scholarly journals Ganoderma lucidumProtects Dopaminergic Neuron Degeneration through Inhibition of Microglial Activation

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Ruiping Zhang ◽  
Shengli Xu ◽  
Yanning Cai ◽  
Ming Zhou ◽  
Xiaohong Zuo ◽  
...  
Keyword(s):  
Microglial Activation ◽  
Neuroprotective Effect ◽  
Mrna Level ◽  
Underlying Mechanism ◽  
Dependent Manner ◽  
Chinese Medicinal Herb ◽  
Neuroprotective Effects ◽  
Promising Therapeutic Target ◽  
Progressive Neurodegeneration ◽  
Dose Dependent

Abundant evidence has suggested that neuroinflammation participates in the pathogenesis of Parkinson's disease (PD). The emerging evidence has supported that microglia may play key roles in the progressive neurodegeneration in PD and might be a promising therapeutic target.Ganoderma lucidum(GL), a traditional Chinese medicinal herb, has been shown potential neuroprotective effects in our clinical trials that make us to speculate that it might possess potent anti-inflammatory and immunomodulating properties. To test this hypothesis, we investigated the potential neuroprotective effect of GL and possible underlying mechanism of action through protecting microglial activation using co-cultures of dopaminergic neurons and microglia. The microglia is activated by LPS and MPP+-treated MES 23.5 cell membranes. Meanwhile, GL extracts significantly prevent the production of microglia-derived proinflammatory and cytotoxic factors [nitric oxide, tumor necrosis factor-α(TNF-α), interlukin 1β(IL-1β)] in a dose-dependent manner and down-regulate the TNF-αand IL-1βexpressions on mRNA level as well. In conclusion, our results support that GL may be a promising agent for the treatment of PD through anti-inflammation.

scholarly journals PDGF Suppresses Oxidative Stress Induced Ca2+Overload and Calpain Activation in Neurons

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Lian-Shun Zheng ◽  
Yoko Ishii ◽  
Qing-Li Zhao ◽  
Takashi Kondo ◽  
Masakiyo Sasahara
Keyword(s):  
Oxidative Stress ◽  
Map Kinases ◽  
Neurological Diseases ◽  
Underlying Mechanism ◽  
Dependent Manner ◽  
Neuroprotective Effects ◽  
Calpain Activation ◽  
Neurotoxic Effects ◽  
Nonapoptotic Cell Death ◽  
Dose Dependent

Oxidative stress is crucially involved in the pathogenesis of neurological diseases such as stroke and degenerative diseases. We previously demonstrated that platelet-derived growth factors (PDGFs) protected neurons from H2O2-induced oxidative stress and indicated the involvement of PI3K-Akt and MAP kinases as an underlying mechanism. Ca2+overload has been shown to mediate the neurotoxic effects of oxidative stress and excitotoxicity. We examined the effects of PDGFs on H2O2-induced Ca2+overload in primary cultured neurons to further clarify their neuroprotective mechanism. H2O2-induced Ca2+overload in neurons in a dose-dependent manner, while pretreating neurons with PDGF-BB for 24 hours largely suppressed it. In a comparative study, the suppressive effects of PDGF-BB were more potent than those of PDGF-AA. We then evaluated calpain activation, which was induced by Ca2+overload and mediated both apoptotic and nonapoptotic cell death. H2O2-induced calpain activation in neurons in a dose-dependent manner. Pretreatment of PDGF-BB completely blocked H2O2-induced calpain activation. To the best of our knowledge, the present study is the first to demonstrate the mechanism underlying the neuroprotective effects of PDGF against oxidative stress via the suppression of Ca2+overload and inactivation of calpain and suggests that PDGF-BB may be a potential therapeutic target of neurological diseases.

scholarly journals Apamin Enhances Neurite Outgrowth and Regeneration after Laceration Injury in Cortical Neurons

Toxins ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 603
Author(s):  
Hyunseong Kim ◽  
Jin Young Hong ◽  
Junseon Lee ◽  
Wan-Jin Jeon ◽  
In-Hyuk Ha
Keyword(s):  
Phospholipase A2 ◽  
Neurite Outgrowth ◽  
Cortical Neurons ◽  
Neurological Diseases ◽  
Minor Component ◽  
Underlying Mechanism ◽  
Bee Venom ◽  
Dependent Manner ◽  
Neuroprotective Effects ◽  
Wide Range

Apamin is a minor component of bee venom and is a polypeptide with 18 amino acid residues. Although apamin is considered a neurotoxic compound that blocks the potassium channel, its neuroprotective effects on neurons have been recently reported. However, there is little information about the underlying mechanism and very little is known regarding the toxicological characterization of other compounds in bee venom. Here, cultured mature cortical neurons were treated with bee venom components, including apamin, phospholipase A2, and the main component, melittin. Melittin and phospholipase A2 from bee venom caused a neurotoxic effect in dose-dependent manner, but apamin did not induce neurotoxicity in mature cortical neurons in doses of up to 10 µg/mL. Next, 1 and 10 µg/mL of apamin were applied to cultivate mature cortical neurons. Apamin accelerated neurite outgrowth and axon regeneration after laceration injury. Furthermore, apamin induced the upregulation of brain-derived neurotrophic factor and neurotrophin nerve growth factor, as well as regeneration-associated gene expression in mature cortical neurons. Due to its neurotherapeutic effects, apamin may be a promising candidate for the treatment of a wide range of neurological diseases.

Adenosine Inhibits Tissue Factor Expression by LPS-stimulated Human Monocytes: Involvement of the A3 Adenosine Receptor

2002 ◽  
Vol 88 (07) ◽  
pp. 123-130 ◽  
Author(s):  
Matthieu Broussas ◽  
Pascale Cornillet-Lefèbvre ◽  
Gérard Potron ◽  
Philippe Nguyên
Keyword(s):  
Tissue Factor ◽  
Rank Order ◽  
Mrna Level ◽  
Dependent Manner ◽  
Human Monocytes ◽  
Extrinsic Pathway ◽  
A3 Adenosine Receptor ◽  
Factor Expression ◽  
Cardioprotective Effects ◽  
Dose Dependent

SummaryTissue Factor (TF), an integral membrane glycoprotein that initiates the extrinsic pathway of blood coagulation, is thought to play a major part in coronary acute events. Adenosine, an endogenous nucleoside produced by the degradation of intracellular adenosine triphosphate, has been shown to exert many cardioprotective effects via an inhibition of platelets and neutrophils. This study was conducted to determine whether adenosine (ADO) could modulate the expression of TF by human monocytes. We found that ADO inhibited TF antigen and activity on endotoxin-stimulated monocytes in a dose-dependent manner. The mechanism was at least pre-translational since ADO caused a change in the TF mRNA level. Using ADO receptor-specific analogs, we showed that highly selective A3 agonist N6-(3-iodobenzyl)-adenosine-5’-N’-methyluronamide (IB-MECA) inhibited LPSinduced TF activity expression more potently than A1 agonist R-phenylisopropyladenosine (R-PIA) and A2 agonist CGS 2180. Furthermore, A1/A3 antagonist, xanthine amine congener (XAC) blocked the effect of ADO whereas A2a, A2b and A1 antagonists were ineffective. In addition, we observed that ADO agonists inhibited monocyte TF expression in LPS-stimulated whole blood. The rank order of agonist potency suggested that A2 and A3 receptors might be involved (2-Cado > CGS = IB-MECA > R-PIA). This was supported by the fact that A2 and A3 antagonists reversed the action of 2-Cado. We conclude that TF inhibition by ADO on human purified monocytes involved A3 receptors.

Rapamycin inhibits the growth of cholangiocarcinoma cells in vitro

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 15153-15153 ◽  
Author(s):  
T. Sawada ◽  
T. Okada ◽  
K. Kubota
Keyword(s):  
Synergistic Effect ◽  
Cell Lines ◽  
Mtt Assay ◽  
Mrna Level ◽  
Dependent Manner ◽  
In Vitro Methods ◽  
Proliferative Effect ◽  
Cholangiocarcinoma Cell ◽  
Dose Dependent

15153 Background: In the present study, anti-neoplastic effect of rapamycin against cholangiocarcinoma was studied in vitro. Methods: Expression of mTOR in 4 cholangiocarcinoma cell lines, TFK1, HuCCT1, NOZW, and OZ was evaluated by real-time PCR. Then, the four cholangiocarcinoma cell lines were cultured with rapamycin (0, 25, 50, 100, 200 nM), gemcitabine (0, 0.5, 1, 2 μM), or both, and anti-proliferative effect was evaluated by MTT assay. Results: All the four cholangiocarcinoma cell lines expressed endogenous mTOR- mRNA. Level of expression was the highest in HuCCT1 (65.8), and the lowest in TFK1 (17.6). Then, rapamycin significantly inhibited the growth of all the four cholangiocarcinoma cell lines, in dose-dependent manner. Gemcitabine inhibited the growth of NOZW (48.4%) and HuCCT1 (48.9%), but less efficiently in TFK1 (5.9%) and OZ (27.4%). Furthermore, synergistic anti-proliferative effect of rapamycin and gemcitabine was observed in TFK1 (39.1%), NOZW (38.9%), and OZ (47.1%), not in HuCCT1 (18.9%). Conclusion: Rapamycin effectively inhibited the growth of the cholangiocarcinoma cell lines, and synergistic effect with gemcitabine was observed in three of the four cell lines. No significant financial relationships to disclose.

Cadmium Inhibits Neurite Outgrowth in Differentiating Human SH-SY5Y Neuroblastoma Cells

2014 ◽  
Vol 33 (5) ◽  
pp. 412-418 ◽  
Author(s):  
Eun Joo Pak ◽  
Gi Dong Son ◽  
Byung Sun Yoo
Keyword(s):  
Neurite Outgrowth ◽  
Neuroblastoma Cells ◽  
Underlying Mechanism ◽  
Ros Generation ◽  
Dependent Manner ◽  
Cadmium Treatment ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Ros Scavenger ◽  
Dose Dependent

Cadmium, a highly ubiquitous heavy metal, is well known to induce neurotoxicity. However, the underlying mechanism of cadmium-mediated neurotoxicity remains unclear. We have studied cadmium inhibition of neurite outgrowth using human SH-SY5Y neuroblastoma cells induced to differentiate by all- trans-retinoic acid (RA). Cadmium, at a concentration of 3 μmol/L, had no significant effect on the viability of differentiating SH-SY5Y cells. However, the neurite outgrowth of the differentiating SH-SY5Y cells 48 hours after cadmium treatment (1-3 μmol/L cadmium) was significantly inhibited in a dose-dependent manner. Treatment of RA-stimulated differentiating SH-SY5Y cells with 1 to 3 μmol/L cadmium resulted in decreased level of cross-reactivities with 43-kDa growth-associated protein (GAP-43) in a dose-dependent manner. The reactive oxygen species (ROS) scavenger, NAC (N-acetyl-l-cysteine), recovered the expression of GAP-43 in cadmium-treated cells. The results indicate that cadmium is able to inhibit neurite outgrowth of differentiating SH-SY5Y cells and that this effect might result from ROS generation by cadmium.

Effect of Plant Compound Curcumin on the Expression of a-Synuclein in Hippocampal Neurons of APPswe/PS1dE9 Double Transgenic Mice

2013 ◽  
Vol 781-784 ◽  
pp. 643-646
Author(s):  
Xiao Lin ◽  
Li Yu
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Transgenic Mice ◽  
Hippocampal Neurons ◽  
Neuroprotective Effect ◽  
Disease Model ◽  
Dependent Manner ◽  
Double Transgenic Mice ◽  
Ad Alzheimer’S Disease ◽  
Dose Dependent

In this study, we aim to investigate the effect of curcumin on the expression of a-synuclein in the APPswe/PS1dE9 double transgenic mice. APPswe/PS1dE9 double transgenic mice were used as AD (Alzheimer's disease) model and fed with different concentrations of curcumin every day for 6 months, then immunohistochemistry method were used to detect the expression of a-synuclein in hippocampus of mice. The expression of a-syn in hippocampal neuron was decreased significantly after treated with 0.16g/kg to 1.0g/kg curcumin, the change was apparent in dose-dependent manner (P<0.05). a-synuclein pay an important role in the genesis and development of Alzheimer's disease and decreased level of a-synuclein might contribute to the neuroprotective effect of Curcumin, which may become a new target for the prevention and treatment of Alzheimer's disease.

scholarly journals Artemisinin derivative SM934, influences the activation, proliferation, differentiation and antibody-secreting capacity of β-cells in systemic lupus erythematosus mice via inhibition of TLR7/9 signaling pathway

2021 ◽  
Vol 18 (7) ◽  
pp. 1391-1396
Author(s):  
Yajuan Li ◽  
Lixin Zhao ◽  
Xuehui Yang ◽  
Jing Chen ◽  
Wenjing Xu ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
B Cells ◽  
B Cell ◽  
Lupus Erythematosus ◽  
B Lymphocyte ◽  
Underlying Mechanism ◽  
Dependent Manner ◽  
Artemisinin Derivative ◽  
Systemic Lupus ◽  
Dose Dependent

Purpose: To study the influence of artemisinin derivative, SM934 on activation, proliferation, differentiation and antibody-secreting capacity of B cells of systemic lupus erythematosus (SLE) mice, and the underlying mechanism. Methods: Female MRL/lpr mice (n = 60) were randomly assigned to four groups of 15 mice each: SLE, 2.5 mg/kg SM934; 5 mg/kg SM934, and 10 mg/kg SM934 groups. Serum levels of interleukins 6, 10, 17 and 21 (IL-6, IL-17, IL-10 and IL-21) were determined. The secretions of immunoglobulins G and M (IgG and IgM) by B cells were determined. The population of B lymphocyte subtypes was determined flow cytometrically. The expressions of Blimp-1 and Bcl-6, Toll-like receptors 7 and 9 (TLR7 and TLR9) mRNAs were determined. Results: SLE-induced upregulation of serum IL-10, IL-6, IL-17 and IL-21 was significantly and dosedependently reduced following a 2-month treatment with SM934 (p < 0.01). Treatment with SM934 significantly and dose-dependently accentuated B cell germinal center B cell populations, but significantly and dose-dependently decreased the populations of plasma and activated B cells (p < 0.01). The splenic levels of IgG and IgM were decreased in a dose-dependent fashion after 8 weeks of treatment (p < 0.01). Artemisinin derivative SM934 decreased the expression of Blimp-1, and upregulated the expression of Bcl-6, both in a dose-dependent manner (p < 0.01). Moreover, SM934 decreased the mRNA expressions of TLR7 and TLR9 in a dose-based manner (p < 0.01). Conclusion: Artemisinin derivative SM934 mitigates LSE syndromes by suppressing the TLR-induced B-cell stimulation and plasma cell generation

scholarly journals The Chronotropic Function of Propofol and the Underlying Mechanism in Rabbits

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Wenjie Cheng ◽  
Xiaohua Sun ◽  
Yanfang Liu ◽  
Shiqi Han ◽  
Wanlu Ren
Keyword(s):  
Heart Rate ◽  
Action Potentials ◽  
Sinus Node ◽  
Underlying Mechanism ◽  
Dependent Manner ◽  
Pacemaker Cells ◽  
Concentration Dependent Manner ◽  
Sinoatrial Nodes ◽  
Chronotropic Action ◽  
Dose Dependent

The report of bradycardia caused by propofol is increasing. In the experiment, we investigated the chronotropic function of propofol and the underlying mechanism. Rabbits of both sexes were randomly divided into 4 groups: propofol 5 mg/kg group, 10 mg/kg group, 15 mg/kg group, and sham group. Heart rate and frequency of vagal efferent discharge were recorded before the injection and 0, 0.5, 1, 2, and 10 min after the injection through intravenous mode. Then, their hearts were removed, and sinoatrial nodes were dissected. The action potentials of the sinus node pacemaker cells were recorded by the intracellular glass microelectrode technique, and the sinoatrial (SA) node was exposed to propofol 1, 3, 5, and 10 µM respectively. The action potentials were recorded after the sinoatrial nodes were exposed to each concentration of propofol for 15 min. Our results show that the heart rate significantly decreased, and the vagal efferent discharge was significantly increased at 0, 0.5, 1, and 2 min after the injection, respectively. Besides, as the dose increases, the magnitude of change shows a dose-dependent manner. Propofol exerts a negative chronotropic action on sinoatrial node pacemaker cells. The drug significantly decreased APA, VDD, RPF, and prolonged APD90 in a concentration-dependent manner. These effects may be the main mechanism of propofol-induced bradycardia in clinical study.

scholarly journals Polyphenols from Broussonetia papyrifera Induce Apoptosis of HepG2 Cells via Inactivation of ERK and AKT Signaling Pathways

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Chen-Zhuo Dou ◽  
Yan-Fen Liu ◽  
Lu-Lu Zhang ◽  
Shao-Hong Chen ◽  
Chuan-Yin Hu ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Hepg2 Cells ◽  
Underlying Mechanism ◽  
Akt Signaling ◽  
Dependent Manner ◽  
Broussonetia Papyrifera ◽  
Cycle Arrest ◽  
Extracellular Signal ◽  
Dose Dependent ◽  
Apoptosis Ratio

The extract of Broussonetia papyrifera has been proved to have antitumor activity. However, the underlying mechanism remains unclear. This study aimed to elucidate the mechanism of apoptosis of HepG2 cells induced by polyphenols from Broussonetia papyrifera (PBPs). The results revealed that PBPs inhibited the proliferation of HepG2 cells in a dose-dependent and time-dependent manner. Flow cytometry analysis showed that PBPs increased the apoptosis ratio of HepG2 cells significantly. PBPs increased intracellular reactive oxygen species (ROS) production and decreased intracellular superoxide dismutase (SOD) level of HepG2 cells. PBPs induced cell cycle arrest at G1 phase. Western blotting showed that PBPs upregulated the ratio of Bax/Bcl-2 and the expression level of Caspase-3, and activated p53 in HepG2 cells. The inhibition of proliferative relative signals (protein kinase B, PKB/AKT) and survival relative signals (extracellular signal-regulated kinase, ERK) were also observed in PBP-treated HepG2 cells. Our findings suggest that apoptosis of HepG2 cells induced by PBPs is mitochondria-mediated via inactivation of ERK and AKT signaling pathways.

scholarly journals Neuroprotection in Rats Following Ischaemia-Reperfusion Injury by GLP-1 Analogues—Liraglutide and Semaglutide

2019 ◽  
Vol 33 (6) ◽  
pp. 661-667 ◽  
Author(s):  
Maryna V. Basalay ◽  
Sean M. Davidson ◽  
Derek M. Yellon
Keyword(s):  
Infarct Size ◽  
Ischaemic Stroke ◽  
Experimental Studies ◽  
Treatment Strategies ◽  
Reperfusion Therapy ◽  
Diabetic Rat ◽  
Dependent Manner ◽  
Ischaemia Reperfusion Injury ◽  
Neuroprotective Effects ◽  
Dose Dependent

Abstract Purpose A substantial number of ischaemic stroke patients who receive reperfusion therapy in the acute phase do not ever fully recover. This reveals the urgent need to develop new adjunctive neuroprotective treatment strategies alongside reperfusion therapy. Previous experimental studies demonstrated the potential of glucagon-like peptide-1 (GLP-1) to reduce acute ischaemic damage in the brain. Here, we examined the neuroprotective effects of two GLP-1 analogues, liraglutide and semaglutide. Methods A non-diabetic rat model of acute ischaemic stroke involved 90, 120 or 180 min of middle cerebral artery occlusion (MCAO). Liraglutide or semaglutide was administered either i.v. at the onset of reperfusion or s.c. 5 min before the onset of reperfusion. Infarct size and functional status were evaluated after 24 h or 72 h of reperfusion. Results Liraglutide, administered as a bolus at the onset of reperfusion, reduced infarct size by up to 90% and improved neuroscore at 24 h in a dose-dependent manner, following 90-min, but not 120-min or 180-min ischaemia. Semaglutide and liraglutide administered s.c. reduced infarct size by 63% and 48%, respectively, and improved neuroscore at 72 h following 90-min MCAO. Neuroprotection by semaglutide was abolished by GLP1-R antagonist exendin(9-39). Conclusion Infarct-limiting and functional neuroprotective effects of liraglutide are dose-dependent. Neuroprotection by semaglutide is at least as strong as by liraglutide and is mediated by GLP-1Rs.

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