function of mucolipin-1 and genotype-phenotype correlations., (Copyright © 2019 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)
- Published
- 2020
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26. The AP-1 transcription factor JunB functions in Xenopus tail regeneration by positively regulating cell proliferation.
- Author
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Nakamura M, Yoshida H, Takahashi E, Wlizla M, Takebayashi-Suzuki K, Horb ME, and Suzuki A
- Subjects
- Animals, Cell Proliferation, Down-Regulation genetics, Gene Expression Regulation, Developmental, Gene Knockout Techniques, Larva physiology, Signal Transduction, Transforming Growth Factor beta metabolism, Regeneration physiology, Tail physiology, Transcription Factor AP-1 metabolism, Xenopus physiology
- Abstract
Xenopus tropicalis tadpoles can regenerate an amputated tail, including spinal cord, muscle and notochord, through cell proliferation and differentiation. However, the molecular mechanisms that regulate cell proliferation during tail regeneration are largely unknown. Here we show that JunB plays an important role in tail regeneration by regulating cell proliferation. The expression of junb is rapidly activated and sustained during tail regeneration. Knockout (KO) of junb causes a delay in tail regeneration and tissue differentiation. In junb KO tadpoles, cell proliferation is prevented before tissue differentiation. Furthermore, TGF-β signaling, which is activated just after tail amputation, regulates the induction and maintenance of junb expression. These findings demonstrate that JunB, a downstream component of TGF-β signaling, works as a positive regulator of cell proliferation during Xenopus tail regeneration., Competing Interests: Declaration of competing interest To the best of our knowledge, the named authors have no conflict of interest, financial or otherwise., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2020
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27. TAK-925, an orexin 2 receptor-selective agonist, shows robust wake-promoting effects in mice.
- Author
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Yukitake H, Fujimoto T, Ishikawa T, Suzuki A, Shimizu Y, Rikimaru K, Ito M, Suzuki M, and Kimura H
- Subjects
- Animals, CHO Cells, Cricetulus, Humans, Hypothalamic Area, Lateral cytology, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Narcolepsy drug therapy, Neurons drug effects, Neurons metabolism, Orexin Receptors genetics, Orexin Receptors metabolism, Orexins metabolism, Sleep genetics, Transfection, Wakefulness genetics, Orexin Receptors agonists, Sleep drug effects, Wakefulness drug effects
- Abstract
Orexin-producing neurons in the lateral hypothalamus are a critical regulator of sleep/wake states, and their loss is associated with narcolepsy type 1 (NT1). Orexin peptides act on two G protein-coupled receptors: orexin 1 receptor (OX1R) and orexin 2 receptor (OX2R). OX2R knockout (KO) mice, but not OX1R KO mice, showed clear narcolepsy-like phenotypes, including fragmented sleep-wake cycles. Moreover, OX2R-selective antagonists have been shown to induce sleepiness in mice, and activation of OX2R has been reported to increase wakefulness. In this study, we characterized in vitro and in vivo profiles of a novel, highly selective OX2R agonist, TAK-925 [methyl (2R,3S)-3-[(methylsulfonyl)amino]-2-{[(cis-4-phenylcyclohexyl)oxy]methyl}piperidine-1-carboxylate]. TAK-925 activated human recombinant OX2R with 50% effective concentration value of 5.5 nM, and showed >5,000-fold selectivity over OX1R in calcium mobilization assays. TAK-925 induced OX2R-downstream signals similar to those displayed by orexin peptides in Chinese hamster ovary cells stably expressing human OX2R. In an electrophysiological study, TAK-925 activated physiological OX2R on histaminergic neurons in the mouse tuberomammillary nucleus (TMN). Subcutaneous (SC) administration of TAK-925 also modulated neuronal activity in various brain regions, including TMN, as measured by an immunohistochemical analysis using an anti-c-fos antibody. TAK-925 (SC) increased wakefulness in wild-type mice, but not in OX2R KO mice, during their sleep phase, demonstrating that a highly selective OX2R agonist can increase wakefulness in mice via OX2R activation. TAK-925 may have therapeutic potential to reduce hypersomnia in multiple disorders including NT1., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
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28. Left ventricular function after noninvasive cardiac ablation using proton beam therapy in a porcine model.
- Author
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Hohmann S, Deisher AJ, Suzuki A, Konishi H, Rettmann ME, Merrell KW, Kruse JJ, Newman LK, Parker KD, Monahan KH, Foote RL, Herman MG, and Packer DL
- Subjects
- Animals, Disease Models, Animal, Dose-Response Relationship, Radiation, Magnetic Resonance Imaging, Radiotherapy Dosage, Stroke Volume, Swine, Tomography, X-Ray Computed, Proton Therapy methods, Tachycardia, Ventricular radiotherapy, Ventricular Function, Left radiation effects
- Abstract
Background: Noninvasive cardiac ablation of ventricular tachycardia (VT) using radiotherapy has recently gained interest among electrophysiologists. The effects of left ventricular (LV) ablative radiation treatment on global LV function and volumes are unknown., Objective: The purpose of this study was to investigate the effects of noninvasive ablation on LV function over time., Methods: Twenty domestic swine underwent proton beam treatment of LV sites in a dose-finding design and were followed for up to 40 weeks by cardiac magnetic resonance imaging at 4-week intervals. Doses investigated were either 40 Gy at 1 site (n = 8) or 30 Gy at 2 sites (n = 4) in the low-dose group and 40 Gy at 3 sites (n = 8) in the high-dose group., Results: LV mean dose (13.2 ± 1.8 Gy vs 4.6 ± 1.8 Gy) and the volume receiving at least 20 Gy (V
20Gy ) (24.7% ± 4.8% vs 6.4% ± 3.0%) differed significantly between groups. Dose-dependent effects on left ventricular ejection fraction (LVEF) and LV end-diastolic volume became manifest about 3 months after treatment. LVEF decline was correlated to mean dose (correlation coefficient ρ = -0.69; P = .008) and V20Gy (ρ = -0.66; P = .01), as was LV dilation (ρ = 0.72; P = .005; and ρ = 0.75, P = .003 respectively)., Conclusion: Possible adverse effects on LV function, seen about 3 months after treatment, are dose dependent. Therefore, precise target definition and focused energy delivery are paramount in catheter-free ablation., (Copyright © 2019 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)- Published
- 2019
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29. TAK-137, an AMPA receptor potentiator with little agonistic effect, produces antidepressant-like effect without causing psychotomimetic effects in rats.
- Author
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Suzuki A, Murakami K, Tajima Y, Hara H, Kunugi A, and Kimura H
- Subjects
- Animals, Antidepressive Agents administration & dosage, Brain-Derived Neurotrophic Factor metabolism, Cerebellar Cortex cytology, Cerebellar Cortex metabolism, Depression drug therapy, Depressive Disorder, Major drug therapy, Dose-Response Relationship, Drug, Excitatory Amino Acid Antagonists pharmacology, Extracellular Signal-Regulated MAP Kinases metabolism, Female, Hallucinogens administration & dosage, Ketamine pharmacology, Locomotion drug effects, Male, Neurons drug effects, Neurons metabolism, Phosphorylation drug effects, Prepulse Inhibition drug effects, Proto-Oncogene Proteins c-akt metabolism, Pyridines administration & dosage, Rats, Rats, Inbred WKY, Rats, Sprague-Dawley, Receptors, AMPA metabolism, Ribosomal Protein S6 Kinases, 70-kDa metabolism, Signal Transduction drug effects, TOR Serine-Threonine Kinases metabolism, Thiadiazines administration & dosage, Antidepressive Agents pharmacology, Hallucinogens pharmacology, Pyridines chemistry, Pyridines pharmacology, Receptors, AMPA agonists, Thiadiazines chemistry, Thiadiazines pharmacology
- Abstract
Ketamine produces a rapid-onset antidepressant effect in patients with treatment-resistant depression (TRD), although it concurrently causes undesirable psychotomimetic side effects. Accumulating evidence suggests that ketamine produces antidepressant effects via activation of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPA-R), with consequent activation of the mammalian target of rapamycin (mTOR) pathway and up-regulation of brain-derived neurotrophic factor (BDNF). We previously reported that TAK-137, an AMPA-R potentiator with little agonistic effect, had potent procognitive effects with lower risks of bell-shaped dose-response and seizure induction. In this study, we characterized the potential of TAK-137 as a novel antidepressant in rats. In rat primary cortical neurons, TAK-137 increased the phosphorylated form of Akt, extracellular signal-regulated kinase, mTOR, and p70S6 kinase, and dose-dependently increased the expression level of BDNF protein. The antidepressant-like effects of ketamine and TAK-137 were assessed on the day after final administration using the novelty-suppressed feeding test in rats. A single intraperitoneal administration of ketamine shortened the latency to feed. Under these conditions, oral administration of TAK-137 for 3 days shortened the feeding latency. Ketamine induced hyperlocomotion and reduced prepulse inhibition, which may be associated with psychotomimetic effects, while TAK-137 did not. TAK-137 may be a safer and rapid-onset therapeutic drug for the treatment of major depressive disorder, including TRD., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
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30. Performance of the COPD Assessment Test in patients with connective tissue disease-associated interstitial lung disease.
- Author
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Suzuki A, Kondoh Y, Swigris JJ, Matsuda T, Kimura T, Kataoka K, Ando M, Hashimoto N, Sakamoto K, and Hasegawa Y
- Subjects
- Adult, Aged, Blood Gas Analysis methods, Connective Tissue Diseases diagnosis, Connective Tissue Diseases physiopathology, Cross-Sectional Studies, Dyspnea physiopathology, Dyspnea psychology, Exercise, Female, Health Status, Humans, Lung Diseases, Interstitial diagnosis, Lung Diseases, Interstitial physiopathology, Male, Middle Aged, Physical Endurance physiology, Pulmonary Disease, Chronic Obstructive blood, Pulmonary Disease, Chronic Obstructive diagnosis, Pulmonary Disease, Chronic Obstructive psychology, Quality of Life, Reproducibility of Results, Respiratory Function Tests methods, Retrospective Studies, Surveys and Questionnaires statistics & numerical data, Connective Tissue Diseases complications, Dyspnea diagnosis, Lung Diseases, Interstitial complications, Pulmonary Disease, Chronic Obstructive physiopathology, Surveys and Questionnaires standards
- Abstract
Background: Patients with connective tissue disease-associated interstitial lung disease (CTD-ILD) often experience impaired health status. In daily clinical practice, a short and easy instrument for assessing health status would be useful to help better understand the patient's condition. The COPD Assessment Test (CAT) is a simple questionnaire about respiratory symptoms and their impact. We aimed to examine the CAT's performance characteristics and to generate data to support its reliability and validity in patients with CTD-ILD., Methods: We used data from 132 CTD-ILD patients evaluated at Tosei General Hospital from July 2011 to July 2016 to assess the cross-sectional and longitudinal validity of the CAT., Results: The mean age of the patients was 64.5 years and 87 (66%) were women. There were no significant differences in CAT score between any of the CTD subgroups. Internal consistency (Cronbach's α = 0.881) and repeatability (intraclass correlation coefficient [ICC] = 0.803) for the CAT score were acceptable. At baseline, CAT score was significantly associated with clinically meaningful measures of physiologic function, exercise capacity, and dyspnea. Change in CAT score over 6-12 months was also associated with change in other measures. In the distribution- and anchor-based analyses, the estimated minimal clinically important difference of CAT score was 1-4 points., Conclusion: These data support the validity and reliability of CAT as a sensitive measure for assessing health status in patients with CTD-ILD., (Copyright © 2019. Published by Elsevier Ltd.)
- Published
- 2019
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31. Essential role of mouse Dead end1 in the maintenance of spermatogonia.
- Author
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Niimi Y, Imai A, Nishimura H, Yui K, Kikuchi A, Koike H, Saga Y, and Suzuki A
- Subjects
- Animals, Cell Differentiation, Embryonic Germ Cells metabolism, Male, Mice, Mice, Transgenic, Neoplasm Proteins physiology, RNA metabolism, RNA, Messenger metabolism, RNA-Binding Proteins metabolism, RNA-Binding Proteins physiology, Reproduction physiology, Spermatogenesis genetics, Spermatogonia cytology, Spermatozoa metabolism, Stem Cells cytology, Testis metabolism, Neoplasm Proteins metabolism, Spermatogonia metabolism
- Abstract
Dead end is a vertebrate-specific RNA-binding protein implicated in germ cell development. We have previously shown that mouse Dead end1 (DND1) is expressed in male embryonic germ cells and directly interacts with NANOS2 to cooperatively promote sexual differentiation of fetal germ cells. In addition, we have also reported that NANOS2 is expressed in self-renewing spermatogonial stem cells and is required for the maintenance of the stem cell state. However, it remains to be determined whether DND1 works with NANOS2 in the spermatogonia. Here, we show that DND1 is expressed in a subpopulation of differentiating spermatogonia and undifferentiated spermatogonia, including NANOS2-positive spermatogonia. Conditional disruption of DND1 depleted both differentiating and undifferentiated spermatogonia; however, the numbers of A
single and Apaired spermatogonia were preferentially decreased as compared with those of Aaligned spermatogonia. Finally, we found that postnatal DND1 associates with NANOS2 in vivo, independently of RNA, and interacts with some of NANOS2-target mRNAs. These data not only suggest that DND1 is a partner of NANOS2 in undifferentiated spermatogonia as well as in male embryonic germ cells, but also show that DND1 plays an essential role in the survival of differentiating spermatogonia., (Copyright © 2018 Elsevier Inc. All rights reserved.)- Published
- 2019
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32. Intraspecific variations in responses to ocean acidification in two branching coral species.
- Author
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Sekizawa A, Uechi H, Iguchi A, Nakamura T, Kumagai NH, Suzuki A, Sakai K, and Nojiri Y
- Subjects
- Animals, Carbon Dioxide, Hydrogen-Ion Concentration, Oceans and Seas, Photosynthesis, Seawater, Adaptation, Physiological, Anthozoa, Coral Reefs
- Abstract
Ocean acidification is widely recognised to have a negative impact on marine calcifying organisms by reducing calcifications, but controversy remains over whether such organisms could cope with ocean acidification within a range of phenotypic plasticity and/or adapt to future acidifying ocean. We performed a laboratory rearing experiment using clonal fragments of the common branching corals Montipora digitata and Porites cylindrica under control and acidified seawater (lower pH) conditions (approximately 400 and 900μatm pCO
2 , respectively) and evaluated the intraspecific variations in their responses to ocean acidification. Intra- and interspecific variations in calcification and photosynthetic efficiency were evident according to both pCO2 conditions and colony, indicating that responses to acidification may be individually variable at the colony level. Our results suggest that some corals may cope with ocean acidification within their present genotypic composition by adaptation through phenotypic plasticity, while others may be placed under selective pressures resulting in population alteration., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2017
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33. Identification and comparative analyses of Siamois cluster genes in Xenopus laevis and tropicalis.
- Author
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Haramoto Y, Saijyo T, Tanaka T, Furuno N, Suzuki A, Ito Y, Kondo M, Taira M, and Takahashi S
- Subjects
- Amino Acid Sequence, Animals, Blastula metabolism, Body Patterning genetics, Chromosome Mapping, Conserved Sequence, Diploidy, Embryo, Nonmammalian metabolism, Gastrula metabolism, Gene Dosage, Gene Expression Regulation, Developmental, Organizers, Embryonic, Sequence Alignment, Sequence Homology, Amino Acid, Species Specificity, Tetraploidy, Wnt Signaling Pathway, Xenopus embryology, Xenopus laevis embryology, Xenopus laevis genetics, Homeodomain Proteins genetics, Multigene Family, Xenopus genetics, Xenopus Proteins genetics
- Abstract
Two siamois-related homeobox genes siamois (sia1) and twin (sia2), have been reported in Xenopus laevis. These genes are expressed in the blastula chordin- and noggin-expressing (BCNE) center and the Nieuwkoop center, and have complete secondary axis-inducing activity when over-expressed on the ventral side of the embryo. Using whole genome sequences of X. tropicalis and X. laevis, we identified two additional siamois-related genes, which are tandemly duplicated near sia1 and sia2 to form the siamois gene cluster. Four siamois genes in X. tropicalis are transcribed at blastula to gastrula stages. In X. laevis, the siamois gene cluster is present on both homeologous chromosomes, XLA3L and XLA3S. Transcripts from seven siamois genes (three on XLA3L and four on XLA3S) in X. laevis were detected at blastula to gastrula stages. A transcribed gene, sia1p. S, encodes an inactive protein without a homeodomain. When over-expressed ventrally, all siamois-related genes tested in this study except for sia1p. S induced a complete secondary axis, indicating that X. tropicalis and X. laevis have four and six active siamois-related genes, respectively. Of note, each gene required different amounts of mRNA for full activity. These results suggest the possibility that siamois cluster genes have functional redundancy to endow robustness and quickness to organizer formation in Xenopus species., (Copyright © 2017. Published by Elsevier Inc.)
- Published
- 2017
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34. Genomic organization and modulation of gene expression of the TGF-β and FGF pathways in the allotetraploid frog Xenopus laevis.
- Author
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Suzuki A, Yoshida H, van Heeringen SJ, Takebayashi-Suzuki K, Veenstra GJC, and Taira M
- Subjects
- Amino Acid Sequence, Animals, Body Patterning genetics, Diploidy, Embryo, Nonmammalian metabolism, Epigenesis, Genetic, Fibroblast Growth Factors genetics, Genetic Speciation, Genomics, Ligands, MAP Kinase Signaling System genetics, Molecular Sequence Annotation, Receptors, Growth Factor physiology, Smad Proteins metabolism, Tetraploidy, Transforming Growth Factor beta genetics, Xenopus genetics, Xenopus Proteins genetics, Xenopus laevis metabolism, Embryonic Induction genetics, Fibroblast Growth Factors metabolism, Gene Expression Regulation, Developmental, Signal Transduction genetics, Transforming Growth Factor beta metabolism, Xenopus Proteins metabolism, Xenopus laevis genetics
- Abstract
Inductive interactions mediated by the TGF-β and FGF-MAPK pathways are essential for specification of the germ layers and embryonic body axes during early vertebrate embryogenesis. TGF-β and FGF ligands signal through receptor Ser/Thr and Tyr kinases, respectively, and these signaling pathways cross-talk to regulate transcription and cell behavior. The allotetraploid Xenopus laevis and its ancestral diploid Xenopus tropicalis are versatile model organisms with which to study the inductive interactions and mechanisms of these signal transduction pathways. Here we have analyzed the draft genome of X. laevis with respect to the genomic organization and differential expression of genes in the TGF-β and FGF pathways. Genomic structure and gene expression analyses of pathway components in X. laevis revealed that genetic modulations, including deletions resulting in singletons and differential expression of homeologs, have occurred frequently among extracellular regulatory factors of the TGF-β pathway after allotetraploidization. Moreover, differential gene expression was found for factors regulating various cellular responses including co-receptors, decoy receptors, and intracellular negative regulators in both the TGF-β and FGF-MAPK pathways. We summarize the patterns of genetic alterations in the allotetraploid frog X. laevis and discuss the importance of these changes with regard to developmental processes., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2017
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35. Genome organization of the vg1 and nodal3 gene clusters in the allotetraploid frog Xenopus laevis.
- Author
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Suzuki A, Uno Y, Takahashi S, Grimwood J, Schmutz J, Mawaribuchi S, Yoshida H, Takebayashi-Suzuki K, Ito M, Matsuda Y, Rokhsar D, and Taira M
- Subjects
- Animals, Biological Evolution, Chromosome Mapping, Evolution, Molecular, Gene Deletion, Gene Duplication, In Situ Hybridization, Fluorescence, Phylogeny, Pseudogenes, Species Specificity, Synteny, Tetraploidy, Xenopus genetics, Genome, Multigene Family, Transforming Growth Factor beta genetics, Xenopus Proteins genetics, Xenopus laevis genetics
- Abstract
Extracellular factors belonging to the TGF-β family play pivotal roles in the formation and patterning of germ layers during early Xenopus embryogenesis. Here, we show that the vg1 and nodal3 genes of Xenopus laevis are present in gene clusters on chromosomes XLA1L and XLA3L, respectively, and that both gene clusters have been completely lost from the syntenic S chromosome regions. The presence of gene clusters and chromosome-specific gene loss were confirmed by cDNA FISH analyses. Sequence and expression analyses revealed that paralogous genes in the vg1 and nodal3 clusters on the L chromosomes were also altered compared to their Xenopus tropicalis orthologs. X. laevis vg1 and nodal3 paralogs have potentially become pseudogenes or sub-functionalized genes and are expressed at different levels. As X. tropicalis has a single vg1 gene on chromosome XTR1, the ancestral vg1 gene in X. laevis appears to have been expanded on XLA1L. Of note, two reported vg1 genes, vg1(S20) and vg1(P20), reside in the cluster on XLA1L. The nodal3 gene cluster is also present on X. tropicalis chromosome XTR3, but phylogenetic analysis indicates that nodal3 genes in X. laevis and X. tropicalis were independently expanded and/or evolved in concert within each cluster by gene conversion. These findings provide insights into the function and molecular evolution of TGF-β family genes in response to allotetraploidization., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2017
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36. The clinical impact of major comorbidities on idiopathic pulmonary fibrosis.
- Author
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Suzuki A and Kondoh Y
- Subjects
- Cardiovascular Diseases epidemiology, Comorbidity, Diabetes Mellitus epidemiology, Disease Progression, Gastroesophageal Reflux epidemiology, Humans, Sleep Apnea, Obstructive epidemiology, Emphysema epidemiology, Hypertension, Pulmonary epidemiology, Idiopathic Pulmonary Fibrosis epidemiology, Lung Neoplasms epidemiology, Pneumonia epidemiology
- Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive and devastating disease with a median survival time of 2-3 years after diagnosis. Patients with IPF exhibit distinct patterns of disease progression, and some patients display a more rapidly progressive clinical course. The clinical course of IPF may also include periods of acute deterioration, which are termed acute exacerbations. Patients with IPF frequently experience various comorbidities, such as pulmonary infection, emphysema, pulmonary hypertension, lung cancer, gastroesophageal reflux, cardiovascular disease, diabetes mellitus, and obstructive sleep apnea. A previous age- and sex-matched study showed that IPF itself was an independent risk factor for these comorbidities. Other studies have demonstrated that these comorbidities are associated with disease progression and mortality in IPF. These variations in the clinical course and comorbidities have affected the researchers' and physicians' understanding of IPF. Therefore, better identification and understanding of these variations may be helpful when making decisions regarding therapeutic interventions. Furthermore, the identification and treatment of comorbidities may have a clinically significant impact on patient survival. Future studies should use well-established definitions for distinct progression patterns and comorbid conditions to obtain greater insights into the pathogenesis and treatment of IPF., (Copyright © 2016 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
37. Colony-specific calcification and mortality under ocean acidification in the branching coral Montipora digitata.
- Author
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Kavousi J, Tanaka Y, Nishida K, Suzuki A, Nojiri Y, and Nakamura T
- Subjects
- Animals, Homeostasis, Hydrogen-Ion Concentration, Oceans and Seas, Seawater chemistry, Anthozoa physiology, Carbon Dioxide, Coral Reefs, Environmental Monitoring, Stress, Physiological
- Abstract
Ocean acidification (OA) threatens calcifying marine organisms including reef-building corals. In this study, we examined the OA responses of individual colonies of the branching scleractinian coral Montipora digitata. We exposed nubbins of unique colonies (n = 15) to ambient or elevated pCO2 under natural light and temperature regimes for 110 days. Although elevated pCO2 exposure on average reduced calcification, individual colonies showed unique responses ranging from declines in positive calcification to negative calcification (decalcification) to no change. Similarly, mortality was greater on average in elevated pCO2, but also showed colony-specific patterns. High variation in colony responses suggests the possibility that ongoing OA may lead to natural selection of OA-tolerant colonies within a coral population., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
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38. Implantable cardioverter defibrillator therapy and sudden death risk stratification in hypertrophic cardiomyopathy patients with midventricular obstruction: A single-center experience.
- Author
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Maeda R, Minami Y, Haruki S, Kanbayashi K, Itani R, Suzuki A, Ejima K, Shiga T, Shoda M, and Hagiwara N
- Subjects
- Adult, Aged, Cardiomyopathy, Hypertrophic complications, Defibrillators, Implantable, Female, Heart Ventricles physiopathology, Humans, Male, Middle Aged, Risk Assessment, Survival Analysis, Treatment Outcome, Ventricular Outflow Obstruction diagnosis, Cardiac Surgical Procedures instrumentation, Cardiomyopathy, Hypertrophic therapy, Death, Sudden, Cardiac prevention & control, Ventricular Outflow Obstruction therapy
- Abstract
Background: Previous studies reported that the presence of midventricular obstruction (MVO) was an independent determinant of sudden death and potentially lethal arrhythmic events in patients with hypertrophic cardiomyopathy (HCM). However, it remains unclear whether implantable cardioverter defibrillator (ICD) improves survival in HCM patients with MVO. In addition, the risk factors for lethal arrhythmic events in MVO-HCM patients are not fully understood. The aim of this study was to provide an overview of the ICD therapy on sudden death prevention, and to determine the risk factors for lethal arrhythmic events in MVO-HCM patients., Methods: This study included 593 HCM patients. Left ventricular MVO was diagnosed when the peak midventricular gradient was estimated as ≥30mmHg., Results: MVO was identified in 56 patients (9.4%), and 15 of the 56 MVO-HCM patients (26.8%) received an ICD. Six of 15 ICD-implanted patients (40.0%) had appropriate ICD interventions over the follow-up period of 6.5±5.1years after ICD implantation. Although two of 42 patients without an ICD died suddenly, no patients experienced sudden death after ICD implantation in patients with an ICD throughout the follow-up period of 9.0±8.0years after referral to our hospital. By multivariate analysis, maximal wall thickness was an independent determinant of lethal arrhythmic events in MVO-HCM patients., Conclusions: A quarter of MVO-HCM patients received an ICD, and the incidence of appropriate ICD intervention was about 6.2%/year. It may be necessary to give careful consideration to the prevention of lethal arrhythmic events in MVO-HCM patients, especially those with severe left ventricular hypertrophy., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
39. Apparent homozygosity due to compound heterozygosity of one point mutation and an overlapping exon deletion mutation in ABCA12: A genetic diagnostic pitfall.
- Author
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Shibata A, Sugiura K, Suzuki A, Ichiki T, and Akiyama M
- Subjects
- DNA Mutational Analysis, Exons, Female, Genetic Carrier Screening, Genetic Testing, Haplotypes, Heterozygote, Homozygote, Humans, Ichthyosis, Lamellar diagnosis, Infant, Infant, Newborn, Introns, Male, Polymorphism, Single Nucleotide, ATP-Binding Cassette Transporters genetics, Base Sequence, Ichthyosis, Lamellar genetics, Point Mutation, Sequence Deletion
- Abstract
Background: Harlequin ichthyosis (HI), one of the most severe genetic skin disorders, is autosomal recessively inherited. Mutations in ABCA12, which encodes ATP-binding cassette transporter A12 (ABCA12), are known to be the cause of HI. It is very difficult to make precise genetic diagnosis when an exon deletion mutation overlaps the site of another causative point mutation. This combination of mutations may lead us to conclude incorrectly that the patient has the point mutation homozygously, a phenomenon called "apparent homozygosity"., Objective: To demonstrate that the present HI patient has apparent homozygosity in ABCA12 mutations., Methods: We performed direct sequencing of gDNA in the entire coding region, including exon-intron boundaries, of ABCA12 in the HI patient and her parents. To further elucidate the mutations in the patient, parental mutation segregation study was done and SNP analysis was conducted on the region flanking ABCA12 in the patients and her parents. Quantitative PCR of gDNA in exon 11 of ABCA12 was also performed. Direct sequencing of cDNA from exon 9 to exon 13 and of gDNA between intron 9 and intron 11 of ABCA12 was done in the HI patient and her parents., Results: Direct sequencing of gDNA in the entire coding region, including exon-intron boundaries, of ABCA12 seemed to indicate that the patient had the novel homozygous nonsense mutation c.1216A>T (p.Lys406X) in exon 11. However, mutation segregation analysis, SNP analysis, qRTPCR of gDNA in exon 11 of ABCA12 and direct sequencing of cDNA from exon 9 to exon 12 of ABCA12 and of gDNA between intron 9 and intron 11 of ABCA12 in the HI patient and her parents demonstrated that the present patient was compound heterozygous for two ABCA12 mutations: c.1216A>T (p.Lys406X) in exon 11 and g.111346_113217del1872 (p.Leu355_Lys428del, Gln354fs7*) which was overlapping exon deletion mutations involving exons 10 and 11., Conclusion: When direct sequencing indicates that a patient from a non-consanguineous family has an apparently homozygous non-founder point mutation, the homozygosity may be "apparent homozygosity", and we should keep in mind the possibility of overlapping exon deletion mutation., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
40. Responses of calcification of massive and encrusting corals to past, present, and near-future ocean carbon dioxide concentrations.
- Author
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Iguchi A, Kumagai NH, Nakamura T, Suzuki A, Sakai K, and Nojiri Y
- Subjects
- Animals, Anthozoa drug effects, Bayes Theorem, Hydrogen-Ion Concentration, Models, Theoretical, Oceans and Seas, Seawater chemistry, Anthozoa metabolism, Calcification, Physiologic drug effects, Carbon Dioxide administration & dosage
- Abstract
In this study, we report the acidification impact mimicking the pre-industrial, the present, and near-future oceans on calcification of two coral species (Porites australiensis, Isopora palifera) by using precise pCO2 control system which can produce acidified seawater under stable pCO2 values with low variations. In the analyses, we performed Bayesian modeling approaches incorporating the variations of pCO2 and compared the results between our modeling approach and classical statistical one. The results showed highest calcification rates in pre-industrial pCO2 level and gradual decreases of calcification in the near-future ocean acidification level, which suggests that ongoing and near-future ocean acidification would negatively impact coral calcification. In addition, it was expected that the variations of parameters of carbon chemistry may affect the inference of the best model on calcification responses to these parameters between Bayesian modeling approach and classical statistical one even under stable pCO2 values with low variations., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
41. Impact of clustered depression and anxiety on mortality and rehospitalization in patients with heart failure.
- Author
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Suzuki T, Shiga T, Kuwahara K, Kobayashi S, Suzuki S, Nishimura K, Suzuki A, Minami Y, Ishigooka J, Kasanuki H, and Hagiwara N
- Subjects
- Disease-Free Survival, Female, Heart Failure psychology, Heart Failure therapy, Humans, Incidence, Japan epidemiology, Male, Middle Aged, Prospective Studies, Psychiatric Status Rating Scales, Risk Factors, Surveys and Questionnaires, Anxiety Disorders psychology, Depressive Disorder psychology, Heart Failure mortality, Hospitalization statistics & numerical data
- Abstract
Background: Anxiety is often present in patients with depression. The aim of this study was to evaluate the impact of clustered depression and anxiety on mortality and rehospitalization in hospitalized patients with heart failure (HF)., Methods: A total of 221 hospitalized patients with HF, who completed the questionnaires, were analyzed in this prospective study (mean age 62±13 years; 28% female). One-third patients had implanted cardiac devices. Depression was defined as a Zung Self-Rating Depression Scale index score of ≥60 and anxiety was defined as a State-Trait Anxiety Inventory score of ≥40 (male) or ≥42 (female). The primary outcome was the composite of death from any cause or rehospitalization due to worsened HF and refractory arrhythmia., Results: Of the 221 HF patients, 29 (13%) had depression alone, 80 (36%) had anxiety alone, and 46 patients (21%) had both depression and anxiety. During an average follow-up of 41±21 months, patients with depression alone and those with clustered depression and anxiety were at an increased risk of the primary outcome [hazard ratio (HR) 2.24, 95% confidence interval (CI): 1.17-4.28, p=0.01 and HR 2.75, 95% CI: 1.51-4.99, p=0.01, respectively] compared to patients with no symptoms. Multivariate analysis after adjusting for age, gender, New York Heart Association functional class, B-type natriuretic peptide, device implantation, renal dysfunction, and left ventricular dysfunction showed clustered depression and anxiety, but not depression alone or anxiety alone, was an independent predictor of the primary outcome (HR 1.96, 95% CI: 1.00-3.27, p=0.04)., Conclusions: Our results showed that clustered depression and anxiety were associated with worse outcomes in patients with HF., (Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
42. Hepatocytes, rather than cholangiocytes, can be the major source of primitive ductules in the chronically injured mouse liver.
- Author
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Sekiya S and Suzuki A
- Subjects
- Albumins metabolism, Animals, Basic Helix-Loop-Helix Transcription Factors metabolism, Bile Ducts physiopathology, Cell Count, Cell Lineage, Chronic Disease, Disease Models, Animal, Hepatocyte Nuclear Factor 4 metabolism, Hepatocytes metabolism, Homeodomain Proteins metabolism, Liver physiopathology, Liver Failure, Acute pathology, Liver Failure, Acute physiopathology, Liver Regeneration, Mice, Inbred C57BL, Pyridines, Receptors, Notch metabolism, Signal Transduction, Transcription Factor HES-1, Bile Ducts pathology, Hepatocytes pathology, Liver injuries, Liver pathology
- Abstract
The proliferation of biliary lineage cells in chronic liver diseases, which leads to formation of primitive ductules in portal areas of the hepatic lobule, may be important not only for liver regeneration, but also for initiation of liver cancer. Thus, understanding how these primitive ductular cells emerge and proliferate in chronically injured liver holds promise for development of therapeutic strategies for liver diseases. However, the origin of these primitive ductular cells remains controversial. Here, we use a method for genetic lineage tracing to determine the origin of cells that form primitive ductules in a mouse model of chronic liver injury. Our results show that hepatocytes, rather than cholangiocytes, are the major source of cells for the primitive ductules formed in response to chronic liver damage. Moreover, activation of the Notch-Hes1 signaling axis is important for conversion of hepatocytes into primitive ductular cells in chronically injured liver. These findings should be valuable in elucidating the mechanism of liver regeneration associated with the fate-conversion of hepatocytes and in developing therapeutic strategies for liver diseases., (Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
43. Negative effects of ocean acidification on two crustose coralline species using genetically homogeneous samples.
- Author
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Kato A, Hikami M, Kumagai NH, Suzuki A, Nojiri Y, and Sakai K
- Subjects
- Animals, Calcification, Physiologic drug effects, Calcification, Physiologic physiology, Coral Reefs, Hydrogen-Ion Concentration, Microscopy, Electron, Scanning, Pacific Ocean, Rhodophyta growth & development, Rhodophyta ultrastructure, Carbon Dioxide pharmacology, Rhodophyta drug effects, Rhodophyta physiology, Seawater chemistry
- Abstract
We evaluated acidification effects on two crustose coralline algal species common to Pacific coral reefs, Lithophyllum kotschyanum and Hydrolithon samoense. We used genetically homogeneous samples of both species to eliminate misidentification of species. The growth rates and percent calcification of the walls of the epithallial cells (thallus surface cells) of both species decreased with increasing pCO₂. However, elevated pCO₂ more strongly inhibited the growth of L. kotschyanum versus H. samoense. The trend of decreasing percent calcification of the cell wall did not differ between these species, although intercellular calcification of the epithallial cells in L. kotschyanum was apparently reduced at elevated pCO₂, a result that might indicate that there are differences in the solubility or density of the calcite skeletons of these two species. These results can provide knowledge fundamental to future studies of the physiological and genetic mechanisms that underlie the response of crustose coralline algae to environmental stresses., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
44. Artificial induction and disease-related conversion of the hepatic fate.
- Author
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Suzuki A
- Subjects
- Cell Lineage, Cellular Reprogramming, Fibroblasts cytology, Fibroblasts metabolism, Hepatocytes metabolism, Humans, Liver metabolism, Liver Diseases genetics, Liver Diseases pathology, Pancreas cytology, Transcription Factors metabolism, Cell Differentiation, Hepatocytes cytology, Liver pathology, Liver Diseases therapy
- Abstract
Under normal physiological conditions, the fates of cells that compose various parts of organs are determined during development, and never change to those of other cell types. However, recent advances in induction of cellular reprogramming provide chances to generate a completely different cell type from an original cell source by artificially modulating the microenvironments or gene expressions pattern of cells. Although hepatocytes normally only reside in the liver, the hepatic program can be induced in skin-derived fibroblasts by expressing defined extrinsic transcription factors. These induced hepatocyte-like cells have hepatocyte-specific properties and functionally restore damaged hepatic tissues after transplantation. On the other hand, hepatocytes themselves can be converted into biliary lineage cells as a causative factor of hepatic diseases. Thus, blockade of such disease-related reprogramming of the hepatic fate will become a new therapeutic strategy for refractory diseases in the liver. Moreover, hepatocytes could partially accept the pancreatic program by expressing transcription factors required for pancreas development, suggesting that insulin-producing cells could be generated from hepatocytes and used to treat diabetes. The above-mentioned progress will stimulate studies on the molecular nature of cellular identity and plasticity in hepatocytes, and contribute to the development of potential therapies for liver diseases., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
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45. Lysophosphatidylcholine acyltransferase 1 altered phospholipid composition and regulated hepatoma progression.
- Author
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Morita Y, Sakaguchi T, Ikegami K, Goto-Inoue N, Hayasaka T, Hang VT, Tanaka H, Harada T, Shibasaki Y, Suzuki A, Fukumoto K, Inaba K, Murakami M, Setou M, and Konno H
- Subjects
- 1-Acylglycerophosphocholine O-Acyltransferase antagonists & inhibitors, 1-Acylglycerophosphocholine O-Acyltransferase genetics, Aged, Aged, 80 and over, Carcinoma, Hepatocellular genetics, Carcinoma, Hepatocellular pathology, Cell Line, Tumor, Cell Movement, Cell Proliferation, Disease Progression, Female, Gene Knockdown Techniques, Hep G2 Cells, Humans, Liver Neoplasms genetics, Liver Neoplasms pathology, Male, Middle Aged, Neoplasm Invasiveness, Phospholipids chemistry, RNA, Messenger genetics, RNA, Messenger metabolism, RNA, Neoplasm genetics, RNA, Neoplasm metabolism, Substrate Specificity, Up-Regulation, 1-Acylglycerophosphocholine O-Acyltransferase metabolism, Carcinoma, Hepatocellular metabolism, Liver Neoplasms metabolism, Phospholipids metabolism
- Abstract
Background & Aims: Several lipid synthesis pathways play important roles in the development and progression of hepatocellular carcinoma (HCC), although the precise molecular mechanisms remain to be elucidated. Here, we show the relationship between HCC progression and alteration of phospholipid composition regulated by lysophosphatidylcholine acyltransferase (LPCAT)., Methods: Molecular lipidomic screening was performed by imaging mass spectrometry (IMS) in 37 resected HCC specimens. RT-PCR and Western blotting were carried out to examine the mRNA and protein levels of LPCATs, which catalyze the conversion of lysophosphatidylcholine (LPC) into phosphatidylcholine (PC) and have substrate specificity for some kinds of fatty acids. We examined the effect of LPCAT1 overexpression or knockdown on cell proliferation, migration, and invasion in HCC cell lines., Results: IMS revealed the increase of PC species with palmitoleic acid or oleic acid at the sn-2-position and the reduction of LPC with palmitic acid at the sn-1-position in HCC tissues. mRNA and protein of LPCAT1, responsible for LPC to PC conversion, were more abundant in HCCs than in the surrounding parenchyma. In cell line experiments, LPCAT1 overexpression enriched PCs observed in IMS and promoted cell proliferation, migration, and invasion. LPCAT1 knockdown did viceversa., Conclusions: Enrichment or depletion of some specific PCs, was found in HCC by IMS. Alteration of phospholipid composition in HCC would affect tumor character. LPCAT1 modulates phospholipid composition to create favorable conditions to HCC cells. LPCAT1 is a potent target molecule to inhibit HCC progression., (Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
46. Impact of diastolic dysfunction on the outcome of catheter ablation in patients with atrial fibrillation.
- Author
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Ejima K, Shoda M, Arai K, Suzuki A, Yagishita D, Yagishita Y, Yashiro B, Sato T, Manaka T, Ashihara K, and Hagiwara N
- Subjects
- Diastole, Female, Humans, Male, Middle Aged, Prospective Studies, Treatment Outcome, Atrial Fibrillation physiopathology, Atrial Fibrillation surgery, Catheter Ablation
- Abstract
Objective: To evaluate the impact of diastolic dysfunction on the outcome of atrial fibrillation (AF) ablation., Methods: Eighty consecutive patients with drug-refractory symptomatic AF who underwent AF ablation were enrolled (65 males, 58 ± 10 years, 65 paroxysmal AF, 15 persistent AF). All patients underwent extensive pulmonary vein isolation with a double lasso technique using CARTO MERGE. Diastolic dysfunction was defined as a ratio of the mitral inflow early filling velocity to the velocity of the early medial mitral annular ascent of >10. The clinical and echocardiographic data were compared between the patients with and without diastolic dysfunction, and between the patients with and without AF recurrences after the AF ablation., Results: Twenty-nine out of all the patients (36.3%) had diastolic dysfunction. Compared with the patients without diastolic dysfunction, the patients with diastolic dysfunction had higher brain natriuretic peptide (p=0.001) and C-reactive protein (p=0.023) levels, and a larger left atrial diameter (P=0.019). The AF-free rate after a single or repeat AF ablation procedure in the patients with diastolic dysfunction was lower than that in those without diastolic dysfunction (p=0.005 and p=0.013 by the log-rank test, respectively). In the univariate analysis, the patients with persistent AF and diastolic dysfunction were likely to have AF recurrences after a single AF ablation. The multivariate analysis indicated diastolic dysfunction as the only independent predictor of an AF recurrence after a single AF ablation (P=0.023)., Conclusion: The patients with diastolic dysfunction had a worse outcome of the AF ablation not only for a single procedure but also a repeat procedure., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
47. Microscopic observation of symbiotic and aposymbiotic juvenile corals in nutrient-enriched seawater.
- Author
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Tanaka Y, Iguchi A, Inoue M, Mori C, Sakai K, Suzuki A, Kawahata H, and Nakamura T
- Subjects
- Animals, Chlorophyll analysis, Chlorophyll A, Microscopy, Nitrogen analysis, Phosphorus analysis, Seawater chemistry, Water Pollutants, Chemical analysis, Anthozoa physiology, Microalgae physiology, Symbiosis
- Abstract
Symbiotic and aposymbiotic juvenile corals, which were grown in the laboratory from the gametes of the scleractinian coral Acropora digitifera and had settled down onto plastic culture plates, were observed with a microscope under different nutrient conditions. The symbiotic corals successfully removed the surrounding benthic microalgae (BMA), whereas the aposymbiotic corals were in close physical contact with BMA. The areal growth rate of the symbiotic corals was significantly higher than that of the aposymbiotic corals. The addition of nutrients to the culture seawater increased the chlorophyll a content in the symbiotic coral polyps and enhanced the growth of some of the symbiotic corals, however the average growth rate was not significantly affected, most likely because of the competition with BMA. The comparison between the symbiotic and aposymbiotic juvenile corals showed that the establishment of a symbiotic association could be imperative for post-settlement juvenile corals to survive in high-nutrient seawater., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
48. BMP inhibition by DAN in Hensen's node is a critical step for the establishment of left-right asymmetry in the chick embryo.
- Author
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Katsu K, Tokumori D, Tatsumi N, Suzuki A, and Yokouchi Y
- Subjects
- Amisulpride, Animals, Avian Proteins metabolism, Benzamides pharmacology, Bone Morphogenetic Protein 4 metabolism, COS Cells, Chick Embryo embryology, Chlorocebus aethiops, Dioxoles pharmacology, Gene Expression Regulation, Developmental, Hedgehog Proteins genetics, Hedgehog Proteins metabolism, In Situ Hybridization, Intracellular Signaling Peptides and Proteins metabolism, Left-Right Determination Factors genetics, Left-Right Determination Factors metabolism, Mesoderm embryology, Mesoderm metabolism, Models, Genetic, Nodal Protein genetics, Nodal Protein metabolism, Notochord embryology, Notochord metabolism, Organizers, Embryonic embryology, Protein Binding, RNA Interference, Reverse Transcriptase Polymerase Chain Reaction, Signal Transduction drug effects, Signal Transduction genetics, Sulpiride analogs & derivatives, Xenopus, Avian Proteins genetics, Body Patterning genetics, Bone Morphogenetic Protein 4 genetics, Chick Embryo metabolism, Intracellular Signaling Peptides and Proteins genetics, Organizers, Embryonic metabolism
- Abstract
During left-right (L-R) axis formation, Nodal is expressed in the node and has a central role in the transfer of L-R information in the vertebrate embryo. Bone morphogenetic protein (BMP) signaling also has an important role for maintenance of gene expression around the node. Several members of the Cerberus/Dan family act on L-R patterning by regulating activity of the transforming growth factor-β (TGF-β) family. We demonstrate here that chicken Dan plays a critical role in L-R axis formation. Chicken Dan is expressed in the left side of the node shortly after left-handed Shh expression and before the appearance of asymmetrically expressed genes in the lateral plate mesoderm (LPM). In vitro experiments revealed that DAN inhibited BMP signaling but not NODAL signaling. SHH had a positive regulatory effect on Dan expression while BMP4 had a negative effect. Using overexpression and RNA interference-mediated knockdown strategies, we demonstrate that Dan is indispensable for Nodal expression in the LPM and for Lefty-1 expression in the notochord. In the perinodal region, expression of Dan and Nodal was independent of each other. Nodal up-regulation by DAN required NODAL signaling, suggesting that DAN might act synergistically with NODAL. Our data indicate that Dan plays an essential role in the establishment of the L-R axis by inhibiting BMP signaling around the node., (Copyright © 2012. Published by Elsevier Inc.)
- Published
- 2012
- Full Text
- View/download PDF
49. Effects of acidified seawater on coral calcification and symbiotic algae on the massive coral Porites australiensis.
- Author
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Iguchi A, Ozaki S, Nakamura T, Inoue M, Tanaka Y, Suzuki A, Kawahata H, and Sakai K
- Subjects
- Acids metabolism, Animals, Anthozoa metabolism, Anthozoa physiology, Calcification, Physiologic physiology, Chlorophyta physiology, Seawater chemistry, Symbiosis
- Abstract
We investigated the effect of acidified seawater on calcification and symbiotic algae (zooxanthellae density, chlorophyll content per single algal cell, fluorescence yield (Fv/Fm)) on a massive coral, Porites australiensis, a common species in the Ryukyu Archipelago of Japan. We found that acidified seawater significantly decreased the calcification and fluorescence yield, but did not affect zooxanthellae density and chlorophyll content per single algal cell. This indicates low levels of photoacclimation to acidified seawater in this species, and this is contrary to the findings of previous studies of Acropora species. A significant correlation between calcification and fluorescence yield was observed, indicating the presence of a strong relationship between calcification and algal photosynthesis. Our results indicate that endosymbiont photosynthetic dysfunction may enhance the decrease of coral calcification in future acidified ocean conditions. Calcification and fluorescence yield among colonies clearly differed, showing that the response to acidified seawater is highly variable among colonies in natural coral populations., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
50. The forkhead transcription factor FoxB1 regulates the dorsal-ventral and anterior-posterior patterning of the ectoderm during early Xenopus embryogenesis.
- Author
-
Takebayashi-Suzuki K, Kitayama A, Terasaka-Iioka C, Ueno N, and Suzuki A
- Subjects
- Animals, Base Sequence, Body Patterning genetics, Bone Morphogenetic Proteins metabolism, Ectoderm embryology, Ectoderm metabolism, Fibroblast Growth Factors physiology, Forkhead Transcription Factors deficiency, Forkhead Transcription Factors genetics, Gene Expression Regulation, Developmental, Gene Knockdown Techniques, HeLa Cells, Humans, Morpholinos genetics, Neurogenesis genetics, Neurogenesis physiology, Oligonucleotides, Antisense genetics, POU Domain Factors physiology, Recombinant Proteins genetics, Recombinant Proteins metabolism, Signal Transduction, Transfection, Up-Regulation, Wnt Proteins physiology, Wnt Signaling Pathway, Xenopus Proteins deficiency, Xenopus Proteins genetics, Xenopus laevis genetics, Body Patterning physiology, Forkhead Transcription Factors physiology, Xenopus Proteins physiology, Xenopus laevis embryology, Xenopus laevis physiology
- Abstract
The formation of the dorsal-ventral (DV) and anterior-posterior (AP) axes, fundamental to the body plan of animals, is regulated by several groups of polypeptide growth factors including the TGF-β, FGF, and Wnt families. In order to ensure the establishment of the body plan, the processes of DV and AP axis formation must be linked and coordinately regulated. However, the molecular mechanisms responsible for these interactions remain unclear. Here, we demonstrate that the forkhead box transcription factor FoxB1, which is upregulated by the neuralizing factor Oct-25, plays an important role in the formation of the DV and AP axes. Overexpression of FoxB1 promoted neural induction and inhibited BMP-dependent epidermal differentiation in ectodermal explants, thereby regulating the DV patterning of the ectoderm. In addition, FoxB1 was also found to promote the formation of posterior neural tissue in both ectodermal explants and whole embryos, suggesting its involvement in embryonic AP patterning. Using knockdown analysis, we found that FoxB1 is required for the formation of posterior neural tissues, acting in concert with the Wnt and FGF pathways. Consistent with this, FoxB1 suppressed the formation of anterior structures via a process requiring the function of XWnt-8 and eFGF. Interestingly, while downregulation of FoxB1 had little effect on neural induction, we found that it functionally interacted with its upstream factor Oct-25 and plays a supportive role in the induction and/or maintenance of neural tissue. Our results suggest that FoxB1 is part of a mechanism that fine-tunes, and leads to the coordinated formation of, the DV and AP axes during early development., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
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