Beta-amyloid oligomers: recent developments

2011 ◽  
Vol 2 (3) ◽  
pp. 211-222 ◽  
Author(s):  
Vilmante Borutaite ◽  
Ramune Morkuniene ◽  
Gintaras Valincius
Keyword(s):  
Critical Role ◽  
Chemical Properties ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Beta Amyloid ◽  
Amyloid Oligomers ◽  
Recent Developments ◽  
Β Amyloid

AbstractRecent studies point to a critical role of soluble β-amyloid oligomers in the pathogenesis of one of the most common neurodegenerative diseases, Alzheimer's disease (AD). Beta-amyloid peptides are cleavage products of a ubiquitously expressed protein, the amyloid precursor protein. Early studies suggested that accumulation of extracellular β-amyloid aggregates are the most toxic species causing synaptic dysfunction and neuronal loss in particular regions of the brain (neurobiological features underlying cognitive decline of the AD patients). In recent years, a shift of pardigm occurred, and now there is accumulating evidence that soluble oligomeric forms of the peptide are the most toxic to neuronal cells. In this review, we discuss recent findings on the toxic effects of amyloid-β oligomers, their physico-chemical properties and the possible pathways of their formation in vitro and in vivo.

scholarly journals The State of the Art and Prospects for Osteoimmunomodulatory Biomaterials

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1357
Author(s):  
Andreea-Mariana Negrescu ◽  
Anisoara Cimpean
Keyword(s):  
Foreign Bodies ◽  
Structural Characteristics ◽  
Critical Role ◽  
Fibrous Tissue ◽  
Bioactive Molecules ◽  
New Bone Formation ◽  
Recent Developments

The critical role of the immune system in host defense against foreign bodies and pathogens has been long recognized. With the introduction of a new field of research called osteoimmunology, the crosstalk between the immune and bone-forming cells has been studied more thoroughly, leading to the conclusion that the two systems are intimately connected through various cytokines, signaling molecules, transcription factors and receptors. The host immune reaction triggered by biomaterial implantation determines the in vivo fate of the implant, either in new bone formation or in fibrous tissue encapsulation. The traditional biomaterial design consisted in fabricating inert biomaterials capable of stimulating osteogenesis; however, inconsistencies between the in vitro and in vivo results were reported. This led to a shift in the development of biomaterials towards implants with osteoimmunomodulatory properties. By endowing the orthopedic biomaterials with favorable osteoimmunomodulatory properties, a desired immune response can be triggered in order to obtain a proper bone regeneration process. In this context, various approaches, such as the modification of chemical/structural characteristics or the incorporation of bioactive molecules, have been employed in order to modulate the crosstalk with the immune cells. The current review provides an overview of recent developments in such applied strategies.

scholarly journals Correction: A glycine zipper motif mediates the formation of toxic beta-amyloid oligomers in vitro and in vivo

2014 ◽  
Vol 9 (1) ◽  
pp. 12
Author(s):  
Virginia Fonte ◽  
Vishantie Dostal ◽  
Christine M Roberts ◽  
Patrick Gonzales ◽  
Pascale N Lacor ◽  
...  
Keyword(s):  
Beta Amyloid ◽  
Amyloid Oligomers

scholarly journals Optical imaging-guided cancer therapy with fluorescent nanoparticles

2009 ◽  
Vol 7 (42) ◽  
pp. 3-18 ◽  
Author(s):  
Shan Jiang ◽  
Muthu Kumara Gnanasammandhan ◽  
Yong Zhang
Keyword(s):  
Cancer Therapy ◽  
Optical Imaging ◽  
Critical Role ◽  
Therapeutic Agents ◽  
Fluorescent Nanoparticles ◽  
Highly Sensitive ◽  
Imaging Probes ◽  
Recent Developments

The diagnosis and treatment of cancer have been greatly improved with the recent developments in nanotechnology. One of the promising nanoscale tools for cancer diagnosis is fluorescent nanoparticles (NPs), such as organic dye-doped NPs, quantum dots and upconversion NPs that enable highly sensitive optical imaging of cancer at cellular and animal level. Furthermore, the emerging development of novel multi-functional NPs, which can be conjugated with several functional molecules simultaneously including targeting moieties, therapeutic agents and imaging probes, provides new potentials for clinical therapies and diagnostics and undoubtedly will play a critical role in cancer therapy. In this article, we review the types and characteristics of fluorescent NPs, in vitro and in vivo imaging of cancer using fluorescent NPs and multi-functional NPs for imaging-guided cancer therapy.

scholarly journals Reducing miR485-3p ameliorates Alzheimer`s disease pathology by regulation of amyloid beta and neuro-inflammation

2020 ◽  
Author(s):  
Han Seok Koh ◽  
Hannah Jang ◽  
SooKil Tae ◽  
mi-sun Lee ◽  
Jae-Woong Min ◽  
...  
Keyword(s):  
Mouse Model ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Precentral Gyrus ◽  
Alzheimer Patient ◽  
5Xfad Mice

Abstract Background Alzheimer`s disease (AD) is a progressive neurodegenerative disease worldwide. Accumulation of amyloid-β (Aβ), neurofibrillary tangles and neuroinflammation play the important neuro-pathology in patients with AD. miRNA is multifunctional and involved in physiological and pathological processes. Recently, microRNAs have been linked to neurodegenerative diseases. However, it is little known whether miRNA dysregulation contributes to AD pathology progression such as Aβ processing, phagocytosis and neuroinflammation. Here, we identify miR485-3p as a novel modulator of AD pathology in 5XFAD mice. Methods To study the role of miR485-3p in AD, we used in control or miR485-3p antisense oligonucleotides (miR485-3p ASO) injected 5XFAD mouse model. Changes of Aβ processing and clearance and inflammation were analyzed by biochemical method in vitro and in vivo. Result This study suggests that miR485-3p, a novel miRNA targeting SIRT1 may contribute to pathogenesis in an AD mouse. We found SIRT1 is significantly reduced in the precentral gyrus of Alzheimer patient`s and in 5XFAD mice. To determine whether the inhibition of miRNA 485-3p would affect AD pathology, we studied the effect of the antisense oligo in the brain of 5XFAD mice through direct intracerebral ventricular injection with miR485-3p ASO. We demonstrated that miR485-3p ASO significantly reduced Aβ plaque and amyloid biosynthetic enzyme. Importantly, the attenuation of Aβ plaques through miR485-3p ASO was mediated through Aβ phagocytic activity of glial cells, by which it can directly target CD36. MiR485-3p ASO also decreased inflammatory responses. Collectively, these responses inhibited neuronal loss caused by Aβ lead to improvements of cognitive impairment. Conclusion Our data provide evidence for the molecular mechanisms which underlie the miR485-3p ASO responses in an AD mouse model. These results suggest that attenuating miRNA 485-3p levels might represent a novel therapeutic approach in AD.

scholarly journals Procyanidins Extracted from Lotus Seedpod Ameliorate Amyloid-β-Induced Toxicity in Rat Pheochromocytoma Cells

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Hao Huang ◽  
Peipei Yan ◽  
Taoping Sun ◽  
Xiaoxing Mo ◽  
Jiawei Yin ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Pc12 Cells ◽  
Senile Plaque ◽  
Critical Role ◽  
Amyloid Β ◽  
Bdnf Signaling ◽  
Lotus Seedpod

Alzheimer’s disease (AD) is a progressive neurodegenerative disease, which is characterized by extracellular senile plaque deposits, intracellular neurofibrillary tangles, and neuronal apoptosis. Amyloid-β (Aβ) plays a critical role in AD that may cause oxidative stress and downregulation of CREB/BDNF signaling. Anti-Aβ effect has been discussed as a potential therapeutic strategy for AD. This study aimed to identify the amelioration of procyanidins extracted from lotus seedpod (LSPC) on Aβ-induced damage with associated pathways for AD treatment. Rat pheochromocytoma (PC12) cells incubated with Aβ25–35 serve as an Aβ damage model to evaluate the effect of LSPC in vitro. Our findings illustrated that LSPC maintained the cellular morphology from deformation and reduced apoptosis rates of cells induced by Aβ25–35. The mechanisms of LSPC to protect cells from Aβ-induced damage were based on its regulation of oxidation index and activation of CREB/BDNF signaling, including brain-derived neurotrophic factor (BDNF) and phosphorylation of cAMP-responsive element-binding (CREB), protein kinase B (also known as AKT), and the extracellular signal-regulated kinase (ERK). Of note, by high-performance liquid chromatography-tandem mass spectroscopy (LC-MS/MS), several metabolites were detected to accumulate in vivo, part of which could take primary responsibility for the amelioration of Aβ-induced damage on PC12 cells. Taken together, our research elucidated the effect of LSPC on neuroprotection through anti-Aβ, indicating it as a potential pretreatment for Alzheimer’s disease.

scholarly journals A glycine zipper motif mediates the formation of toxic β-amyloid oligomers in vitro and in vivo

2011 ◽  
Vol 6 (1) ◽  
pp. 61 ◽  
Author(s):  
Virginia Fonte ◽  
Vishantie Dostal ◽  
Christine M Roberts ◽  
Patrick Gonzales ◽  
Pascale Lacor ◽  
...  
Keyword(s):  
Amyloid Oligomers ◽  
Β Amyloid

scholarly journals Reducing miR485-3p ameliorates Alzheimer`s disease pathology by regulation of amyloid beta and neuro-inflammation

2020 ◽  
Author(s):  
Han Seok Koh ◽  
Hannah Jang ◽  
Sookil Tae ◽  
mi-sun Lee ◽  
Jae-Woong Min ◽  
...  
Keyword(s):  
Mouse Model ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Precentral Gyrus ◽  
Alzheimer Patient ◽  
5Xfad Mice

Abstract Background Alzheimer`s disease (AD) is a progressive neurodegenerative disease worldwide. Accumulation of amyloid-β (Aβ), neurofibrillary tangles and neuroinflammation play the important neuro-pathology in patients with AD. miRNA is multifunctional and involved in physiological and pathological processes. Recently, microRNAs have been linked to neurodegenerative diseases. However, it is little known whether miRNA dysregulation contributes to AD pathology progression such as Ab processing, phagocytosis and neuroinflammation. Here, we identify miR485-3p as a novel modulator of AD pathology in 5XFAD mice. Methods To study the role of miR485-3p in AD, we used in control or miR485-3p antisense oligonucleotides (miR485-3p ASO) injected 5XFAD mouse model. Changes of Ab processing, clearance and inflammation were analyzed by biochemical method in vitro and in vivo. Results This study suggests that miR485-3p, a novel miRNA targeting SIRT1 may contribute to pathogenesis in an AD mouse. We found SIRT1 is significantly reduced in the precentral gyrus of Alzheimer patient`s and in 5XFAD mice. To determine whether the inhibition of miRNA 485-3p would affect AD pathology, we studied the effect of the antisense oligo in the brain of 5XFAD mice through direct intracerebral ventricular injection with miR485-3p ASO. We demonstrated that miR485-3p ASO significantly reduced Aβ plaque and amyloid biosynthetic enzyme. Importantly, the attenuation of Aβ plaques through miR485-3p ASO was mediated through Aβ phagocytic activity of glial cells, by which it can directly target CD36. MiR485-3p ASO also decreased inflammatory responses. Collectively, these responses inhibited neuronal loss caused by Aβ lead to improvements of cognitive impairment. Conclusion Our data provide evidence for the molecular mechanisms which underlie the miR485-3p ASO responses in an AD mouse model. These results suggest that attenuating miRNA 485-3p levels might represent a novel therapeutic approach in AD.

scholarly journals A novel missense variant in ACAA1 contributes to early-onset Alzheimer’s disease, impairs lysosomal function, and facilitates amyloid-β pathology and cognitive decline

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Rongcan Luo ◽  
Yu Fan ◽  
Jing Yang ◽  
Maosen Ye ◽  
Deng-Feng Zhang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Early Onset ◽  
Neurofibrillary Tangle ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Missense Variant ◽  
Lysosomal Function

AbstractAlzheimer’s disease (AD) is characterized by progressive synaptic dysfunction, neuronal death, and brain atrophy, with amyloid-β (Aβ) plaque deposits and hyperphosphorylated tau neurofibrillary tangle accumulation in the brain tissue, which all lead to loss of cognitive function. Pathogenic mutations in the well-known AD causal genes including APP, PSEN1, and PSEN2 impair a variety of pathways, including protein processing, axonal transport, and metabolic homeostasis. Here we identified a missense variant rs117916664 (c.896T>C, p.Asn299Ser [p.N299S]) of the acetyl-CoA acyltransferase 1 (ACAA1) gene in a Han Chinese AD family by whole-genome sequencing and validated its association with early-onset familial AD in an independent cohort. Further in vitro and in vivo evidence showed that ACAA1 p.N299S contributes to AD by disturbing its enzymatic activity, impairing lysosomal function, and aggravating the Aβ pathology and neuronal loss, which finally caused cognitive impairment in a murine model. Our findings reveal a fundamental role of peroxisome-mediated lysosomal dysfunction in AD pathogenesis.

scholarly journals Perturbation of Transcription Factor Nur77 Expression Mediated by Myocyte Enhancer Factor 2D (MEF2D) Regulates Dopaminergic Neuron Loss in Response to 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)

2013 ◽  
Vol 288 (20) ◽  
pp. 14362-14371 ◽  
Author(s):  
Matthew P. Mount ◽  
Yi Zhang ◽  
Mandana Amini ◽  
Steve Callaghan ◽  
Jerzy Kulczycki ◽  
...  
Keyword(s):  
Critical Role ◽  
Neuronal Loss ◽  
Nigrostriatal System ◽  
Myocyte Enhancer Factor ◽  
Mptp Treatment ◽  
Dopaminergic Neuronal Loss ◽  
Dopaminergic Neuron Loss ◽  
Enhancer Factor

We have earlier reported the critical nature of calpain-CDK5-MEF2 signaling in governing dopaminergic neuronal loss in vivo. CDK5 mediates phosphorylation of the neuronal survival factor myocyte enhancer factor 2 (MEF2) leading to its inactivation and loss. However, the downstream factors that mediate MEF2-regulated survival are unknown. Presently, we define Nur77 as one such critical downstream survival effector. Following 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment in vivo, Nur77 expression in the nigrostriatal region is dramatically reduced. This loss is attenuated by expression of MEF2. Importantly, MEF2 constitutively binds to the Nur77 promoter in neurons under basal conditions. This binding is lost following 1-methyl-4-phenylpyridinium treatment. Nur77 deficiency results in significant sensitization to dopaminergic loss following 1-methyl-4-phenylpyridinium/MPTP treatment, in vitro and in vivo. Furthermore, Nur77-deficient MPTP-treated mice displayed significantly reduced levels of dopamine and 3,4-Dihydroxyphenylacetic acid in the striatum as well as elevated post synaptic FosB activity, indicative of increased nigrostriatal damage when compared with WT MPTP-treated controls. Importantly, this sensitization in Nur77-deficient mice was rescued with ectopic Nur77 expression in the nigrostriatal system. These results indicate that the inactivation of Nur77, induced by loss of MEF2 activity, plays a critical role in nigrostriatal degeneration in vivo.

Phenolic Acids Exert Anticholinesterase and Cognition-Improving Effects

2018 ◽  
Vol 15 (6) ◽  
pp. 531-543 ◽  
Author(s):  
Dominik Szwajgier ◽  
Ewa Baranowska-Wojcik ◽  
Kamila Borowiec
Keyword(s):  
Phenolic Acids ◽  
Ex Vivo ◽  
Amyloid Β ◽  
Inhibitory Effect ◽  
In Vivo Studies ◽  
Amyloid Β Peptide ◽  
Beneficial Effects ◽  
Aβ Fibrils

Numerous authors have provided evidence regarding the beneficial effects of phenolic acids and their derivatives against Alzheimer's disease (AD). In this review, the role of phenolic acids as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) is discussed, including the structure-activity relationship. In addition, the inhibitory effect of phenolic acids on the formation of amyloid β-peptide (Aβ) fibrils is presented. We also cover the in vitro, ex vivo, and in vivo studies concerning the prevention and treatment of the cognitive enhancement.

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