Akira Kubo

Dr. Akira Kubo


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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MKMichitaka Kato
Michitaka Kato
FGFumi Green
Fumi Green
KHKazuki Hotta
Kazuki Hotta
TTToshiya Tsukamoto
Toshiya Tsukamoto
YKYasunari Kurita
Yasunari Kurita
HTHisato Takagi
Hisato Takagi
Background: Aerobic exercise is known to reduce arterial stiffness; however, high-intensity resistance exercise is associated with increased arterial stiffness. Stretching exercises are another exercise modality, and their effect on arterial stiffness remains unclear. The purpose of this study was to determine whether stretching exercises reduce arterial stiffness in middle-aged and older adults, performing the first meta-analysis of currently available studies. Methods: We searched the literature for randomized controlled trials (RCTs) and non-RCTs published up to January 2020 describing middle-aged and older adults who participated in a stretching intervention vs. controls without exercise training. The primary and secondary outcomes were changes in arterial stiffness and vascular endothelial function and hemodynamic status. Pooled mean differences (MDs) and standard MDs (SMDs) with 95% confidence intervals (CIs) between the intervention and control groups were calculated using a random effects model. Results: We identified 69 trials and, after an assessment of relevance, eight trials, including a combined total of 213 subjects, were analyzed. Muscle stretching exercises were shown to significantly reduce arterial stiffness and improve vascular endothelial function (SMD: −1.00, 95% CI: −1.57 to −0.44, p = 0.0004; SMD: 1.15, 95% CI: 0.26 to 2.03, p = 0.01, respectively). Resting heart rate (HR) and diastolic blood pressure (DBP) decreased significantly after stretching exercise intervention (MD: −0.95 beats/min, 95% CI: −1.67 to −0.23 beats/min, p = 0.009; MD: −2.72 mm Hg, 95% CI: −4.01 to −1.43 mm Hg, p < 0.0001, respectively) Conclusions: Our analyses suggest that stretching exercises reduce arterial stiffness, HR, and DBP, and improve vascular endothelial function in middle-aged and older adults.

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HSHaruka Sudo
Haruka Sudo
AKAkira Kubo
Akira Kubo
Diabetes mellitus (DM) is considered to be associated with an increased risk of colorectal cancer. Recent studies have also revealed that tubulin hyperacetylation is caused by a diabetic status and we have reported previously that, under microtubule hyperacetylation, a microtubule severing protein, katanin-like (KL) 1, is upregulated and contributes to tumorigenesis. To further explore this phenomenon, we tested the effects of the ketone bodies, acetoacetate and β-hydroxybutyrate, in colon and fibroblast cells. Both induced microtubule hyperacetylation that responded differently to a histone deacetylase 3 knockdown. These two ketone bodies also generated intracellular reactive oxygen species (ROS) and hyperacetylation was commonly inhibited by ROS inhibitors. In a human fibroblast-based microtubule sensitivity test, only the KL1 human katanin family member showed activation by both ketone bodies. In primary cultured colon epithelial cells, these ketone bodies reduced the tau protein level and induced KL1- and α-tubulin acetyltransferase 1 (ATAT1)-dependent micronucleation. Resveratrol, known for its tumor preventive and tubulin deacetylation effects, inhibited this micronucleation. Our current data thus suggest that the microtubule hyperacetylation induced by ketone bodies may be a causal factor linking DM to colorectal carcinogenesis and may also represent an adverse effect of them that needs to be controlled if they are used as therapeutics.

18 May 2022 in Healthcare
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TTToshiya Tsukamoto
Toshiya Tsukamoto
MKMichitaka Kato
Michitaka Kato
YKYasunari Kurita
Yasunari Kurita
MUMasaki Uchida
Masaki Uchida
AKAkira Kubo
Akira Kubo
HMHitoshi Maruyama
Hitoshi Maruyama
This study aimed to evaluate the effects of expiratory muscle training (EMT) on respiratory muscle strength and respiratory distress during inspiratory load. Thirty-one healthy adult males were randomly divided into an EMT group who underwent EMT (n = 15) and a control group who did not undergo EMT (n = 16). The EMT group underwent EMT with a 50% load of maximum expiratory mouth pressure (PEmax) for 15 min, twice a day, every day, for 4 weeks. The parameter of respiratory muscle fatigue was a decrease in maximum inspiratory mouth pressure (PImax) and PEmax during 20 min of inspiratory load; thus, PImax and PEmax during inspiratory load were measured. Respiratory distress during inspiratory load was assessed using the Borg scale. These assessments were performed on the same subjects in each group before and after the 4 week study. In the EMT group, the PEmax values after the study were significantly higher than those before the study (p < 0.01). Furthermore, before the study, the PImax and PEmax values for the EMT group during inspiratory load were significantly lower than those before inspiratory load (p < 0.01). However, after the study, there was no difference in these values between during and before inspiratory load. In the EMT group, the Borg scale value during inspiratory load from 6 to 20 min was significantly lower after the study than before the study (p < 0.05). EMT increases expiratory muscle strength, thereby attenuating decreased respiratory muscle strength (PImax and PEmax) and respiratory distress during inspiratory load in healthy subjects.

17 July 2025 in Research Square
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DYDonghoon Yoon
Donghoon Yoon
ALAlex Jinpyo Lee
Alex Jinpyo Lee
IYIrawan Yusuf
Irawan Yusuf
TPTerawan Agus Putranto
Terawan Agus Putranto
LSLyana Setiawan
Lyana Setiawan
JPJong Park
Jong Park
Introduction. Osteoporosis is a long-term bone disease that causes a gradual loss of bone density and weakens its internal structure, increasing the risk of bone fractures. Prior preclinical studies have demonstrated that Sigma Anti-bonding Molecule Calcium Carbonate (SAC) exhibits beneficial effects on bone integrity in ovariectomized rat models. This clinical investigation evaluates the impact of SAC supplementation on bone mineral density(BMD) in an Asian cohort. Methods. A total of 82 participants were enrolled and stratified into three groups based on T-score: normal bone density (n=18), osteopenia (n=31), and osteoporosis (n=33). T-scores, BMD, and speed of sound (SOS) were measured at baseline and following approximately eight months of SAC intervention. All measurements were conducted at the distal radius, a clinically relevant site for assessing peripheral bone density. Results. After SAC administration, T-scores improved significantly (from -2.0 to -0.85, p<0.0001) along with increased BMD (from 0.95 to 1.10 g/cm², p<0.0001) across all age and gender groups. SAC treatment also significantly increased SOS values from 3,946 to 4,079 (p < 0.0001). Further, 65% of participants with osteopenia (20/31) improved to the normal group after treatment, while 64% of participants with osteoporosis (21/33) were reclassified into the osteopenia group. Remarkably, 12% of participants with baseline osteoporosis (4/33) transitioned into the normal bone density range. Discussion. Our findings suggest that SAC supplementation leads to significant improvements in bone health in Asian individuals, a population with higher susceptibility to osteoporosis. These results indicate that SAC could be a useful option to slow down age-related bone loss.