Amyloid β(Aβ)1-42 fibrillation is a crucial step in the development of pathological hallmarks, such as neuritic plaques and neurofibrillary tangles, of Alzheimer’s disease (AD). In this study, we evaluated the effe...Amyloid β(Aβ)1-42 fibrillation is a crucial step in the development of pathological hallmarks, such as neuritic plaques and neurofibrillary tangles, of Alzheimer’s disease (AD). In this study, we evaluated the effects of free docosahexaenoic acid (DHA), an essential brain polyunsaturated fatty acid (PUFA), on the inhibition of Aβ1-42 fibrillation by fluorescence correlation spectroscopy (FCS), a technique capable of detecting molecular movements and interactions in solution. We also examined whether free arachidonic acid (AA), eicosapentaenoic acid (EPA), and metabolites of DHA, including neuroprotectin D1 (NPD1, 10S, 17S-dihydroxy-DHA), resolvin D1 (RvD1, 7S, 8R, 17S-trihydroxy-DHA), and didocosahexaenoyl glycerol (diDHA), affect Aβ1-42 polymerization. The results of the FCS study reveal that DHA and AA significantly reduced the diffusion time of TAMRA (5-carboxytetramethylrhoda-mine)-Aβ1-42 by 28% and 31%, respectively, while EPA, NPD1, RvD1, and diDHA had no effects on diffusion time. These results indicate that DHA and AA inhibited Aβ1-42 polymerization and that their inhibitory effects occurred at the initial stage of Aβ1-42 polymerization. This study will advance the research on PUFAs in preventing AD progression.展开更多
The accumulation of amyloid β peptide 1 - 42 (Aβ1-42) in the brain of Alzheimer’s disease (AD) patients is known to be associated with neurodegeneration and memory impairment. More recently, we reported that madeca...The accumulation of amyloid β peptide 1 - 42 (Aβ1-42) in the brain of Alzheimer’s disease (AD) patients is known to be associated with neurodegeneration and memory impairment. More recently, we reported that madecassoside, an active component of Centella asiatica, improved memory impairment in an Aβ1-42 infusion rat model of AD, ameliorated neurotoxicity in SH-SY5Y cells, and inhibited in vitro Aβ1-42 fibril formation. In the present study, we investigated the utility of in silico analyses in corroborating observed in vivo and in vitro effects of madecassoside in AD to further assess the therapeutic benefits of madecassoside. The 3D structure of Aβ1-42 was downloaded from the Research Collaboratory for Structural Bioinformatics (RCSB) Protein Data Bank (PDB). The binding of madecassoside to Aβ1-42 was assessed by molecular docking. The chemical structure of madecassoside was modeled and converted to the PDB format. Madecassoside was found to successfully dock with Aβ1-42. Computational demonstration of the binding of madecassoside to Aβ1-42 further corroborated the inhibitory effect of madecassoside on Aβ1-42 fibrillogenesis which was demonstrated in our previous study. These data showed the potential utility of madecassoside as a preventive medication in Aβ1-42-induced neurodegenerative diseases such as AD.展开更多
The accumulation of amyloid β peptide<sub>1-42</sub> (Aβ<sub>1-42</sub>) masses in the brains of Alzheimer’s Disease (AD) patients is associated with neuronal loss and memory deficits. We ha...The accumulation of amyloid β peptide<sub>1-42</sub> (Aβ<sub>1-42</sub>) masses in the brains of Alzheimer’s Disease (AD) patients is associated with neuronal loss and memory deficits. We have previously reported that oral administration of docosahexaenoic acid (DHA, C22:6, n-3) significantly decreases Aβ burden in the brains of AD model rats and that direct in vitro incubation of DHA with Aβ<sub>1-42</sub> curbs the progression of amyloid fibrillation. In the present in silico study, we investigated whether DHA computationally binds with amyloid peptides. The NMR solution structures of Aβ<sub>1-42</sub> were downloaded from the Protein Data Bank (PDB IDs: 1Z0Q and 2BEG). The binding of DHA to Aβ peptides was assessed by molecular docking using both a flexible and rigid docking system. Thioflavin T (ThT) was used as positive control. The chemical structures of ThT and DHA were modeled and converted to the PDB format using PRODRUG. Drug-like properties of DHA were evaluated by ADME (Absorption, Distribution, Metabolism, and Excretion). DHA was found to successfully dock with Aβ<sub>1-42</sub>. Computational analyses of the binding of DHA to Aβ<sub>1-42</sub>, as evaluated by docking studies, further corroborated the inhibitory effect of DHA on in vitro Aβ<sub>1-42</sub> fibrillogenesis and might explain the in vivo reduction of amyloid burden observed in the brains of DHA-administered AD model rats demonstrated in our previous study. These computational data suggest the potential utility of DHA as a preventive medication in Aβ-induced neurodegenerative diseases, including AD.展开更多
The present study employed an imaging mass spectrometry (IMS) method to evaluate the effect of dietary n – 3 fatty acids on the fatty acid composition in rat brain. Rats were divided into two groups and fed either an...The present study employed an imaging mass spectrometry (IMS) method to evaluate the effect of dietary n – 3 fatty acids on the fatty acid composition in rat brain. Rats were divided into two groups and fed either an n – 3 fatty acid-deficient or adequate diet. We determined the decreased n – 3 fatty acids in the hippocampus of rats fed an n – 3 fatty acid-deficient diet compared to the control. IMS visualization was achieved at a resolution of 100 m in rat brain, and showed decreased docosahexaenoic acid (DHA)-containing phosphatidyl choline (PC) or phosphatidyl ethanolamine (PE) in the hippocampus of rats fed an n – 3 fatty acid-deficient diet.展开更多
文摘Amyloid β(Aβ)1-42 fibrillation is a crucial step in the development of pathological hallmarks, such as neuritic plaques and neurofibrillary tangles, of Alzheimer’s disease (AD). In this study, we evaluated the effects of free docosahexaenoic acid (DHA), an essential brain polyunsaturated fatty acid (PUFA), on the inhibition of Aβ1-42 fibrillation by fluorescence correlation spectroscopy (FCS), a technique capable of detecting molecular movements and interactions in solution. We also examined whether free arachidonic acid (AA), eicosapentaenoic acid (EPA), and metabolites of DHA, including neuroprotectin D1 (NPD1, 10S, 17S-dihydroxy-DHA), resolvin D1 (RvD1, 7S, 8R, 17S-trihydroxy-DHA), and didocosahexaenoyl glycerol (diDHA), affect Aβ1-42 polymerization. The results of the FCS study reveal that DHA and AA significantly reduced the diffusion time of TAMRA (5-carboxytetramethylrhoda-mine)-Aβ1-42 by 28% and 31%, respectively, while EPA, NPD1, RvD1, and diDHA had no effects on diffusion time. These results indicate that DHA and AA inhibited Aβ1-42 polymerization and that their inhibitory effects occurred at the initial stage of Aβ1-42 polymerization. This study will advance the research on PUFAs in preventing AD progression.
文摘The accumulation of amyloid β peptide 1 - 42 (Aβ1-42) in the brain of Alzheimer’s disease (AD) patients is known to be associated with neurodegeneration and memory impairment. More recently, we reported that madecassoside, an active component of Centella asiatica, improved memory impairment in an Aβ1-42 infusion rat model of AD, ameliorated neurotoxicity in SH-SY5Y cells, and inhibited in vitro Aβ1-42 fibril formation. In the present study, we investigated the utility of in silico analyses in corroborating observed in vivo and in vitro effects of madecassoside in AD to further assess the therapeutic benefits of madecassoside. The 3D structure of Aβ1-42 was downloaded from the Research Collaboratory for Structural Bioinformatics (RCSB) Protein Data Bank (PDB). The binding of madecassoside to Aβ1-42 was assessed by molecular docking. The chemical structure of madecassoside was modeled and converted to the PDB format. Madecassoside was found to successfully dock with Aβ1-42. Computational demonstration of the binding of madecassoside to Aβ1-42 further corroborated the inhibitory effect of madecassoside on Aβ1-42 fibrillogenesis which was demonstrated in our previous study. These data showed the potential utility of madecassoside as a preventive medication in Aβ1-42-induced neurodegenerative diseases such as AD.
文摘The accumulation of amyloid β peptide<sub>1-42</sub> (Aβ<sub>1-42</sub>) masses in the brains of Alzheimer’s Disease (AD) patients is associated with neuronal loss and memory deficits. We have previously reported that oral administration of docosahexaenoic acid (DHA, C22:6, n-3) significantly decreases Aβ burden in the brains of AD model rats and that direct in vitro incubation of DHA with Aβ<sub>1-42</sub> curbs the progression of amyloid fibrillation. In the present in silico study, we investigated whether DHA computationally binds with amyloid peptides. The NMR solution structures of Aβ<sub>1-42</sub> were downloaded from the Protein Data Bank (PDB IDs: 1Z0Q and 2BEG). The binding of DHA to Aβ peptides was assessed by molecular docking using both a flexible and rigid docking system. Thioflavin T (ThT) was used as positive control. The chemical structures of ThT and DHA were modeled and converted to the PDB format using PRODRUG. Drug-like properties of DHA were evaluated by ADME (Absorption, Distribution, Metabolism, and Excretion). DHA was found to successfully dock with Aβ<sub>1-42</sub>. Computational analyses of the binding of DHA to Aβ<sub>1-42</sub>, as evaluated by docking studies, further corroborated the inhibitory effect of DHA on in vitro Aβ<sub>1-42</sub> fibrillogenesis and might explain the in vivo reduction of amyloid burden observed in the brains of DHA-administered AD model rats demonstrated in our previous study. These computational data suggest the potential utility of DHA as a preventive medication in Aβ-induced neurodegenerative diseases, including AD.
文摘The present study employed an imaging mass spectrometry (IMS) method to evaluate the effect of dietary n – 3 fatty acids on the fatty acid composition in rat brain. Rats were divided into two groups and fed either an n – 3 fatty acid-deficient or adequate diet. We determined the decreased n – 3 fatty acids in the hippocampus of rats fed an n – 3 fatty acid-deficient diet compared to the control. IMS visualization was achieved at a resolution of 100 m in rat brain, and showed decreased docosahexaenoic acid (DHA)-containing phosphatidyl choline (PC) or phosphatidyl ethanolamine (PE) in the hippocampus of rats fed an n – 3 fatty acid-deficient diet.
