Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
98
result(s) for
"Kitamura, Yoshihisa"
Sort by:
Nicotinic Acetylcholine Receptors and Microglia as Therapeutic and Imaging Targets in Alzheimer’s Disease
by
Kitamura, Yoshihisa
,
Shimohama, Shun
,
Takata, Kazuyuki
in
Alzheimer's disease
,
Apoptosis
,
Brain research
2022
Amyloid-β (Aβ) accumulation and tauopathy are considered the pathological hallmarks of Alzheimer’s disease (AD), but attenuation in choline signaling, including decreased nicotinic acetylcholine receptors (nAChRs), is evident in the early phase of AD. Currently, there are no drugs that can suppress the progression of AD due to a limited understanding of AD pathophysiology. For this, diagnostic methods that can assess disease progression non-invasively before the onset of AD symptoms are essential, and it would be valuable to incorporate the concept of neurotheranostics, which simultaneously enables diagnosis and treatment. The neuroprotective pathways activated by nAChRs are attractive targets as these receptors may regulate microglial-mediated neuroinflammation. Microglia exhibit both pro- and anti-inflammatory functions that could be modulated to mitigate AD pathogenesis. Currently, single-cell analysis is identifying microglial subpopulations that may have specific functions in different stages of AD pathologies. Thus, the ability to image nAChRs and microglia in AD according to the stage of the disease in the living brain may lead to the development of new diagnostic and therapeutic methods. In this review, we summarize and discuss the recent findings on the nAChRs and microglia, as well as their methods for live imaging in the context of diagnosis, prophylaxis, and therapy for AD.
Journal Article
Hochuekkito attenuates anxiety-like behavior associated with pulmonary inflammation induced by intratracheal lipopolysaccharides in mice
2026
We have previously demonstrated that intratracheal lipopolysaccharide (LPS) injection induces significant pulmonary inflammation accompanied by hippocampal microglial activation, indicative of neuroinflammation. Hochuekkito (HET) is a traditional Japanese herbal medicine used to treat various conditions, including mental disorders and physical weakness. We have previously reported that HET ameliorates anxiety-like behaviors induced by intraperitoneal LPS injections in mice. However, its anxiolytic effects on anxiety-like behaviors due to pulmonary inflammation remain poorly understood. Therefore, in the present study, we aimed to investigate the effects of HET on anxiety-like behaviors induced by intratracheal LPS injection in mice.
Mice received HET (1.0 g/kg) once daily for 2 weeks through oral gavage prior to LPS treatment. The light-dark box test was conducted 24 h following LPS injection to assess anxiety-like behaviors. Diazepam, a clinically used anxiolytic, served as a positive control. The lung wet-to-dry weight ratio was determined, and the concentrations of interleukin-6 (IL-6) in the lungs and serum were assessed.
Repeated administration of HET prevented the development of anxiety-like behaviors and reduced serum IL-6 concentrations and hippocampal
mRNA expression levels in LPS-treated mice. Diazepam failed to exert significant effects in LPS-treated mice, whereas HET remained effective under inflammatory conditions. Moreover, LPS injections significantly increased the number of Iba-1-immunoreactive microglial cells in the CA1 region of the hippocampus, whereas this effect was suppressed by treatment with HET. In the bronchoalveolar lavage fluid (BALF), the LPS-induced increase in white blood cell count was significantly reduced by treatment with HET. Furthermore, HET alleviated LPS-induced pulmonary inflammation, as evidenced by decreased lung wet-to-dry weight ratios.
This study suggests that inflammation induced by intratracheal LPS injection contributes to anxiety-like behaviors in mice and that IL-6 may play a key role in linking peripheral inflammation to neuroinflammatory responses. The anxiolytic effects of HET appear to be associated, at least in part, with the suppression of IL-6 elevation in both the periphery and the hippocampus, along with attenuation of microglial activation. Our findings suggest that HET may serve as a potential therapeutic agent for anxiety-like behaviors associated with pulmonary inflammation.
Journal Article
The neuroprotective effects of FG-4592, a hypoxia-inducible factor-prolyl hydroxylase inhibitor, against oxidative stress induced by alpha-synuclein in N2a cells
by
Ohuchi, Kazuki
,
Kitamura, Yoshihisa
,
Wu, Zhiliang
in
692/617/375/1718
,
692/617/375/365
,
Cell death
2023
Parkinson’s disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra. The pathological hallmark of PD is the appearance of intraneuronal cytoplasmic α-synuclein (α-Syn) aggregation, called Lewy bodies. α-Syn aggregation is deeply involved in the pathogenesis of PD. Oxidative stress is also associated with the progression of PD. In the present study, to investigate whether a hypoxia-inducible factor (HIF)-prolyl hydroxylase (PH) inhibitor, FG-4592 (also called roxadustat), has neuroprotective effects against α-Syn-induced neurotoxicity, we employed a novel α-Syn stably expressing cell line (named α-Syn-N2a cells) utilizing a piggyBac transposon system. In α-Syn-N2a cells, oxidative stress and cell death were induced by α-Syn, and FG-4592 showed significant protection against this neurotoxicity. However, FG-4592 did not affect α-Syn protein levels. FG-4592 triggered heme oxygenase-1 (HO-1) expression downstream of HIF-1α in a concentration-dependent manner. In addition, FG-4592 decreased the production of reactive oxygen species possibly via the activation of HO-1 and subsequently suppressed α-Syn-induced neurotoxicity. Moreover, FG-4592 regulated mitochondrial biogenesis and respiration via the induction of the peroxisome proliferator-activated receptor-γ coactivator-1α. As FG-4592 has various neuroprotective effects against α-Syn and is involved in drug repositioning, it may have novel therapeutic potential for PD.
Journal Article
Ameliorating effect of chotosan and its active component, Uncaria hook, on lipopolysaccharide-induced anxiety-like behavior in mice
2024
In this study, we aimed to examine the effects of chotosan, a traditional Japanese botanical drug, and its active component,
hook, on anxiety-like behaviors induced by systemic inflammation in mice.
To induce systemic inflammation, the mice were treated with lipopolysaccharide (LPS), a bacterial endotoxin. Prior to LPS treatment, the mice were administered chotosan or
hook orally each day for 14 days. Anxiety-like behavior of the mice was evaluated using the light-dark test 24 h after LPS treatment.
Repeated administration of chotosan prevented anxiety-like behavior in both normal and LPS-treated mice. Similarly, administration of
hook suppressed LPS-induced anxiety-like behavior in mice. Furthermore, treatment with tandospirone, a 5-HT
receptor agonist, alleviated anxiety-like behavior in mice, whereas treatment with DOI, a 5-HT
receptor agonist, enhanced anxiety-like behavior in mice. LPS treatment significantly increased serotonin (5-HT)
receptor mRNA expression in the frontal cortex, whereas 5-HT
receptor mRNA expression remained unchanged in the hippocampus. Notably, chotosan significantly suppressed the mRNA expression of 5-HT
receptor.
These findings indicate that chotosan exerts anxiolytic-like effects in the context of inflammation-induced anxiety, potentially mediated by the inhibition of 5-HT
receptor hyperfunction in LPS-treated mice. Consequently, we postulate that chotosan may be effective in managing inflammation-induced anxiety-like behaviors.
Journal Article
Usefulness of rapid MR angiography using two-point Dixon for evaluating carotid and aortic plaques
by
Nakano, Tatsu
,
Kitamura, Yoshihisa
,
Mori, Kentaro
in
Angiography
,
Angiography - adverse effects
,
Aorta
2022
Purpose
Recently, various magnetic resonance imaging (MRI) modalities have been developed to easily detect carotid and aortic plaques, but these techniques are time-consuming and vulnerable to motion artifacts. We investigated the utility of a gradient echo MRI technique known as liver acquisition with volume acceleration flexible (LAVA-Flex) to detect carotid and aortic atherosclerotic plaques.
Methods
Ten patients who underwent carotid endarterectomy (CEA) were assessed regarding the correspondence between LAVA-Flex findings and the histopathology of excised carotid plaques. In addition, 47 patients with cryptogenic ischemic stroke underwent LAVA-Flex and transesophageal echocardiography (TEE) for detection of embolic sources in the thoracic aorta. We analyzed the relationship between the thickness of the aortic plaque measured by TEE and the presence of high-intensity lesions on LAVA-Flex.
Results
Nine of 10 patients (90.0%) who underwent CEA showed a high-intensity carotid lesion on LAVA-Flex, which corresponded pathologically to plaques containing large lipid cores and hemorrhage. Twenty-four (51.1%) of 47 cryptogenic stroke patients showed a high-intensity lesion in the thoracic aorta on LAVA-Flex; of these, 21 (87.5%) also demonstrated a large plaque (thickness ≥4 mm) on TEE. Twenty-two (95.7%) of 23 patients without a high-intensity lesion on LAVA-Flex demonstrated no large plaque on TEE. LAVA-Flex had a sensitivity of 95.5% and a specificity of 88.0% in patients with large plaques.
Conclusion
This study showed that LAVA-Flex successfully detected carotid and aortic plaques. This imaging technique may be useful to rapidly diagnose and evaluate carotid and aortic plaques, which are critical risk factors for aortogenic stroke.
Journal Article
MEK/ERK Signaling Regulates Reconstitution of the Dopaminergic Nerve Circuit in the Planarian Dugesia japonica
by
Inoue, Takeshi
,
Kitamura, Yoshihisa
,
Takata, Kazuyuki
in
6-Hydroxydopamine
,
Amputation
,
Biochemistry
2022
Planarian
Dugesia japonica
is a flatworm that can autonomously regenerate its own body after an artificial amputation. A recent report showed the role of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK) pathway in the head morphogenesis during the planarian regeneration process after amputation; however, neuron-specific regeneration mechanisms have not yet been reported. Here, whether MEK/ERK pathway was involved in the dopaminergic neuronal regeneration in planarians was investigated. Planarians regenerated their body within 14 days after amputation; however, the head region morphogenesis was inhibited by MEK inhibitor U0126 (3 or 10 μM). Furthermore, the number of planarian tyrosine hydroxylase (DjTH)-positive dopaminergic neurons in the regenerated head region was also decreased by U0126. The 6-hydroxydopamine (6-OHDA), a dopaminergic neurotoxin, can decrease the number of dopaminergic neurons; however, planarians can regenerate dopaminergic neurons after injecting 6-OHDA into the intestinal tract. MEK inhibitor PD98059 (30 μM) or U0126 (10 μM) significantly decreased dopaminergic neurons 5 days after the 6-OHDA injection. During the regeneration process of dopaminergic neurons, phosphorylated histone H3 (H3P)-positive stem cells known as “neoblasts” were increased in the head region; however, MEK inhibitors significantly decreased the number of H3P-positive neoblasts. These results suggested that dopaminergic neuronal regeneration in planarian was regulated by the MEK/ERK pathway.
Journal Article
Lipoxin A4 Receptor Stimulation Attenuates Neuroinflammation in a Mouse Model of Intracerebral Hemorrhage
by
Kitamura, Yoshihisa
,
Futokoro, Risa
,
Hijioka, Masanori
in
Agonists
,
Alzheimer's disease
,
Arachidonic acid
2022
Intracerebral hemorrhage (ICH) is caused by the rupture of blood vessels in the brain. The excessive activation of glial cells and the infiltration of numerous inflammatory cells are observed during bleeding. Thrombin is a key molecule that triggers neuroinflammation in the ICH brain. In this study, we focused on lipoxin A4 (LXA4), an arachidonic acid metabolite that has been reported to suppress inflammation and cell migration. LXA4 and BML-111, an agonist of the LXA4 receptor/formyl peptide receptor 2 (ALX/FPR2), suppressed microglial activation; LXA4 strongly inhibited the migration of neutrophil-like cells in vitro. ALX/FPR2 was expressed on neutrophils in the ICH mouse brain and the daily administration of BML-111 attenuated the motor coordination dysfunction and suppressed the production of proinflammatory cytokines in the ICH mouse brain. On the other hand, BML-111 did not show a significant reduction in the number of microglia and neutrophils. These results suggest that systemic administration of ALX/FPR2 agonists may suppress the neuroinflammatory response of microglia and neutrophils without a change in cell numbers. Additionally, their combination with molecules that reduce cell numbers, such as modulators of leukotriene B4 signaling, may be required in future studies.
Journal Article
A cross-sectional study of psychological distress, burnout, and the associated risk factors in hospital pharmacists in Japan
by
Kitamura, Yoshihisa
,
Fujimori, Maiko
,
Uchitomi, Yosuke
in
Adult
,
Aged
,
Attention deficit hyperactivity disorder
2016
Background
Opportunities for face-to-face communication with patients is increasing in modern hospital pharmacist practice. This may impose new burdens on hospital pharmacists. We performed a cross-sectional study to examine the prevalence of psychological distress, burnout, and compassion fatigue among hospital pharmacists. We also investigated possible relevant factors, such as sex, years of experience, hospital size, interpersonal work hours, and personality traits related to communication.
Methods
We mailed self-administered questionnaires to all pharmacists (
n
= 823) belonging to the prefectural society of hospital pharmacists in Japan. The questionnaires were the General Health Questionnaire (GHQ-12), Burnout (BO) and Compassion Fatigue and Secondary Traumatic Stress (CF/STS) subscales of the Professional Quality of Life Scale, the Autism Spectrum Quotient (AQ), and the Adult ADHD (attention deficit hyperactivity disorder) Self-Report Scale (ASRS). We examined associations between personality traits (AQ, ASRS) and psychological burden (GHQ-12, BO, CF/STS) using rank ANCOVA or multivariate logistic regression analyses.
Results
Complete responses were obtained from 380 pharmacists (46.2 % response rate). A substantial number of participants obtained scores that were higher than the cutoff points of the GHQ-12 (54.7 %), BO (49.2 %), and CF/STS (29.2 %). The GHQ-12 scores were negatively affected by years of experience (
p
< 0.001), and positively affected by AQ (
p
< 0.001) and ASRS (
p
< 0.001) scores. The BO scores was positively affected by AQ (
p
< 0.001) and ASRS (
p
= 0.001) scores, while the CF/STS (
p
= 0.023) score was negatively affected by years of experience, and positively affected by AQ (
p
< 0.001) and ASRS (
p
< 0.001) scores.
Conclusions
There is a high prevalence of psychological distress and work-related burnout/CF among hospital pharmacists. Additionally, two common personality traits, such as autistic-like traits and ADHD-like symptoms, which might be related to communication style, could increase the risk of psychological distress and burnout/CF. Early risk assessment and preventive interventions that are specialized for these characteristics could protect individuals with these specific traits from burnout.
Journal Article
Mirtazapine exerts astrocyte-mediated dopaminergic neuroprotection
by
Kitamura, Yoshihisa
,
Moriyama, Masaaki
,
Murakami, Shinki
in
6-Hydroxydopamine
,
631/378/1689/1718
,
692/617/375
2020
Mirtazapine, a noradrenergic and specific serotonergic antidepressant (NaSSA), is known to activate serotonin (5-HT) 1A receptor. Our recent study demonstrated that stimulation of astrocytic 5-HT1A receptors promoted astrocyte proliferation and upregulated antioxidative property in astrocytes to protect dopaminergic neurons against oxidative stress. Here, we evaluated the neuroprotective effects of mirtazapine against dopaminergic neurodegeneration in models of Parkinson’s disease (PD). Mirtazapine administration attenuated the loss of dopaminergic neurons in the substantia nigra and increased the expression of the antioxidative molecule metallothionein (MT) in the striatal astrocytes of 6-hydroxydopamine (6-OHDA)-injected parkinsonian mice via 5-HT1A receptors. Mirtazapine protected dopaminergic neurons against 6-OHDA-induced neurotoxicity in mesencephalic neuron and striatal astrocyte cocultures, but not in enriched neuronal cultures. Mirtazapine-treated neuron-conditioned medium (Mir-NCM) induced astrocyte proliferation and upregulated MT expression via 5-HT1A receptors on astrocytes. Furthermore, treatment with medium from Mir-NCM-treated astrocytes protected dopaminergic neurons against 6-OHDA neurotoxicity, and these effects were attenuated by treatment with a MT-1/2-specific antibody or 5-HT1A antagonist. Our study suggests that mirtazapine could be an effective disease-modifying drug for PD and highlights that astrocytic 5-HT1A receptors may be a novel target for the treatment of PD.
Journal Article
Association Between Skin Autofluorescence and White Blood Cell Counts in Older Adults
2023
Background/Aim: Advanced glycation end products (AGEs) accumulate in the body with increasing age. However, their excessive accumulation may lead to various inflammatory and chronic diseases. While it is common for older adults to experience various comorbidities, there is a scarcity of published literature documenting the specific impact of ageing and comorbidities on AGEs in this population. The present study aimed to retrospectively evaluate the correlation among AGEs in the skin, calendar age, and comorbidities in older adults. Patients and Methods: Accumulated AGEs in the skin were assessed by non-invasive measurement of skin autofluorescence (SAF) inside the forearm. This retrospective study included individuals who underwent SAF measurements at Shujitsu University Community Pharmacy with or without a prescription from October 2019 to October 2021. Subsequently, the associations between SAF, calendar age, comorbidities, and blood test parameters were investigated. Results: SAF showed a positive correlation with calendar age for all enrolled participants; the correlation weakened for participants aged ≥50 years and plateaued for those aged ≥60 years. Furthermore, we observed a significant increase in SAF among all participants with comorbidities compared to those without comorbidities. By contrast, among participants aged ≥50 years, SAF did not show a significant association with comorbidities. However, SAF was significantly positively correlated with white blood cell (WBC) counts in these aged populations. Conclusion: The non-invasive assessment of SAF holds promise in evaluating changes in the physical condition associated with WBC counts among older adults.
Journal Article