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274
result(s) for
"Matsuda Tsuyoshi"
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Spinal astrocytes in superficial laminae gate brainstem descending control of mechanosensory hypersensitivity
2020
Astrocytes are critical regulators of CNS function and are proposed to be heterogeneous in the developing brain and spinal cord. Here we identify a population of astrocytes located in the superficial laminae of the spinal dorsal horn (SDH) in adults that is genetically defined by Hes5. In vivo imaging revealed that noxious stimulation by intraplantar capsaicin injection activated Hes5+ SDH astrocytes via α1A-adrenoceptors (α1A-ARs) through descending noradrenergic signaling from the locus coeruleus. Intrathecal norepinephrine induced mechanical pain hypersensitivity via α1A-ARs in Hes5+ astrocytes, and chemogenetic stimulation of Hes5+ SDH astrocytes was sufficient to produce the hypersensitivity. Furthermore, capsaicin-induced mechanical hypersensitivity was prevented by the inhibition of descending locus coeruleus–noradrenergic signaling onto Hes5+ astrocytes. Moreover, in a model of chronic pain, α1A-ARs in Hes5+ astrocytes were critical regulators for determining an analgesic effect of duloxetine. Our findings identify a superficial SDH-selective astrocyte population that gates descending noradrenergic control of mechanosensory behavior.Kohro et al. identify a population of astrocytes located in the superficial dorsal horn of adult spinal cord (genetically defined by Hes5) that acts as a gate for locus coeruleus descending noradrenergic control of mechanosensory hypersensitivity.
Journal Article
Top-down descending facilitation of spinal sensory excitatory transmission from the anterior cingulate cortex
2018
Spinal sensory transmission is under descending biphasic modulation, and descending facilitation is believed to contribute to chronic pain. Descending modulation from the brainstem rostral ventromedial medulla (RVM) has been the most studied, whereas little is known about direct corticospinal modulation. Here, we found that stimulation in the anterior cingulate cortex (ACC) potentiated spinal excitatory synaptic transmission and this modulation is independent of the RVM. Peripheral nerve injury enhanced the spinal synaptic transmission and occluded the ACC-spinal cord facilitation. Inhibition of ACC reduced the enhanced spinal synaptic transmission caused by nerve injury. Finally, using optogenetics, we showed that selective activation of ACC-spinal cord projecting neurons caused behavioral pain sensitization, while inhibiting the projection induced analgesic effects. Our results provide strong evidence that ACC stimulation facilitates spinal sensory excitatory transmission by a RVM-independent manner, and that such top-down facilitation may contribute to the process of chronic neuropathic pain.
It is known that descending facilitation of spinal responses may contribute to chronic pain, however many studies have focussed on brainstem mechanisms. Here the authors show that stimulation of the anterior cingulate cortex increases excitatory transmission in the dorsal horn, and that this may be via a direct pathway independent of the brainstem.
Journal Article
Observation of the magnetic flux and three-dimensional structure of skyrmion lattices by electron holography
2014
Skyrmions are nanoscale spin textures that are viewed as promising candidates as information carriers in future spintronic devices
1
,
2
,
3
. Skyrmions have been observed using neutron scattering
4
,
5
and microscopy techniques
6
,
7
,
8
,
9
,
10
,
11
. Real-space imaging using electrons is a straightforward way to interpret spin configurations by detecting the phase shifts due to electromagnetic fields. Here, we report the first observation by electron holography of the magnetic flux and the three-dimensional spin configuration of a skyrmion lattice in Fe
0.5
Co
0.5
Si thin samples. The magnetic flux inside and outside a skyrmion was directly visualized and the handedness of the magnetic flux flow was found to be dependent on the direction of the applied magnetic field. The electron phase shifts
φ
in the helical and skyrmion phases were determined using samples with a stepped thickness
t
(from 55 nm to 510 nm), revealing a linear relationship (
φ
= 0.00173
t
). The phase measurements were used to estimate the three-dimensional structures of both the helical and skyrmion phases, demonstrating that electron holography is a useful tool for studying complex magnetic structures and for three-dimensional, real-space mapping of magnetic fields
12
.
Electron holography is used to visualize the three-dimensional structure of a skyrmion lattice and the magnetic flux inside and outside a skyrmion.
Journal Article
Pharmacological Effects and Potential Clinical Usefulness of Polyphenols in Benign Prostatic Hyperplasia
by
Junki Harada
,
Tsuyoshi Matsuda
,
Yuta Mukae
in
Anti-Inflammatory Agents
,
Anti-Inflammatory Agents - therapeutic use
,
Antioxidants
2021
Benign prostatic hyperplasia (BPH) is arguably the most common benign disease among men. This disease is often associated with lower urinary tract symptoms (LUTS) in men and significantly decreases the quality of life. Polyphenol consumption reportedly plays an important role in the prevention of many diseases, including BPH. In recent years, in addition to disease prevention, many studies have reported the efficacy and safety of polyphenol treatment against various pathological conditions in vivo and in vitro. Furthermore, numerous studies have also revealed the molecular mechanisms of the antioxidant and anti-inflammatory effects of polyphenols. We believe that an improved understanding of the detailed pharmacological roles of polyphenol-induced activities at a molecular level is important for the prevention and treatment of BPH. Polyphenols are composed of many members, and their biological roles differ. In this review, we first provide information regarding the pathological roles of oxidative stress and inflammation in BPH. Next, the antioxidant and anti-inflammatory effects of polyphenols, including those of flavonoids and non-flavonoids, are discussed. Finally, we talk about the results and limitations of previous clinical trials that have used polyphenols in BPH, with particular focus on their molecular mechanisms of action.
Journal Article
Oral administration of E-type prostanoid (EP) 1 receptor antagonist suppresses carcinogenesis and development of prostate cancer via upregulation of apoptosis in an animal model
2021
Prostaglandin E2 plays an important role in carcinogenesis and malignant potential of prostate cancer (PC) cells by binding to its specific receptors, E-type prostanoid (EP) receptors. However, anti-carcinogenic effects of the EP receptor antagonist are unclear. In this study, we used a mouse model of PC. The mice were provided standard feed (control) or feed containing the EP1 receptor antagonist and were sacrificed at 10, 15, 30, and 52 weeks of age. Apoptosis was evaluated by immunohistochemical analysis using a cleaved caspase-3 assay. The incidence of cancer in the experimental group was significantly lower than that in the control group at 15, 30, and 52 weeks of age. The percentage of poorly differentiated PC cells was significantly lower in the experimental group than in the control group at 30 and 52 weeks of age. The percentage of apoptotic cells in the experimental group was significantly higher than that in the control group at 15, 30, and 52 weeks of age. These findings indicate that feeding with the addition of EP1 receptor antagonist delayed PC progression via the upregulation of apoptosis. We suggest that the EP1 receptor antagonist may be a novel chemopreventive agent for PC.
Journal Article
Non-Invasive Evaluation of the GABAergic/Glutamatergic System in Autistic Patients Observed by MEGA-Editing Proton MR Spectroscopy Using a Clinical 3 Tesla Instrument
by
Harada, Masafumi
,
Mori, Kenji
,
Nishitani, Hiromu
in
Amino acids
,
Analysis of Variance
,
Aspartate
2011
Amino acids related to neurotransmitters and the GABAergic/glutamatergic system were measured using a 3 T-MRI instrument in 12 patients with autism and 10 normal controls. All measurements were performed in the frontal lobe (FL) and lenticular nuclei (LN) using a conventional sequence for n-acetyl aspartate (NAA) and glutamate (Glu), and the MEGA-editing method for GABA. The GABA level and [GABA]/[NAA] ratio were significantly lower (
p
< 0.01) in the FL, but not the LN, in patients with autism compared to normal controls. The [GABA]/[Glu] ratio in the FL was also significantly lower (
p
< 0.05) in the patients than in the normal controls, thus suggesting a possible abnormality in the regulation between GABA and Glu.
Journal Article
Arterial Transit Time Mapping Obtained by Pulsed Continuous 3D ASL Imaging with Multiple Post-Label Delay Acquisitions: Comparative Study with PET-CBF in Patients with Chronic Occlusive Cerebrovascular Disease
by
Kikuta, Ken-ichiro
,
Tsujikawa, Tetsuya
,
Isozaki, Makoto
in
Adult
,
Aged
,
Biology and Life Sciences
2016
Arterial transit time (ATT) is most crucial for measuring absolute cerebral blood flow (CBF) by arterial spin labeling (ASL), a noninvasive magnetic resonance (MR) perfusion assessment technique, in patients with chronic occlusive cerebrovascular disease. We validated ASL-CBF and ASL-ATT maps calculated by pulsed continuous ASL (pCASL) with multiple post-label delay acquisitions in patients with occlusive cerebrovascular disease. Fifteen patients underwent MR scans, including pCASL, and positron emission tomography (PET) scans with 15O-water to obtain PET-CBF. MR acquisitions with different post-label delays (1.0, 1.5, 2.0, 2.5 and 3.0 sec) were also obtained for ATT correction. The theoretical framework of 2-compartmental model (2CM) was also used for the delay compensation. ASL-CBF and ASL-ATT were calculated based on the proposed 2CM, and the effect on the CBF values and the ATT correction characteristics were discussed. Linear regression analyses were performed both on pixel-by-pixel and region-of-interest bases in the middle cerebral artery (MCA) territory. There were significant correlations between ASL-CBF and PET-CBF both for voxel values (r = 0.74 ± 0.08, slope: 0.87 ± 0.22, intercept: 6.1 ± 4.9) and for the MCA territorial comparison in both affected (R2 = 0.67, y = 0.83x + 6.3) and contralateral sides (R2 = 0.66, y = 0.74x + 6.3). ASL-ATTs in the affected side were significantly longer than those in the contralateral side (1.51 ± 0.41 sec and 1.12 ± 0.30 sec, respectively, p <0.0005). CBF measurement using pCASL with delay compensation was feasible and fairly accurate even in altered hemodynamic states.
Journal Article
Ceruloplasmin Levels in Cancer Tissues and Urine Are Significant Biomarkers of Pathological Features and Outcome in Bladder Cancer
2021
Background/Aim: A previous report showed that immune complex-ceruloplasmin (CP) in urine is associated with carcinogenesis and malignant behavior in bladder cancer (BC). We investigated the pathological significance and prognostic roles of urine and tissue levels of CP protein in BC patients. Materials and Methods: Urine CP levels were measured using an enzyme-linked immunosorbent assay in 97 patients. CP expression in BC tissues was evaluated by immunohistochemical analysis in 176 patient samples. Results: Urine CP levels were positively associated with tumor grade and pT stage in non-muscle invasive BC (NMIBC). CP expression in BC tissues was positively associated with tumor growth and progression. Multivariate analysis demonstrated that high urine CP levels was an independent predictor of recurrence in the urinary tract in NMIBC (hazard ratio=2.87, p=0.016). Conclusion: CP-related markers, especially urine CP levels, are useful biomarkers of malignant potential and prognosis in NMIBC.
Journal Article
Assessment of magnetic field interactions and heating for cerebral aneurysm flow diverters during 7T MRI
2023
Flow diverters (FDs) are utilized for a wide range of aneurysms, but show safety issues such as adverse interactions with static magnetic fields (displacement force and torque) and radiofrequency-induced heating during magnetic resonance imaging (MRI). The present study aimed to assess these adverse interactions in a 7-tesla (7T) static magnetic field and radiofrequency-induced heating during a 7T MRI for two types of FD. Displacement force and magnetically induced torque were assessed using the deflection angle method and low friction surface method, respectively. To assess heating, each FD was set in a phantom filled with gelled-saline mixed with polyacrylic acid and underwent a 7T MRI using a three-dimensional fast spin echo method. Displacement force and magnetically induced torque in the 7T static magnetic field were undetectable, and radiofrequency-induced heating during 7T MRI remained ≤ 0.6 °C for both types of FD, suggesting that magnetic field interactions and heating on FDs during a 7T MRI are acceptable from a safety perspective.
Journal Article
Pathological and Pharmacological Roles of Mitochondrial Reactive Oxygen Species in Malignant Neoplasms: Therapies Involving Chemical Compounds, Natural Products, and Photosensitizers
by
Harada, Junki
,
Matsuda, Tsuyoshi
,
Matsuo, Tomohiro
in
Amaryllidaceae Alkaloids - pharmacology
,
Animals
,
Antineoplastic Agents - pharmacology
2020
Oxidative stress plays an important role in cellular processes. Consequently, oxidative stress also affects etiology, progression, and response to therapeutics in various pathological conditions including malignant tumors. Oxidative stress and associated outcomes are often brought about by excessive generation of reactive oxygen species (ROS). Accumulation of ROS occurs due to dysregulation of homeostasis in an otherwise strictly controlled physiological condition. In fact, intracellular ROS levels are closely associated with the pathological status and outcome of numerous diseases. Notably, mitochondria are recognized as the critical regulator and primary source of ROS. Damage to mitochondria increases mitochondrial ROS (mROS) production, which leads to an increased level of total intracellular ROS. However, intracellular ROS level may not always reflect mROS levels, as ROS is not only produced by mitochondria but also by other organelles such as endoplasmic reticulum and peroxisomes. Thus, an evaluation of mROS would help us to recognize the biological and pathological characteristics and predictive markers of malignant tumors and develop efficient treatment strategies. In this review, we describe the pathological significance of mROS in malignant neoplasms. In particular, we show the association of mROS-related signaling in the molecular mechanisms of chemically synthesized and natural chemotherapeutic agents and photodynamic therapy.
Journal Article