Research activity information

• Apr. 2020 Physiological Reports, TOP DOWNLOADED PAPER 2018-2019


• Sep. 2019 日本体力医学会, 第四回日本体力医学会国際学術交流奨励賞


• Sep. 2017 日本体力医学会, 第2回 国際学術交流奨励賞

  竹垣 淳也


• Sep. 2016 日本体力医学会, 第1回 国際学術交流奨励賞

  竹垣 淳也

• Effects of electromyostimulation on sarcolipin and Ca2+ signaling in rat skeletal muscles.

  Koki Okumura, Junya Takegaki, Kohei Sase, Naoki Fukao, Satoshi Fujita

  Calcium ion (Ca2+) acts as a second messenger involved in various adaptations by activating signaling pathways. The expression of Ca2+ regulators is modified by resistance training. Thus, Ca2+ signaling may be altered during a period of resistance training. In this study, male Sprague-Dawley rats underwent repeated resistance exercise via transcutaneous electromyostimulation, and the expression of Ca2+-related factors was examined 3 h after the 1st, 5th, and 10th exercise sessions. Expression of sarcolipin (SLN) and regulator of calcineurin 1 (RCAN1) was significantly higher in exercised legs than control legs after the 5th (p < 0.001) and 10th sessions (p < 0.001). Calcineurin expression showed significant main effects of exercise (p = 0.009) and session (p < 0.001). A significant main effect of session was also observed for Ca2+/calmodulin-dependent protein kinase II (CaMKII) (p < 0.001), CaMKII α (p < 0.046), CaMKII β (p = 0.002), and CaMKII γ (p < 0.001). In contrast, expression of sarcoplasmic reticulum Ca2+-ATPase (SERCA) did not change with repeated electromyostimulation. Pearson's correlation analysis showed a significant positive correlation between the expression of SLN and RCAN1 (r = 0.630, p = 0.005) and between SLN and CaMKII γ (r = 0.471, p = 0.048), as well as a trend for a positive correlation between SLN and CaMKII (r = 0.463, p = 0.053). These results suggest that repeated sessions of electromyostimulation increase SLN expression, which may in turn contribute to enhanced Ca2+ signaling after exercise.

  Jun. 2026, Biochemistry and biophysics reports, 46, 102588 - 102588, English, International magazine

  [Refereed]

  Scientific journal


• Pyruvate Dehydrogenase Kinase 4 Gene Expression Is Highly Responsive to Hypertonic Saline Administration in Chicks.

  Nnamdi Godswill Dialoke, Kaoruko Murata, Yumi Sakanashi, Junya Takegaki, Takaoki Saneyasu, Kazuhisa Honda

  Proteins and lipids are used as sources of endogenous water under dehydrated conditions in birds. However, it is unclear whether protein and fat are catabolized by dehydration in chickens. Elevated plasma osmolality is one of the responses to dehydration. The present study attempted to clarify the dose-dependent effects of hypertonic saline on plasma components and protein and lipid metabolism-related gene expression in the breast muscle and adipose tissue of chicks. The intraperitoneal administration of 1.2 M NaCl (5 mL/kg body weight) to 21-day-old chicks significantly increased the plasma concentration of nonesterified fatty acids, pyruvate dehydrogenase kinase 4 (PDK4) mRNA levels in breast muscle and adipose tissue, and atrogin-1 mRNA levels in breast muscle after 60 min. In the case of 0.6 M NaCl, a significant effect was only observed in PDK4 mRNA levels in both tissues. PDK4 functions as the metabolic switch from glucose to fatty acid utilization. Thus, hypertonic saline-induced changes in gene expression profiles suggest a potential shift toward lipid utilization in the peripheral tissues of chicks.

  2026, Animal science journal = Nihon chikusan Gakkaiho, 97(1) (1), e70196, English, International magazine

  [Refereed]

  Scientific journal


• Peripheral Administration of Hypertonic Saline Affects Nutrient Metabolism-related Gene Expression in Chicks

  Kaoruko Murata, Nnamdi Godswill Dialoke, Yuhui Zhang, Junya Takegaki, Takaoki Saneyasu, Kazuhisa Honda

  Japan Poultry Science Association, 2026, The Journal of Poultry Science, 63, n/a - n/a, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Effect of Centrally Administered Neuropeptide Y and α-Melanocyte-stimulating Hormone on Water Intake in Chicks

  Nnamdi Godswill Dialoke, Kaoruko Murata, Yuhui Zhang, Yuji Taniguchi, Sei-ichi Hinomoto, Junya Takegaki, Takaoki Saneyasu, Kazuhisa Honda

  Japan Poultry Science Association, 2026, The Journal of Poultry Science, 63, n/a - n/a, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Role of Medullary AKT and p38 MAPK in Regulating Feeding of Broiler Chicks

  Takaoki Saneyasu, Miyu Kaihatsu, Kanami Nagata, Aika Kitayama, Haruka Sakai, Hiroshi Kamisoyama, Junya Takegaki, Kazuhisa Honda

  Japan Poultry Science Association, 2026, The Journal of Poultry Science, 63, n/a - n/a, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Treatment with L-type amino acid transporter 1 inhibitor JPH203 enhances protein synthesis in C2C12 myotubes

  Junya Takegaki, Takaoki Saneyasu, Kazuhisa Honda

  Abstract Excessive muscle protein synthesis causes skeletal muscle hypertrophy. Essential amino acids are substrates for muscle proteins and stimulate muscle protein synthesis. Several essential amino acids are taken up into muscle cells through L-type amino acid transporter 1 (LAT1). However, LAT1 may influence protein synthesis in an amino acid uptake-independent manner. Here, we investigated the effects of LAT1 inhibition on protein synthesis in C2C12 myotubes and the associated mechanisms. JPH203 (50 μM), a selective inhibitor of LAT1, stimulated protein synthesis without changing expression of phosphorylated p70S6K (T389) and 4EBP1 (T37/46), an indicator of mTORC1 activity. Culturing in amino acid-free media did not suppress JPH203-induced protein synthesis. The mTORC1 inhibitor rapamycin (100 nM) did not suppress JPH203-induced protein synthesis. ATP-competitive mTOR inhibitor AZD8055 (1 μM) suppressed JPH203-induced protein synthesis. JPH203 treatment increased intracellular glutamine concentration. These results suggest that inhibition of LAT1 function augments muscle protein synthesis, possibly through the activation of rapamycin-insensitive mTOR signaling; elevated intracellular glutamine levels may contribute to the enhancement of muscle protein synthesis induced by LAT1 inhibition.

  Springer Science and Business Media LLC, Nov. 2025, Scientific Reports, 15(1) (1), English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Effect of collagen peptides rich in hydroxyprolyl-glycine on anabolic signals in mouse skeletal muscle

  Junya Takegaki, Takumi Yokokawa, Risako Mori, Daiki Nakano, Aya Matsushita, Seiko Koizumi, Satoshi Fujita

  Lead, Elsevier BV, Nov. 2025, Journal of Functional Foods, 134, 107063 - 107063, English

  [Refereed]

  Scientific journal


• Osmotic Stress-induced Gene Expression in the Diencephalon, Kidney, Liver, and Breast Muscle of Chicks

  Yuhui Zhang, Kaoruko Murata, Junya Takegaki, Takaoki Saneyasu, Kazuhisa Honda

  Japan Poultry Science Association, 2025, The Journal of Poultry Science, 62, n/a - n/a, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Effects of Central Administration of Opioid Peptides, Vasotocin, Mesotocin, and Corticotrophin-Releasing Factor on Water Intake in Chicks

  Yuhui Zhang, Kaoruko Murata, Junya Takegaki, Takaoki Saneyasu, Kazuhisa Honda

  Japan Poultry Science Association, 2025, The Journal of Poultry Science, 62, n/a - n/a, English

  [Refereed]

  Scientific journal


• Exogenous Beta-guanidinopropionic acid administration enhances electromyostimulation-induced mitochondrial biogenesis in rat skeletal muscle

  Naoki Fukao, Junya Takegaki, Ryo Takagi, Koki Okumura, Satoshi Fujita

  Abstract Objectives Exercise training induces several skeletal muscle adaptations. Beta-guanidinopropionic acid (β-GPA) is a creatine analog that simulates the effect of exercise to induce mitochondrial biogenesis. However, the effects of β-GPA on resistance training adaptation, such as muscle hypertrophy and mitochondrial biogenesis, are unclear. Therefore, using a resistance exercise model in rats, the present study was designed to investigate the effects of β-GPA administration on resistance training adaptations. Methods This study was approved by the Ethics Committee for Animal Experiments at Ritsumeikan University (approval number: BKC2022-009). Male Sprague Dawley rats were randomly divided into placebo or β-GPA groups. β-GPA (1000 mg/kg) was orally administered once daily, starting seven days before the initiation of electromyostimulation as a model for resistance exercise, and continued throughout the training period. Electromyostimulation was applied to the right gastrocnemius muscle via electrical stimulation every other day for a total of 12 sessions Results Peroxisome proliferators-activated receptor-γ co-activator-1α, a regulator of mitochondrial biogenesis, was significantly increased by the combination of training and β-GPA compared to the training leg (p<0.05). Protein expression of Total OXPHOS, a marker of mitochondrial content, was significantly increased by the combination of training and β-GPA compared to the training leg (p<0.05). β-GPA intake reduced muscle mass (main effect of β-GPA, p<0.05) and was associated with muscle protein breakdown-related Fbx32 and LC3-II protein expression levels but did not counteract the increase in muscle mass caused by resistance training. Conclusions Administration of exogenous β-GPA enhanced resistance training-induced mitochondrial biogenesis. Moreover, β-GPA still permitted resistance electromyostimulation-induced muscle mass gains, but that effect was attenuated as compared to placebo.

  Walter de Gruyter GmbH, Sep. 2024, Translational Exercise Biomedicine, 1(3-4) (3-4), 295 - 304, English

  [Refereed]

  Scientific journal


• Effect of Oral Skim Milk Administration on Skeletal Muscle Protein Synthesis after Total Gastrectomy in Rat.

  Atsushi Sawada, Ryo Takagi, Junya Takegaki, Naoki Fukao, Koki Okumura, Satoshi Fujita

  Leucine is a branched-chain amino acid that is present in protein, and it is an essential factor in activating the mechanistic target of the rapamycin complex 1 signaling pathway and increasing muscle protein synthesis. However, the loss of digestive function after total gastrectomy leads to impaired protein absorption, potentially failing to stimulate muscle protein synthesis. Therefore, this study aimed to investigate whether muscle protein synthesis is enhanced by oral skim milk administration after total gastrectomy. Male Sprague Dawley rats were divided into total gastrectomy (TG) and sham surgery (S) groups. After five weeks postoperatively, we orally administered skim milk to achieve 3.1 g protein/kg body weight and collected blood and gastrocnemius muscle. The gastrocnemius muscle weight was significantly lower in the TG group than in the S group (p < 0.05). The increase in plasma leucine concentration was significantly lower in the TG group than in the S group (p < 0.05). The skeletal muscle protein synthesis and the phosphorylation of p70S6K and 4E-BP1 showed a similar increase in both groups. Even after TG, muscle protein synthesis was stimulated by consuming skim milk, accompanied by a sufficient rise in plasma leucine concentration.

  Jul. 2024, Nutrients, 16(15) (15), English, International magazine

  [Refereed]

  Scientific journal


• Intramuscular injection of mesenchymal stem cells augments basal muscle protein synthesis after bouts of resistance exercise in male mice

  Junya Takegaki, Kohei Sase, Yusuke Kono, Takuya Fujita, Satoshi Konishi, Satoshi Fujita

  Abstract Skeletal muscle mass is critical for activities of daily living. Resistance training maintains or increases muscle mass, and various strategies maximize the training adaptation. Mesenchymal stem cells (MSCs) are multipotent cells with differential potency in skeletal muscle cells and the capacity to secrete growth factors. However, little is known regarding the effect of intramuscular injection of MSCs on basal muscle protein synthesis and catabolic systems after resistance training. Here, we measured changes in basal muscle protein synthesis, the ubiquitin‐proteasome system, and autophagy‐lysosome system‐related factors after bouts of resistance exercise by intramuscular injection of MSCs. Mice performed three bouts of resistance exercise (each consisting of 50 maximal isometric contractions elicited by electrical stimulation) on the right gastrocnemius muscle every 48 h, and immediately after the first bout, mice were intramuscularly injected with either MSCs (2.0 × 10⁶ cells) labeled with green fluorescence protein (GFP) or vehicle only placebo. Seventy‐two hours after the third exercise bout, GFP was detected only in the muscle injected with MSCs with concomitant elevation of muscle protein synthesis. The injection of MSCs also increased protein ubiquitination. These results suggest that the intramuscular injection of MSCs augmented muscle protein turnover at the basal state after consecutive resistance exercise.

  Lead, Wiley, Apr. 2024, Physiological Reports, 12(7) (7), English

  [Refereed]

  Scientific journal


• Cooling-promoted myogenic differentiation of murine bone marrow mesenchymal stem cells through TRPM8 activation in vitro.

  Ryo Takagi, Junya Takegaki, Shion Osana, Yutaka Kano, Satoshi Konishi, Satoshi Fujita

  TRPM8 agonist has been reported to promote osteogenic differentiation of mesenchymal stem cells (MSCs), therefore we evaluated whether cooling-induced activation of TRPM8 promotes myogenic differentiation of MSCs. We used 5-azacytidine as a myogenic differentiation inducer in murine bone marrow-derived MSCs. Addition of menthol, a TRPM8 agonist, to the differentiation induction medium significantly, increased the percentage of MyoD-positive cells, a specific marker of myogenic differentiation. We performed intracellular Ca2+ imaging experiments using fura-2 to confirm TRPM8 activation by cooling stimulation. The results confirmed that intracellular Ca2+ concentration ([Ca2+ ]i) increases due to TRPM8 activation, and TRPM8 antagonist inhibits increase in [Ca2+ ]i at medium temperatures below 19°C. We also examined the effect of cooling exposure time on myogenic differentiation of MSCs using an external cooling stimulus set at 17°C. The results showed that 60 min of cooling had an acceleratory effect on differentiation (2.18 ± 0.27 times). We observed that the TRPM8 antagonist counteracted the differentiation-promoting effect of the cooling. These results suggest that TRPM8 might modulate the multiple differentiation pathways of MSCs, and that cooling is an effective way of activating TRPM8, which regulates MSCs differentiation in vitro.

  Dec. 2023, Physiological reports, 11(23) (23), e15855, English, International magazine

  [Refereed]

  Scientific journal


• Resistance training rejuvenates aging skin by reducing circulating inflammatory factors and enhancing dermal extracellular matrices

  Shu Nishikori, Jun Yasuda, Kao Murata, Junya Takegaki, Yasuko Harada, Yuki Shirai, Satoshi Fujita

  Jun. 2023, Scientific Reports, 13, 10214, English

  [Refereed]

  Scientific journal


• Relation between protein intake and resistance training-induced muscle hypertrophy in middle-aged women: a pilot study

  Jun Yasuda, Kao Murata, Tsubasa Hasegawa, Mana Yamamura, Sumiaki Maeo, Junya Takegaki, Nobuaki Tottori, Takumi Yokokawa, Risako Mori, Takuma Arimitsu, Shu Nishikori, Satoshi Fujita

  Elsevier BV, Jan. 2022, Nutrition, 97, 111607 - 111607, English

  [Refereed]

  Scientific journal


• Intramuscular injection of mesenchymal stem cells activates anabolic and catabolic systems in mouse skeletal muscle.

  Junya Takegaki, Kohei Sase, Yusuke Kono, Daiki Nakano, Takuya Fujita, Satoshi Konishi, Satoshi Fujita

  Skeletal muscle mass is critical for good quality of life. Mesenchymal stem cells (MSCs) are multipotent stem cells distributed across various tissues. They are characterized by the capacity to secrete growth factors and differentiate into skeletal muscle cells. These capabilities suggest that MSCs might be beneficial for muscle growth. Nevertheless, little is known regarding the effects on muscle protein anabolic and catabolic systems of intramuscular injection of MSCs into skeletal muscle. Therefore, in the present study, we measured changes in mechanistic target of rapamycin complex 1 (mTORC1) signaling, the ubiquitin-proteasome system, and autophagy-lysosome system-related factors after a single intramuscular injection of MSCs with green fluorescence protein (GFP) into mouse muscles. The intramuscularly-injected MSCs were retained in the gastrocnemius muscle for 7 days after the injection, indicated by detection of GFP and expression of platelet-derived growth factor receptor-alpha. The injection of MSCs increased the expression of satellite cell-related genes, activated mTORC1 signaling and muscle protein synthesis, and increased protein ubiquitination and autophagosome formation (indicated by the expression of microtubule-associated protein 1 light chain 3-II). These results suggest that the intramuscular injection of MSCs activated muscle anabolic and catabolic systems and accelerated muscle protein turnover.

  Lead, Oct. 2021, Scientific reports, 11(1) (1), 21224 - 21224, English, International magazine

  [Refereed]

  Scientific journal


• Repeated bouts of resistance exercise in rats alter mechanistic target of rapamycin complex 1 activity and ribosomal capacity but not muscle protein synthesis.

  Takaya Kotani, Junya Takegaki, Yuki Tamura, Karina Kouzaki, Koichi Nakazato, Naokata Ishii

  NEW FINDINGS: What is the central question of this study? Is muscle protein synthesis (MPS) additionally activated following exercise when ribosomal capacity is increased after repeated bouts of resistance exercise (RE)? What is the main finding and its importance? Skeletal muscles with increased ribosome content through repeated RE bouts showed sufficient activation of MPS with lower mechanistic target of rapamycin complex 1 signalling. Thus, repeated bouts of RE possibly change the translational capacity and efficiency to optimize translation activation following RE. ABSTRACT: Resistance exercise (RE) activates ribosome biogenesis and increases ribosome content in skeletal muscles. However, it is unclear whether the increase in ribosome content subsequently causes an increase in RE-induced activation of muscle protein synthesis (MPS). Thus, this study aimed to investigate the relationship between ribosome content and MPS after exercise using a rat RE model. Male Sprague-Dawley rats were categorized into three groups (n = 6 for each group): sedentary (SED) and RE trained with one bout (1B) or three bouts (3B). The RE stimulus was applied to the right gastrocnemius muscle by transcutaneous electrical stimulation under isoflurane anaesthesia. The 3B group underwent stimulation every other day. Our results revealed that 6 h after the last bout of RE, muscles in the 3B group showed an increase in total RNA and 18S+28S rRNA content per muscle weight compared with the SED and 1B groups. In both the 1B and 3B groups, MPS, estimated by puromycin incorporation in proteins, was higher than that in the SED group 6 h after exercise; however, no significant difference was observed between the 1B and 3B groups. In the 1B and 3B groups, phosphorylated p70S6K at Thr-389 increased, indicating mechanistic target of rapamycin complex 1 (mTORC1) activity. p70S6K phosphorylation level was lower in the 3B group than in the 1B group. Finally, protein synthesis per ribosome (indicator of translation efficiency) was lower in the 3B group than in the 1B group. Thus, three bouts of RE changed the ribosome content and mTORC1 activation, but not the degree of RE-induced global MPS activation.

  Jul. 2021, Experimental physiology, 106(9) (9), 1950 - 1960, English, International magazine

  [Refereed]

  Scientific journal


• The effect of repeated bouts of electrical stimulation-induced muscle contractions on proteolytic signaling in rat skeletal muscle.

  Takaya Kotani, Junya Takegaki, Yuki Tamura, Karina Kouzaki, Koichi Nakazato, Naokata Ishii

  Mechanistic target of rapamycin complex 1 (mTORC1) plays a central role in muscle protein synthesis and repeated bouts of resistance exercise (RE) blunt mTORC1 activation. However, the changes in the proteolytic signaling when recurrent RE bouts attenuate mTORC1 activation are unclear. Using a RE model of electrically stimulated rat skeletal muscle, this study aimed to clarify the effect of repeated RE bouts on acute proteolytic signaling, particularly the calpain, autophagy-lysosome, and ubiquitin-proteasome pathway. p70S6K and rpS6 phosphorylation, indicators of mTORC1 activity, were attenuated by repeated RE bouts. Calpain 3 protein was decreased at 6 h post-RE in all exercised groups regardless of the bout number. Microtubule-associated protein 1 light chain 3 beta-II, an indicator of autophagosome formation, was increased at 3 h and repeated RE bouts increased at 6 h, post-RE. Ubiquitinated proteins were increased following RE, but these increases were independent of the number of RE bouts. These results suggest that the magnitude of autophagosome formation was increased following RE when mTORC1 activity was attenuated with repeated bouts of RE.

  May 2021, Physiological reports, 9(9) (9), e14842, English, International magazine

  [Refereed]

  Scientific journal


• Magnetization of mesenchymal stem cells using magnetic liposomes enhances their retention and immunomodulatory efficacy in mouse inflamed skeletal muscle

  Yusuke Kono, Junya Takegaki, Takeshi Ohba, Koji Matsuda, Ryosuke Negoro, Satoshi Fujita, Takuya Fujita

  Mar. 2021, INTERNATIONAL JOURNAL OF PHARMACEUTICS, 596, English

  [Refereed]

  Scientific journal


• The distribution of eukaryotic initiation factor 4E after bouts of resistance exercise is altered by shortening of recovery periods.

  Junya Takegaki, Riki Ogasawara, Karina Kouzaki, Satoshi Fujita, Koichi Nakazato, Naokata Ishii

  Insufficient duration of recovery between resistance exercise bouts reduces the effects of exercise training, but the influence on muscle anabolic responses is not fully understood. Here, we investigated the changes in the distribution of eukaryotic initiation factor (eIF) 4E, a key regulator of translation initiation, and related factors in mouse skeletal muscle after three successive bouts of resistance exercise with three durations of recovery periods (72 h: conventional, 24 h: shorter, and 8 h: excessively shorter). Bouts of resistance exercise dissociated eIF4E from eIF4E binding protein 1, with the magnitude increasing with shorter recovery. Whereas bouts of resistance exercise with 72 h recovery increased the association of eIF4E and eIF4G, those with shorter recovery did not. Similar results were observed in muscle protein synthesis. These results suggest that insufficient recovery inhibited the association of eIF4E and eIF4G, which might cause attenuation of protein synthesis activation after bouts of resistance exercise.

  Nov. 2020, The journal of physiological sciences : JPS, 70(1) (1), 54 - 54, English, Domestic magazine

  [Refereed]

  Scientific journal


• The effect of leucine-enriched essential amino acid supplementation on anabolic and catabolic signaling in human skeletal muscle after acute resistance exercise: a randomized, double-blind, placebo-controlled, parallel-group comparison trial

  Junya Takegaki, Kohei Sase, Jun Yasuda, Daichi Shindo, Hiroyuki Kato, Sakiko Toyoda, Toshiyuki Yamada, Yasushi Shinohara, Satoshi Fujita

  Resistance exercise transiently activates anabolic and catabolic systems in skeletal muscle. Leucine-enriched essential amino acids (LEAAs) are reported to stimulate the muscle anabolic response at a lower dose than whey protein. However, little is known regarding the effect of LEAA supplementation on the resistance exercise-induced responses of the anabolic and catabolic systems. Here, we conducted a randomized, double-blind, placebo-controlled, parallel-group comparison trial to investigate the effect of LEAA supplementation on mechanistic target of rapamycin complex 1 (mTORC1), the ubiquitin–proteasome system and inflammatory cytokines after a single bout of resistance exercise in young men. A total of 20 healthy young male subjects were supplemented with either 5 g of LEAA or placebo, and then they performed 10 reps in three sets of leg extensions and leg curls (70% one-repetition maximum). LEAA supplementation augmented the phosphorylation of mTORSer2448 (+77.1%, p < 0.05), p70S6KThr389 (+1067.4%, p < 0.05), rpS6Ser240/244 (+171.3%, p < 0.05) and 4EBP1Thr37/46 (+33.4%, p < 0.05) after resistance exercise. However, LEAA supplementation did not change the response of the ubiquitinated proteins, MuRF-1 and Atrogin-1 expression. Additionally, the mRNA expression of IL-1β and IL-6 did not change. These data indicated that LEAA supplementation augments the effect of resistance exercise by enhancing mTORC1 signal activation after exercise.

  Lead, MDPI AG, Aug. 2020, Nutrients, 12(8) (8), 2421 - 2421, English

  [Refereed]

  Scientific journal


• Apple polyphenols induce browning of white adipose tissue.

  Yuki Tamura, Shigeto Tomiya, Junya Takegaki, Karina Kouzaki, Arata Tsutaki, Koichi Nakazato

  We and others have shown that apple polyphenols decrease adipose tissue mass. To better understand the underlying mechanisms and to expand clinical applicability, we herein examine whether apple polyphenols induce adipose thermogenic adaptations (browning) and prevent diet-induced obesity and related insulin resistance. In mice fed a standard diet, daily apple polyphenol consumption induced thermogenic adaptations in inguinal white adipose tissue (iWAT), based on increases in the expression of brown/beige adipocyte selective genes (Ucp1, Cidea, Tbx1, Cd137) and protein content of uncoupling protein 1 and mitochondrial oxidative phosphorylation enzymes. Among the upstream regulatory factors of browning, fibroblast growth factor 21 (FGF21) and peroxisome proliferator-activated receptor gamma coactivator 1 α (PGC-1α) levels were concomitantly up-regulated by apple polyphenols. In the primary cell culture experiment, the results did not support a direct action of apple polyphenols on beige adipogenesis. Instead, apple polyphenols increased tyrosine hydroxylase (a rate-limiting enzyme of catecholamine synthesis) in iWAT, which activates the adipocyte thermogenic program possibly via intratissue cellular communications. In high-fat fed mice, apple polyphenols induced beige adipocyte development in iWAT, reduced fat accumulation, and increased glucose disposal rates in the glucose and insulin tolerance tests. Taken together, dietary administration of apple polyphenols induced beige adipocyte development in iWAT possibly via activation/induction of the peripheral catecholamine synthesis-FGF21-PGC-1α cascade. Results from diet-induced obese mice indicate that apple polyphenols have therapeutic potential for obesity and related metabolic disorders.

  Mar. 2020, The Journal of nutritional biochemistry, 77, 108299 - 108299, English, International magazine

  [Refereed]

  Scientific journal


• Influence of shortened recovery between resistance exercise sessions on muscle-hypertrophic effect in rat skeletal muscle.

  Junya Takegaki, Riki Ogasawara, Takaya Kotani, Yuki Tamura, Ryo Takagi, Koichi Nakazato, Naokata Ishii

  Jun. 2019, Physiological Reports, 7(13) (13), e14155, English

  [Refereed]

  Scientific journal


• Repeated bouts of resistance exercise attenuate mitogen-activated protein-kinase signal responses in rat skeletal muscle.

  Takegaki J, Sase K, Fujita S

  Lead, 2019, Biochem Biophys Res Commun., 520(1) (1), 73-78

  [Refereed]


• Consecutive bouts of electrical stimulation-induced contractions alter ribosome biogenesis in rat skeletal muscle.

  Takaya Kotani, Junya Takegaki, Ryo Takagi, Koichi Nakazato, Naokata Ishii

  2019, Journal of Applied Physiology, 126(6) (6), 1673 - 1680, English

  [Refereed]


• Past injurious exercise attenuates activation of primary calcium-dependent injury pathways in skeletal muscle during subsequent exercise.

  Ryo Takagi, Riki Ogasawara, Junya Takegaki, Yuki Tamura, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  Past contraction-induced skeletal muscle injury reduces the degree of subsequent injury; this phenomenon is called the "repeated bout effect (RBE)." This study addresses the mechanisms underlying the RBE, focusing on primary calcium-dependent injury pathways. Wistar rats were subdivided into single injury (SI) and repeated injury (RI) groups. At age 10 weeks, the right gastrocnemius muscle in each rat in the RI group was subjected to strenuous eccentric contractions (ECs). Subsequently, mild ECs were imposed on the same muscle of each rat at 14 weeks of age in both groups. One day after the exercise, the RI group showed a lower strength deficit than did the SI group, and neither group manifested any increase in membrane permeability. The concentration of protein carbonyls and activation of total calpain increased after ECs given at the age of 14 weeks. Nonetheless, these increases were lower in the RI group than in the SI group. Furthermore, calcium-dependent autolysis of calpain-1 and calpain-3 in the RI group was diminished as compared with that in the SI group. Although peak ankle joint torque and total force generation during ECs at the age of 14 weeks were similar between the two groups, phosphorylation of JNK (Thr183 /Tyr185 ), an indicator of mechanical stress applied to a muscle, was lower in the RI group than in the SI group. These findings suggest that activation of the primary calcium-dependent injury pathways is attenuated by past injurious exercise, and mechanical stress applied to muscle fibers during ECs may decrease in the RBE.

  Mar. 2018, Physiological reports, 6(6) (6), e13660, English, International magazine

  [Refereed]

  Scientific journal


• Influence of past injurious exercise on fiber type-specific acute anabolic response to resistance exercise in skeletal muscle.

  Ryo Takagi, Riki Ogasawara, Junya Takegaki, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  We investigated the influence of past injurious exercise on anabolic response of skeletal muscle fibers to resistance exercise (RE). Wistar rats were divided into exercise (E) and exercise-after-injury (I-E) groups. At age 10 wk, the right gastrocnemius muscle in each rat in the I-E group was subjected to strenuous eccentric contractions. Subsequently, RE was imposed on the same muscle of each rat at 14 wk of age in both groups. Peak joint torque and total force generation per body mass during RE were similar between the groups. Muscle protein synthesis (MPS) in the I-E group was higher than that in the E group 6 h after RE. Furthermore, levels of phospho-p70S6 kinase (Thr389) and phospho-ribosomal protein S6 (phospho-rpS6) (Ser240/244), a downstream target of p70S6 kinase, were higher in the I-E group than in the E group. For the anabolic response in each fiber type, the I-E group showed a higher MPS response in type IIb, IIa, and I fibers and a higher phospho-rpS6 response in type IIx, IIa, and I fibers than the E group. In the I-E group, the relative content of myosin heavy chain (MHC) IIa was higher and that of MHC IIb was lower than those in the E group. In addition, type IIa fibers showed a lower MPS response to RE than type IIb fibers in the I-E group. In conclusion, the past injurious exercise enhanced the MPS and phospho-rpS6 responses in type IIb, IIa, and I fibers and type IIx, IIa, and I fibers, respectively. NEW & NOTEWORTHY Past injurious exercise increased the muscle protein synthesis (MPS) response and mammalian target of rapamycin complex 1 (mTORC1) signaling activation to resistance exercise. In the responses of each fiber type, the past injurious exercise increased the MPS and phosphorylation ribosomal protein (Ser240/244) responses in type IIb, IIa, and I fibers and type IIx, IIa, and I fibers, respectively.

  Jan. 2018, Journal of applied physiology (Bethesda, Md. : 1985), 124(1) (1), 16 - 22, English, International magazine

  [Refereed]

  Scientific journal


• Repeated bouts of resistance exercise with short recovery periods activates mTOR signaling, but not protein synthesis, in mouse skeletal muscle.

  Junya Takegaki, Riki Ogasawara, Yuki Tamura, Ryo Takagi, Yuki Arihara, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  The recovery period between bouts of exercise is one of the major factors influencing the effects of resistance exercise, in addition to exercise intensity and volume. However, the effects of shortening the recovery time between bouts of resistance exercise on subsequent protein synthesis remain unclear. In this study, we investigated the consequences of shortening the recovery time between bouts of resistance exercise on protein synthesis and related processes in mouse skeletal muscles. Eighteen male C57BL/6J mice were randomly subjected to three bouts of resistance exercise with 72 (72H), 24 (24H), or 8 h (8H) of recovery periods between bouts. Resistance exercise, consisting of five sets of 3 s × 10 isometric contractions with 3 min rest between sets, was elicited on the right tibialis anterior muscle via percutaneous electrical stimulation on the deep peroneal nerve under isoflurane anesthesia. The left muscle served as an internal control. Six hours after the third bout of exercise, protein synthesis was found to be activated in the 72H and 24H groups, but not in the 8H group. Phosphorylation of p70S6K at Thr 389, a marker of mammalian target of rapamycin (mTOR) signaling, was increased in all groups, with the 8H group showing the highest magnitude. In contrast, protein carbonylation was observed only in mice in the 8H group. These results suggest that repeated bouts of resistance exercise with 8 h of recovery periods do not effectively increase the levels of muscle protein synthesis despite activation of the mTOR signaling pathway, which likely involves oxidative stress.

  Nov. 2017, Physiological reports, 5(22) (22), e13515, English, International magazine

  [Refereed]

  Scientific journal


• Relationship between exercise volume and muscle protein synthesis in a rat model of resistance exercise

  Riki Ogasawara, Yuki Arihara, Junya Takegaki, Koichi Nakazato, Naokata Ishii

  Oct. 2017, JOURNAL OF APPLIED PHYSIOLOGY, 123(4) (4), 710 - 716, English

  [Refereed]

  Scientific journal


• Influence of past injurious exercise on fiber type specific acute anabolic response to resistance exercise.

  Ryo Takagi, Riki Ogasawara, Junya Takegaki, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  2017, Journal of Applied Physiology, 124(1) (1), 16 - 22

  [Refereed]


• Preventive effects of kilohertz frequency electrical stimulation on sepsis-induced muscle atrophy.

  Minoru Tanaka, Kohei Tanaka, Junya Takegaki, Hidemi Fujino

  2016, Journal of Musculoskeletal and Neuronal Interactions, 16(2) (2), 152 - 160, English

  [Refereed]


• Preventive effects of electrical stimulation on inflammation-induced muscle mitochondrial dysfunction

  Kohei Tanaka, Minoru Tanaka, Junya Takegaki, Hidemi Fujino

  2016, ACTA HISTOCHEMICA, 118(5) (5), 464 - 470, English

  [Refereed]

  Scientific journal


• Time course of ubiquitin-proteasome and macroautophagy-lysosome pathways in skeletal muscle in rats with heart failure

  Naoto Fujita, Hidemi Fujino, Hiroki Sakamoto, Junya Takegaki, Masataka Deie

  2015, BIOMEDICAL RESEARCH-TOKYO, 36(6) (6), 383 - 392, English

  [Refereed]

  Scientific journal

• デュシェンヌ型筋ジストロフィーモデルラットにおいて心筋型トロポニンTが高発現している

  鴻崎 香里奈, 竹垣 淳也, 田村 優樹, 中里 浩一

  日本筋学会, Aug. 2018, 日本筋学会学術集会プログラム・抄録集, 4回, 157 - 157, Japanese


• レジスタンストレーニング回数の増加が筋タンパク質分解系におよぼす影響

  小谷 鷹哉, 竹垣 淳也, 高木 領, 蔦木 新, 中里 浩一, 石井 直方

  日本トレーニング科学会, Dec. 2017, Journal of Training Science for Exercise and Sport, 29(2) (2), 195 - 195, Japanese


• デュシェンヌ型筋ジストロフィーモデルラットにおける筋機能と骨格筋内ミトコンドリアの特徴

  鴻崎 香里奈, 竹垣 淳也, 田村 優樹, 小林 正利, 中村 桂一郎, 太田 啓介, 中里 浩一

  日本筋学会, Jul. 2017, 日本筋学会学術集会プログラム・抄録集, 3回, 76 - 76, Japanese


• デュシェンヌ型筋ジストロフィーモデルラットにおける筋機能と骨格筋内ミトコンドリアの特徴

  鴻崎 香里奈, 竹垣 淳也, 田村 優樹, 小林 正利, 中村 桂一郎, 太田 啓介, 中里 浩一

  日本筋学会, Jul. 2017, 日本筋学会学術集会プログラム・抄録集, 3回, 76 - 76, Japanese


• Ribosome biogenesis is activated during the early period of resistance training in rat skeletal muscle

  Takaya Kotani, Junya Takegaki, Satoshi Nakada, Ryo Takagi, Shigeto Tomiya, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  Apr. 2017, FASEB JOURNAL, 31, English

  Summary international conference


• Resistance training with short interval does not induce skeletal muscle hypertrophy in rats

  Junya Takegaki, Takaya Kotani, Riki Ogasawara, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  Apr. 2017, FASEB JOURNAL, 31, English

  Summary international conference


• Repeated bouts of resistance training with short interval activate Akt-mTOR signaling, but not protein synthesis in mouse skeletal muscle

  Junya Takegaki, Yuki Arihara, Riki Ogasawara, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  Apr. 2016, FASEB JOURNAL, 30, English

  Summary international conference


• 敗血症に伴う全身性炎症による筋萎縮に対する電気刺激の予防効果

  田中 稔, 田中 孝平, 竹垣 淳也, 藤野 英己

  (一社)日本体力医学会, Dec. 2015, 体力科学, 64(6) (6), 670 - 670, Japanese


• Low-intensity Ultrasound Enhances Histon Acetylation and Improves Anti-inflammatory Effects by Short Chain Fatty Acid Treatments in Human Dermal Fibroblasts

  Noriaki Maeshige, Yuka Koga, Junya Takegaki, Masayuki Tanaka, Michiko Aoyama-Ishikawa, Makoto Miyoshi, Makoto Usami, Hidemi Fujino

  Apr. 2015, FASEB JOURNAL, 29, English

  Summary international conference


• Preventive Effects of Electrical Stimulation on Cachexia-Induced Muscle Mitochondrial Dysfunction

  Kohei Tanaka, Minoru Tanaka, Junya Takegaki, Hidemi Fujino

  Apr. 2015, FASEB JOURNAL, 29, English

  Summary international conference


• Preventive effects of middle frequency electrical stimulation on cachexia-induced muscle atrophy.

  Minoru Tanaka, Kohei Tanaka, Junya Takegaki, Hidemi Fujino

  Mar. 2015, Experimental Biology2015

  [Refereed]


• 不活動に伴う毛細血管退行に対するVEGF及びangiopoietin経路を介したアスタキサンチンの予防効果

  金指 美帆, 田中 雅侑, 竹垣 淳也, 近藤 浩代, 永友 文子, 石原 昭彦, 藤野 英己

  (一社)日本体力医学会, Dec. 2014, 体力科学, 63(6) (6), 613 - 613, Japanese


• 敗血症に伴う筋萎縮に対する電気刺激の予防効果

  田中 稔, 田中 孝平, 竹垣 淳也, 藤野 英己

  日本物理療法学会, Sep. 2014, 日本物理療法学会学術大会抄録集, 22回, 39 - 39, Japanese


• 悪液質に伴うミトコンドリア代謝障害に対する治療的電気刺激による予防効果

  田中 孝平, 田中 稔, 竹垣 淳也, 藤野 英己

  日本物理療法学会, Sep. 2014, 日本物理療法学会学術大会抄録集, 22回, 40 - 40, Japanese


• Astaxanthin attenuates lipopolysaccharide-induced atrogin-1 expression in C2C12 myotubes

  Junya Takegaki, Hiroyo Kondo, Hidemi Fujino

  Apr. 2014, FASEB JOURNAL, 28(1) (1), English

  Summary international conference

• 分子運動生理学入門

  小谷鷹哉, 竹垣 淳也

  Joint translation, 第3章 シグナル伝達と運動適応, 有限会社 ナップ, Jul. 2019

• 肥満マウスに対するロイシン摂取および自発運動の効果

  厚地美遥, 竹之内悠利, 稲岡岳人, 渡部智也, 實安隆興, 本田和久, 竹垣淳也

  第40回日本体力医学会近畿地方会, Feb. 2026


• 筋管細胞へのグルタミン曝露がタンパク質合成制御に及ぼす影響

  今福龍人, 實安隆興, 本田和久, 竹垣淳也

  第40回日本体力医学会近畿地方会, Feb. 2026


• ニワトリの腹腔内脂肪組織における脂肪分解調節機構の解明

  神谷梨乃, 竹垣淳也, 本田和久, 實安隆興

  第75回関西畜産学会大会, Nov. 2025


• ブロイラーとマウスにおける筋タンパク質合成の差異の解明

  稲岡岳人, 實安隆興, 本田和久, 竹垣淳也

  第75回関西畜産学会大会, Nov. 2025


• SNAT2の競合基質曝露が骨格筋細胞のタンパク質合成および分化に及ぼす影響

  渡部智也, 實安隆興, 本田和久, 竹垣淳也

  第75回関西畜産学会大会, Nov. 2025


• AZD8055, a pan mTOR inhibitor, abolishes protein synthesis promoted by L-type amino acid transporter 1 inhibition in C2C12 myotubes.

  Junya Takegaki, Takaoki Saneyasu, Kazuhisa Honda

  40th congress of the International Union of Physiological Sciences, Sep. 2025


• The effect of mesenchymal stem cells injection on muscle protein synthesis after resistance exercise in type 2 diabetes mellitus mouse.

  Junya Takegaki, Ryo Takagi, Mito Watanabe, Satoshi Fujita

  World Physiotherapy Congress 2025, May 2025, English

  Poster presentation


• 玄米主体低窒素飼料へのアミノ酸添加がブロイラーの成長成績に及ぼす影響

  右田梨紗, 竹垣淳也, 實安隆興, 本田和久

  日本家禽学会2025年度春季大会, Mar. 2025


• 高張液投与がニワトリのタンパク質・脂質代謝関連遺伝子の発現に及ぼす影響

  村田薫子, ZHANG Yuhui, 竹垣淳也, 實安隆興, 本田和久

  日本家禽学会2025年度春季大会, Mar. 2025


• 延髄のp38 MAPKのリン酸化はニワトリヒナにおける食後の満腹感の誘導に関与するか？

  改發美友, 竹垣淳也, 本田和久, 實安隆興

  日本家禽学会2025年度春季大会, Mar. 2025


• L型アミノ酸輸送体1の阻害剤がC2C12筋管細胞のタンパク質合成に及ぼす影響

  竹垣 淳也, 實安 隆興, 本田 和久

  第78回日本栄養・食糧学会大会, May 2024


• 間食としてのたんぱく質摂取は、運動の有無に関わらず筋タンパク質合成を賦活しない

  竹垣 淳也, 八木 雅斗, 深尾 直生, 奥村 公基, 長谷川 翔, 松元 奈津記, 須長 佳太郎, 雪本 貴哉, 糸川 夏菜, 鈴木 妙実, 首藤 由佳, 高木 領, 安田 純, 吉居 尚美, Daniel Wilkinson, Kenneth Smith,Philip Atherton, 海老 久美子, 篠原 靖司, 藤田 聡

  第17回日本アミノ酸学会大会, Sep. 2023, Co-authored internationally


• The effect of l-type amino acid transporter 1 overexpression in response to leucine administration in C2C12 muscle cells.

  Junya Takegaki, Naoki Fukao, Satoshi Fujita

  Physiology 2023, Jul. 2023

  Poster presentation


• The effects of β-GPA on resistance training adaptations in rat skeletal muscle.

  Naoki Fukao, Junya Takegaki, Ryo Takagi, Koki Okumura, Satoshi Fujita

  Physiology 2023, Jul. 2023


• 間葉系幹細胞の静脈投与が協働筋切除による過負荷を与えた筋のmTORC1シグナル応答に及ぼす影響

  竹垣 淳也, 河野 裕允, 藤田 卓也, 小西 聡, 藤田 聡

  第77回日本体力医学会大会, Sep. 2022


• 間葉系幹細胞による骨格筋の運動適応の変化

  竹垣 淳也

  第12回分子骨格筋代謝研究会, Sep. 2022

  [Invited]


• Changes in sarcolipin expression during the early phase of resistance training in rat skeletal

  Koki Okumura, Junya Takegaki, Kohei Sase, Naoki Fukao, Satoshi Fujita

  27th Conference on ECSS, Sep. 2022


• Effect of β-GPA on Mitochondrial Oxidative Phosphorylation after Muscle Contraction.

  Naoki Fukao, Junya Takegaki, Koki Okumura, Satoshi Fujita

  27th Conference on ECSS, Sep. 2022


• Intramuscular injection of mesenchymal stem cells not only accelerates muscle protein anabolic response but also activates catabolic systems after acute bouts of resistance exercise in mice.

  Junya Takegaki, Yusuke Kono, Takuya Fujita, Satoshi Konishi, Satoshi Fujita

  27th Conference on ECSS, Sep. 2022


• 間葉系幹細胞の静脈投与が協働筋切除による筋肥大に与える影響

  中野 大輝, 竹垣 淳也, 河野 裕允, 藤田 卓也, 小西 聡, 藤田 聡

  第76回日本体力医学会大会, Sep. 2021


• レジスタンス運動の繰り返しに伴うFAKおよびLAT1の応答変化

  深尾 直生, 竹垣 淳也, 佐瀬 晃平, 奥村 公基, 藤田 聡

  第76回日本体力医学会大会, Sep. 2021


• レジスタンス運動実施に伴う骨格筋内のサルコリピン発現量の変化

  奥村 公基, 竹垣 淳也, 佐瀬 晃平, 深尾 直生, 藤田 聡

  第76回日本体力医学会大会, Sep. 2021


• 間葉系幹細胞の筋肉内注射はレジスタンス運動後のタンパク質合成作用を促進させる

  竹垣 淳也, 河野 裕允, 藤田 卓也, 小西 聡, 藤田 聡

  第76回日本体力医学会大会, Sep. 2021


• Intramuscular injection of mesenchymal stem cells activates not only muscle protein anabolic but also catabolic system after three successive bouts of resistance exercise in mouse.

  Junya Takegaki, Kohei Sase, Yusuke Kono, Takuya Fujita, Satoshi Konishi, Satoshi Fujita

  26th Conference on ECSS, Sep. 2021


• The changes in the responses of autophagy-related factors with repeated bouts of resistance exercise

  Junya Takegaki, Kohei Sase, Satoshi Fujita

  Integrative Physiology of Exercise 2020 Conference, Nov. 2020


• Effect of acute bout of resistance exercise in combination with leucine-enriched essential amino acids intake on the protein expression of vitamin D receptor in human skeletal muscle.

  Risako Mori, Junya Takegaki, Kohei Sase, Jun Yasuda, Yasushi Shinohara, Satoshi Fujita

  Integrative Physiology of Exercise 2020 Conference, Sep. 2020


• Molecular mechanisms involved in reduced mTORC1 signal responses after repeated bouts of resistance exercise.

  Junya Takegaki, Kohei Sase, Satoshi Fujita

  24th Conference on ECSS, Jul. 2019


• Effect of combined antioxidant supplementation and resistance exercise on disuse muscle atrophy.

  Masafumi Noda, Junya Takegaki, Takaya Kotani, Koichi Nakazato, Naokata Ishii

  ACSM conference on Integrative Physiology of Exercise, Sep. 2018


• Mitochondria and myosin heavy chain in skeletal muscle of dystrophin deficient rat.

  Karina Kouzaki, Junya Takegaki, Yuki Tamura, Koichi Nakazato

  ACSM conference on Integrative Physiology of Exercise, Sep. 2018


• The effects of prolonged recovery after bouts of resistance exercise with excessively short interval.

  Junya Takegaki, Riki Ogasawara, Satoshi Fujita, Koichi Nakazato, Naokata Ishii

  ACSM conference on Integrative Physiology of Exercise, Sep. 2018


• Changes in ribosomal content and muscle protein synthesis with increasing bouts of electrical muscle stimulation.

  Takaya Kotani, Junya Takegaki, Masafumi Noda, Koichi Nakazato, Naokata Ishii

  ACSM conference on Integrative Physiology of Exercise, Sep. 2018


• デュシェンヌ型筋ジストロフィーモデルラットにおいて心筋型トロポニンTが高発現している．

  鴻崎 香里奈, 竹垣 淳也, 田村 優樹, 中里 浩一

  第4回日本筋学会学術集会, Aug. 2018


• セッション間の回復時間の違いが急性期のタンパク質分解系の挙動に与える影響．

  竹垣 淳也, 小笠原 理紀, 中里 浩一, 石井 直方

  第26回日本運動生理学会大会, Jul. 2018


• 抗酸化剤が廃用性筋萎縮に及ぼす効果．

  野田 雅文, 竹垣 淳也, 小谷 鷹哉, 中里 浩一, 石井 直方

  第26回日本運動生理学会, Jul. 2018


• Effect of repeated bouts of resistance training on skeletal muscle proteolytic response in rat.

  Takaya Kotani, Junya Takegaki, Ryo Takagi, Koichi Nakazato, Naokata Ishii

  American College of Sports Medicine’s 65th Annual Meeting, Jun. 2018


• Muscle protein synthesis during the early period of resistance training in rats.

  Takaya Kotani, Junya Takegaki, Masahumi Noda, Ryo Takagi, Koichi Nakazato, Naokata Ishii

  Experimental Biology 2018, Apr. 2018


• セッション間の回復時間の違いによるレジスタンストレーニング効果の変化-なぜ、やり過ぎてはいけないのか？-．

  竹垣 淳也

  東京大学スポーツ先端科学研究拠点・立命館大学スポーツ健康科学研究センター協同ワークショップ-トレーニング研究の最新知見×若手研究者, Mar. 2018

  [Invited]


• レジスタンストレーニング回数の増加が筋タンパク質分解系におよぼす影響.

  小谷 鷹哉, 竹垣 淳也, 高木 領, 東宮 繁人, 蔦木 新, 中里 浩一, 石井 直方

  第30回日本トレーニング科学会大会, Oct. 2017


• 継続的なレジスタンストレーニングによるリボソーム量の増加メカニズムの検討.

  小谷 鷹哉, 竹垣 淳也, 高木 領, 東宮 繁人, 蔦木 新, 中里 浩一, 石井 直方

  第72回日本体力医学会大会, Sep. 2017


• セッション間の回復時間の違いがレジスタンス運動後の筋タンパク質分解系に与える影響．

  竹垣 淳也, 小谷 鷹哉, 小笠原 理紀, 蔦木 新, 中里 浩一, 石井 直方

  第72回日本体力医学会大会, Sep. 2017


• レジスタンストレーニング初期におけるリボソーム合成に関わる因子の変化.

  小谷 鷹哉, 竹垣 淳也, 高木 領, 東宮 繁人, 蔦木 新, 中里 浩一, 石井 直方

  第25回日本運動生理学会大会, Jul. 2017


• セッション間の回復時間の違いが同強度・同回数のレジスタンス運動の効果に与える影響．

  竹垣 淳也, 小谷 鷹哉, 小笠原 理紀, 蔦木 新, 中里 浩一, 石井 直方

  第25回日本運動生理学会大会, Jul. 2017


• Changes in ribosome content during early and middle period of resistance training in rat skeletal muscle.

  Takaya Kotani, Junya Takegaki, Ryo Takagi, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  Interdisciplinary Symposium for Up-and-coming Material Scientists 2017, Jun. 2017


• High frequency resistance training does not cause skeletal muscle hypertrophy due to activation of proteolytic systems in rat skeletal muscle.

  Junya Takegaki, Riki Ogasawara, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  Cell symposia: Exercise Metabolism, May 2017


• Ribosome biogenesis is activated during the early period of resistance training in rat skeletal muscle.

  Takaya Kotani, Junya Takegaki, Satoshi Nakada, Ryo Takagi, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  Experimental Biology 2017, Apr. 2017


• Resistance training with short interval between bouts does not induce skeletal muscle hypertrophy in rats.

  Junya Takegaki, Takaya Kotani, Riki Ogasawara, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  Experimental Biology 2017, Apr. 2017


• Response of skeletal Muscle injured by eccentric contractions to training.

  Ryo Takagi, Riki Ogasawara, Junya Takegaki, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  5th NSCA International Conference, Jan. 2017


• Consecutive bouts of resistance exercise cause increase in ribosomes in rat training model.

  Takaya Kotani, Junya Takegaki, Satoshi Nakada, Ryo Takagi, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  5th NSCA International Conference, Jan. 2017


• Single session of resistance exercise reduces endurance-adaptive factors in mouse skeletal muscle.

  Junya Takegaki, Riki Ogasawara, Ryo Takagi, Takaya Kotani, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  5th NSCA International Conference, Jan. 2017


• Effect of increasing exercise bout on skeletal muscle ribosome biogenesis.

  Takaya Kotani, Satoshi Nakada, Junya Takegaki, Ryo Takagi, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  10th International Conference On Strength Training., Nov. 2016


• Fiber type- dependent differences in anabolic response of rat skeletal muscle to resistance exercise.

  Ryo Takagi, Riki Ogasawara, Junya Takegaki, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  Integrative Biology of Exercise VII, Nov. 2016


• Relationship between training frequency and muscle protein synthesis in resistance exercise elicited by electrical stimulation.

  Junya Takegaki, Riki Ogasawara, Arata Tsutaki, Ryo Takagi, Koichi Nakazato, Naokata Ishii

  Integrative Biology of Exercise VII, Nov. 2016


• レジスタンストレーニング回数の違いがリボソーム生合成におよぼす影響.

  小谷 鷹哉, 中田 智史, 竹垣 淳也, 高木 領, 東宮 繁人, 蔦木 新, 中里 浩一, 石井直方

  第71回日本体力医学会, Sep. 2016


• レジスタンストレーニングの回復時間の違いがリボソーム量に及ぼす影響．

  竹垣 淳也, 小笠原 理紀, 蔦木 新, 高木 領, 小谷 鷹哉, 中里 浩一, 石井 直方

  第71回日本体力医学会大会, Sep. 2016


• 後肢懸垂はアゾキシメタン投与による大腸腫瘍形成を増悪させなかった.

  東宮 繁人, 松本 啓志, 塩谷 昭子, 鴻崎 香里奈, 竹垣 淳也, 蔦木 新, 中里 浩一

  第71回日本体力医学会大会, Sep. 2016


• 伸張性収縮による繰り返し効果における骨格筋の適応

  高木 領, 小笠原 理紀, 竹垣 淳也, 蔦木 新, 中里 浩一, 石井 直方

  第2回日本筋学会学術集会, Aug. 2016


• レジスタンストレーニングの頻度の違いが骨格筋タンパク合成に及ぼす影響．

  竹垣 淳也, 小笠原 理紀, 高木 領, 蔦木 新, 中里 浩一, 石井 直方

  第24回日本運動生理学会, Jul. 2016


• Repeated bouts of resistance training activate Akt-mTOR signaling, but not protein synthesis in mouse skeletal muscle.

  Junya Takegaki, Yuki Arihara, Riki Ogasawara, Arata Tsutaki, Koichi Nakazato, Naokata Ishii

  , Experimental Biology 2016, Apr. 2016


• 敗血症に伴う全身性炎症による筋萎縮に対する電気刺激の予防効果．

  田中 稔, 田中 孝平, 竹垣 淳也, 藤野 英己

  第70回日本体力医学会大会, Sep. 2015


• モノクロタリン誘導性右心不全ラットの骨格筋におけるタンパク質分解系の経時的変化．

  藤田 直人, 藤野 英己, 坂本 裕規, 竹垣 淳也, 出家 正隆

  第70回日本体力医学会大会, Sep. 2015


• C2C12筋管細胞を用いた悪液質性筋萎縮に対するパルス超音波の予防効果と至適出力強度の検討．

  上野 瑞季, 竹垣 淳也, 前重 伯壮, 藤野 英己

  第50回日本理学療法学術大会, Jun. 2015


• Low-intensity Ultrasound Enhances Histon Acetylation and Improves Anti-inflammatory Effects by Short Chain Fatty Acid Treatments in Human Dermal Fibroblasts.

  Noriaki Maeshige, Yuka Koga, Junya Takegaki, Masayuki Tanaka, Michiko Aoyama-Ishikawa, Makoto Miyoshi, Makoto Usami, Hidemi Fujino

  Experimental Biology 2015, Apr. 2015


• Preventive effects of middle frequency electrical stimulation on cachexia-induced muscle atrophy.

  Minoru Tanaka, Kohei Tanaka, Junya Takegaki, Hidemi Fujino

  Experimental Biology 2015, Mar. 2015


• Preventive Effects of Electrical Stimulation on Cachexia-Induced Muscle Mitochondrial Dysfunction.

  Kohei Tanaka, Minoru Tanaka, Junya Takegaki, Hidemi Fujino

  Experimental Biology 2015, Mar. 2015


• 悪液質の骨格筋における酸化的リン酸化障害に対する治療的電気刺激の効果．

  田中 孝平, 田中 稔, 竹垣 淳也, 藤野 英己

  日本基礎理学療法学会, Nov. 2014


• 敗血症に伴うマウス骨格筋の萎縮に対する電気刺激の予防効果．

  田中 稔, 田中 孝平, 竹垣 淳也, 藤野 英己

  日本基礎理学療法学会, Nov. 2014


• 悪液質に伴うミトコンドリア代謝障害に対する治療的電気刺激による予防効果．

  田中 孝平, 田中 稔, 竹垣 淳也, 藤野 英己

  第22回日本物理療法学会学術大会, Oct. 2014


• 敗血症に伴う筋萎縮に対する電気刺激の予防効果．

  田中 稔, 田中 孝平, 竹垣 淳也, 藤野 英己

  第22回日本物理療法学会学術大会, Oct. 2014


• 不活動に伴う毛細血管対抗に対するVEGF及びangiopoietin経路を介したアスタキサンチンの予防効果．

  金指 美帆, 田中 雅侑, 竹垣 淳也, 近藤 浩代, 永友 文子, 石原 昭彦, 藤野 英己

  第69回日本体力医学会大会, Sep. 2014


• リポポリサッカリドによるC2C12筋管細胞のAtrogin-1発現増加に対するアスタキサンチンの予防効果．

  竹垣 淳也, 金指 美帆, 前重 伯壮, 近藤 浩代, 永友 文子, 石原 昭彦, 藤野 英己

  第69回日本体力医学会大会, Sep. 2014


• 悪液質による筋萎縮に対する抗酸化物質を用いた栄養サポートの予防効果．

  竹垣 淳也, 近藤 浩代, 藤野 英己

  第49回日本理学療法学術大会, Jun. 2014


• Astaxanthin attenuates lipopolysaccharide-induced atrogin-1 expression in C2C12 myotubes.

  Junya Takegaki, Hiroyo Kondo, Hidemi Fujino

  Experimental Biology 2014, May 2014


• 栄養サポートが線維芽細胞に対する酸化ストレスに及ぼす保護効果の検証．

  竹垣 淳也, 藤田 直人, 近藤 浩代, 藤野 英己

  第48回日本理学療法学術大会, May 2013

• L型アミノ酸輸送体が骨格筋肥大応答に果たす役割の解明とサルコペニア対策に向けた応用

  竹垣 淳也

  日本学術振興会, 科学研究費助成事業, 基盤研究(C), 神戸大学, Apr. 2025 - Mar. 2028


• グルタミン／グルタミン酸代謝ダイナミクスに基づく筋タンパク質合成制御機構の解明

  公益財団法人 伊藤記念財団, 令和8年度助成, Jul. 2026 - Mar. 2027


• ブロイラー摂食後血清によるmTORC1非依存的な筋タンパク質合成の検証

  一般財団法人 旗影会, 2026年度研究助成, Jun. 2026 - Mar. 2027


• リボソーム量の変化は、栄養刺激に対する骨格筋タンパク質合成応答を調節するか？

  竹垣淳也

  一般財団法人 加藤育英基金, 学術研究助成（2024年度）, Apr. 2025 - Oct. 2026, Principal investigator


• Dietary Considerations for Exercise Intervention to Prevent Sarcopenia

  藤田 聡, 篠原 靖司, 竹垣 淳也, 吉崎 貴大

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Ritsumeikan University, 01 Apr. 2022 - 31 Mar. 2026

  栄養摂取と運動は共に骨格筋量の維持および増加において重要であるが、サルコペニア予防にどのような栄養摂取や運動が効果的かは未だ未解明な点が多い。本研究では、たんぱく質摂取に焦点をあて、食事で不足するたんぱく質の補完とレジスタンス運動の組み合わせが、筋たんぱく質の代謝調節に与える影響を明らかにすることを目的としている。 2023年度は2022年度に引き続き、食間のたんぱく質摂取が7日間の筋たんぱく質合成速度および関連因子の発現にどのような影響を及ぼすかを検討するために、以下の研究実施と組織の分析を行った。 対象は20-40歳の健康な男性で、プラセボ間食群とたんぱく質間食群の2群に分けた。7日間の間に2.2 g/kg体重のたんぱく質を総摂取量として与え、その内1.2 g/kgはホエイプロテインとして3回に分けて摂取させた。たんぱく質間食群は朝・昼食間、昼・夕食間、就寝前に、プラセボ間食群は各食後にプロテインを摂取した。介入期間中にレジスタンス運動と筋生検を実施し、筋タンパク質合成速度と関連因子の変化を評価した。その結果、7日間の介入後、運動により両群の筋タンパク質合成速度は有意に増加したが（プラセボ間食群1.50±0.23 %/日、たんぱく質間食群1.68±0.24 %/日、P < 0.05）、間食のタイミングによる差異は認められなかった。また、アミノ酸輸送体LAT1の発現も両群で増加したが（P < 0.01）、こちらも間食のタイミングによる差異はなかった。以上のことから、運動を伴う場合、間食によるたんぱく質の摂取タイミングが筋タンパク質合成速度に追加的な効果をもたらすことは確認できなかった。したがって、3食の食事によるたんぱく質摂取が筋タンパク質合成の主要な促進手段であると結論づけた。


• Dietary Considerations for Exercise Intervention to Prevent Sarcopenia

  藤田 聡, 篠原 靖司, 竹垣 淳也, 吉崎 貴大

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Ritsumeikan University, 01 Apr. 2022 - 31 Mar. 2026


• Molecular bases of vitamin D-induced skeletal muscle mass regulation: using a novel tracer method

  藤田 聡, 増山 律子, 竹垣 淳也, 中野 大輝

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Fund for the Promotion of Joint International Research (Fostering Joint International Research (B)), Ritsumeikan University, 07 Oct. 2021 - 31 Mar. 2026

  近年、高齢期におけるビタミンD不足がサルコペニアリスクに繋がるなど、骨格筋量の維持・改善におけるビタミンDの重要性が着目されている。ビタミンDが筋タンパク質の合成や分解を調節することが骨格筋細胞を用いた研究で明らかとなっている。しかし、動物モデルや臨床試験においては、筋タンパク質の合成や分解の速度を同時に定量化することができず、ビタミンD代謝と筋タンパク質代謝の関係性を検証することができなかった。 本研究では、安定同位体トレーサー法を用いて筋タンパク質合成と分解を同時に 測定する手段を開発する。さらに、この新規の筋タンパク質代謝測定法を応用し、 ビタミンD欠乏食/過剰食，筋特異的ビタミンD受容体ノックアウトマウス/過剰発現マウ スを用いて、運動/不活動時の筋タンパク質代謝バランスの推移およびそのメカニズムを解 明する。これらの検討により、骨格筋量の調節におけるビタミンD代謝の役割・ 重要性を包括的に明らかにし、サルコペニア対策におけるパラダイムシフトを実現する。 2021年度においては、筋たんぱく質合成とタンパク質分解を同時に測定可能な新規トレーサー法の確立に向けた予備実験を実施した。マウスに対して [メチルD3]-13C-メチオニンを腹腔投与した後、マウス尾静脈より投与前、投与後において経時的に採血を行った。中・長期的な筋タンパク質代謝の測定においては、体内のトレーサー濃度の変化を適切に確認・管理することが重要であるため、血液サンプルを液体クロマトグラフ質量分析計とガスクロマトグラフ質量分析計の2つの装置を併用した分析を行い、血液中のトレーサー濃度の動態を確認した。上記の組織分析については2022年度も引き続き実験を行い、新規トレーサー法の確立に繋げる予定である。


• サルコペニア予防に向けた、アミノ酸による筋タンパク質合成制御機構の解明

  公益財団法人 三島海雲記念財団, 2024年度学術研究奨励金, Jun. 2024 - May 2025


• 必須アミノ酸の継続摂取に伴う骨格筋の応答変化の解明：筋内・外の両側面からの検討

  竹垣 淳也

  日本学術振興会, 科学研究費助成事業, 若手研究, 立命館大学, 01 Apr. 2022 - 31 Mar. 2025


• ロイシン摂取によるニワトリの肥満抑制並びに低脂肪食肉の産生

  公益財団法人 伊藤記念財団, 令和6年度助成, Jun. 2024 - Mar. 2025


• 間葉系幹細胞は運動による糖尿病誘発性筋萎縮の改善効果を促進するか？

  公益財団法人 中冨健康科学振興財団, 第35回研究助成金, Apr. 2023 - Mar. 2024, Principal investigator


• リボソームへのアプローチに基づく、新規のレジスタンストレーニング効率化手段の開発

  竹垣 淳也

  日本学術振興会, 科学研究費助成事業, 特別研究員奨励費, 立命館大学, 24 Apr. 2020 - 31 Mar. 2023

  骨格筋量を増大させる手段として、レジスタンストレーニング（筋力トレーニング）は非常に有用である。レジスタンストレーニングによる筋量の増加は、細胞内でタンパク質合成を担っているリボソームの活性化による、筋細胞の活発なタンパク質合成の累積によって得られる。本研究は、予めリボソーム量を増加させておくことにより、運動による筋タンパク質合成作用を高め、トレーニングによる筋量増大効果の向上を狙うものである。 本年度は、リボソーム量を増加させておくことでレジスタンス運動効果が高まるか否かの検討を行った。ラットを対象に、トレーニングを実施させ、リボソーム量が増加している3Bout目と、増加していない1Bout目の筋タンパク質合成応答を比較した。その結果、運動によって両群とも同程度筋タンパク質合成が増大しており、群間差は認められなかった。その要因としては、運動を繰り返し実施することにより運動によるシグナルの活性化が鈍化することが挙げられる。従って、リボソーム量を増加させた上で、シグナル応答を同程度引き起こすような介入が必要となると考えられる。また、並行して、重水を用いた筋タンパク質合成方法の検討も実施した。ラットを対象に重水を投与し、アミノ酸を摂取させ、2・4時間後に筋を摘出し、解析を行った。その結果、プラセボと比較してアミノ酸を摂取させたラットで筋中の重水素を取り込んだアラニンの含有比が高かったことから、筋タンパク質合成が亢進していたことが示され、評価系が機能していることが検証された。この結果から、ラットを用いた長期間のトレーニング介入効果の検証並びに、今後実施予定のヒト生体を対象とした検討を行う上での基盤が築かれた。


• The mechanism for attenuation of anabolic responses in skeletal muscle per exercise sessions in continuous resistance training

  Takegaki Junya

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Early-Career Scientists, Ritsumeikan University, Apr. 2019 - Mar. 2022, Principal investigator

  Resistance exercise training induces skeletal muscle hypertrophy, but repeated bouts gradually attenuate this effect. Attenuation of mTORC1 activation is suggested to be involved in this process, but the mechanism has not been clarified. The purpose of this study was to elucidate the mechanism for the attenuation of mTORC1 activation in continuous resistance exercise training. Here, we showed that resistance exercise activated mTORC1, but its magnitude was decreased with repeated bouts (10 bouts) in rat skeletal muscle. At the same time, the phosphorylation of ERK1/2 and p38 MAPK were also decreased. These observations indicate that repeated bouts of resistance exercise desensitized MAPKs, which may have been partly responsible for the blunting of muscle hypertrophic effect in continuous resistance exercise training.

  Competitive research funding


• レジスタンストレーニングの継続に伴う筋肥大応答の減弱メカニズムの解明

  公益財団法人 石本記念デサントスポーツ科学振興財団, 第42回学術研究助成 自由課題学術研究, Apr. 2020 - Mar. 2021, Principal investigator


• オーバートレーニングを検出する血中バイオマーカーの確立に向けた研究

  竹垣 淳也

  独立行政法人 日本学術振興会, 科学研究費補助金, 研究活動スタート支援, 立命館大学, Aug. 2018 - Mar. 2020, Principal investigator

  レジスタンストレーニング（いわゆる筋力トレーニング）は骨格筋量を維持・増大させる手段であるが、高頻度でトレーニングを行うと、回復時間が不足し、オーバートレーニングに至る。しかしながら、オーバートレーニングの発生を検出するツールは未だ発見されていない。その理由として、オーバートレーニングによる運動効果の阻害メカニズムが不明である点が挙げられる。本課題では、オーバートレーニングのメカニズムを解明し、そこから得られた知見を活かしてオーバートレーニングの血中バイオマーカーの同定を目指す。 平成30年度は、オーバートレーニングによる運動効果の阻害メカニズムを検討した。C57BL/6Jマウスを、レジスタンス運動を72時間毎、24時間毎、8時間毎に行う3群に分類し、それぞれ右腓腹筋に対して3回のレジスタンス運動（3秒間の最大等尺性収縮を10回5セット）を実施した。各群最終セッションの6時間後に筋を摘出し、筋タンパク質合成及び関連する因子について検討した。その結果、72時間毎・24時間毎に行う群では生じていた筋タンパク質合成の活性化が8時間毎に行う群では消失しており、さらにそれが酸化ストレスの蓄積に伴う翻訳開始因子複合体の形成不全による可能性が示唆された。当初、これらの結果を踏まえて8時間毎に行う群に抗酸化剤を投与することを予定していたが、酸化ストレス自体も運動効果の一因となりうるため予定を変更し、酸化ストレスが抑制されるまで最終の運動終了からの回復時間を延長する検討を行った。その結果、運動終了12時間後には酸化ストレスの蓄積が解消され、筋タンパク質合成の活性化も生じることが明らかとなった。以上のことから、オーバートレーニングによる運動効果の阻害メカニズムには、酸化ストレスの蓄積が関与する可能性が示唆された。今後は、酸化ストレスに関連する指標を検討し、血中バイオマーカーの確立を目指す。

  Competitive research funding


• オーバートレーニングに着目した、新規のトレーニング効率化戦略の構築

  竹垣 淳也

  独立行政法人 日本学術振興会, 研究者養成事業, 特別研究員奨励費, 東京大学, Apr. 2017 - Mar. 2019, Principal investigator

  筋力トレーニングは筋量増加の手段として、スポーツ・リハビリ現場で広く用いられている。一方で、過度な頻度で行うとオーバートレーニングに至り効果が低減することが知られているが、そのメカニズムは明らかとなっていない。本研究は、オーバートレーニングによる筋肥大効果減弱メカニズムから着想を得て、新たなトレーニング効率化の手段を確立することを目的としている。 本年度は、オーバートレーニングによる筋肥大減弱メカニズムと、臨床実験を行う際の安全性について検討した。 C57BL/6Jマウスにおいて、3秒間の最大等尺性収縮10回5セットのレジスタンス運動を8時間毎に3セット繰り返した6時間後、筋タンパク質合成が抑制されていた。その際のメカニズム候補として、リボソーム量の変化を検討した。その結果、リボソーム量は通常の回復時間（72時間）で同回数実施した場合と同程度に増加していた。別のメカニズム候補として、酸化ストレスの変化について検討したところ、酸化ストレスは8時間毎に運動を行った場合のみ増加していた。従って、オーバートレーニングによる運動効果の阻害メカニズムには、酸化ストレスが関与している可能性が示唆された。一方で、臨床実験を行う際の安全性の確認として、炎症反応及び筋損傷の発生について検討を行った。その結果、運動を18セッション行った場合には筋損傷の発生・炎症応答の高度な亢進が見受けられたが、3セッションであればこれらの所見は認められなかった。従って、少ない回数での検討であれば、臨床実験においても実施可能である可能性が示唆された。今後、より詳細なトレーニング効果の阻害メカニズムの解明、並びに効果を維持した高頻度トレーニング実現のための介入法の探索などを行っていく必要があると考える。

  Competitive research funding


• 廃用性筋萎縮を最小化するレジスタンストレーニング戦略の構築-酸化ストレスに着目して-

  竹垣 淳也

  公益財団法人 中冨健康科学振興財団, 平成28年度研究助成, Mar. 2017 - Mar. 2018, Principal investigator

  Competitive research funding


• Relationship between training frequency and muscle protein synthesis in resistance training performed by electrical stimulation

  竹垣 淳也

  一般財団法人 丸文財団, 平成28年度 国際交流助成, Jul. 2016 - Jul. 2016, Principal investigator

  Competitive research funding