226 results on '"Y, Kitaoka"'
Search Results
2. 11B-NMR study in boron-doped diamond films
- Author
-
H. Mukuda, T. Tsuchida, A. Harada, Y. Kitaoka, T. Takenouchi, Y. Takano, M. Nagao, I. Sakaguchi and H. Kawarada
- Subjects
Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Biotechnology ,TP248.13-248.65 - Abstract
We have investigated an origin of the superconductivity discovered in boron (B)-doped diamonds by means of 11B-NMR on heteroepitaxially grown (1 1 1) and (1 0 0) films and polycrystalline film. The characteristic difference of B-NMR spectral shape for the (1 1 1) and (1 0 0) thin films is demonstrated as arising from the difference in the concentration (nB(1)) of boron substituted for carbon. It is revealed from a scaling between a superconducting transition temperature Tc and nB(1) that the holes doped into diamond via the substitution of boron for carbon are responsible for the onset of superconductivity. The result suggests that the superconductivity in boron-doped diamond is mediated by the electron–phonon interaction brought about a high Debye temperature ~1860 K characteristic for the diamond structure.
- Published
- 2006
3. Axonal protection by Nmnat3 overexpression with involvement of autophagy in optic nerve degeneration.
- Author
-
Y. Kitaoka, Y. Munemasa, K. Kojima, A. Hirano, S. Ueno, and H. Takagi
- Published
- 2013
- Full Text
- View/download PDF
4. Ferromagnetic Correlations in Ca-Doped Sr2RuO4: 87Sr NMR Study.
- Author
-
K. Ishida, Y. Minami, Y. Kitaoka, S. Nakatsuji, and Y. Maeno
- Abstract
Abstract Magnetic properties on Sr2-xCaxRuO4 have been investigated by a microscopic probe of 87Sr-NMR in order to understand the magnetic character on spin-triplet superconductor of Sr2RuO4, which has multibands on the Fermi surface. With substituting Ca for Sr which gives rise to crystal distortion, the Knight shift (K) and the nuclear spin-lattice relaxation rate divided by temperature (1/T1T) increases progressively up to x=1.5. The Korringa relation from K and 1/T1T becomes smaller, indicative of development of ferromagnetic fluctuations with increasing Ca content. This suggests that the q-independent spin fluctuations originating from the 2-dimensional ? band are changed to the ferromagnetic ones by the Ca doping. [ABSTRACT FROM AUTHOR]
- Published
- 2003
5. Usefulness and limits of CA-125 in diagnosis of endometriosis without associated ovarian endometriomas.
- Author
-
J. Kitawaki, H. Ishihara, H. Koshiba, M. Kiyomizu, M. Teramoto, Y. Kitaoka, and H. Honjo
- Published
- 2007
- Full Text
- View/download PDF
6. Comparison of long- and short-rest periods during high-intensity interval exercise on transcriptomic responses in equine skeletal muscle.
- Author
-
Takahashi K, Mukai K, Takahashi Y, Ebisuda Y, Hatta H, and Kitaoka Y
- Subjects
- Animals, Horses genetics, Horses physiology, Gene Expression Profiling methods, Male, Gene Expression Regulation, Oxygen Consumption genetics, Oxygen Consumption physiology, Muscle, Skeletal metabolism, Muscle, Skeletal physiology, Physical Conditioning, Animal physiology, Transcriptome genetics, Rest physiology, High-Intensity Interval Training methods
- Abstract
The purpose of this study was to elucidate the skeletal muscle transcriptomic response unique to rest duration during high-intensity interval exercise. Thoroughbred horses performed three 1-min bouts of exercise at their maximal oxygen uptake (10.7-12.5 m/s), separated by 15 min (long) or 2 min (short) walking at 1.7 m/s. Gluteus medius muscle was collected before and at 4 h after the exercise and used for RNA sequencing. We identified 1,756 and 1,421 differentially expressed genes in response to the long and short protocols, respectively, using DEseq2 analysis [false discovery rate (FDR) cutoff = 0.05, minimal fold change = 1.5]. The overall transcriptional response was partially aligned, with 43% ( n = 949) of genes altered in both protocols, whereas no discordant directional changes were observed. K-means clustering and gene set enrichment analyses based on Gene Ontology biological process terms showed that genes associated with muscle adaptation and development were upregulated regardless of exercise conditions; genes related to immune and cytokine responses were more upregulated following the long protocol, and protein folding and temperature response were highly expressed after the short protocol. We found that 11 genes were upregulated to a greater extent by the short protocol and one was by the long protocol, with GNA13 , SPART , PHAF1 , and PTX3 identified as potential candidates for skeletal muscle remodeling. Our results suggest that altered metabolic fluctuations dependent on the intermittent pattern of interval exercise modulate skeletal muscle gene expression, and therefore, rest interval length could be an important consideration in optimizing skeletal muscle adaptation. NEW & NOTEWORTHY This is the first study to address the comparison of transcriptional responses to high-intensity interval exercise with two different rest periods in skeletal muscle. The expression of genes related to metabolic adaptations altered in both conditions, while genes associated with immune and cytokine responses and protein folding and temperature response were varied with the length of the rest period. These results provide evidence for rest duration-specific transcriptional response to high-intensity interval training.
- Published
- 2025
- Full Text
- View/download PDF
7. Preservation of masseter muscle until the end stage in the SOD1G93A mouse model for ALS.
- Author
-
Kawata S, Seki S, Nishiura A, Kitaoka Y, Iwamori K, Fukada SI, Kogo M, and Tanaka S
- Subjects
- Animals, Mice, Superoxide Dismutase-1 genetics, Superoxide Dismutase-1 metabolism, Mice, Transgenic, Satellite Cells, Skeletal Muscle pathology, Satellite Cells, Skeletal Muscle metabolism, Motor Neurons pathology, Motor Neurons metabolism, Male, Amyotrophic Lateral Sclerosis pathology, Amyotrophic Lateral Sclerosis genetics, Masseter Muscle pathology, Disease Models, Animal
- Abstract
Amyotrophic lateral sclerosis (ALS) progressively impairs motor neurons, leading to muscle weakness and loss of voluntary muscle control. This study compared the effects of SOD1 mutation on masticatory and limb muscles from disease onset to death in ALS model mice. Notably, limb muscles begin to atrophy soon after ALS-like phenotype appear, whereas masticatory muscles maintain their volume and function in later stages. Our analysis showed that, unlike limb muscles, masticatory muscles retain their normal structure and cell makeup throughout most of the disease course. We found an increase in the number of muscle satellite cells (SCs), which are essential for muscle repair, in masticatory muscles. In addition, we observed no reduction in the number of muscle nuclei and no muscle fibre-type switching in masticatory muscles. This indicates that masticatory muscles have a higher resistance to ALS-related damage than limb muscles, likely because of differences in cell composition and repair mechanisms. Understanding why masticatory muscles are less affected by ALS could lead to the development of new treatments. This study highlights the importance of studying different muscle groups in ALS to clarify disease aetiology and mechanisms., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
8. RETINAL MIGRATION AND SURGICAL OUTCOME AFTER HEMI-TEMPORAL INTERNAL LIMITING MEMBRANE PEELING VERSUS CONVENTIONAL PEELING FOR MACULAR HOLE: A Multicenter, Randomized, Controlled Trial.
- Author
-
Jujo T, Shiono A, Sato K, Sekine R, Uchiyama N, Kakehashi K, Endo A, Arakawa A, Shinkai Y, and Kitaoka Y
- Subjects
- Humans, Female, Male, Aged, Treatment Outcome, Middle Aged, Follow-Up Studies, Epiretinal Membrane surgery, Epiretinal Membrane physiopathology, Prospective Studies, Endotamponade methods, Sulfur Hexafluoride administration & dosage, Retinal Perforations surgery, Retinal Perforations diagnosis, Retinal Perforations physiopathology, Vitrectomy methods, Visual Acuity physiology, Basement Membrane surgery, Tomography, Optical Coherence methods
- Abstract
Purpose: To investigate the anatomical changes and surgical outcomes of hemi-temporal internal limiting membrane (ILM) peeling and conventional ILM peeling for idiopathic macular hole (MH)., Methods: This randomized controlled trial was conducted at 3 centers and included 50 participants with MHs of <400 µm in minimum diameter for a duration of <6 months. All participants had undergone vitrectomy with either hemi-temporal ILM peeling (Hemi group) or 360° ILM peeling (360° group) with an injection of 5% sulfur hexafluoride gas, with or without simultaneous cataract surgery, from July 2017 to January 2021. The rate of MH closure and distance of retinal migration were examined., Results: Of 50 eyes randomized in the 3 centers, the Hemi group comprised 23 eyes, the 360° group 23 eyes, and 4 eyes were eliminated from final analysis. There was a significantly higher rate of primary MH closure in the 360° group (Hemi group: 73.9% vs. 360° group: 100%, P = 0.009). Retinal migration to the optic disk on the nasal side was significantly shorter in the Hemi group at 1, 3, and 6 months postoperatively than in the 360° group. There was no significant difference between the two groups in retinal migration to the optic disk on the temporal side., Conclusion: Nasal retinal migration in patients who underwent the hemi-temporal ILM peeling method was significantly less than in those who underwent the 360° ILM peeling method. However, less nasal retinal migration did not contribute to the MH closure rate., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Opthalmic Communications Society, Inc.)
- Published
- 2024
- Full Text
- View/download PDF
9. Influence of foot strike pattern on co-contraction around the ankle and oxygen uptake during running at 19 km/h.
- Author
-
Kubo S, Yaeshima K, Suzuki T, Daigo E, Kitaoka Y, and Kinugasa R
- Subjects
- Humans, Male, Adult, Ankle physiology, Young Adult, Electromyography, Running physiology, Muscle, Skeletal physiology, Muscle, Skeletal metabolism, Oxygen Consumption physiology, Foot physiology, Muscle Contraction physiology
- Abstract
This study investigated the coactivation of plantar flexor and dorsiflexor muscles and oxygen uptake during running with forefoot and rearfoot strikes at 15 and 19 km/h. We included 16 male runners in this study. The participants ran each foot strike pattern for 5 min at 15 and 19 km/h on a treadmill. During the running, respiratory gas exchange data and surface electromyographic (EMG) activity of the medial gastrocnemius (MG), lateral gastrocnemius (LG), soleus, and tibialis anterior muscles of the right lower limb were continuously recorded. The indices of oxygen uptake, energy expenditure (EE), and muscle activation were calculated during the last 2 min in each condition. During the stance phase of running at 15 and 19 km/h, activation of the tibialis anterior and MG muscles was lower and higher, respectively, with forefoot strike than with rearfoot strike. The foot strike pattern did not influence the oxygen uptake. These results suggest that the foot strike pattern has no clear effect on the oxygen uptake when running at 15 and 19 km/h. However, forefoot strike leads to plantar flexion dominance during co-contraction of the tibialis anterior and MG muscles, which are an antagonist and agonist for plantar flexion, respectively, during the stance phase., (© 2024 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)
- Published
- 2024
- Full Text
- View/download PDF
10. Akt1 deficiency does not affect fiber type composition or mitochondrial protein expression in skeletal muscle of male mice.
- Author
-
Miyaji T, Kasuya R, Sawada A, Sawamura D, Kitaoka Y, and Miyazaki M
- Subjects
- Animals, Male, Mice, Muscle, Skeletal metabolism, Mitochondria, Muscle metabolism, Mitochondrial Proteins metabolism, Mitochondrial Proteins genetics, Mitochondrial Proteins deficiency, Mice, Inbred C57BL, Muscle Fibers, Skeletal metabolism, ATP Citrate (pro-S)-Lyase metabolism, ATP Citrate (pro-S)-Lyase genetics, ATP Citrate (pro-S)-Lyase deficiency, Proto-Oncogene Proteins c-akt metabolism, Proto-Oncogene Proteins c-akt genetics, Mice, Knockout
- Abstract
Insulin-like growth factor-1-induced activation of ATP citrate lyase (ACLY) improves muscle mitochondrial function through an Akt-dependent mechanism. In this study, we examined whether Akt1 deficiency alters skeletal muscle fiber type and mitochondrial function by regulating ACLY-dependent signaling in male Akt1 knockout (KO) mice (12-16 weeks old). Akt1 KO mice exhibited decreased body weight and muscle wet weight, with reduced cross-sectional areas of slow- and fast-type muscle fibers. Loss of Akt1 did not affect the phosphorylation status of ACLY in skeletal muscle. The skeletal muscle fiber type and expression of mitochondrial oxidative phosphorylation complex proteins were unchanged in Akt1 KO mice compared with the wild-type control. These observations indicate that Akt1 is important for the regulation of skeletal muscle fiber size, whereas the regulation of muscle fiber type and muscle mitochondrial content occurs independently of Akt1 activity., (© 2024 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)
- Published
- 2024
- Full Text
- View/download PDF
11. Effects of pacing strategy on metabolic responses to 2-min intense exercise in Thoroughbred horses.
- Author
-
Takahashi K, Mukai K, Ebisuda Y, Sugiyama F, Yoshida T, Hatta H, and Kitaoka Y
- Subjects
- Animals, Horses, Oxygen Consumption, Muscle, Skeletal metabolism, Male, Exercise Test, Glycolysis, Female, Citric Acid Cycle, Physical Conditioning, Animal physiology, Lactic Acid blood, Lactic Acid metabolism, Glycogen metabolism
- Abstract
Evidence suggests that positive pacing strategy improves exercise performance and fatigue tolerance in athletic events lasting 1-5 min. This study investigated muscle metabolic responses to positive and negative pacing strategies in Thoroughbred horses. Eight Thoroughbred horses performed 2 min treadmill running using positive (1 min at 110% maximal O
2 uptake [V̇O2 max], followed by 1 min at 90% V̇O2 max) and negative (1 min at 90% V̇O2 max, followed by 1 min at 110% V̇O2 max) pacing strategies. The arterial-mixed venous O2 difference did not significantly differ between the two strategies. Plasma lactate levels increased toward 2 min, with significantly higher concentrations during positive pacing than during negative pacing. Muscle glycogen level was significantly lower at 1 and 2 min of positive pacing than those of negative pacing. Metabolomic analysis showed that the sum of glycolytic intermediates increased during the first half of positive pacing and the second half of negative pacing. Regardless of pacing strategy, the sum of tricarboxylic acid cycle metabolites increased during the first half but remained unchanged thereafter. Our data suggest that positive pacing strategy is likely to activate glycolytic metabolism to a greater extent compared to negative pacing, even though the total workload is identical., (© 2024. The Author(s).)- Published
- 2024
- Full Text
- View/download PDF
12. Better maintenance of enzymatic capacity and higher levels of substrate transporter proteins in skeletal muscle of aging female mice.
- Author
-
Takahashi K, Kitaoka Y, and Hatta H
- Subjects
- Animals, Female, Male, Mice, Glycogen metabolism, Glucose Transporter Type 4 metabolism, Adenylate Kinase metabolism, L-Lactate Dehydrogenase metabolism, Sex Factors, Creatine Kinase metabolism, Hexokinase metabolism, Triglycerides metabolism, Phosphofructokinases metabolism, Glycolysis physiology, Muscle, Skeletal metabolism, Aging metabolism
- Abstract
This study investigated sex-specific differences in high-energy phosphate, glycolytic, and mitochondrial enzyme activities and also metabolite transporter protein levels in the skeletal muscles of adult (5 months old), middle-aged (12 months old), and advanced-aged (24 months old) mice. While gastrocnemius glycogen content increased with age regardless of sex, gastrocnemius triglyceride levels increased only in advanced-aged female mice. Aging decreased creatine kinase and adenylate kinase activities in the plantaris muscle of both sexes and in the soleus muscle of male mice but not in female mice. Irrespective of sex, phosphofructokinase and lactate dehydrogenase (LDH) activities decreased in the plantaris and soleus muscles. Additionally, hexokinase activity in the plantaris muscle and LDH activity in the soleus muscle decreased to a greater extent in aged male mice compared with those in aged female mice. Mitochondrial enzyme activities increased in the plantaris muscle of aged female mice but did not change in male mice. The protein content of the glucose transporter 4 in the aged plantaris muscle and fatty acid translocase/cluster of differentiation 36 increased in the aged plantaris and soleus muscles of both sexes, with a significantly higher content in female mice. These findings suggest that females possess a better ability to maintain metabolic enzyme activity and higher levels of metabolite transport proteins in skeletal muscle during aging, despite alterations in lipid metabolism. Our data provide a basis for studying muscle metabolism in the context of age-dependent metabolic perturbations and diseases that affect females and males differently., Competing Interests: The authors declare no competing interests.
- Published
- 2024
- Full Text
- View/download PDF
13. Differential patterns of sweat and blood lactate concentration response during incremental exercise in varied ambient temperatures: A pilot study.
- Author
-
Takei N, Inaba T, Morita Y, Kakinoki K, Hatta H, and Kitaoka Y
- Abstract
Blood lactate concentration during exercise is a reliable indicator of energy metabolism and endurance performance. Lactate is also present in sweat, and sweating plays an important role in thermoregulation, especially in hot conditions. Recently, wearable sensors have enabled the real-time and noninvasive measurement of sweat lactate concentration, potentially serving as an alternative indicator of blood lactate response. However, the evidence regarding the relationship between sweat and blood lactate responses during incremental exercise in hot conditions is lacking. In a randomized cross-over design, six highly trained male runners completed two incremental treadmill tests under normal (20°C/50%RH) or hot (30°C/50%RH) conditions. The tests include 3-min running stages and 1-min recovery, starting at 12 km/h and increasing by 1 km/h at each stage. Blood and sweat lactate concentrations were measured at each stage to determine blood and sweat lactate thresholds (LT). Blood lactate concentrations were higher under hot conditions ( p < 0.01), but there was no difference in the response pattern or velocity at blood LT between conditions. Significant early increase ( p < 0.01) in sweat lactate and low velocity at sweat LT ( p < 0.05) were observed under hot conditions. A significant correlation between blood and sweat lactate concentrations was found under normal conditions ( p < 0.001) but not under hot conditions, and no significant correlations were observed between the velocity at blood and sweat LT. In conclusion, sweat lactate concentration does not consistently reflect blood lactate concentration during incremental exercise., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)
- Published
- 2024
- Full Text
- View/download PDF
14. Effects of endurance training under calorie restriction on energy substrate metabolism in mouse skeletal muscle and liver.
- Author
-
Takahashi K, Kitaoka Y, and Hatta H
- Subjects
- Animals, Male, Mice, Mice, Inbred ICR, Endurance Training methods, Glucose Transporter Type 4 metabolism, Adaptation, Physiological physiology, Citrate (si)-Synthase metabolism, Muscle Proteins, Muscle, Skeletal metabolism, Caloric Restriction methods, Liver metabolism, Physical Conditioning, Animal physiology, Energy Metabolism physiology, Monocarboxylic Acid Transporters metabolism
- Abstract
We investigated whether calorie restriction (CR) enhances metabolic adaptations to endurance training (ET). Ten-week-old male Institute of Cancer Research (ICR) mice were fed ad libitum or subjected to 30% CR. The mice were subdivided into sedentary and ET groups. The ET group performed treadmill running (20-25 m/min, 30 min, 5 days/week) for 5 weeks. We found that CR decreased glycolytic enzyme activity and monocarboxylate transporter (MCT) 4 protein content, while enhancing glucose transporter 4 protein content in the plantaris and soleus muscles. Although ET and CR individually increased citrate synthase activity in the plantaris muscle, the ET-induced increase in respiratory chain complex I protein content was counteracted by CR. In the soleus muscle, mitochondrial enzyme activity and protein levels were increased by ET, but decreased by CR. It has been suggested that CR partially interferes with skeletal muscle adaptation to ET., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
15. Axonal protection by combination of ripasudil and brimonidine with upregulation of p-AMPK in TNF-induced optic nerve degeneration.
- Author
-
Otsubo M, Sase K, Tsukahara C, Fujita N, Arizono I, Tokuda N, and Kitaoka Y
- Subjects
- Humans, Brimonidine Tartrate, Up-Regulation, Axons, Nerve Degeneration, AMP-Activated Protein Kinases, Optic Atrophy, Isoquinolines, Sulfonamides
- Abstract
Purpose: The ROCK inhibitor ripasudil hydrochloride hydrate was shown to have axonal protective effects in TNF-induced optic nerve degeneration. The α2-adrenoreceptor agonist brimonidine was also shown to exert axonal protection. The current study aimed to elucidate whether additive axonal protection was achieved by the simultaneous injection of ripasudil and brimonidine and examine the association with AMPK activation., Methods: Intravitreal administration was performed in the following groups: PBS, TNF, or TNF with ripasudil, with brimonidine, or with a combination of ripasudil and brimonidine. Axon numbers were counted to evaluate the effects against axon loss. Immunoblot analysis was performed to examine phosphorylated AMPK expression in optic nerves, and immunohistochemical analysis was performed to evaluate the expression levels of p-AMPK and neurofilament in the optic nerve., Results: Both ripasudil alone or brimonidine alone resulted in significant neuroprotection against TNF-induced axon loss. The combination of ripasudil and brimonidine showed additive protective effects. Combined ripasudil and brimonidine plus TNF significantly upregulated p-AMPK levels in the optic nerve compared with the TNF groups. Immunohistochemical analysis revealed that p-AMPK is present in axons and enhanced by combination therapy., Conclusion: The combination of ripasudil and brimonidine may have additive protective effects compared with single-agent treatment alone. These protective effects may be at least partially associated with AMPK activation., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
16. Control of pleural effusion with prednisolone in a patient with yellow nail syndrome: A case report.
- Author
-
Taguchi M, Masuko H, Kawashima K, Yamagishi T, Kitaoka Y, Shigemasa R, Yoshida K, Tsurushige C, Satoh H, and Hizawa N
- Abstract
Yellow nail syndrome (YNS) can induce bilateral exudative pleural effusion; however, to the best of our knowledge, no standard treatment for YNS has been established. The present study describes a patient with YNS for whom the pleural effusion was controlled by prednisolone. A 73-year-old man was referred to the University of Tsukuba Hospital (Ibaraki, Japan) complaining of shortness of breath, which was diagnosed as being due to bilateral pleural effusion. Based on the presence of yellowing and growth retardation of the toenails, lymphedema, bilateral exudative pleural fluid of unknown etiology, and lymphatic congestion on lymphoscintigraphy, the patient was diagnosed with YNS. The pleural fluid was predominantly lymphocytic and responded to systemic steroid administration [prednisolone 30 mg/day (0.5 mg/kg) for 2 weeks, with subsequent weekly tapering]. The general condition of the patient and their dyspnea also improved with treatment. These findings indicated that systemic steroid administration should be considered as one of the treatment options for patients with YNS who are reluctant to undergo chest drainage or pleurodesis due to the potential for a decrease in their ability to perform daily activities and respiratory function., Competing Interests: The authors declare that they have no competing interests., (Copyright: © 2024 Taguchi et al.)
- Published
- 2024
- Full Text
- View/download PDF
17. Pth1r in Neural Crest Cells Regulates Nasal Cartilage Differentiation.
- Author
-
Amano K, Okuzaki D, Kitaoka Y, Kato S, Fujiwara M, Tanaka S, and Iida S
- Subjects
- Animals, Mice, Cell Differentiation, Chondrocytes metabolism, Hedgehog Proteins metabolism, Mice, Knockout, Skull, Nasal Cartilages metabolism, Neural Crest, Receptor, Parathyroid Hormone, Type 1 metabolism
- Abstract
Neural crest cells (NCC) arise from the dorsal margin of the neural plate border and comprise a unique cell population that migrates to and creates the craniofacial region. Although factors including Shh, Fgf8, and bone morphogenetic proteins have been shown to regulate these biological events, the role of parathyroid hormone 1 receptor (Pth1r) has been less studied. We generated an NCC-specific mouse model for Pth1r and researched gene expression, function, and interaction focusing on nasal cartilage framework and midfacial development. Wnt1-Cre;Pth1r
fl / fl ; Tomatofl /+ mice had perinatal lethality, but we observed short snout and jaws, tongue protrusion, reduced NCC-derived cranial length, increased mineralization in nasal septum and hyoid bones, and less bone mineralization at interfrontal suture in mutants at E18.5. Importantly, the mutant nasal septum and turbinate cartilage histologically revealed gradual, premature accelerated hypertrophic differentiation. We then studied the underlying molecular mechanisms by performing RNA seq analysis and unexpectedly found that expression of Ihh and related signaling molecules was enhanced in mutant nasomaxillary tissues. To see if Pth1r and Ihh signaling are associated, we generated a Wnt1-Cre; Ihhfl / fl ; Pth1rfl / fl ; Tomatofl /+ (DKO) mouse and compared the phenotypes to those of each single knockout mouse: Wnt1-Cre; Ihhfl / fl ; Pth1rfl /+ ; Tomatofl /+ (Ihh-CKO) and Wnt1-Cre;Ihhfl /+ ; Pth1rfl / fl ; Tomatofl /+ (Pth1r-CKO). Ihh-CKO mice displayed a milder effect. Of note, the excessive hypertrophic conversion of the nasal cartilage framework observed in Pth1r-CKO was somewhat rescued DKO embryos. Further, a half cAMP responsive element and the 4 similar sequences containing 2 mismatches were identified from the promoter to the first intron in Ihh gene. Gli1-CreERT2 ; Pth1rfl / fl ; Tomatofl /+ , a Pth1r-deficient model targeted in hedgehog responsive cells, demonstrated the enlarged hypertrophic layer and significantly more Tomato-positive chondrocytes accumulated in the nasal septum and ethmoidal endochondral ossification. Collectively, the data suggest a relevant Pth1r/Ihh interaction. Our findings obtained from novel mouse models for Pth1r signaling illuminate previously unknown aspects in craniofacial biology and development., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.- Published
- 2024
- Full Text
- View/download PDF
18. Metabolomic responses to high-intensity interval exercise in equine skeletal muscle: effects of rest interval duration.
- Author
-
Takahashi K, Mukai K, Takahashi Y, Ebisuda Y, Hatta H, and Kitaoka Y
- Subjects
- Humans, Animals, Horses, Exercise Therapy, Oxygen Consumption physiology, Rest, Muscle, Skeletal physiology, Physical Conditioning, Animal
- Abstract
High-intensity interval training has attracted considerable attention as a time-efficient strategy for inducing physiological adaptations, but the underlying mechanisms have yet to be elucidated. By using metabolomics techniques, we investigated changes in the metabolic network responses in Thoroughbred horses to high-intensity interval exercise performed with two distinct (15 min or 2 min) rest intervals. The peak plasma lactate level was higher during high-intensity exercise with a 2 min rest duration than that with a 15 min rest duration (24.5±6.8 versus 13.3±2.7 mmol l-1). The arterial oxygen saturation was lower at the end of all exercise sessions with a 2 min rest duration than that with a 15 min rest duration. Metabolomic analysis of skeletal muscle revealed marked changes in metabolite concentrations in the first and third bouts of the 15 min rest interval conditions. In contrast, there were no metabolite concentrations or pathways that significantly changed during the third bout of exercise performed with a 2 min rest interval. Our findings suggest that the activity of each energy production system is not necessarily reflected by apparent changes in metabolite concentrations, potentially due in part to a better match between metabolite flux into and out of the pathway and cycle, as well as between metabolite production and disposal. This study provides evidence that changes in metabolite concentrations vary greatly depending on the number of repetitions and the length of rest periods between exercises, even if the exercises themselves are identical., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)
- Published
- 2024
- Full Text
- View/download PDF
19. Molecular aspects of optic nerve autophagy in glaucoma.
- Author
-
Kitaoka Y and Sase K
- Subjects
- Animals, Humans, Disease Models, Animal, Axons metabolism, Autophagy genetics, Optic Nerve metabolism, Glaucoma genetics, Glaucoma metabolism
- Abstract
The optic nerve consists of the glia, vessels, and axons including myelin and axoplasm. Since axonal degeneration precedes retinal ganglion cell death in glaucoma, the preceding axonal degeneration model may be helpful for understanding the molecular mechanisms of optic nerve degeneration. Optic nerve samples from these models can provide information on several aspects of autophagy. Autophagosomes, the most typical organelles expressing autophagy, are found much more frequently inside axons than around the glia. Thus, immunoblot findings from the optic nerve can reflect the autophagy state in axons. Autophagic flux impairment may occur in degenerating optic nerve axons, as in other central nervous system neurodegenerative diseases. Several molecular candidates are involved in autophagy enhancement, leading to axonal protection. This concept is an attractive approach to the prevention of further retinal ganglion cell death. In this review, we describe the factors affecting autophagy, including nicotinamide riboside, p38, ULK, AMPK, ROCK, and SIRT1, in the optic nerve and propose potential methods of axonal protection via enhancement of autophagy., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
20. Characteristics of Sensory Neuron Dysfunction in Amyotrophic Lateral Sclerosis (ALS): Potential for ALS Therapy.
- Author
-
Seki S, Kitaoka Y, Kawata S, Nishiura A, Uchihashi T, Hiraoka SI, Yokota Y, Isomura ET, Kogo M, and Tanaka S
- Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterised by the progressive degeneration of motor neurons, resulting in muscle weakness, paralysis, and, ultimately, death. Presently, no effective treatment for ALS has been established. Although motor neuron dysfunction is a hallmark of ALS, emerging evidence suggests that sensory neurons are also involved in the disease. In clinical research, 30% of patients with ALS had sensory symptoms and abnormal sensory nerve conduction studies in the lower extremities. Peroneal nerve biopsies show histological abnormalities in 90% of the patients. Preclinical research has reported several genetic abnormalities in the sensory neurons of animal models of ALS, as well as in motor neurons. Furthermore, the aggregation of misfolded proteins like TAR DNA-binding protein 43 has been reported in sensory neurons. This review aims to provide a comprehensive description of ALS-related sensory neuron dysfunction, focusing on its clinical changes and underlying mechanisms. Sensory neuron abnormalities in ALS are not limited to somatosensory issues; proprioceptive sensory neurons, such as MesV and DRG neurons, have been reported to form networks with motor neurons and may be involved in motor control. Despite receiving limited attention, sensory neuron abnormalities in ALS hold potential for new therapies targeting proprioceptive sensory neurons.
- Published
- 2023
- Full Text
- View/download PDF
21. Pth1r Signal in Gli1+ Cells Maintains Postnatal Cranial Base Synchondrosis.
- Author
-
Amano K, Kitaoka Y, Kato S, Fujiwara M, Okuzaki D, Aikawa T, Kogo M, and Iida S
- Subjects
- Mice, Animals, Zinc Finger Protein GLI1, Cartilage, Chondrocytes, Osteogenesis genetics, Hedgehogs, Skull Base
- Abstract
Cranial base synchondroses are the endochondral ossification centers for cranial base growth and thus indispensable for proper skull, brain, and midfacial development. The synchondroses are composed of mirror-image growth plates that are continuously maintained from the embryonic to postnatal stage through chondrocyte differentiation. Several factors, including Pth1r signaling, are known to control fetal synchondrosis development. However, there are currently no reports regarding any role for Pth1r signaling in postnatal cranial base and synchondrosis development. Also, the mesenchymal cells that source Pth1r signaling for synchondroses are not known. Here, we employed an inducible mouse model, a hedgehog-responsive Gli1-Cre
ERT2 driver, focusing on the postnatal study. We performed 2 inducible protocols using Gli1-CreERT2 ;Tomatofl/+ mice that uncovered distinct patterning of Gli1-positive and Gli1-negative chondrocytes in the synchondrosis cartilage. Moreover, we generated Gli1-CreERT2 ;Pth1rfl/fl ;Tomatofl/+ mice to assess their functions in postnatal synchondrosis and found that the mutants had survived postnatally. The mutant skulls morphologically presented unambiguous phenotypes where we noticed the shortened cranial base and premature synchondrosis closure. Histologically, gradual disorganization in mutant synchondroses caused an uncommon remaining central zone between hypertrophic zones on both sides while the successive differentiation of round, flat, and hypertrophic chondrocytes was observed in control sections. These mutant synchondroses disappeared and were finally replaced by bone. Of note, the mutant fusing synchondroses lost their characteristic patterning of Gli1-positive and Gli1-negative chondrocytes, suggesting that loss of Pth1r signaling alters the distribution of hedgehog-responsive chondrocytes. Moreover, we performed laser microdissection and RNA sequencing to characterize the flat proliferative and round resting chondrocytes where we found flat chondrocytes have a characteristic feature of both chondrocyte proliferation and maturation. Taken together, these data demonstrate that Pth1r signaling in Gli1-positive cells is essential for postnatal development and maintenance in cranial base synchondroses. Our findings will elucidate previously unknown aspects of Pth1r functions in cranial biology and development., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.- Published
- 2023
- Full Text
- View/download PDF
22. Understanding impacts of COVID-19 restrictions on glycemic control for patients with diabetes in Japan.
- Author
-
Uno-Eder K, Satoh-Asahara N, Hibiya M, Uno K, Uchino T, Morita K, Ishikawa T, Kaneko T, Yamakage H, Kitaoka Y, Sawa T, Tsukamoto K, and Teramoto T
- Abstract
Objective: This study evaluated the changes in the status of glycemic control and lipid management in patients with diabetes under COVID-19 containment restrictions, in order to better understand the impacts of events causing lifestyle restrictions. Patient characteristics with worsened glycemic control were also assessed., Methods: We conducted a retrospective and observational cohort study using the electronic health records of 5,169 patients with diabetes seeking medical care in two healthcare centers. Laboratory test results including glycemic and lipid goal attainment rates were compared between pre-COVID-19 (January to December 2019) and the first wave of COVID-19 (February to June 2020). Multiple regression models were used to evaluate the association between glycated hemoglobin (HbA1c) at baseline and during the first wave with covariates such as concomitant medications and comorbidities., Results: The HbA1c goal achievement rate improved significantly from 39.0% to 43.1% ( p < 0.0001) overall, and more patients reached their glycemic target during COVID-19 restrictions. No significant changes were observed in lipid control. An indexed change in HbA1c level showed that glycemic control improved in 2,230 patients and worsened in 1,619 patients. Administration of insulin, GLP-1, and sulfonylureas were each identified as factors correlated with elevated HbA1c, during the first wave of COVID-19., Conclusion: Although the glycemic control in patients with diabetes improved overall under COVID-19 restrictions, those on insulin, GLP-1, or sulfonylureas worsened. These findings suggest the need to better understand what drives differences in glycemic control to better support people with diabetes for future epidemiological outbreaks., Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-023-01302-5., Competing Interests: The authors have no conflicts of interest to declare that are relevant to the content of this article.Conflict of interestNone of the authors have any potential conflicts of interest associated with this research., (© The Author(s), under exclusive licence to Tehran University of Medical Sciences 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)
- Published
- 2023
- Full Text
- View/download PDF
23. Inhibition of p38 ameliorates axonal loss with modulation of autophagy in TNF-induced optic nerve damage.
- Author
-
Sase K, Tsukahara C, Fujita N, Arizono I, Otsubo M, and Kitaoka Y
- Subjects
- Rats, Animals, Optic Nerve, Axons metabolism, Autophagy, Optic Nerve Injuries, Optic Nerve Diseases chemically induced
- Abstract
Purpose: A relationship between p38 and autophagy remains debated. The aim of the current study is to investigate whether an inhibitor of p38 prevents axon loss induced by TNF and whether it affects autophagy., Methods: Rats were given intravitreal injection of TNF, TNF plus SB203580, a p38 inhibitor, or SB203580 alone. Immunoblot analysis was performed to examine p62 expression which is a marker of autophagic flux and LC3-II expression which is an autophagy marker in optic nerves 1 week after intravitreal injection. Morphometric analysis of axons was performed to evaluate the effects of SB203580 against TNF-induced optic nerve damage 2 weeks after intravitreal injection. Immunohistochemical analysis was performed to evaluate the expressions of LC3, neurofilament, phosphorylated p38 and p62 in the optic nerve., Results: Quantification of axon number showed that TNF-induced axon loss was significantly protected by SB203580. Immunoblot analysis showed that the increase of p62 induced by TNF was totally eliminated by SB203580, and the SB203580 alone injection decreased the expression of p62. The level of LC3-II was significantly upregulated in the TNF plus SB203580 group compared with the TNF alone group, and the SB203580 alone injection increased the expression of LC3-II. Immunohistochemical analysis showed that LC3 immunoreactivity was found in the neurofilament positive fibers and that these immunoreactivities were enhanced by SB203580. Some colocalizations of p-p38 and p62 were observed in the TNF-treated optic nerve., Conclusion: These results suggest that inhibition of p38 exerts axonal protection with upregulated autophagy in TNF-induced optic nerve damage., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
24. Axonal Protection by Oral Nicotinamide Riboside Treatment with Upregulated AMPK Phosphorylation in a Rat Glaucomatous Degeneration Model.
- Author
-
Arizono I, Fujita N, Tsukahara C, Sase K, Sekine R, Jujo T, Otsubo M, Tokuda N, and Kitaoka Y
- Abstract
Nicotinamide riboside (NR), a precursor of nicotinamide adenine dinucleotide (NAD
+ ), has been studied to support human health against metabolic stress, cardiovascular disease, and neurodegenerative disease. In the present study, we investigated the effects of oral NR on axonal damage in a rat ocular hypertension model. Intraocular pressure (IOP) elevation was induced by laser irradiation and then the rats received oral NR of 1000 mg/kg/day daily. IOP elevation was seen 7, 14, and 21 days after laser irradiation compared with the controls. We confirmed that oral NR administration significantly increased NAD+ levels in the retina. After 3-week oral administration of NR, morphometric analysis of optic nerve cross-sections showed that the number of axons was protected compared with that in the untreated ocular hypertension group. Oral NR administration significantly prevented retinal ganglion cell (RGC) fiber loss in retinal flat mounts, as shown by neurofilament immunostaining. Immunoblotting samples from the optic nerves showed that oral NR administration augmented the phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK) level in rats with and without ocular hypertension induction. Immunohistochemical analysis showed that some p-AMPK-immunopositive fibers were colocalized with neurofilament immunoreactivity in the control group, and oral NR administration enhanced p-AMPK immunopositivity. Our findings suggest that oral NR administration protects against glaucomatous RGC axonal degeneration with the possible upregulation of p-AMPK.- Published
- 2023
- Full Text
- View/download PDF
25. Sex-specific differences in the metabolic enzyme activity and transporter levels in mouse skeletal muscle during postnatal development.
- Author
-
Takahashi K, Kitaoka Y, and Hatta H
- Subjects
- Male, Mice, Female, Animals, Electron Transport Complex IV metabolism, Glycolysis, Hexokinase metabolism, Muscle, Skeletal physiology, Energy Metabolism
- Abstract
Although sex-associated differences in energy metabolism in adults are well-characterized, developmental sex-specific changes in skeletal muscle metabolism are largely unknown. This study investigated sex differences in high-energy phosphate, glycolytic, and mitochondrial enzyme activities and metabolite transporter protein levels in mouse skeletal muscles during the early postnatal period (day 10), post-weaning (day 28), sexual maturity (day 56), and adult life (day 140). No significant sex-specific differences were observed on days 10 and 28, except for glucose transporter (GLUT) 4 level. The hexokinase, phosphofructokinase, and lactate dehydrogenase activities of skeletal muscle were higher and the citrate synthase, cytochrome c oxidase, and β-hydroxyacyl-CoA dehydrogenase activities were lower in female mice than those in male mice on days 56 and 140. The GLUT4 and FAT/CD36 protein levels were higher and the monocarboxylate transporter 4 level was lower in the skeletal muscles of female mice than those of male mice, particularly on days 56 and 140. At 140 days of age, the respiratory exchange ratio during treadmill running (15 m/min, 60 min) was lower in females than that in males, despite no sex differences at rest. In summary, sex differences were not evident in the early postnatal and post-weaning periods but became apparent after the mice reached sexual maturity. These findings indicate that sexually mature animals are a better model for investigating sex differences, particularly in the context of studying energy metabolism in mice.
- Published
- 2023
- Full Text
- View/download PDF
26. Analysis of Feeding Behavior Characteristics in the Cu/Zn Superoxide Dismutase 1 (SOD1) SOD1G93A Mice Model for Amyotrophic Lateral Sclerosis (ALS).
- Author
-
Kitaoka Y, Seki S, Kawata S, Nishiura A, Kawamura K, Hiraoka SI, Kogo M, and Tanaka S
- Subjects
- Mice, Animals, Superoxide Dismutase-1, Superoxide Dismutase, Artificial Intelligence, Mice, Transgenic, Motor Neurons physiology, Disease Models, Animal, Feeding Behavior, Zinc therapeutic use, Amyotrophic Lateral Sclerosis drug therapy
- Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive disease affecting upper and lower motor neurons. Feeding disorders are observed in patients with ALS. The mastication movements and their systemic effects in patients with ALS with feeding disorders remain unclear. Currently, there is no effective treatment for ALS. However, it has been suggested that treating feeding disorders and improving nutritional status may prolong the lives of patients with ALS. Therefore, this study elucidates feeding disorders observed in patients with ALS and future therapeutic agents. We conducted a temporal observation of feeding behavior and mastication movements using an open-closed mouth evaluation artificial intelligence (AI) model in an ALS mouse model. Furthermore, to determine the cause of masticatory rhythm modulation, we conducted electrophysiological analyses of mesencephalic trigeminal neurons (MesV). Here, we observed the modulation of masticatory rhythm with a prolonged open phase in the ALS mouse model from the age of 12 weeks. A decreased body weight was observed simultaneously, indicating a correlation between the prolongation of the open phase and the decrease observed. We found that the percentage of firing MesV was markedly decreased. This study partially clarifies the role of feeding disorders in ALS.
- Published
- 2023
- Full Text
- View/download PDF
27. Branched-chain amino acid supplementation suppresses the detraining-induced reduction of mitochondrial content in mouse skeletal muscle.
- Author
-
Matsunaga Y, Tamura Y, Takahashi K, Kitaoka Y, Takahashi Y, Hoshino D, Kadoguchi T, and Hatta H
- Subjects
- Male, Mice, Animals, Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha metabolism, Muscle, Skeletal metabolism, Dietary Supplements, Amino Acids, Branched-Chain metabolism, Mitochondria metabolism
- Abstract
Exercise training enhances oxidative capacity whereas detraining reduces mitochondrial content in skeletal muscle. The strategy to suppress the detraining-induced reduction of mitochondrial content has not been fully elucidated. As previous studies reported that branched-chain amino acid (BCAA) ingestion increased mitochondrial content in skeletal muscle, we evaluated whether BCAA supplementation could suppress the detraining-induced reduction of mitochondrial content. Six-week-old male Institute of Cancer Research (ICR) mice were randomly divided into four groups as follows: control (Con), endurance training (Tr), detraining (DeTr), and detraining with BCAA supplementation (DeTr + BCAA). Mice in Tr, DeTr, and DeTr + BCAA performed treadmill running exercises [20-30 m/min, 60 min, 5 times/week, 4 weeks]. Then, mice in DeTr and DeTr + BCAA were administered with water or BCAA [0.6 mg/g of body weight, twice daily] for 2 weeks of detraining. In whole skeletal muscle, mitochondrial enzyme activities and protein content were decreased after 2 weeks of detraining, but the reduction was suppressed by BCAA supplementation. Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) protein content, a master regulator of mitochondrial biogenesis, was decreased by detraining irrespective of BCAA ingestion. Regarding mitochondrial degradation, BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), a mitophagy-related protein, was significantly higher in the Tr group than in the DeTr + BCAA group, but not different from in the DeTr group. With respect to mitochondrial quality, BCAA ingestion did not affect oxygen consumption rate (OCR) and reactive oxygen species (ROS) production in isolated mitochondria. Our findings suggest that BCAA ingestion suppresses the detraining-induced reduction of mitochondrial content partly through inhibiting mitophagy., (© 2022 The Authors. The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)
- Published
- 2022
- Full Text
- View/download PDF
28. Regulation of protein and oxidative energy metabolism are down-regulated in the skeletal muscles of Asiatic black bears during hibernation.
- Author
-
Miyazaki M, Shimozuru M, Kitaoka Y, Takahashi K, and Tsubota T
- Subjects
- Animals, Muscular Atrophy metabolism, Muscle, Skeletal metabolism, Energy Metabolism, Muscle Proteins metabolism, Oxidative Stress, Hibernation physiology, Ursidae physiology
- Abstract
Hibernating animals exhibit an unexplained physiological characteristic of skeletal muscles being atrophy resistance, in which case muscle mass and strength remain almost unchanged both before and after hibernation. In this study, we examined the alterations in the regulatory systems of protein and energy metabolism in the skeletal muscles of Asiatic black bears during hibernation. Skeletal muscle samples (vastus lateralis muscle) were collected from identical individuals (n = 8) during the active (July) and hibernating (February) periods, while histochemical and biochemical analyses were performed. We observed no significant alterations in body weight, muscle fiber size, and fiber type composition during the active and hibernating periods, indicating that the skeletal muscles of bears are very well preserved during hibernation. In hibernating bear skeletal muscles, both regulatory pathways of muscle protein synthesis (Akt/mechanistic target of rapamycin and mitogen-activated protein kinase systems) and proteolysis (ubiquitin-proteasome and autophagy systems) were down-regulated. Gene expression levels of factors regulating oxidative metabolism were also decreased in hibernating bear skeletal muscles. This is likely an adaptive strategy to minimize the energy wasting of amino acids and lipids during hibernation, which is accompanied by a prolonged period of disuse and starvation., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
29. Inhibition of monocarboxylate transporters (MCT) 1 and 4 reduces exercise capacity in mice.
- Author
-
Kitaoka Y, Takahashi K, and Hatta H
- Subjects
- Animals, Body Weight, Exercise Tolerance, Glycogen metabolism, Lactic Acid metabolism, Mice, Muscle Proteins metabolism, Muscle, Skeletal metabolism, Monocarboxylic Acid Transporters metabolism, Symporters metabolism
- Abstract
The concept of lactate shuttle is widely accepted in exercise physiology. Lactate transport is mediated by monocarboxylate transporters (MCT), which enable cells to take up and release lactate. However, the role of lactate during exercise has not yet been fully elucidated. In this study, we investigated the effects of lactate transport inhibition on exercise capacity and metabolism in mice. Here, we demonstrated that MCT1 inhibition by α-cyano-4-hydroxycinnamate administration (4-CIN, 200 mg/g of body weight) reduced the treadmill running duration at 20 m/min. The administration of 4-CIN increased the blood lactate concentration immediately after exercise. With matched exercise duration, the muscle lactate concentration was higher while muscle glycogen content was lower in 4-CIN-administered mice. Further, we showed that MCT4 inhibition by bindarit administration (50 mg/kg of body weight) reduced the treadmill running duration at 40 m/min. Bindarit administration increased the muscle lactate but did not alter the blood lactate and glucose concentrations, as well as muscle glycogen content, immediately after exercise. A negative correlation was observed between exercise duration at 40 m/min and muscle lactate concentration immediately after exercise. Our results suggest that lactate transport via MCT1 and MCT4 plays a pivotal role in sustaining exercise., (© 2022 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)
- Published
- 2022
- Full Text
- View/download PDF
30. Effects of lactate administration on hypertrophy and mTOR signaling activation in mouse skeletal muscle.
- Author
-
Shirai T, Kitaoka Y, Uemichi K, Tokinoya K, Takeda K, and Takemasa T
- Subjects
- Animals, Hypertrophy metabolism, Male, Mice, Mice, Inbred ICR, Phosphorylation, TOR Serine-Threonine Kinases metabolism, Lactic Acid, Muscle, Skeletal metabolism
- Abstract
Lactate is a metabolic product of glycolysis and has recently been shown to act as a signaling molecule that induces adaptations in oxidative metabolism. In this study, we investigated whether lactate administration enhanced muscle hypertrophy and protein synthesis responses during resistance exercise in animal models. We used male ICR mice (7-8 weeks old) were used for chronic (mechanical overload induced by synergist ablation: [OL]) and acute (high-intensity muscle contraction by electrical stimulation: [ES]) resistance exercise models. The animals were intraperitoneally administrated a single dose of sodium lactate (1 g/kg of body weight) in the ES study, and once a day for 14 consecutive days in the OL study. Two weeks of mechanical overload increased plantaris muscle wet weight (main effect of OL: p < 0.05) and fiber cross-sectional area (main effect of OL: p < 0.05), but those were not affected by lactate administration. Following the acute resistance exercise by ES, protein synthesis and phosphorylation of p70 S6 kinase and ribosomal protein S6, which are downstream molecules in the anabolic signaling cascade, were increased (main effect of ES: p < 0.05), but lactate administration had no effect. This study demonstrated that exogenous lactate administration has little effect on the muscle hypertrophic response during resistance exercise using acute ES and chronic OL models. Our results do not support the hypothesis that elevated blood lactate concentration induces protein synthesis responses in skeletal muscle., (© 2022 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)
- Published
- 2022
- Full Text
- View/download PDF
31. Comparison of minimally invasive glaucoma surgery with trabecular micro-bypass stent and microhook ab interno trabeculotomy performed in conjunction with cataract surgery.
- Author
-
Tokuda N, Kitaoka Y, Tsukamoto A, Toyoda Y, Yamada Y, Sase K, and Takagi H
- Abstract
Aim: To evaluate the effectuality and safety of cataract surgery combined with either ab interno trabeculotomy by the microhook (µLOT) or a single iStent
® trabecular bypass implantation (iStent) in eyes with cataract and mild-to-moderate glaucoma., Methods: This study enrolled subjects with mild-to-moderate open angle glaucoma with visually significant cataract who used two or more ophthalmic antiglaucoma agents between 60 and 90y of age. Patients underwent cataract surgery cooperated with either implantation of an iStent (iStent-phaco) or excisional goniotomy with the µLOT (µLOT-phaco). Patients underwent µLOT-phaco in the eye with lower the mean deviation, according to the Humphrey field analyzer, while iStent-phaco was carried out on the other eye. Intraocular pressure (IOP) pre- and post-surgery, alterations in anterior chamber flare (ACF), and corneal endothelial cell density (ECD) were estimated., Results: Twenty subjects were enrolled (mean age: 73.6±7.3y). The mean medicated preoperative IOP was 16.7 mm Hg in the µLOT and 16.2 mm Hg in the iStent eyes. The mean final IOP at 12mo was 13.6 mm Hg in the µLOT eyes and 13.6 mm Hg in the iStent eyes, representing a 17.8% and 17.2% reduction, respectively. The preoperative ACF in the µLOT eyes was 9.5 pc/ms and it returned to normal in 30d postoperatively, with a value of 11.4 pc/ms. In the iStent eyes, ACF was 9.6 pc/ms preoperatively and it returned to normal by 7d postoperatively (11.2 pc/ms at day 7), demonstrating that postoperative inflammation was less in the iStent eyes. The corneal ECD in both groups was not significantly decreased., Conclusion: In this study, iStent and µLOT are both effective through 12mo of follow-up. Safety is more favorable in the iStent eyes, based on early anterior chamber inflammation., (International Journal of Ophthalmology Press.)- Published
- 2022
- Full Text
- View/download PDF
32. Effects of Lactate Administration on Mitochondrial Respiratory Function in Mouse Skeletal Muscle.
- Author
-
Takahashi K, Tamura Y, Kitaoka Y, Matsunaga Y, and Hatta H
- Abstract
Recent evidence has shown that mitochondrial respiratory function contributes to exercise performance and metabolic health. Given that lactate is considered a potential signaling molecule that induces mitochondrial adaptations, we tested the hypothesis that lactate would change mitochondrial respiratory function in skeletal muscle. Male ICR mice (8 weeks old) received intraperitoneal injection of PBS or sodium lactate (1 g/kg BW) 5 days a week for 4 weeks. Mitochondria were isolated from freshly excised gastrocnemius muscle using differential centrifugation and were used for all analyses. Lactate administration significantly enhanced pyruvate + malate- and glutamate + malate-induced (complex I-driven) state 3 (maximal/ATP synthesis-coupled) respiration, but not state 2 (basal/proton conductance) respiration. In contrast, lactate administration significantly decreased succinate + rotenone-induced (complex II-driven) state 3 and 2 respiration. No significant differences were observed in malate + octanoyl-l-carnitine-induced state 3 or 2 respiration. The enzymatic activity of complex I was tended to increase and those of complexes I + III and IV were significantly increased after lactate administration. No differences were observed in the activities of complexes II or II + III. Moreover, lactate administration increased the protein content of NDUFS4, a subunit of complex I, but not those of the other components. The present findings suggest that lactate alters mitochondrial respiratory function in skeletal muscle., 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 © 2022 Takahashi, Tamura, Kitaoka, Matsunaga and Hatta.)
- Published
- 2022
- Full Text
- View/download PDF
33. Effects of endurance training on metabolic enzyme activity and transporter protein levels in the skeletal muscles of orchiectomized mice.
- Author
-
Takahashi K, Kitaoka Y, and Hatta H
- Subjects
- Animals, Glycogen metabolism, Mice, Muscle, Skeletal metabolism, Physical Endurance physiology, Endurance Training, Physical Conditioning, Animal physiology, Running
- Abstract
This study investigated whether endurance training attenuates orchiectomy (ORX)-induced metabolic alterations. At 7 days of recovery after sham operation or ORX surgery, the mice were randomized to remain sedentary or undergo 5 weeks of treadmill running training (15-20 m/min, 60 min, 5 days/week). ORX decreased glycogen concentration in the gastrocnemius muscle, enhanced phosphofructokinase activity in the plantaris muscle, and decreased lactate dehydrogenase activity in the plantaris and soleus muscles. Mitochondrial enzyme activities and protein content in the plantaris and soleus muscles were also decreased after ORX, but preserved, in part, by endurance training. In the treadmill running test (15 m/min, 60 min) after 4 weeks of training, orchiectomized sedentary mice showed impaired exercise performance, which was restored by endurance training. Thus, endurance training could be a potential therapeutic strategy to prevent the hypoandrogenism-induced decline in muscle mitochondrial content and physical performance., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
34. Axonal Protection by Netarsudil, a ROCK Inhibitor, Is Linked to an AMPK-Autophagy Pathway in TNF-Induced Optic Nerve Degeneration.
- Author
-
Kitaoka Y, Sase K, Tsukahara C, Fujita N, Arizono I, Kogo J, Tokuda N, and Takagi H
- Subjects
- AMP-Activated Protein Kinases antagonists & inhibitors, Animals, Axons enzymology, Axons pathology, Biphenyl Compounds pharmacology, Enzyme Inhibitors pharmacology, Immunohistochemistry, Intravitreal Injections, Male, Microscopy, Electron, Microtubule-Associated Proteins metabolism, Nerve Degeneration enzymology, Optic Nerve ultrastructure, Protein Kinase Inhibitors pharmacology, Pyrazoles pharmacology, Pyrimidines pharmacology, Pyrones pharmacology, Rats, Rats, Wistar, Sequestosome-1 Protein metabolism, Thiophenes pharmacology, beta-Alanine pharmacology, AMP-Activated Protein Kinases metabolism, Autophagy physiology, Axons drug effects, Benzoates pharmacology, Nerve Degeneration prevention & control, Optic Nerve drug effects, Tumor Necrosis Factor-alpha toxicity, beta-Alanine analogs & derivatives, rho-Associated Kinases antagonists & inhibitors
- Abstract
Purpose: Netarsudil, a Rho kinase inhibitor with norepinephrine transport inhibitory effect, lowers intraocular pressure, however, its effect on axon damage remains to be elucidated. The aim of the current study was to investigate the effect of netarsudil on TNF-induced axon loss and to examine whether it affects phosphorylated-AMP-activated kinase (p-AMPK) and autophagy in the optic nerve., Methods: Intravitreal administration of TNF or TNF with netarsudil was carried out on rats and quantification of axon number was determined. Electron microscopy determined autophagosome numbers. Localization of p-AMPK expression was examined by immunohistochemistry. The changes in p62, LC3-II, and p-AMPK levels were estimated in the optic nerve by immunoblot analysis. The effect of an AMPK activator A769662 or an AMPK inhibitor dorsomorphin on axon number was evaluated., Results: Morphometric analysis revealed apparent protection by netarsudil against TNF-induced axon degeneration. Netarsudil increased autophagosome numbers inside axons. Netarsudil treatment significantly upregulated optic nerve LC3-II levels in both the TNF-treated eyes and the control eyes. Increased p62 protein level induced by TNF was significantly ameliorated by netarsudil. The netarsudil administration alone lessened p62 levels. Netarsudil significantly upregulated the optic nerve p-AMPK levels. A769662 exhibited obvious axonal protection against TNF-induced damage. A769662 treatment upregulated LC3-II levels and the increment of p62 level induced by TNF was significantly ameliorated by A769662. Immunohistochemical analysis revealed that p-AMPK is present in axons. Netarsudil-mediated axonal protection was significantly suppressed by dorsomorphin administration., Conclusions: Netarsudil upregulated p-AMPK and autophagy. Netarsudil-mediated axonal protection may be associated with upregulated p-AMPK.
- Published
- 2022
- Full Text
- View/download PDF
35. Distribution of Aspergillus section Nigri at shochu fermenting places in Japan.
- Author
-
Hashimoto K, Kawakami Y, Hashimoto R, Kitaoka Y, Onji Y, Oda H, Watanabe M, Takahashi H, and Yokoyama K
- Subjects
- Fermentation, Japan, Aspergillus genetics, Ochratoxins
- Abstract
Koji mold, which belongs to the Aspergillus section Nigri , is used in the production of shochu. The section Nigri is composed of very morphologically similar members that in some cases produce mycotoxins, which rises concerns as to whether the presence of mycotoxin-producing fungi in shochu producing sites can compromise consumer safety. Thus, we examined the presence of mycotoxin-producing sec. Nigri fungi in six shochu factories (named A-F) in Japan. Airborne fungal levels in the factories were determined, and a traditional koji called " kona-koji " made from the mold naturally present in factory C (Aogashima village) was analyzed. Isolates of sec. Nigri fungi were identified morphologically and confirmed via cytochrome b gene analysis. In factory A (Nago city), airborne fungal levels of sec. Nigri were 4,000 and 100 cfu/m
3 in the koji-making and fermentation rooms, respectively. In factories B, C, and D, the levels were 40, >104 cfu/m3 , and 100 cfu/m3 , respectively. In factory F (Iki city), there were high levels of airborne white-koji mold (a white mutant of Asp. luchuensis ). The most dominant fungal species of sec. Nigri was isolated and identified as Asp. luchuensis via genetic analysis. This is likely to have originated from the commercial fermentation culture used. Asp. niger and Asp. luchuensis were isolated from kona-koji . Mycotoxin production (ochratoxin and fumonisin B2) by Asp. luchuensis (eight strains) and Asp. niger (three strains) was virtually inexistent; only one strain of Asp. niger was positive for fumonisin B2 . This study clearly shows that mycotoxin-producing fungi are not dominant in the fungal flora present in the shochu factories examined and therefore, that the liquor can be safely fermented. Implications : In this study, we examined the presence of mycotoxin-producing Aspergillus sec. Nigri fungi in six shochu (Japanese distilled beverage) factories. The most dominant fungal species of sec. Nigri was isolated and identified as Aspergillus luchuensis (black-koji mold). The proportion of mycotoxin-producing Aspergillus niger and Aspergillus carbonarius was very small. In addition, the Asp. niger isolated from koji mold did not have the ability to produce ochratoxins or fumonisin B. This study clearly shows that shochu can be safely fermented.- Published
- 2022
- Full Text
- View/download PDF
36. Efficacy of Fovea-Sparing Internal Limiting Membrane Peeling for Epiretinal Membrane Foveoschisis.
- Author
-
Sekine R, Kogo J, Jujo T, Sato K, Arizono I, Kawagoe T, Tokuda N, Kitaoka Y, and Takagi H
- Subjects
- Aged, Basement Membrane surgery, Humans, Middle Aged, Retrospective Studies, Tomography, Optical Coherence methods, Visual Acuity, Vitrectomy methods, Epiretinal Membrane complications, Epiretinal Membrane diagnosis, Epiretinal Membrane surgery, Macular Edema surgery, Myopia, Degenerative surgery, Retinoschisis complications, Retinoschisis diagnosis, Retinoschisis surgery
- Abstract
Introduction: The aim of the study was to investigate the outcomes of vitrectomy with fovea-sparing internal limiting membrane (ILM) peeling (FSIP) for epiretinal membrane (ERM) foveoschisis based on new optical coherence tomography definitions., Methods: Twenty-three eyes of 22 patients (69.7 ± 9.9 years old) who underwent vitrectomy with FSIP without gas tamponade for ERM foveoschisis were analyzed. All patients underwent follow-up examinations for at least 12 months. In the FSIP technique, the ILM is peeled off in a donut shape, preserving the foveal ILM. The logarithm of the minimal angle of resolution best-corrected visual acuity (BCVA), central macular thickness (CMT), and surgical complications were examined., Results: The BCVA at 12 months improved significantly from baseline (p < 0.001). Baseline ellipsoid zone defects were found in 2 eyes (9%), and all defective eyes had recovered at 12 months. CMT decreased significantly from baseline (p < 0.001). Acute macular edema, full-thickness macular hole, and recurrence of ERM were not observed during follow-up., Discussion/conclusion: FSIP achieved good visual outcome and retinal morphological change. Moreover, FSIP might avoid acute macular edema in ERM foveoschisis surgery., (© 2021 The Author(s). Published by S. Karger AG, Basel.)
- Published
- 2022
- Full Text
- View/download PDF
37. Moderate-intensity training in hypoxia improves exercise performance and glycolytic capacity of skeletal muscle in horses.
- Author
-
Mukai K, Kitaoka Y, Takahashi Y, Takahashi T, Takahashi K, and Ohmura H
- Subjects
- Animals, Female, Male, Oxygen Consumption physiology, Exercise Tolerance physiology, Glycolysis physiology, Horses physiology, Hypoxia, Muscle, Skeletal physiology, Physical Conditioning, Animal physiology
- Abstract
We investigated whether moderate-intensity training of horses in moderate hypoxia for 4 weeks elicits greater adaptations in exercise performance, aerobic capacity, and glycolytic/oxidative metabolism in skeletal muscle compared to normoxic training. In a randomized crossover study design, seven untrained Thoroughbred horses (5.9 ± 1.1 years, 508 ± 9 kg) completed 4 weeks (3 sessions/week) of two training protocols consisting of 3-min cantering at 70% of maximal oxygen consumption ( V ˙ O 2 max ) in hypoxia (HYP; F
I O2 = 14.7%) and normoxia (NOR; FI O2 = 21.0%) with a 4-month washout period. Normoxic incremental exercise tests (IET) were conducted before and after training. Biopsy samples were obtained from the middle gluteal muscle before IET and monocarboxylate transporter (MCT) protein expression and glycolytic/mitochondrial enzyme activities were analyzed. Data were analyzed using mixed models (p < 0.05). Running speed was 7.9 ± 0.2 m/s in both groups and arterial oxygen saturation during training in NOR and HYP were 92.9 ± 0.9% and 75.7 ± 3.9%, respectively. Run time in HYP (+9.7%) and V ˙ O 2 max in both groups (NOR, +6.4%; HYP, +4.3%) at IET increased after 4 weeks of training. However, cardiac output, arterial-mixed venous O2 difference, and hemoglobin concentration at exhaustion were unchanged in both conditions. While MCT1 protein and citrate synthase activity did not increase in both conditions after training, MCT4 protein (+13%), and phosphofructokinase activity (+42%) increased only in HYP. In conclusion, 4 weeks of moderate-intensity hypoxic training improves exercise performance and glycolytic capacity of skeletal muscle in horses., (© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)- Published
- 2021
- Full Text
- View/download PDF
38. The Role of Nrf2 in Skeletal Muscle on Exercise Capacity.
- Author
-
Kitaoka Y
- Abstract
Nuclear factor erythroid 2-related factor 2 Nfe2l2 (Nrf2) is believed to play a crucial role in protecting cells against oxidative stress. In addition to its primary function of maintaining redox homeostasis, there is emerging evidence that Nrf2 is also involved in energy metabolism. In this review, we briefly discuss the role of Nrf2 in skeletal muscle metabolism from the perspective of exercise physiology. This article is part of a special issue "Mitochondrial Function, Reactive Oxygen/Nitrogen Species and Skeletal Muscle" edited by Håkan Westerblad and Takashi Yamada.
- Published
- 2021
- Full Text
- View/download PDF
39. Lactate administration does not affect denervation-induced loss of mitochondrial content and muscle mass in mice.
- Author
-
Takahashi K, Kitaoka Y, Matsunaga Y, and Hatta H
- Subjects
- Animals, Male, Mice, Mitochondria, Muscle, Skeletal metabolism, Sciatic Nerve metabolism, Lactic Acid metabolism, Muscle Denervation
- Abstract
Lactate is considered to be a signaling molecule that induces mitochondrial adaptation and muscle hypertrophy. The purpose of this study was to examine whether lactate administration attenuates denervation-induced loss of mitochondrial content and muscle mass. Eight-week-old male Institute of Cancer Research mice underwent unilateral sciatic nerve transection surgery. The contralateral hindlimb served as a sham-operated control. From the day of surgery, mice were injected intraperitoneally with PBS or sodium lactate (equivalent to 1 g·kg
-1 body weight) once daily for 9 days. After 10 days of denervation, gastrocnemius muscle weight decreased to a similar extent in both the PBS- and lactate-injected groups. Denervation significantly decreased mitochondrial enzyme activity, protein content, and MCT4 protein content in the gastrocnemius muscle. However, lactate administration did not have any significant effects. The current observations suggest that daily lactate administration for 9 days does not affect denervation-induced loss of mitochondrial content and muscle mass., (© 2021 The Authors. FEBS Open Bio published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)- Published
- 2021
- Full Text
- View/download PDF
40. Effect of lactate administration on mouse skeletal muscle under calorie restriction.
- Author
-
Shirai T, Uemichi K, Hidaka Y, Kitaoka Y, and Takemasa T
- Abstract
Calorie restriction (CR) involves a reductions of calorie intake without altering the nutritional balance, and has many beneficial effects, such as improving oxidative metabolism and extending lifespan. However, CR decreases in skeletal muscle mass and fat mass in correlation with the reduction in food intake. Lactate is known to have potential as a signaling molecule rather than a metabolite during exercise. In this study, we examined the effects of the combination of caloric restriction and lactate administration on skeletal muscle adaptation in order to elucidate a novel role of lactate. We first demonstrated that daily lactate administration (equivalent to 1 g/kg of body weight) for 2 weeks suppressed CR-induced muscle atrophy by activating mammalian/mechanistic target of rapamycin (mTOR) signaling, a muscle protein synthesis pathway, and inhibited autophagy-induced muscle degradation. Next, we found that lactate administration under calorie restriction enhanced mitochondrial enzyme activity (citrate synthase and succinate dehydrogenase) and the expression of oxidative phosphorylation (OXPHOS) protein expression. Our results suggest that lactate administration under caloric restriction not only suppresses muscle atrophy but also improves mitochondrial function., Competing Interests: 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., (© 2021 The Author(s).)
- Published
- 2021
- Full Text
- View/download PDF
41. Voluntary exercise prevents abnormal muscle mitochondrial morphology in cancer cachexia mice.
- Author
-
Kitaoka Y, Miyazaki M, and Kikuchi S
- Subjects
- Animals, Cachexia etiology, Citrate (si)-Synthase metabolism, Dynamins metabolism, Electron Transport Complex IV metabolism, GTP Phosphohydrolases metabolism, Male, Mice, Mitochondria, Muscle metabolism, Motor Activity, Muscle, Skeletal metabolism, Muscle, Skeletal ultrastructure, Oxidative Stress, Protein Carbonylation, Cachexia prevention & control, Mitochondria, Muscle ultrastructure, Neoplasms complications, Physical Conditioning, Animal methods
- Abstract
This study aimed to examine the effects of voluntary wheel running on cancer cachexia-induced mitochondrial alterations in mouse skeletal muscle. Mice bearing colon 26 adenocarcinoma (C26) were used as a model of cancer cachexia. C26 mice showed a lower gastrocnemius and plantaris muscle weight, but 4 weeks of voluntary exercise rescued these changes. Further, voluntary exercise attenuated observed declines in the levels of oxidative phosphorylation proteins and activities of citrate synthase and cytochrome c oxidase in the skeletal muscle of C26 mice. Among mitochondrial morphology regulatory proteins, mitofusin 2 (Mfn2) and dynamin-related protein 1 (Drp1) were decreased in the skeletal muscle of C26 mice, but exercise resulted in similar improvements as seen in markers of mitochondrial content. In isolated mitochondria, 4-hydroxynonenal and protein carbonyls were elevated in C26 mice, but exercise blunted the increases in these markers of oxidative stress. In addition, electron microscopy revealed that exercise alleviated the observed increase in the percentage of damaged mitochondria in C26 mice. These results suggest that voluntary exercise effectively counteracts mitochondrial dysfunction to mitigate muscle loss in cachexia., (© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)
- Published
- 2021
- Full Text
- View/download PDF
42. Comparisons between retinal vessel calibers and various optic disc morphologic parameters with different optic disc appearances: The Glaucoma Stereo Analysis Study.
- Author
-
Sugihara K, Takai Y, Kawasaki R, Nitta K, Katai M, Kitaoka Y, Yokoyama Y, Omodaka K, Naito T, Yamashita T, Mizoue S, Iwase A, Nakazawa T, and Tanito M
- Subjects
- Humans, Female, Male, Middle Aged, Aged, Intraocular Pressure, Visual Fields, Adult, Aged, 80 and over, Optic Disk pathology, Optic Disk diagnostic imaging, Retinal Vessels diagnostic imaging, Retinal Vessels pathology, Glaucoma pathology, Glaucoma diagnostic imaging
- Abstract
The Glaucoma Stereo Analysis Study (GSAS) is a multicenter collaborative study of the characteristics of glaucomatous optic disc morphology using a stereo fundus camera. This study evaluated the retinal vessel calibers and correlations using GSAS fundus photographs between retinal vessels and 38 optic nerve head (ONH) morphologic parameters comprehensively. In all 240 eyes, the mean central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) were 138.4 and 216.5 μm, respectively; the CRAE correlated with age, visual field scores and 19 ONH parameters and CRVE correlated with age, intraocular pressure, visual field scores and 11 ONH parameters. Among the different optic disc appearances including focal ischemia (FI) (n = 53, 22%), generalized enlargement (GE) (n = 53, 22%), myopic glaucoma (MY) (n = 112, 47%), and senile sclerosis (SS) (n = 22, 9%), the CRAE did not differ significantly; CRVE was significantly narrower in SS than in FI and MY. In FI, GE, MY, and SS disc types, CRAE correlated with 3, 14, 9, and 2 ONH parameters, respectively, and CRVE corelated with 9, 0, 12, and 6 ONH parameters, respectively. We confirmed previous observations on the effect of retinal vessel narrowing on glaucomatous changes in the ONH and visual field. The associations between retinal vessel caliber and ONH morphologic parameters vary among different optic disc appearances, suggesting different effects of vascular changes in each disc type., Competing Interests: Drs. Maki Katai, Yasushi Kitaoka, Yu Yokoyama, Kazuko Omodaka, Tomoko Naito, Takehiro Yamashita, Shiro Mizoue, and Toru Nakazawa used a stereo fundus camera provided by Kowa Company, Ltd., to conduct the study. Drs. Masaki Tanito, Koji Nitta, Yu Yokoyama, and Toru Nakazawa have received lecture honoraria and/or consultation fees from Kowa Company, Ltd. This does not alter our adherence to PLOS ONE policies on sharing data and materials. All other authors have no conflict to declare.
- Published
- 2021
- Full Text
- View/download PDF
43. Retraction Note to: Exercise-induced mitochondrial p53 repairs mtDNA mutations in mutator mice.
- Author
-
Safdar A, Khrapko K, Flynn JM, Saleem A, De Lisio M, Johnston APW, Kratysberg Y, Samjoo IA, Kitaoka Y, Ogborn DI, Little JP, Raha S, Parise G, Akhtar M, Hettinga BP, Rowe GC, Arany Z, Prolla TA, and Tarnopolsky MA
- Published
- 2021
- Full Text
- View/download PDF
44. Four weeks of high-intensity training in moderate, but not mild hypoxia improves performance and running economy more than normoxic training in horses.
- Author
-
Mukai K, Ohmura H, Takahashi Y, Kitaoka Y, and Takahashi T
- Subjects
- Animals, Biomarkers blood, Cross-Over Studies, Exercise Test veterinary, Exercise Tolerance, Female, Heart Rate, Horses blood, Lactic Acid blood, Male, Oxygen Consumption, Time Factors, Cardiorespiratory Fitness, Horses physiology, Hypoxia, Physical Conditioning, Animal, Physical Endurance, Running
- Abstract
We investigated whether horses trained in moderate and mild hypoxia demonstrate greater improvement in performance and aerobic capacity compared to horses trained in normoxia and whether the acquired training effects are maintained after 2 weeks of post-hypoxic training in normoxia. Seven untrained Thoroughbred horses completed 4 weeks (3 sessions/week) of three training protocols, consisting of 2-min cantering at 95% maximal oxygen consumption V ˙ O 2 max under two hypoxic conditions (H16, F
I O2 = 16%; H18, FI O2 = 18%) and in normoxia (N21, FI O2 = 21%), followed by 2 weeks of post-hypoxic training in normoxia, using a randomized crossover study design with a 3-month washout period. Incremental treadmill tests (IET) were conducted at week 0, 4, and 6. The effects of time and groups were analyzed using mixed models. Run time at IET increased in H16 and H18 compared to N21, while speed at V ˙ O 2 max was increased significantly only in H16. V ˙ O 2 max in all groups and cardiac output at exhaustion in H16 and H18 increased after 4 weeks of training, but were not significantly different between the three groups. In all groups, run time, V ˙ O 2 max , V V ˙ O 2 max , Q ˙ max , and lactate threshold did not decrease after 2 weeks of post-hypoxic training in normoxia. These results suggest that 4 weeks of training in moderate (H16), but not mild (H18) hypoxia elicits greater improvements in performance and running economy than normoxic training and that these effects are maintained for 2 weeks of post-hypoxic training in normoxia., (© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)- Published
- 2021
- Full Text
- View/download PDF
45. 27-gauge trocar-assisted sutureless intraocular lens fixation.
- Author
-
Jujo T, Kogo J, Sasaki H, Sekine R, Sato K, Ebisutani S, Toyoda Y, Kitaoka Y, and Takagi H
- Subjects
- Humans, Retrospective Studies, Sclera surgery, Surgical Instruments, Suture Techniques, Lens Implantation, Intraocular, Lenses, Intraocular
- Abstract
Backgrounds: However there have been numerous investigations of intrascleral intraocular lens (IOL) fixation techniques, there is room for improvement in terms of simplifying complicated techniques and reducing the high levels of skill required. This study aimed to report a novel technique for sutureless intrascleral fixation of the IOL using retinal forceps with a 27-gauge trocar., Methods: Nineteen eyes of 18 patients underwent intrascleral fixation of the IOL from July 2018 to September 2019 were enrolled in this study. A 27-gauge trocar formed 3-mm scleral tunnels positioned at 4 and 10 o'clock, 2 mm from the corneal limbus. We used a 3-piece IOL haptic grasped by a 27-gauge retinal forceps and pulled from the 27-gauge trocar. The IOL was fixed by making a flange. Main outcome measures were visual acuity, corneal endothelial cell density, IOL tilt, decentration, predicted error of refraction and complications., Results: The 19 eyes were followed up for 1 month. The mean pre- and postoperative logMAR uncorrected visual acuity (UCVA) was 1.06 ± 0.63 and 0.40 ± 0.26, respectively (p < 0.01), while the mean pre- and postoperative logMAR best corrected visual acuity (BCVA) was 0.27 ± 0.51 and 0.06 ± 0.15, respectively (p = 0.09). The mean corneal endothelial cell density was 2406 ± 625 to 2004 ± 759 cells/mm
2 at 1 month (p = 0.13). The mean IOL tilt was 3.52 ± 3.00°, and the mean IOL decentration was 0.39 ± 0.39 mm. There was no correlation among IOL tilt, decentration and BCVA (p > 0.05). The mean prediction error of the target refraction was - 0.03 ± 0.93 D. The complications were vitreous hemorrhage (3 eyes), hyphema (1 eye), IOP elevation (1 eye), iris capture of the IOL (1 eye) and hypotony (2 eyes). No IOL dislocation occurred., Conclusions: IOL intrascleral fixation with a flange achieved good IOL fixation and visual outcome in the scleral tunnels created with the 27-gauge trocar.- Published
- 2021
- Full Text
- View/download PDF
46. Pemafibrate prevents retinal neuronal cell death in NMDA-induced excitotoxicity via inhibition of p-c-Jun expression.
- Author
-
Fujita N, Sase K, Tsukahara C, Arizono I, Takagi H, and Kitaoka Y
- Subjects
- Animals, Cell Death drug effects, Diabetic Retinopathy genetics, Diabetic Retinopathy pathology, Disease Models, Animal, Male, N-Methylaspartate genetics, Neurons pathology, Phosphorylation drug effects, Rats, Retina drug effects, Retina pathology, Retinal Ganglion Cells drug effects, Benzoxazoles pharmacology, Butyrates pharmacology, Diabetic Retinopathy drug therapy, JNK Mitogen-Activated Protein Kinases genetics, Neurons drug effects, PPAR alpha genetics
- Abstract
Excitotoxicity is involved in the retinal neuronal cell death in diabetic retinopathy. Although fenofibrate has been shown to ameliorate the progression of diabetic retinopathy, the effect of pemafibrate, which is highly selective for peroxisome proliferator-activated receptor α on retinal neuronal cell death has not been documented. Here, we investigated whether pemafibrate exerts a beneficial effect against retinal ganglion cell (RGC) death induced by N-methyl-D-aspartate (NMDA) in rats. Experiments were performed on adult male Wistar rats that received an intravitreal injection of 20 nmol NMDA. Fluoro-Gold labeled RGC morphometry showed that oral intake of pemafibrate once a day for 7 days resulted in significant protection on RGC death induced by NMDA. Phosphorylated c-Jun protein, which is involved in apoptosis, was upregulated after NMDA exposure, and this increase was significantly lessened by the systemic pemafibrate treatment. Phosphorylated c-Jun immunopositive cells were colocalized with Thy-1 immunopositive cells, and the increased these cells were ameliorated by the pemafibrate treatment. An increase in TUNEL-positive cells was significantly suppressed by the pemafibrate treatment. Phosphorylated c-Jun immunopositive cells were colocalized with TUNEL-positive cells, and they were decreased by pemafibrate treatment. These results suggest that the RGC protection achieved with pemafibrate appears to be associated with inhibition of phosphorylated c-Jun and its anti-apoptotic effect.
- Published
- 2021
- Full Text
- View/download PDF
47. Axonal Protection by Nicotinamide Riboside via SIRT1-Autophagy Pathway in TNF-Induced Optic Nerve Degeneration.
- Author
-
Kitaoka Y, Sase K, Tsukahara C, Fujita N, Arizono I, and Takagi H
- Subjects
- Animals, Axons drug effects, Male, Microtubule-Associated Proteins metabolism, Niacinamide pharmacology, Optic Nerve drug effects, Phosphotransferases (Alcohol Group Acceptor), Rats, Wistar, Retina drug effects, Retina metabolism, Sequestosome-1 Protein metabolism, Sirtuin 1 antagonists & inhibitors, Tumor Necrosis Factor-alpha, Autophagy drug effects, Axons pathology, Nerve Degeneration pathology, Neuroprotection drug effects, Niacinamide analogs & derivatives, Optic Nerve pathology, Pyridinium Compounds pharmacology, Sirtuin 1 metabolism
- Abstract
Nicotinamide adenine dinucleotide (NAD
+ ) synthesis pathway has been involved in many biological functions. Nicotinamide riboside (NR) is widely used as an NAD+ precursor and known to increase NAD+ level in several tissues. The present study aimed to examine the effect of NR on tumor necrosis factor (TNF)-induced optic nerve degeneration and to investigate whether it alters SIRT1 expression and autophagic status in optic nerve. We also examined the localization of nicotinamide riboside kinase 1 (NRK1), which is a downstream enzyme for NR biosynthesis pathway in retina and optic nerve. Intravitreal injection of TNF or TNF plus NR was performed on rats. The p62 and LC3-II protein levels were examined to evaluate autophagic flux in optic nerve. Immunohistochemical analysis was performed to localize NRK1 expression. Morphometric analysis showed substantial axonal protection by NR against TNF-induced axon loss. TNF-induced increment of p62 protein level was significantly inhibited by NR administration. NR administration alone significantly increased the LC3-II levels and reduced p62 levels compared with the basal levels, and upregulated SIRT1 levels in optic nerve. Immunohistochemical analysis showed that NRK1 exists in retinal ganglion cells (RGCs) and nerve fibers in retina and optic nerve. NR administration apparently upregulated NRK1 levels in the TNF-treated eyes as well as the control eyes. Pre-injection of an SIRT1 inhibitor resulted in a significant increase of p62 levels in the NR plus TNF treatment group, implicating that SIRT1 regulates autophagy status. In conclusion, NRK1 exists in RGCs and optic nerve axons. NR exerted protection against axon loss induced by TNF with possible involvement of upregulated NRK1 and SIRT1-autophagy pathway.- Published
- 2020
- Full Text
- View/download PDF
48. Akebia Saponin D prevents axonal loss against TNF-induced optic nerve damage with autophagy modulation.
- Author
-
Sase K, Tsukahara C, Fujita N, Arizono I, Takagi H, and Kitaoka Y
- Subjects
- Animals, Autophagy drug effects, Axons drug effects, Axons pathology, Glaucoma pathology, Male, Optic Nerve pathology, Rats, Rats, Wistar, p38 Mitogen-Activated Protein Kinases metabolism, Glaucoma drug therapy, Nerve Degeneration drug therapy, Neuroprotective Agents administration & dosage, Neuroprotective Agents pharmacology, Optic Nerve drug effects, Saponins administration & dosage, Saponins pharmacology
- Abstract
Akebia Saponin D (ASD), a triterpenoid saponin, was shown to have protective effects in certain neuronal cells. The purpose of the present study was to investigate the possibility of ASD to prevent tumor necrosis factor (TNF)-induced axonal loss and the ASD modulation of the biologic process of autophagy in optic nerves. Rats were given intravitreal administration of TNF, simultaneous administration of 2, 20, or 200 pmol ASD and TNF, or ASD alone. LC3-II and p62 expression, which is a marker of autophagic flux, and phosphorylated p38 (p-p38) expression in optic nerves were examined by immunoblot analysis. Morphometric analysis revealed a significant ameliorated effect of ASD against TNF-induced optic nerve damage. p62 was significantly increased in the optic nerve in TNF-treated eyes, but this increase was totally prevented by ASD. The ASD alone injection showed significant reduction of p62 levels compared with the PBS-treated control eyes. LC3-II was significantly increased by ASD treatment in the TNF-injected eyes. p-p38 was significantly increased in the optic nerve in TNF-treated eyes, but this increase was completely prevented by ASD. The protective effects of ASD may be associated with enhanced autophagy activation and inhibition of p-p38.
- Published
- 2020
- Full Text
- View/download PDF
49. A Case of Pulmonary Metastasis of Breast Cancer 23 Years after Surgery Accompanied with Non-Tuberculous Mycobacterium Infection.
- Author
-
Yabuuchi Y, Nakagawa T, Shimanouchi M, Usui S, Hayashihara K, Oh-Ishi S, Saito T, Kanazawa J, Miura Y, Kubota S, Kawashima K, Shimada T, Oshima H, Hirano H, Nonaka M, Kitaoka Y, Arai N, Hyodo K, Nakazawa A, and Minami Y
- Abstract
Recurrence of oestrogen receptor (ER)-positive breast cancer rarely occurs postoperatively after a long period. Breast cancer cells survive and settle in distant organs in a dormant state, a phenomenon known as "tumour dormancy." Here, we present a 66-year-old woman with recurrence of ER-positive breast cancer in the left lung 23 years after surgery accompanied with non-tuberculous mycobacterium infection (NTM). At the age of 43 years, the patient underwent a right mastectomy and adjuvant hormonotherapy to completely cure breast cancer. Twenty-three years after the operation, when the patient was 66 years old, computed tomography presented nodular shadows in the lower lobes bilaterally with bronchiectasis and ill-defined satellite tree-in-bud nodules. Mycobacterium intracellulare was detected in cultured bronchoalveolar lavage fluid obtained from the left lower lobe by bronchoscopy. Rifampicin, ethambutol, and clarithromycin were started, which resulted in shrinkage of the nodule in the right lower lobe and satellite nodules; however, the nodule in the left lower lobe increased in size gradually. Wedge resection of the left lower lobe containing the nodule by video-assisted thoracoscopic surgery was performed, which demonstrated that the nodule was adenocarcinoma in intraoperative pathological diagnosis; therefore, a left lower lobectomy and mediastinal lymph node dissection were performed. The tumour was revealed to be consistent with recurrence of previous breast cancer according to its morphology and immunohistochemical staining. Furthermore, caseous epithelioid cell granulomas existed in the periphery of the tumour. It is reported that inflammatory cytokines induce reawakening of dormant oestrogen-dependent breast cancer and, in our case, NTM infection might have stimulated the dormant tumour cells in the lower lobe., Competing Interests: The authors state that they have no conflict of interest., (Copyright © 2020 by S. Karger AG, Basel.)
- Published
- 2020
- Full Text
- View/download PDF
50. Effect of post-exercise lactate administration on glycogen repletion and signaling activation in different types of mouse skeletal muscle.
- Author
-
Takahashi K, Kitaoka Y, Matsunaga Y, and Hatta H
- Abstract
Lactate is not merely a metabolic intermediate that serves as an oxidizable and glyconeogenic substrate, but it is also a potential signaling molecule. The objectives of this study were to investigate whether lactate administration enhances post-exercise glycogen repletion in association with cellular signaling activation in different types of skeletal muscle. Eight-week-old male ICR mice performed treadmill running (20 m/min for 60 min) following overnight fasting (16 h). Immediately after the exercise, animals received an intraperitoneal injection of phosphate-buffered saline or sodium lactate (equivalent to 1 g/kg body weight), followed by oral ingestion of water or glucose (2 g/kg body weight). At 60 min of recovery, glucose ingestion enhanced glycogen content in the soleus, plantaris, and gastrocnemius muscles. In addition, lactate injection additively increased glycogen content in the plantaris and gastrocnemius muscles, but not in the soleus muscle. Nevertheless, lactate administration did not significantly alter protein levels related to glucose uptake and oxidation in the plantaris muscle, but enhanced phosphorylation of TBC1D1, a distal protein regulating GLUT4 translocation, was observed in the soleus muscle. Muscle FBP2 protein content was significantly higher in the plantaris and gastrocnemius muscles than in the soleus muscle, whereas MCT1 protein content was significantly higher in the soleus muscle than in the plantaris and gastrocnemius muscles. The current findings suggest that an elevated blood lactate concentration and post-exercise glucose ingestion additively enhance glycogen recovery in glycolytic phenotype muscles. This appears to be associated with glyconeogenic protein content, but not with enhanced glucose uptake, attenuated glucose oxidation, or lactate transport protein., Competing Interests: 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., (© 2020 The Author(s).)
- Published
- 2020
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.