scholarly journals Derailed Intraneuronal Signalling Drives Pathogenesis in Sporadic and Familial Alzheimer’s Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Tom Van Dooren ◽  
Katrien Princen ◽  
Koen De Witte ◽  
Gerard Griffioen
Keyword(s):  
Risk Factors ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neuronal Degeneration ◽  
Feedback Mechanism ◽  
Membrane Receptors ◽  
Neuronal Function ◽  
Systematic Analysis ◽  
Positive Feedback Mechanism ◽  
Or Genes

Although a wide variety of genetic and nongenetic Alzheimer’s disease (AD) risk factors have been identified, their role in onset and/or progression of neuronal degeneration remains elusive. Systematic analysis of AD risk factors revealed that perturbations of intraneuronal signalling pathways comprise a common mechanistic denominator in both familial and sporadic AD and that such alterations lead to increases in Aβoligomers (Aβo) formation and phosphorylation of TAU. Conversely, Aβo and TAU impact intracellular signalling directly. This feature entails binding of Aβo to membrane receptors, whereas TAU functionally interacts with downstream transducers. Accordingly, we postulate a positive feedback mechanism in which AD risk factors or genes trigger perturbations of intraneuronal signalling leading to enhanced Aβo formation and TAU phosphorylation which in turn further derange signalling. Ultimately intraneuronal signalling becomes deregulated to the extent that neuronal function and survival cannot be sustained, whereas the resulting elevated levels of amyloidogenic Aβo and phosphorylated TAU species self-polymerizes into the AD plaques and tangles, respectively.

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.

Elucidating the risk factors for progression from amyloid-negative amnestic mild cognitive impairment to dementia

2020 ◽  
Vol 17 ◽  
Author(s):  
Hyung-Ji Kim ◽  
Jae-Hong Lee ◽  
E-nae Cheong ◽  
Sung-Eun Chung ◽  
Sungyang Jo ◽  
...  
Keyword(s):  
Risk Factors ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Amnestic Mild Cognitive Impairment ◽  
Amyloid Pet ◽  
Clinical Progression ◽  
Amnestic Mci

Background: Amyloid PET allows for the assessment of amyloid β status in the brain, distinguishing true Alzheimer’s disease from Alzheimer’s disease-mimicking conditions. Around 15–20% of patients with clinically probable Alzheimer’s disease have been found to have no significant Alzheimer’s pathology on amyloid PET. However, a limited number of studies had been conducted this subpopulation in terms of clinical progression. Objective: We investigated the risk factors that could affect the progression to dementia in patients with amyloid-negative amnestic mild cognitive impairment (MCI). Methods: This study was a single-institutional, retrospective cohort study of patients over the age of 50 with amyloidnegative amnestic MCI who visited the memory clinic of Asan Medical Center with a follow-up period of more than 36 months. All participants underwent brain magnetic resonance imaging (MRI), detailed neuropsychological testing, and fluorine-18[F18]-florbetaben amyloid PET. Results: During the follow-up period, 39 of 107 patients progressed to dementia from amnestic MCI. In comparison with the stationary group, the progressed group had a more severe impairment in verbal and visual episodic memory function and hippocampal atrophy, which showed an Alzheimer’s disease-like pattern despite the lack of evidence for significant Alzheimer’s disease pathology. Voxel-based morphometric MRI analysis revealed that the progressed group had a reduced gray matter volume in the bilateral cerebellar cortices, right temporal cortex, and bilateral insular cortices. Conclusion: Considering the lack of evidence of amyloid pathology, clinical progression of these subpopulation may be caused by other neuropathologies such as TDP-43, abnormal tau or alpha synuclein that lead to neurodegeneration independent of amyloid-driven pathway. Further prospective studies incorporating biomarkers of Alzheimer’s diseasemimicking dementia are warranted.

scholarly journals Examining the possible causal relationship between lung function, COPD and Alzheimer’s disease: a Mendelian randomisation study

2021 ◽  
Vol 8 (1) ◽  
pp. e000759
Author(s):  
Daniel Higbee ◽  
Raquel Granell ◽  
Esther Walton ◽  
Roxanna Korologou-Linden ◽  
George Davey Smith ◽  
...  
Keyword(s):  
Risk Factors ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Lung Function ◽  
Causal Relationship ◽  
Mendelian Randomisation ◽  
P Value ◽  
Unmeasured Confounding ◽  
Increased Risk ◽  
Shared Risk

RationaleLarge retrospective case-control studies have reported an association between chronic obstructive pulmonary disease (COPD), reduced lung function and an increased risk of Alzheimer’s disease. However, it remains unclear if these diseases are causally linked, or due to shared risk factors. Conventional observational epidemiology suffers from unmeasured confounding and reverse causation. Additional analyses addressing causality are required.ObjectivesTo examine a causal relationship between COPD, lung function and Alzheimer’s disease.MethodsUsing two-sample Mendelian randomisation, we used single nucleotide polymorphisms (SNPs) identified in a genome wide association study (GWAS) for lung function as instrumental variables (exposure). Additionally, we used SNPs discovered in a GWAS for COPD in those with moderate to very severe obstruction. The effect of these SNPs on Alzheimer’s disease (outcome) was taken from a GWAS based on a sample of 24 807 patients and 55 058 controls.ResultsWe found minimal evidence for an effect of either lung function (OR: 1.02 per SD; 95% CI 0.91 to 1.13; p value 0.68) or liability for COPD on Alzheimer’s disease (OR: 0.97 per SD; 95% CI 0.92 to 1.03; p value 0.40).ConclusionNeither reduced lung function nor liability COPD are likely to be causally associated with an increased risk of Alzheimer’s, any observed association is likely due to unmeasured confounding. Scientific attention and health prevention policy may be better focused on overlapping risk factors, rather than attempts to reduce risk of Alzheimer’s disease by targeting impaired lung function or COPD directly.

scholarly journals Physical Mistreatment in Persons with Alzheimer’s Disease

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Carla VandeWeerd ◽  
Gregory J. Paveza ◽  
Margaret Walsh ◽  
Jaime Corvin
Keyword(s):  
Risk Factors ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Conflict Resolution ◽  
Physical Violence ◽  
Emotional Health ◽  
Alcohol Problems ◽  
Community Based ◽  
Conflict Resolution Strategy ◽  
Resolution Strategy

Physical mistreatment has been estimated to affect 2 million older persons each year and dramatically affects health outcomes. While researchers have attempted to examine risk factors for specific forms of abuse, many have been able to focus on only victim or perpetrator characteristics, or a limited number of psychosocial variables at any one time. Additionally, data on risk factors for subgroups such as persons with Alzheimer’s disease who may have heightened and/or unique risk profiles has also been limited. This paper examines risk for physical violence in caregiver/patient dyads who participated in the Aggression and Violence in Community-Based Alzheimer’s Families Grant. Data were collected via in-person interview and mailed survey and included demographics as well as measures of violence, physical and emotional health, and health behaviors. Logistic regression analysis indicated that caregivers providing care to elders with high levels of functional impairment or dementia symptoms, or who had alcohol problems, were more likely to use violence as a conflict resolution strategy, as were caregivers who were providing care to elders who used violence against them. By contrast, caregivers with high self-esteem were less likely to use violence as a conflict resolution strategy. Significant interaction effects were also noted.

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