Norio Takagi

Prof. Norio Takagi

Tokyo University of Pharmacy and Life Sciences

Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

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

Representative Publications

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14 August 2019 in BMC Complementary and Alternative Medicine
Verified
Journal Article
Open access
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MYMingjiang Yao
Mingjiang Yao
XFXiaodi Fan
Xiaodi Fan
BYBo Yuan
Bo Yuan
NTNorio Takagi
Norio Takagi
SLSai Liu
Sai Liu
JLJianxun Liu
Jianxun Liu
Breast cancer is still the most common malignant tumor that threatens the female’s life in the world, especially triple-negative breast cancer (TNBC), one of the most difficult subtypes. Lack of targeted therapies brings about urgent demand for novel treatments. In this study we aim to investigate the anti-tumor activity of Berberine (BBR), a Chinese plant-derived alkaloid, against the TNBC cell line MDA-MB-231 and elucidate its mechanism referring to anti-inflammation. Cell inhibition rate was measured by Cell Proliferation Assay, the cytotoxic effects was detected by Lactate dehydrogenase (LDH) leakage assay, the colony formation and migration potential were evaluated by colony formation assay and wound healing assay, the release of inflammatory cytokines was detected by EMD multifactor detection, and alterations of proteins and genes related to the NLR family pyrin domain containing 3 (NLRP3) inflammasome pathway were analyzed using western blotting and real-time Polymerase Chain Reaction (PCR). BBR reduce the viability of MDA-MB-231 cells and increased the release of LDH from the cells in a dose-dependent manner, with and inhibition of colony formation potential and migration of the cells. BBR also caused a marked reduction in the secretion of proinflammatory cytokines, Interleukin-1α (IL-1α), Interleukin-1β (IL-1β), Interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). Besides, a down-regulated behavior was observed with the expression of P2X purinoceptor 7 (P2X7), NLRP3, pro-caspase-1, apoptosis-associated speck-like protein containing a caspase-activation and recruitment domain (ASC), caspase-1 p20, Interleukin-18 (IL-18), IL-1β proteins and NLRP3, Caspase-1 and ASC mRNAs in the NLRP3 inflammasome cascade. Our results confirmed that BBR can effectively affect both tumor outgrowth and spontaneous metastasis in TNBC, and that we identified a new mechanism associated with inhibition the NLRP3 inflammasome pathway, suggesting its potential therapeutic relevance in clinical use.


19 November 2016 in Molecular Neurobiology
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Journal Article
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KKKeishi Kisoh
Keishi Kisoh
HHHideki Hayashi
Hideki Hayashi
TITsuyoshi Itoh
Tsuyoshi Itoh
MAMayumi Asada
Mayumi Asada
MAMiho Arai
Miho Arai
NTNorio Takagi
Norio Takagi
Glycogen synthase kinase (GSK)-3β, which is abundantly expressed in the central nervous system, regulates various cellular processes including gene expression, cell proliferation, and differentiation. However, involvement of GSK-3β in cerebral ischemia-induced endogenous neurogenesis is not yet fully understood. Appropriate strategies to prevent ischemic cell damage and subsequent severe sequelae are needed. The purpose of the present study was to determine the relationship between pathophysiological alteration of the GSK-3β signaling pathway and cerebral ischemia-induced endogenous neurogenesis in rats. Severe cerebral ischemia was produced by the injection of 700 microspheres into the right internal carotid artery of rats. We demonstrated that phosphorylation of GSK-3β at its Ser9 and that of Akt was significantly enhanced on day 7 after the cerebral ischemia, as was the number of NeuroD-positive cells. Treatment with a phosphatidylinositol 3-kinase (PI3-K) inhibitor decreased the cerebral ischemia-induced phosphorylation of Akt and that of GSK-3β at its Ser9. In addition, as the protein levels of insulin-like growth factor-1 (IGF-1) and brain-derived neurotrophic factor (BDNF) were decreased, they might not have been essential for activation of the PI3-K/Akt/GSK-3β pathway after severe cerebral ischemia. Although it remains to be determined what factors activate this pathway, our results suggest that PI3K/Akt-dependent GSK-3β signaling and subsequent expression of NeuroD were involved in the neurogenesis elicited by cerebral ischemia.

21 September 2015 in Pharmaceutics
Verified
Journal Article
Open access
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YNYoichi Negishi
Yoichi Negishi
MYMasaya Yamane
Masaya Yamane
NKNaho Kurihara
Naho Kurihara
YEYoko Endo-Takahashi
Yoko Endo-Takahashi
SSSanae Sashida
Sanae Sashida
KMKazuo Maruyama
Kazuo Maruyama
The blood–brain barrier (BBB) is a major obstacle that prevents therapeutic drugs or genes from being delivered to the central nervous system. Therefore, it is important to develop methods to enhance the permeability of the BBB. We have developed echo-contrast gas (C3F8) entrapping liposomes (Bubble liposomes, BLs) that can work as a gene delivery tool in combination with ultrasound (US) exposure. Here, we studied whether the permeability of the BBB can be enhanced by the combination of BLs and high-intensity focused ultrasound (HIFU). Mice were intravenously injected with Evans blue (EB). BLs were subsequently injected, and the right hemispheres were exposed to HIFU. As a result, the accumulation of EB in the HIFU-exposed brain hemispheres was increased over that observed in the non-HIFU-exposed hemispheres, depending on the intensity and the duration of the HIFU. Similarly, the combination of BLs and HIFU allowed fluorescent-labeled antisense oligonucleotides to be delivered into the HIFU-exposed left hemispheres of the treated mice. Furthermore, a firefly luciferase-expressing plasmid DNA was delivered to the brain by the combination method of BLs and HIFU, which resulted in the increased gene expression in the brain at the focused-US exposure site. These results suggest that the method of combining BLs and HIFU together serves as a useful means for accelerating the permeability of BBB and thereby enabling antisense oligonucleotides or genes to be delivered to the focused brain site.

1 August 2021 in Biomedicine & Pharmacotherapy
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Journal Article
Open access
MWMin Wang
Min Wang
HHHideki Hayashi
Hideki Hayashi
IHIchiro Horinokita
Ichiro Horinokita
MAMayumi Asada
Mayumi Asada
YIYui Iwatani
Yui Iwatani
NTNorio Takagi
Norio Takagi
Glutamate-induced neurotoxicity is one of the most important pathogenic mechanisms in neurological diseases and is widely used as an in vitro model for ischemic stroke. Senkyunolide I (SEI), an active constituent derived from traditional Chinese medicine Ligusticum chuanxiong Hort. and Angelica sinensis (Oliv.) Diels, has been shown to have beneficial effects against focal cerebral ischemia-reperfusion in rats. However, the mechanisms underlying SEI-mediated neuroprotection remain not well understood. Thus, we explored the influence of SEI in glutamate-mediated injury to mouse neuroblastoma (Neuro2a) cells and determined the mechanisms involved. Neuro2a cells were treated with SEI under exposure to glutamate for 24 h. Cell viability was assessed by using WST-1 reagents, and apoptosis was evaluated using Annexin V-FITC and a PI double staining kit. The protein expression levels of p-AKT, AKT, p-GSK3β, GSK3β, p-p38, p38, p-ERK, ERK, p-JNK, JNK, Bcl-2, Bax, Bcl-xl, p-Bad, Bad, p53, and cleaved caspase-3 were determined by Western blot analysis. Glutamate significantly decreased cell viability and elevated the level of apoptosis. Treatment with SEI reversed those effects. Furthermore, the expression of p-JNK/JNK and cleaved caspase-3 were also reduced after treatment with SEI. Our findings demonstrate that SEI protected Neuro2a cells against glutamate toxicity by regulating JNK/caspase-3 pathway and apoptosis. Thus, SEI maybe a promising candidate for neuroprotection.

Verified
Journal Article
Open access
PDF file
IHIchiro Horinokita
Ichiro Horinokita
HHHideki Hayashi
Hideki Hayashi
RORika Oteki
Rika Oteki
RMRisa Mizumura
Risa Mizumura
TYTatsuaki Yamaguchi
Tatsuaki Yamaguchi
NTNorio Takagi
Norio Takagi
Progranulin (PGRN) plays a crucial role in diverse biological processes, including cell proliferation and embryonic development. PGRN can be cleaved by neutrophil elastase to release granulin (GRN). PGRN has been found to inhibit inflammation. Whereas, GRN plays a role as a pro-inflammatory factor. However, the pathophysiological roles of PGRN and GRN, at early stages after cerebral ischemia, have not yet been fully understood. The aim of this study was to obtain further insight into the pathologic roles of PGRN and GRN. We demonstrated that the amount of PGRN was significantly increased in microglial cells after cerebral ischemia in rats and that neutrophil elastase activity was also increased at an early stage after cerebral ischemia, resulting in the production of GRN. The inhibition of neutrophil elastase activity suppressed PGRN cleavage and GRN production, as well as the increase in pro-inflammatory cytokines, after cerebral ischemia. The administration of an elastase inhibitor decreased the number of injured cells and improved the neurological deficits test scores. Our findings suggest that an increase in the activity of elastase to cleave PGRN, and to produce GRN, was involved in an inflammatory response at the early stages after cerebral ischemia, and that inhibition of elastase activity could suppress the progression of cerebral ischemic injury.