16 results on '"Uehara L"'
Search Results
2. The Impact of Stimulation Parameters on Cardiovascular Outcomes in Chronic Stroke Patients Following Transcranial Direct Current Stimulation-A Pilot Controlled, Randomized, Double-Blind Crossover Trial.
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Corrêa FI, Uehara L, de Andrade ML, da Silva GO, De Angelis K, Viana A, Bertani CNS, Corrêa JCF, and Fregni F
- Abstract
Background: Stroke survivors often experience autonomic nervous system (ANS) dysfunction. While Transcranial Direct Current Stimulation (tDCS) has been shown to modulate the ANS when applied to the left hemisphere, its effects on the right hemisphere remain unexplored., Objective: We aimed to compare the effects of tDCS applied to both the injured and the contralateral hemispheres on heart rate variability (HRV) and functional capacity in individuals post-stroke., Methods: Twenty individuals with cerebral hemisphere lesions (ten with right-hemisphere lesions and ten with left-hemisphere lesions) were randomized into four groups: anodal and sham tDCS on the left temporal cortex (T3) and anodal and sham tDCS on the right temporal cortex (T4). HRV was assessed before the intervention, after the six-minute walk test (6MWT), and following tDCS. HRV data were categorized into frequency ranges: low frequency (LF), high frequency (HF), and sympathovagal balance. The 6MWT (meters) was conducted both pre- and post-tDCS., Results: In individuals with right-hemisphere lesions, a higher global LF value was observed (right side: 71.4 ± 16.8 nu vs. left side: 65.7 ± 17.3 nu; p = 0.008), as well as lower values of the HF component (right side: 29.5 ± 18.9 nu vs. left side: 34.0 ± 17.4 nu; p = 0.047), consequently exhibiting higher global values of the low/high-frequency ratio (right side: 3.9 ± 2.8 vs. left side: 2.9 ± 2.4). Regarding the stimulation site, tDCS over T3 led to a lower overall value of the low/high-frequency ratio (left hemisphere: 3.0 ± 2.2 vs. right hemisphere: 3.7 ± 2.9; p = 0.040) regardless of the lesion location. A significant increase in the distance covered in the 6MWT was observed for individuals with lesions in both hemispheres after tDCS at T3., Conclusions: Participants with right-hemisphere lesions exhibited superior global sympathetic autonomic nervous system activity. When the tDCS was applied on the left hemisphere, it maintained lower sympathovagal balance values and improved functional capacity regardless of the hemisphere affected by the stroke.
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- 2024
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3. Does Transcranial Direct Current Stimulation reduce central and peripheral muscle fatigue in recreational runners? A triple-blind, sham-controlled, randomized, crossover clinical study.
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Uehara L, Coelho DB, Baptista AF, Santana L, Moreira RJD, Zana Y, Malosá L, Lima T, Valentim G, Cardenas-Rojas A, Fregni F, Corrêa JCF, and Corrêa FI
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- Humans, Evoked Potentials, Motor physiology, Torque, Lactic Acid blood, Muscle Fatigue physiology, Transcranial Direct Current Stimulation methods, Cross-Over Studies, Running physiology
- Abstract
Background: Runners seek health benefits and performance improvement. However, fatigue might be considered a limiting factor. Transcranial Direct Current Stimulation (tDCS) has been investigated to improve performance and reduce fatigue in athletes. While some studies showing that tDCS may improve a variety of physical measures, other studies failed to show any benefit., Objective: To evaluate the acute effects of tDCS on central and peripheral fatigue compared to a sham intervention in recreational runners., Methods: This is a triple-blind, controlled, crossover study of 30 recreational runners who were randomized to receive one of the two interventions, anodal or sham tDCS, after the fatigue protocol. The interventions were applied to the quadriceps muscle hotspot for 20 min. Peak torque, motor-evoked potential, and perceived exertion rate were assessed before and after the interventions, and blood lactate level was assessed before, during, and after the interventions. A generalized estimated equation was used to analyze the peak torque, motor-evoked potential, and blood lactate data, and the Wilcoxon test was used for perceived exertion rate data., Results: Our findings showed no difference between anodal tDCS and sham tDCS on peak torque, motor-evoked potential, blood lactate, and perceived exertion rate., Conclusion: The tDCS protocol was not effective in improving performance and reducing fatigue compared to a sham control intervention., Brazilian Clinical Trials Registry: RBR-8zpnxz., Competing Interests: Conflicts of interest The authors declare no conflicts of interest., (Copyright © 2024 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier España, S.L.U. All rights reserved.)
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- 2024
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4. Effect of transcranial direct current stimulation combined with pelvic muscle training in women: Randomized, controlled, double-blind, and clinical trial.
- Author
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Corrêa FI, Ledur ÂC, Uehara L, de Andrade ML, Corrêa JCF, and Fregni F
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- Female, Humans, Exercise Therapy, Muscle, Skeletal, Pelvic Floor, Quality of Life, Treatment Outcome, Double-Blind Method, Transcranial Direct Current Stimulation, Urinary Incontinence, Stress
- Abstract
Background: Pelvic floor muscle training (PFMT) is widely used for pelvic floor muscle (PFM) weakness in women; however, it has no prolonged effects., Objective: To evaluate the effect of Transcranial Direct Current Stimulation (tDCS) associated with PFMT on PFM contraction, sexual function and quality of life (QoL) in healthy women., Study Design: 32 nulliparous women, aged 22.7 ± 0.42 years, were randomized into two groups: G1 (active tDCS combined with PFMT) and G2 (sham tDCS combined with PFMT). The treatment was performed three times a week for 4 weeks, totaling 12 sessions. PFM function was assessed using the PERFECT scheme (P = power, E = endurance, R = repetitions, F = rapid contractions, ECT = each timed contraction) and the perineometer (cmH
2 O). Sexual function was assessed by The Female Sexual Function Index, and QoL by the SF-36 questionnaire. These assessments were performed before and after the 12nd treatment session and after 30-day follow-up., Results: There was a significant increase (p = 0.037) in the power of G2 compared to G1; repetitions and fast contraction increased in the G1 group, and the resistance increased in both groups, however, without statistical difference between the groups. ECT increased in the G1 group (p = 0.0)., Conclusion: Active tDCS combined with PFMT did not potentiate the effect of the PFMT to increase the PFM function, QoL, and sexual function in healthy women. However, adjunctive tDCS to PFMT improved the time of contractions, maintaining it during follow-up., (© 2024 Wiley Periodicals LLC.)- Published
- 2024
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5. In fission yeast, 65 non-essential mitochondrial proteins related to respiration and stress become essential in low-glucose conditions.
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Mori A, Uehara L, Toyoda Y, Masuda F, Soejima S, Saitoh S, and Yanagida M
- Abstract
Mitochondria perform critical functions, including respiration, ATP production, small molecule metabolism, and anti-oxidation, and they are involved in a number of human diseases. While the mitochondrial genome contains a small number of protein-coding genes, the vast majority of mitochondrial proteins are encoded by nuclear genes. In fission yeast Schizosaccharomyces pombe , we screened 457 deletion ( del ) mutants deficient in nuclear-encoded mitochondrial proteins, searching for those that fail to form colonies in culture medium containing low glucose (0.03-0.1%; low-glucose sensitive, lgs ), but that proliferate in regular 2-3% glucose medium. Sixty-five (14%) of the 457 deletion mutants displayed the lgs phenotype. Thirty-three of them are defective either in dehydrogenases, subunits of respiratory complexes, the citric acid cycle, or in one of the nine steps of the CoQ10 biosynthetic pathway. The remaining 32 lgs mutants do not seem to be directly related to respiration. Fifteen are implicated in translation, and six encode transporters. The remaining 11 function in anti-oxidation, amino acid synthesis, repair of DNA damage, microtubule cytoskeleton, intracellular mitochondrial distribution or unknown functions. These 32 diverse lgs genes collectively maintain mitochondrial functions under low (1/20-1/60× normal) glucose concentrations. Interestingly, 30 of them have homologues associated with human diseases., Competing Interests: We declare we have no competing interests., (© 2023 The Authors.)
- Published
- 2023
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6. Transcutaneous auricular vagus nerve stimulation effects on inflammatory markers and clinical evolution of patients with COVID-19: a pilot randomized clinical trial.
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Uehara L, Corrêa JCF, Ritti R, Leite P, de Faria DRG, Pacheco-Barrios K, Castelo-Branco L, Fregni F, and Corrêa FI
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- Humans, Pilot Projects, Hydrocortisone, Interleukin-6, Vagus Nerve, Vagus Nerve Stimulation, COVID-19 therapy, Transcutaneous Electric Nerve Stimulation
- Abstract
Objective: To evaluate the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on inflammatory markers and clinical outcomes in patients with COVID-19., Methods: A randomized blinded pilot study was carried out with 21 individuals hospitalized with COVID-19 who received 14 sessions of active (a-taVNS) or sham taVNS (s-taVNS). The level of interleukin-6 (IL-6), interleukin-10 (IL-10), cortisol, and C-reactive protein (CRP) in plasma and clinical evolution pre- and post-intervention were evaluated. The memory and attention levels were evaluated 14 days after the end of the treatment., Results: After treatment, significant intragroup differences were found in the CRP (p = 0.01), IL-6 (p = 0.01), and cortisol (p = 0.01) levels; however, in the comparison between the groups, only the CRP level was statistically lower for the a-taVNS (p = 0.04). The impression of improvement in memory and attention was greater in the a-taVNS than in the s-taVNS (p = 0.01, p = 0.04, respectively). There was no difference between the other clinical outcomes., Conclusions: taVNS is a viable and safe intervention in the acute care of patients with COVID-19, which can modulate their inflammatory profile and improve cognitive symptoms. However, improvements in overall clinical outcomes were not detected. Larger sample sizes and longer follow-ups are needed to confirm the anti-inflammatory and clinical effects of taVNS in patients with COVID-19., Trials Registry: The Brazilian Registry of Clinical Trials (RBR-399t4g5).
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- 2022
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7. Transcutaneous Auricular Vagus Nerve Stimulation Improves Inflammation but Does Not Interfere with Cardiac Modulation and Clinical Symptoms of Individuals with COVID-19: A Randomized Clinical Trial.
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Corrêa FI, Souza PHL, Uehara L, Ritti-Dias RM, Oliveira da Silva G, Segheto W, Pacheco-Barrios K, Fregni F, and Corrêa JCF
- Abstract
Transcranial auricular vagus nerve stimulation (taVNS) has shown effectiveness in reducing inflammation and depression. Thus, this study evaluated its effect on inflammation, cardiac autonomic modulation, and clinical symptoms in individuals affected by COVID-19. Methods: There were 52 randomized participants hospitalized with COVID-19 diagnosis who were to receive active (a-taVNS) or sham taVNS (s-taVNS) for 90 min twice a day for seven consecutive days. Interleukin 6 (IL-6), 10 (IL-10), cortisol, C-reactive protein (CRP), heart rate variability (HRV), and clinical symptoms were assessed before and after seven days of treatment. There were also seven- and fourteen-day follow-ups for clinical symptoms, including anxiety and depression levels, as well as a six-month follow-up for memory and attention levels. Results: There was significant reduction in CRP −23.9%, (95% CI −46.3 to −1.4) and IL-6 −37.7%, (95% CI −57.6 to −17.7) for the a-taVNS group. There were no changes in IL-10, cortisol levels, or in HRV results (p > 0.05) in both groups. There were no changes regarding clinical symptoms, except for a significant decrease in depression level (−2.85, 95% CI −5.44 to −0.27) in the a-taVNS group. Conclusion: taVNS showed effects on CRP, IL-6, and depression levels; however, it did not affect other clinical symptoms.
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- 2022
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8. Effects of Transcranial Direct Current Stimulation on Muscle Fatigue in Recreational Runners: Randomized, Sham-Controlled, Triple-Blind, Crossover Study-Protocol Study.
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Uehara L, Boari Coelho D, Leal-Junior ECP, Vicente de Paiva PR, Batista AF, Duarte Moreira RJ, Faria Coura MH, Hideki Okano A, Ferrari Corrêa JC, and Corrêa FI
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- Adult, Cross-Over Studies, Electromyography, Humans, Middle Aged, Muscle Fatigue physiology, Quadriceps Muscle physiology, Resistance Training methods, Running physiology, Transcranial Direct Current Stimulation methods
- Abstract
Objectives: The aim of this study is to evaluate the effects of transcranial direct current stimulation (tDCS) on central and peripheral fatigue in recreational runners., Design: This is a clinical randomized, sham-controlled, triple-blind, crossover study. Twenty adult runners will be randomized on the first day of the intervention to receive active or sham tDCS before fatigue protocol. After 1 wk, the participants will receive the opposite therapy to the one that they received on the first day. The tDCS, 2 mA, will be applied for 20 mins over the motor cortex. The fatigue protocol will be performed after tDCS, in which the participant should perform concentric knee flexion/extension contractions until reaching three contractions at only 50% of maximum voluntary contraction. Central fatigue will be evaluated with the motor evoked potential of the quadriceps muscle; peripheral fatigue with the peak torque (N.m) using an isokinetic dynamometer; the electrical activity of the quadriceps muscle using surface electromyography (Hz); blood lactate level (mmol/L); and the subjective perception of effort (Borg scale). All evaluations will be repeated before and after the interventions., Conclusion: This study will evaluate the effect of tDCS on fatigue in runners, possibly determining an application protocol for this population., Competing Interests: Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2022
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9. The Influence of Equipment and Environment on Children and Young Adults Learning Aquatic Skills.
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van Duijn T, Ng JL, Burnay C, Anderson N, Uehara L, Cocker K, and Button C
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Learning aquatic skills is an important component of developing physical literacy in children. Aquatic skills such as floating, swimming and safe entry/exit promote engagement in different water environments and may help preserve lives in an emergency. This scoping review was conducted to evaluate the influence of task constraints (i.e., equipment) and environmental constraints (i.e., physical and social) on how children learn foundational aquatic skills. In developed countries, children are typically taught in swimming pools under direct supervision. It is also not uncommon to see children and infants learning to swim with assistive equipment (e.g., buoyancy aids). However, perhaps surprisingly, the evidence on how and where children learn aquatic skills does not uniformly promote such practices. For example, the use of flotation devices has not been proven to aid skill learning. Some researchers have advocated that children should learn aquatic skills whilst wearing outdoor clothing. One benefit of children wearing clothing is an increased capacity to practice in colder water (such as the ocean, rivers, or lakes). Overall, whilst practitioners often use equipment for various reasons it seems that not all equipment is equally useful in promoting the acquisition of aquatic skills. In less developed countries, with limited access to swimming pools and fewer resources for private instruction, a range of different open water aquatic environments and practices, such as swimming in temporarily flooded areas, have been reported. Such strategies are in urgent demand of further research given that drowning rates in less developed countries around the world exceed those in developed nations. It can be argued that learning in pools does not afford the opportunities to develop the whole range of adaptive skills that may be required in different open water environments such as navigating currents and waves, floating whilst clothed, or making life-saving decisions. Consequently, a shift toward teaching in open water environments has occurred in several countries. This review provides an evidence-base upon which practitioners can design more effective aquatic education programs for children., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 van Duijn, Ng, Burnay, Anderson, Uehara, Cocker and Button.)
- Published
- 2021
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10. Multiple nutritional phenotypes of fission yeast mutants defective in genes encoding essential mitochondrial proteins.
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Uehara L, Saitoh S, Mori A, Sajiki K, Toyoda Y, Masuda F, Soejima S, Tahara Y, and Yanagida M
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- Energy Metabolism, Gene Expression Profiling, Gene Expression Regulation, Fungal, Genes, Essential, Humans, Stress, Physiological, Mitochondrial Proteins genetics, Mitochondrial Proteins metabolism, Mutation, Phenotype, Schizosaccharomyces physiology, Schizosaccharomyces pombe Proteins genetics, Schizosaccharomyces pombe Proteins metabolism
- Abstract
Mitochondria are essential for regulation of cellular respiration, energy production, small molecule metabolism, anti-oxidation and cell ageing, among other things. While the mitochondrial genome contains a small number of protein-coding genes, the great majority of mitochondrial proteins are encoded by chromosomal genes. In the fission yeast Schizosaccharomyces pombe , 770 proteins encoded by chromosomal genes are located in mitochondria. Of these, 195 proteins, many of which are implicated in translation and transport, are absolutely essential for viability. We isolated and characterized eight temperature-sensitive ( ts ) strains with mutations in essential mitochondrial proteins. Interestingly, they are also sensitive to limited nutrition (glucose and/or nitrogen), producing low-glucose-sensitive and 'super-housekeeping' phenotypes. They fail to produce colonies under low-glucose conditions at the permissive temperature or lose cell viability under nitrogen starvation at the restrictive temperature. The majority of these ts mitochondrial mutations may cause defects of gene expression in the mitochondrial genome. mrp4 and mrp17 are defective in mitochondrial ribosomal proteins. ppr3 is defective in rRNA expression, and trz2 and vrs2 are defective in tRNA maturation. This study promises potentially large dividends because mitochondrial quiescent functions are vital for human brain and muscle, and also for longevity.
- Published
- 2021
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11. The Poor "Wealth" of Brazilian Football: How Poverty May Shape Skill and Expertise of Players.
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Uehara L, Falcous M, Button C, Davids K, Araújo D, de Paula AR, and Saunders J
- Abstract
Worldwide, 1.3 billion people live in Poverty , a socio-economic status that has been identified as a key determinant of a lack of sports participation. Still, numerous athletes around the world have grown up in underprivileged socio-economic conditions. This is the case in Brazil, a country with around 13.5 million impoverished citizens, yet, over decades, many of its best professional footballers have emerged from its favelas. In this article, we explore the role of the socio-cultural-economic constraints in shaping the development of skill and expertise of Brazilian professional football players. The methodological and epistemological assumptions of the " Contextualized Skill Acquisition Research " (CSAR) approach are used as an underpinning framework for organizing and analyzing data. Results suggested that, at the exosystemic level of Brazilian society, Poverty emerges as an influential constraint that can potentially enrich football development experiences of Brazilian players. Poverty , however, is not the direct causation of outstanding football skill development. Rather, from the perspective of ecological dynamics, Poverty creates specific contexts that can lead to the emergence of physical as well as socio-cultural environment constraints (e.g., Pelada, Malandragem ) that can shape affordances (opportunities) for skill acquisition. These ideas suggest the need to ensure that environmental constraints can support people to amuse themselves cheaply, gain access to employment opportunities and maintain health and well-being through (unstructured and more structured) sport and physical activities in dense urban environments such as favelas, inner city areas, and banlieues. For this purpose, design of open play areas and even parkour installations can provide affordances landscapes for physical activity and sports participation in urban settings., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Uehara, Falcous, Button, Davids, Araújo, de Paula and Saunders.)
- Published
- 2021
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12. Genetic regulation of mitotic competence in G 0 quiescent cells.
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Sajiki K, Tahara Y, Uehara L, Sasaki T, Pluskal T, and Yanagida M
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- Cells, Cultured, Metabolome, Schizosaccharomyces growth & development, Schizosaccharomyces metabolism, Schizosaccharomyces pombe Proteins metabolism, Autophagy, Cell Nucleus genetics, Gene Expression Regulation, Fungal, Mitosis, Resting Phase, Cell Cycle physiology, Schizosaccharomyces genetics, Schizosaccharomyces pombe Proteins genetics
- Abstract
Quiescent (G
0 phase) cells must maintain mitotic competence (MC) to restart the cell cycle. This is essential for reproduction in unicellular organisms and also for development and cell replacement in higher organisms. Recently, suppression of MC has gained attention as a possible therapeutic strategy for cancer. Using a Schizosaccharomyces pombe deletion-mutant library, we identified 85 genes required to maintain MC during the G0 phase induced by nitrogen deprivation. G0 cells must recycle proteins and RNA, governed by anabolism, catabolism, transport, and availability of small molecules such as antioxidants. Protein phosphatases are also essential to maintain MC. In particular, Nem1-Spo7 protects the nucleus from autophagy by regulating Ned1, a lipin. These genes, designated GZE (G-Zero Essential) genes, reveal the landscape of genetic regulation of MC.- Published
- 2018
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13. Glucose restriction induces transient G2 cell cycle arrest extending cellular chronological lifespan.
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Masuda F, Ishii M, Mori A, Uehara L, Yanagida M, Takeda K, and Saitoh S
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- CDC2 Protein Kinase genetics, Cell Cycle Proteins biosynthesis, Culture Media chemistry, DNA Damage genetics, G2 Phase Cell Cycle Checkpoints genetics, Gene Expression Regulation, Fungal drug effects, Glucose pharmacology, Humans, Nuclear Proteins biosynthesis, Phosphorylation, Protein-Tyrosine Kinases biosynthesis, Schizosaccharomyces genetics, Schizosaccharomyces growth & development, Schizosaccharomyces pombe Proteins biosynthesis, Cell Cycle Proteins genetics, Cell Division genetics, G2 Phase Cell Cycle Checkpoints drug effects, Glucose metabolism, Nuclear Proteins genetics, Protein-Tyrosine Kinases genetics, Schizosaccharomyces pombe Proteins genetics
- Abstract
While glucose is the fundamental source of energy in most eukaryotes, it is not always abundantly available in natural environments, including within the human body. Eukaryotic cells are therefore thought to possess adaptive mechanisms to survive glucose-limited conditions, which remain unclear. Here, we report a novel mechanism regulating cell cycle progression in response to abrupt changes in extracellular glucose concentration. Upon reduction of glucose in the medium, wild-type fission yeast cells undergo transient arrest specifically at G2 phase. This cell cycle arrest is dependent on the Wee1 tyrosine kinase inhibiting the key cell cycle regulator, CDK1/Cdc2. Mutant cells lacking Wee1 are not arrested at G2 upon glucose limitation and lose viability faster than the wild-type cells under glucose-depleted quiescent conditions, suggesting that this cell cycle arrest is required for extension of chronological lifespan. Our findings indicate the presence of a novel cell cycle checkpoint monitoring glucose availability, which may be a good molecular target for cancer therapy.
- Published
- 2016
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14. Mechanisms of expression and translocation of major fission yeast glucose transporters regulated by CaMKK/phosphatases, nuclear shuttling, and TOR.
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Saitoh S, Mori A, Uehara L, Masuda F, Soejima S, and Yanagida M
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- Active Transport, Cell Nucleus drug effects, Calcium-Calmodulin-Dependent Protein Kinase Kinase genetics, Cell Cycle Proteins genetics, Cell Cycle Proteins metabolism, Cell Nucleus metabolism, Gene Expression Regulation, Fungal drug effects, Glucose metabolism, Glucose pharmacokinetics, Glucose pharmacology, Glucose Transport Proteins, Facilitative genetics, Green Fluorescent Proteins genetics, Green Fluorescent Proteins metabolism, HSP70 Heat-Shock Proteins genetics, HSP70 Heat-Shock Proteins metabolism, Humans, Immunoblotting, Mechanistic Target of Rapamycin Complex 2, Microscopy, Fluorescence, Monosaccharide Transport Proteins genetics, Monosaccharide Transport Proteins metabolism, Multiprotein Complexes genetics, Multiprotein Complexes metabolism, Mutation, Phosphoprotein Phosphatases genetics, Protein Isoforms genetics, Protein Isoforms metabolism, Schizosaccharomyces genetics, Schizosaccharomyces pombe Proteins genetics, TOR Serine-Threonine Kinases genetics, Time-Lapse Imaging methods, Calcium-Calmodulin-Dependent Protein Kinase Kinase metabolism, Glucose Transport Proteins, Facilitative metabolism, Phosphoprotein Phosphatases metabolism, Schizosaccharomyces metabolism, Schizosaccharomyces pombe Proteins metabolism, TOR Serine-Threonine Kinases metabolism
- Abstract
Hexose transporters are required for cellular glucose uptake; thus they play a pivotal role in glucose homeostasis in multicellular organisms. Using fission yeast, we explored hexose transporter regulation in response to extracellular glucose concentrations. The high-affinity transporter Ght5 is regulated with regard to transcription and localization, much like the human GLUT transporters, which are implicated in diabetes. When restricted to a glucose concentration equivalent to that of human blood, the fission yeast transcriptional regulator Scr1, which represses Ght5 transcription in the presence of high glucose, is displaced from the nucleus. Its displacement is dependent on Ca(2+)/calmodulin-dependent kinase kinase, Ssp1, and Sds23 inhibition of PP2A/PP6-like protein phosphatases. Newly synthesized Ght5 locates preferentially at the cell tips with the aid of the target of rapamycin (TOR) complex 2 signaling. These results clarify the evolutionarily conserved molecular mechanisms underlying glucose homeostasis, which are essential for preventing hyperglycemia in humans., (© 2015 Saitoh et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).)
- Published
- 2015
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15. Klf1, a C2H2 zinc finger-transcription factor, is required for cell wall maintenance during long-term quiescence in differentiated G0 phase.
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Shimanuki M, Uehara L, Pluskal T, Yoshida T, Kokubu A, Kawasaki Y, and Yanagida M
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- Cell Wall genetics, Chitin genetics, Chitin metabolism, Mutation, Schizosaccharomyces genetics, Schizosaccharomyces pombe Proteins genetics, Transcription Factors genetics, Zinc Fingers, Cell Wall metabolism, Resting Phase, Cell Cycle physiology, Schizosaccharomyces metabolism, Schizosaccharomyces pombe Proteins metabolism, Signal Transduction physiology, Transcription Factors metabolism
- Abstract
Fission yeast, Schizoaccharomyces pombe, is a model for studying cellular quiescence. Shifting to a medium that lacks a nitrogen-source induces proliferative cells to enter long-term G0 quiescence. Klf1 is a Krüppel-like transcription factor with a 7-amino acid Cys2His2-type zinc finger motif. The deletion mutant, ∆klf1, normally divides in vegetative medium, but proliferation is not restored after long-term G0 quiescence. Cell biologic, transcriptomic, and metabolomic analyses revealed a unique phenotype of the ∆klf1 mutant in quiescence. Mutant cells had diminished transcripts related to signaling molecules for switching to differentiation; however, proliferative metabolites for cell-wall assembly and antioxidants had significantly increased. Further, the size of ∆klf1 cells increased markedly during quiescence due to the aberrant accumulation of Calcofluor-positive, chitin-like materials beneath the cell wall. After 4 weeks of quiescence, reversible proliferation ability was lost, but metabolism was maintained. Klf1 thus plays a role in G0 phase longevity by enhancing the differentiation signal and suppressing metabolism for growth. If Klf1 is lost, S. pombe fails to maintain a constant cell size and normal cell morphology during quiescence.
- Published
- 2013
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16. Two-step, extensive alterations in the transcriptome from G0 arrest to cell division in Schizosaccharomyces pombe.
- Author
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Shimanuki M, Chung SY, Chikashige Y, Kawasaki Y, Uehara L, Tsutsumi C, Hatanaka M, Hiraoka Y, Nagao K, and Yanagida M
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- Base Sequence, Cell Cycle Proteins metabolism, Cell Division, Chromosomes, Fungal genetics, Cyclin B, DNA Primers genetics, Genes, Fungal, Multigene Family, Nitrogen metabolism, Oligonucleotide Array Sequence Analysis, Protein Biosynthesis, RNA, Fungal genetics, RNA, Fungal metabolism, Resting Phase, Cell Cycle, Ribosomes metabolism, Schizosaccharomyces metabolism, Schizosaccharomyces pombe Proteins metabolism, Transcription, Genetic, Schizosaccharomyces cytology, Schizosaccharomyces genetics
- Abstract
Body cells in multicellular organisms are in the G0 state, in which cells are arrested and terminally differentiated. To understand how the G0 state is maintained, the genes that are specifically expressed or repressed in G0 must be identified, as they control G0. In the fission yeast Schizosaccharomyces pombe, haploid cells are completely arrested under nitrogen source starvation with high viability. We examined the global transcriptome of G0 cells and cells on the course to resume vegetative growth. Approximately 20% of the transcripts of approximately 5000 genes increased or decreased more than fourfold in the two-step transitions that occur prior to replication. Of the top 30 abundant transcripts in G0, 23 were replaced by ribosome- and translation-related transcripts in the dividing vegetative state. Eight identified clusters with distinct alteration patterns of approximately 2700 transcripts were annotated by Gene Ontology. Disruption of 53 genes indicated that nine of them were necessary to support the proper G0 state. These nine genes included two C2H2 zinc finger transcription factors, a cyclin-like protein implicated in phosphorylation of RNA polymerase II, two putative autophagy regulators, a G-protein activating factor, and two CBS domain proteins, possibly involved in AMP-activated kinase.
- Published
- 2007
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