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Mingdong Dong - One of the best experts on this subject based on the ideXlab platform.
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Differential Modulating Effect of MoS2 on Amyloid Peptide Assemblies.
Chemistry - A European Journal, 2018Co-Authors: Jie Wang, Lei Liu, Hongxing Zhang, Yonghai Feng, Yibang Zhang, Menglin Chen, Mingdong DongAbstract:The abnormal fibrillogenesis of Amyloid Peptides such as Amyloid fibril and senior Amyloid plaques, is associated with the pathogenesis of many Amyloid diseases. Hence, modulation of Amyloid assemblies is related to the possible pathogenesis of some diseases. Some two-dimensional nanomaterials, that is, graphene oxide, tungsten disulfide, exhibit strong modulation effects on the Amyloid fibrillogenesis. Herein, the modulation effect of molybdenum disulfide on two Amyloid Peptide assemblies based on the label-free techniques is presented, including quartz crystal microbalance (QCM), AFM, and CD spectroscopy. MoS2 presents different modulating effects on the assembly of Amyloid-β Peptide (33-42) [Aβ (33-42)] and amylin (20-29), mainly owing to the distinct affinity between Amyloid Peptides and MoS2 . This is to our knowledge the first report of MoS2 as a modulator for Amyloid aggregation. It enriches the variety of 2D nanomodulators of Amyloid fibrillogenesis and explains the mechanism for the self-assembly of Amyloid Peptides, and expands the applications of MoS2 in biology.
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Identification of a Novel Parallel β-Strand Conformation within Molecular Monolayer of Amyloid Peptide.
Advanced Science, 2016Co-Authors: Lei Liu, Flemming Besenbacher, Shuai Zhang, Xiaofeng Wang, Søren Vrønning Hoffmann, Zheng Liu, Mingdong DongAbstract:The differentiation of protein properties and biological functions arises from the variation in the primary and secondary structure. Specifically, in abnormal assemblies of protein, such as Amyloid Peptide, the secondary structure is closely correlated with the stable ensemble and the cytotoxicity. In this work, the early Aβ33-42 aggregates forming the molecular monolayer at hydrophobic interface are investigated. The molecular monolayer of Amyloid Peptide Aβ33-42 consisting of novel parallel β-strand-like structure is further revealed by means of a quantitative nanomechanical spectroscopy technique with force controlled in pico-Newton range, combining with molecular dynamic simulation. The identified parallel β-strand-like structure of molecular monolayer is distinct from the antiparallel β-strand structure of Aβ33-42 Amyloid fibril. This finding enriches the molecular structures of Amyloid Peptide aggregation, which could be closely related to the pathogenesis of Amyloid disease.
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Size Effect of Graphene Oxide on Modulating Amyloid Peptide Assembly
Chemistry - A European Journal, 2015Co-Authors: Jie Wang, Lei Liu, Yunpeng Cao, Mingdong DongAbstract:Protein misfolding and abnormal assembly could lead to aggregates such as oligomer, proto-fibril, mature fibril, and senior Amyloid plaques, which are associated with the pathogenesis of many Amyloid diseases. These irreversible Amyloid aggregates typically form in vivo and researchers have been endeavoring to find new modulators to invert the aggregation propensity in vitro, which could increase understanding in the mechanism of the aggregation of Amyloid protein and pave the way to potential clinical treatment. Graphene oxide (GO) was shown to be a good modulator, which could strongly control the Amyloidosis of Aβ (33-42). In particular, quartz crystal microbalance (QCM), circular dichroism (CD) spectroscopy, and atomic force microscopy (AFM) measurements revealed the size-dependent manner of GO on modulating the assembly of Amyloid Peptides, which could be a possible way to regulate the self-assembled nanostructure of Amyloid Peptide in a predictable manner.
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Molecular tethering effect of C-terminus of Amyloid Peptide aβ42.
ACS Nano, 2014Co-Authors: Lei Liu, Lin Niu, Qiusen Han, Hongyang Duan, Mingdong Dong, Flemming Besenbacher, Chen Wang, Yanlian YangAbstract:Amyloid Peptides are considered to be the main contributor for the membrane disruption related to the pathogenesis of degenerative diseases. The variation of amino acids at the carboxylic terminus of Amyloid Peptide has revealed significant effects on the modulation of abnormal assemblies of Amyloid Peptides. In this work, molecular binding agents were tethered to the C-terminus of β-Amyloid Peptide 1–42 (Aβ42). The molecular interaction between Aβ42 and molecule tethers was identified at single molecule level by using scanning tunneling microscopy (STM). The mechanistic insight into the feature variation of the self-assembly of Aβ42 Peptide caused by molecular tethering at C-terminus was clearly revealed, which could appreciably affect the nucleation of Amyloid Peptide, thus reducing the membrane disruptions.
Stacey Vile - One of the best experts on this subject based on the ideXlab platform.
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β-Amyloid Peptide-induced Apoptosis Regulated by a Novel Protein Containing a G Protein Activation Module
Journal of Biological Chemistry, 2001Co-Authors: Eileen Marie Kajkowski, Xiaoping Ning, Stephen G. Walker, Heidi Jane Sofia, Weiye Wang, Wade Edris, Pranab K. Chanda, Erik Wagner, Stacey VileAbstract:Abstract Degeneration of neurons in Alzheimer's disease is mediated by β-Amyloid Peptide by diverse mechanisms, which include a putative apoptotic component stimulated by unidentified signaling events. This report describes a novel β-Amyloid Peptide-binding protein (denoted BBP) containing a G protein-coupling module. BBP is one member of a family of three proteins containing this conserved structure. The BBP subtype bound human β-Amyloid Peptidein vitro with high affinity and specificity. Expression of BBP in cell culture induced caspase-dependent vulnerability to β-Amyloid Peptide toxicity. Expression of a signaling-deficient dominant negative BBP mutant suppressed sensitivity of human Ntera-2 neurons to β-Amyloid Peptide mediated toxicity. These findings suggest that BBP is a target of neurotoxic β-Amyloid Peptide and provide new insight into the molecular pathophysiology of Alzheimer's disease.
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μ-Amyloid Peptide-induced Apoptosis Regulated by a Novel Protein Containing a G Protein Activation Module *
The Journal of biological chemistry, 2001Co-Authors: Eileen Marie Kajkowski, Xiaoping Ning, Stephen G. Walker, Heidi Jane Sofia, Weiye Wang, Wade Edris, Pranab K. Chanda, Erik Wagner, Stacey VileAbstract:Degeneration of neurons in Alzheimer's disease is mediated by μ-Amyloid Peptide by diverse mechanisms, which include a putative apoptotic component stimulated by unidentified signaling events. This report describes a novel μ-Amyloid Peptide-binding protein (denoted BBP) containing a G protein-coupling module. BBP is one member of a family of three proteins containing this conserved structure. The BBP subtype bound human μ-Amyloid Peptidein vitro with high affinity and specificity. Expression of BBP in cell culture induced caspase-dependent vulnerability to μ-Amyloid Peptide toxicity. Expression of a signaling-deficient dominant negative BBP mutant suppressed sensitivity of human Ntera-2 neurons to μ-Amyloid Peptide mediated toxicity. These findings suggest that BBP is a target of neurotoxic μ-Amyloid Peptide and provide new insight into the molecular pathophysiology of Alzheimer's disease.
Chieh-fu Chen - One of the best experts on this subject based on the ideXlab platform.
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Effects of baicalein on β-Amyloid Peptide-(25–35)-induced amnesia in mice
European Journal of Pharmacology, 2004Co-Authors: Sheng-yun Wang, Hui-hung Wang, Chieh-fu Chen, Chin-wen Chi, Jyh-fei LiaoAbstract:Baicalein may act on the benzodiazepine binding sites to exert an anxiolytic-like effect in mice. Since many benzodiazepine drugs have amnesic side-effect and baicalein can protect cultured cortical neurons from beta-Amyloid Peptide-(25-35)-induced toxicity, this study examined the amnesic effect of baicalein and its effects on beta-Amyloid Peptide-(25-35) (3 nmol/mouse, i.c.v.)-induced amnesia in mice. Using the step-through passive avoidance test, the results showed that baicalein (10-100 mg/kg, i.p.), unlike the benzodiazepine drug chlordiazepoxide (10 mg/kg, i.p.), had no significant amnesic effect. Baicalein (10-50 mg/kg, i.p.) also had no facilitating effect on the learning and memory. However, one dosage pretreatment, but not post-treatment, of baicalein (5 or 10 mg/kg, i.p.) attenuated beta-Amyloid Peptide-(25-35)-induced amnesia. Interestingly, post-treatment for 7 or 13 days of baicalein (10-15 mg/kg/day, i.p.), like melatonin (10 mg/kg/day, i.p.), also attenuated beta-Amyloid Peptide-(25-35)-induced amnesia. Therefore, this study demonstrated that baicalein has protective effect on beta-Amyloid Peptide-(25-35)-induced amnesia.
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Dehydroevodiamine attenuates β-Amyloid Peptide-induced amnesia in mice
European Journal of Pharmacology, 2001Co-Authors: Hui-hung Wang, Cheng-jen Chou, Jyh-fei Liao, Chieh-fu ChenAbstract:Abstract Dehydroevodiamine has been reported to have anticholinesterase activity and an anti-amnesic effect. This study examined the effects of dehydroevodiamine on scopolamine- and β-Amyloid Peptide-(25–35)-induced amnesia in mice, using a step-through passive avoidance test. Similarly to the cholinesterase inhibitor, physostigmine (0.03–0.3 mg/kg, i.p.), dehydroevodiamine (0.75–12.0 mg/kg, i.p.) administered 30 min before the training trial, immediately after the training trial, and 30 min before the retention test significantly improved scopolamine- and β-Amyloid Peptide-(25–35)-induced amnesia. In β-Amyloid Peptide-(25–35)-induced amnesia, the rank order of anti-amnesic potency in these three administration schedules for dehydroevodiamine was different from that for physostigmine. Furthermore, dehydroevodiamine was more potent to improve β-Amyloid Peptide-(25–35)-induced amnesia than scopolamine-induced amnesia when administered before the training trial. These results suggested that dehydroevodiamine may have an action other than that of an anticholinesterase and may be a novel and effective ligand for improvement of β-Amyloid type amnesia.
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Dehydroevodiamine attenuates beta-Amyloid Peptide-induced amnesia in mice.
European Journal of Pharmacology, 2001Co-Authors: Hui-hung Wang, Cheng-jen Chou, Jyh-fei Liao, Chieh-fu ChenAbstract:Dehydroevodiamine has been reported to have anticholinesterase activity and an anti-amnesic effect. This study examined the effects of dehydroevodiamine on scopolamine- and beta-Amyloid Peptide-(25--35)-induced amnesia in mice, using a step-through passive avoidance test. Similarly to the cholinesterase inhibitor, physostigmine (0.03--0.3 mg/kg, i.p.), dehydroevodiamine (0.75--12.0 mg/kg, i.p.) administered 30 min before the training trial, immediately after the training trial, and 30 min before the retention test significantly improved scopolamine- and beta-Amyloid Peptide-(25--35)-induced amnesia. In beta-Amyloid Peptide-(25--35)-induced amnesia, the rank order of anti-amnesic potency in these three administration schedules for dehydroevodiamine was different from that for physostigmine. Furthermore, dehydroevodiamine was more potent to improve beta-Amyloid Peptide-(25--35)-induced amnesia than scopolamine-induced amnesia when administered before the training trial. These results suggested that dehydroevodiamine may have an action other than that of an anticholinesterase and may be a novel and effective ligand for improvement of beta-Amyloid type amnesia.
Jean-noël Octave - One of the best experts on this subject based on the ideXlab platform.
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Missense mutations associated with familial Alzheimer's disease in Sweden lead to the production of the Amyloid Peptide without internalization of its precursor.
Biochemical and Biophysical Research Communications, 1996Co-Authors: Rachid Essalmani, A. F. Macq, Luc Mercken, Jean-noël OctaveAbstract:Production of soluble Amyloid Peptide precursor (APP) and Amyloid Peptide (A beta) was measured in CHO cells transfected by the wild-type APP 695 cDNA sequence or by the same sequence carrying missense mutations associated with familial Alzheimer's disease in Sweden. Deletion of the C-terminal domain of the protein corresponding to residues 654 to 695 of APP 695 not only inhibited very significantly the internalization of APP at 37 degrees C, but also led to the secretion of an uncleaved APP in the culture medium of CHO cells. This deletion did not affect A beta production from the Swedish APP but was able to inhibit the production of the wild-type APP. These results demonstrate that, in CHO cells, the internalization of the wild-type APP is needed for A beta production, while the production of the Amyloid Peptide from Swedish APP is independent of the internalization process.
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The Amyloid Peptide and its precursor in Alzheimer's disease.
Reviews in the Neurosciences, 1995Co-Authors: Jean-noël OctaveAbstract:Alzheimer's disease, the most frequent cause of dementia, is characterized by the formation in the brain of neurofibrillary tangles and senile plaques. Neurofibrillary tangles are composed of bundles of paired helical filaments containing the microtubule-associated protein tau. In autopsy-derived brain samples from patients with Alzheimer's disease, tau is hyperphosphorylated and constitutes a promising disease marker. Senile plaques contain a small Amyloid Peptide derived from the Amyloid precursor protein. Mutations of the Amyloid precursor protein gene have been identified in rare cases of familial Alzheimer's disease, suggesting a causal role for Amyloid Peptide deposition in the disease. However, Alzheimer's disease has been demonstrated to be characterized by an important genetic heterogeneity. The identification of pathogenic DNA mutations, different from those of the Amyloid precursor protein gene, will reveal whether the corresponding genes are involved in either an increased production of the Amyloid Peptide or a decrease of its removal, or in the fibrillogenic properties of the Peptide, which seem to be related to its toxicity. Several mammalian cells are able to produce the Amyloid Peptide from its precursor. Understanding the cellular mechanisms that determine how cleavages occur in cells could help to identify new strategies for modulating Amyloid Peptide production. In attempts to produce animal models of Alzheimer's disease, investigators have used transgenic strategies. To date, these efforts have not been very successful. However, the expression in transgenic mice of both mutated Amyloid Peptide precursor and Amyloid associated proteins should prove useful for examining the importance of putative etiological factors, and for testing novel therapies including anti-Amyloidogenic strategies.
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The Amyloid Peptide of Alzheimer's disease is not produced by internal initiation of translation generating C-terminal Amyloidogenic fragments of its precursor
Neuroscience Letters, 1994Co-Authors: A. F. Macq, Barbara Philippe, Jean-noël OctaveAbstract:The molecular mechanisms of the Amyloid Peptide (A beta) production from the Amyloid precursor protein (APP) remain unclear and it has been suggested that initiation of translation at methionine 596, which immediately precedes the A beta sequence, could generate soluble Amyloidogenic fragments. We show that the Amyloid Peptide is actually produced by expression of the C-terminal 100 residues of the APP, using methionine 596 as an initiation codon. However, the Amyloid Peptide is no longer detectable when a stop codon is introduced in the APP mRNA, before the A beta coding region. These results strongly suggest that A beta is produced by degradation of APP and not by local translation of its mRNA.
Hui-hung Wang - One of the best experts on this subject based on the ideXlab platform.
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Effects of baicalein on β-Amyloid Peptide-(25–35)-induced amnesia in mice
European Journal of Pharmacology, 2004Co-Authors: Sheng-yun Wang, Hui-hung Wang, Chieh-fu Chen, Chin-wen Chi, Jyh-fei LiaoAbstract:Baicalein may act on the benzodiazepine binding sites to exert an anxiolytic-like effect in mice. Since many benzodiazepine drugs have amnesic side-effect and baicalein can protect cultured cortical neurons from beta-Amyloid Peptide-(25-35)-induced toxicity, this study examined the amnesic effect of baicalein and its effects on beta-Amyloid Peptide-(25-35) (3 nmol/mouse, i.c.v.)-induced amnesia in mice. Using the step-through passive avoidance test, the results showed that baicalein (10-100 mg/kg, i.p.), unlike the benzodiazepine drug chlordiazepoxide (10 mg/kg, i.p.), had no significant amnesic effect. Baicalein (10-50 mg/kg, i.p.) also had no facilitating effect on the learning and memory. However, one dosage pretreatment, but not post-treatment, of baicalein (5 or 10 mg/kg, i.p.) attenuated beta-Amyloid Peptide-(25-35)-induced amnesia. Interestingly, post-treatment for 7 or 13 days of baicalein (10-15 mg/kg/day, i.p.), like melatonin (10 mg/kg/day, i.p.), also attenuated beta-Amyloid Peptide-(25-35)-induced amnesia. Therefore, this study demonstrated that baicalein has protective effect on beta-Amyloid Peptide-(25-35)-induced amnesia.
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Dehydroevodiamine attenuates β-Amyloid Peptide-induced amnesia in mice
European Journal of Pharmacology, 2001Co-Authors: Hui-hung Wang, Cheng-jen Chou, Jyh-fei Liao, Chieh-fu ChenAbstract:Abstract Dehydroevodiamine has been reported to have anticholinesterase activity and an anti-amnesic effect. This study examined the effects of dehydroevodiamine on scopolamine- and β-Amyloid Peptide-(25–35)-induced amnesia in mice, using a step-through passive avoidance test. Similarly to the cholinesterase inhibitor, physostigmine (0.03–0.3 mg/kg, i.p.), dehydroevodiamine (0.75–12.0 mg/kg, i.p.) administered 30 min before the training trial, immediately after the training trial, and 30 min before the retention test significantly improved scopolamine- and β-Amyloid Peptide-(25–35)-induced amnesia. In β-Amyloid Peptide-(25–35)-induced amnesia, the rank order of anti-amnesic potency in these three administration schedules for dehydroevodiamine was different from that for physostigmine. Furthermore, dehydroevodiamine was more potent to improve β-Amyloid Peptide-(25–35)-induced amnesia than scopolamine-induced amnesia when administered before the training trial. These results suggested that dehydroevodiamine may have an action other than that of an anticholinesterase and may be a novel and effective ligand for improvement of β-Amyloid type amnesia.
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Dehydroevodiamine attenuates beta-Amyloid Peptide-induced amnesia in mice.
European Journal of Pharmacology, 2001Co-Authors: Hui-hung Wang, Cheng-jen Chou, Jyh-fei Liao, Chieh-fu ChenAbstract:Dehydroevodiamine has been reported to have anticholinesterase activity and an anti-amnesic effect. This study examined the effects of dehydroevodiamine on scopolamine- and beta-Amyloid Peptide-(25--35)-induced amnesia in mice, using a step-through passive avoidance test. Similarly to the cholinesterase inhibitor, physostigmine (0.03--0.3 mg/kg, i.p.), dehydroevodiamine (0.75--12.0 mg/kg, i.p.) administered 30 min before the training trial, immediately after the training trial, and 30 min before the retention test significantly improved scopolamine- and beta-Amyloid Peptide-(25--35)-induced amnesia. In beta-Amyloid Peptide-(25--35)-induced amnesia, the rank order of anti-amnesic potency in these three administration schedules for dehydroevodiamine was different from that for physostigmine. Furthermore, dehydroevodiamine was more potent to improve beta-Amyloid Peptide-(25--35)-induced amnesia than scopolamine-induced amnesia when administered before the training trial. These results suggested that dehydroevodiamine may have an action other than that of an anticholinesterase and may be a novel and effective ligand for improvement of beta-Amyloid type amnesia.