Energy Metabolism, Oxidative Stress and Neuronal Degeneration in Alzheimer's Disease

1996 ◽  
Vol 5 (4) ◽  
pp. 435-440 ◽  
Author(s):  
Neil R. Sims
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Energy Metabolism ◽  
Neuronal Degeneration

scholarly journals Ceramides in Alzheimer’s Disease: Key Mediators of Neuronal Apoptosis Induced by Oxidative Stress and AβAccumulation

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Maja Jazvinšćak Jembrek ◽  
Patrick R. Hof ◽  
Goran Šimić
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neuronal Apoptosis ◽  
Neurodegenerative Disorder ◽  
Neuronal Degeneration ◽  
Sphingolipid Metabolism ◽  
Cytochrome C Release ◽  
Biochemical Alterations

Alzheimer’s disease (AD), the most common chronic and progressive neurodegenerative disorder, is characterized by extracellular deposits of amyloidβ-peptides (Aβ) and intracellular deposits of hyperphosphorylated tau (phospho-tau) protein. Ceramides, the major molecules of sphingolipid metabolism and lipid second messengers, have been associated with AD progression and pathology via Aβgeneration. Enhanced levels of ceramides directly increase Aβthrough stabilization ofβ-secretase, the key enzyme in the amyloidogenic processing of Aβprecursor protein (APP). As a positive feedback loop, the generated oligomeric and fibrillar Aβinduces a further increase in ceramide levels by activating sphingomyelinases that catalyze the catabolic breakdown of sphingomyelin to ceramide. Evidence also supports important role of ceramides in neuronal apoptosis. Ceramides may initiate a cascade of biochemical alterations, which ultimately leads to neuronal death by diverse mechanisms, including depolarization and permeabilization of mitochondria, increased production of reactive oxygen species (ROS), cytochrome c release, Bcl-2 depletion, and caspase-3 activation, mainly by modulating intracellular signalling, particularly along the pathways related to Akt/PKB kinase and mitogen-activated protein kinases (MAPKs). This review summarizes recent findings related to the role of ceramides in oxidative stress-driven neuronal apoptosis and interplay with Aβin the cascade of events ending in neuronal degeneration.

scholarly journals Mitochondrial- and Endoplasmic Reticulum-Associated Oxidative Stress in Alzheimer's Disease: From Pathogenesis to Biomarkers

2012 ◽  
Vol 2012 ◽  
pp. 1-23 ◽  
Author(s):  
E. Ferreiro ◽  
I. Baldeiras ◽  
I. L. Ferreira ◽  
R. O. Costa ◽  
A. C. Rego ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Endoplasmic Reticulum ◽  
Mitochondrial Dysfunction ◽  
Neuronal Degeneration ◽  
Apoptotic Cell ◽  
Biological Fluids ◽  
Critical Role ◽  
Antioxidant Defenses

Alzheimer's disease (AD) is the most common cause of dementia in the elderly, affecting several million of people worldwide. Pathological changes in the AD brain include the presence of amyloid plaques, neurofibrillary tangles, loss of neurons and synapses, and oxidative damage. These changes strongly associate with mitochondrial dysfunction and stress of the endoplasmic reticulum (ER). Mitochondrial dysfunction is intimately linked to the production of reactive oxygen species (ROS) and mitochondrial-driven apoptosis, which appear to be aggravated in the brain of AD patients. Concomitantly, mitochondria are closely associated with ER, and the deleterious crosstalk between both organelles has been shown to be involved in neuronal degeneration in AD. Stimuli that enhance expression of normal and/or folding-defective proteins activate an adaptive unfolded protein response (UPR) that, if unresolved, can cause apoptotic cell death. ER stress also induces the generation of ROS that, together with mitochondrial ROS and decreased activity of several antioxidant defenses, promotes chronic oxidative stress. In this paper we discuss the critical role of mitochondrial and ER dysfunction in oxidative injury in AD cellular and animal models, as well as in biological fluids from AD patients. Progress in developing peripheral and cerebrospinal fluid biomarkers related to oxidative stress will also be summarized.

scholarly journals N-Acetyl Cysteine Supplement Minimize Tau Expression and Neuronal Loss in Animal Model of Alzheimer’s Disease

2018 ◽  
Vol 8 (10) ◽  
pp. 185 ◽  
Author(s):  
Teresa Joy ◽  
Muddanna Rao ◽  
Sampath Madhyastha
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Animal Model ◽  
Neuronal Degeneration ◽  
Neuronal Loss ◽  
Model Of Alzheimer’S Disease ◽  
Acetyl Cysteine ◽  
The Brain ◽  
Tau Expression

Alzheimer’s disease (AD) is characterized by the accumulation of neurofibrillary tangles (NFT), deposition of beta amyloid plaques, and consequent neuronal loss in the brain tissue. Oxidative stress to the neurons is often attributed to AD, but its link to NFT and β-amyloid protein (BAP) still remains unclear. In an animal model of AD, we boosted the oxidative defense by N-Acetyl cysteine (NAC), a precursor of glutathione, a powerful antioxidant and free radical scavenger, to understand the link between oxidative stress and NFT. In mimicking AD, intracerebroventricular (ICV) colchicine, a microtubule disrupting agent also known to cause oxidative stress was administered to the rats. The animal groups consisted of an age-matched control, sham operated, AD, and NAC treated in AD models of rats. Cognitive function was evaluated in a passive avoidance test; neuronal degeneration was quantified using Nissl staining. NFT in the form of abnormal tau expression in different regions of the brain were evaluated through immunohistochemistry using rabbit anti-tau antibody. ICV has resulted in significant cognitive and neuronal loss in medial prefrontal cortex (MFC) and all the regions of the hippocampus. It has also resulted in increased accumulation of intraneuronal tau in the hippocampus and MFC. NAC treatment in AD model rats has reversed the cognitive loss and neuronal degeneration. The intraneuronal tau expression also minimized with NAC treatment in AD model rats. Thus, our findings suggest that an antioxidant supplement during the progression of AD is likely to prevent neuronal degeneration by minimizing the neurofibrillary degeneration in the form of tau accumulation.

Oxidative Stress and Amyloid Beta Toxicity in Alzheimer’s Disease: Intervention in a Complex Relationship by Antioxidants

2013 ◽  
Vol 20 (37) ◽  
pp. 4648-4664 ◽  
Author(s):  
S. Chakrabarti ◽  
M. Sinha ◽  
I. Thakurta ◽  
P. Banerjee ◽  
M. Chattopadhyay
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Beta ◽  
Complex Relationship

An Insight in Pathophysiological Mechanism of Alzheimer’s Disease and its Management using Plant Natural Products

2020 ◽  
Vol 20 ◽  
Author(s):  
Zeba Firdaus ◽  
Tryambak Deo Singh
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Natural Products ◽  
Side Effects ◽  
Neuronal Degeneration ◽  
Acetylcholinesterase Inhibitor ◽  
Pathophysiological Mechanism ◽  
Limited Effectiveness ◽  
Drug Development Research ◽  
Sites Of Action

: Alzheimer’s disease (AD) is an age-associated nervous system disorder and a leading cause of dementia worldwide. Clinically it is described by cognitive impairment, and pathophysiologically by deposition of amyloid plaques and neurofibrillary tangles in the brain and neurodegeneration. This article reviews the pathophysiology, course of neuronal degeneration, and the various possible hypothesis of AD progression. These hypotheses include amyloid cascade, tau hyperphosphorylation, cholinergic disruption, metal dysregulation, vascular dysfunction, oxidative stress, and neuroinflammation. There is an exponential increase in the occurrence of the AD in recent few years that indicate an urgent need to develop some effective treatment. Currently, only 2 classes of drugs are available for AD treatment namely acetylcholinesterase inhibitor and NMDA receptor antagonist. Since AD is a complex neurological disorder and these drugs use a single target approach, alternatives are needed due to limited effectiveness and unpleasant side-effects of these drugs. Currently, plants have been used for drug development research especially because of their multiple sites of action and fewer side effects. Uses of some herbs and phytoconstituents for the management of neuronal disorders like AD have been documented in this article. Phytochemical screening of these plants shows the presence of many beneficial constituents like flavonoids, triterpenes, alkaloids, sterols, polyphenols, and tannins. These compounds show a wide array of pharmacological activities such as anti-amyloidogenic, anticholinesterase, and antioxidant. This article summarizes the present understanding of AD progression and gathers biochemical evidence from various works on natural products that can be useful in the management of this disease.

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