SAMP8 Mice as a Model of Age-Related Cognition Decline with Underlying Mechanisms in Alzheimer’s Disease

2020 ◽  
Vol 75 (2) ◽  
pp. 385-395 ◽  
Author(s):  
Bo Liu ◽  
Jie Liu ◽  
Jing-Shan Shi
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Age Related ◽  
Underlying Mechanisms ◽  
Samp8 Mice

scholarly journals Large Artery Stiffness and Brain Health: Insights from Animal Models

2020 ◽  
Author(s):  
Nicholas R Winder ◽  
Emily H Reeve ◽  
Ashley E Walker
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Animal Models ◽  
Brain Aging ◽  
Large Artery ◽  
Neurocognitive Dysfunction ◽  
Disease Etiology ◽  
Age Related ◽  
Artery Stiffness ◽  
Underlying Mechanisms

There are no effective treatments available to halt or reverse the progression of age-related cognitive decline and Alzheimer's disease. Thus, there is an urgent need to understand the underlying mechanisms of disease etiology and progression in order to identify novel therapeutic targets. Age-related changes to vasculature, particularly increases in stiffness of the large elastic arteries, are now recognized as important contributors to brain aging. There is a growing body of evidence for an association between greater large artery stiffness and cognitive impairment among both healthy older adults and patients with Alzheimer's disease. However, studies in humans are limited to only correlative evidence while animal models allow researchers to explore the causative mechanisms linking arterial stiffness to neurocognitive dysfunction and disease. Recently, several rodent models of direct modulation of large artery stiffness and the consequent effects on the brain have been reported. Common outcomes among these models have emerged, including evidence that greater large artery stiffness causes cerebrovascular dysfunction associated with increased oxidative stress and inflammatory signaling. The purpose of this mini review is to highlight recent findings associating large artery stiffness with deleterious brain outcomes, with a specific focus on causative evidence obtained from animal models. We will also discuss the gaps in knowledge that remain in our understanding of how large artery stiffness affects brain function and disease outcomes.

scholarly journals Current State of the Art in Preclinical Research in Alzheimer’s Disease - A Focus on Mode of Action in Pharmacological and Non-pharmacological Approaches

2012 ◽  
Vol 7 (4) ◽  
pp. 216
Author(s):  
Kiren Ubhi ◽  
Eliezer Masliah ◽  
◽  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
Cholinergic Neurons ◽  
Therapeutic Approaches ◽  
Preclinical Research ◽  
Current State ◽  
Age Related ◽  
Cognitive Disturbances ◽  
Underlying Mechanisms

Alzheimer’s disease (AD) is an age-related neurodegenerative disorder characterised by progressive memory deficits and other cognitive disturbances. Neuropathologically, AD is characterised by synaptic deficits, progressive loss of neocortical, limbic and basal forebrain cholinergic neurons and the abnormal extracellular accumulation of amyloid-beta (Aß) and the intracellular aggregation of the cvtoskeletal protein tau. Currently available AD therapies either only temporarily delay disease progression or address the symptoms but are unable to alter the underlying mechanisms of disease. Therefore, ongoing AD research is focused at better understanding pathogenesis and at developing disease-modifying experimental therapeutic approaches. This review will summarise the main areas of preclinical research for AD therapeutics that includes those aimed at modulating the processing of amyloid precursor protein (APP) and the production of Aß; ameliorating the pathological accumulation of Aß or tau; augmenting neuroprotective activities in the AD brain; and augmenting neurorestoration in the AD brain. The review will also discuss a novel multimodal therapeutic approach to AD using Cerebrolysin, a peptidergic mixture with neurotrophic-like effects.

Emerging Promise of Immunotherapy for Alzheimer’s Disease: A New Hope for the Development of Alzheimer’s Vaccine

2020 ◽  
Vol 20 (13) ◽  
pp. 1214-1234 ◽  
Author(s):  
Md. Tanvir Kabir ◽  
Md. Sahab Uddin ◽  
Bijo Mathew ◽  
Pankoj Kumar Das ◽  
Asma Perveen ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Immune Response ◽  
Neutralizing Antibodies ◽  
Neurodegenerative Disorder ◽  
Symptomatic Relief ◽  
Aβ Oligomers ◽  
Th2 Immune Response ◽  
Age Related ◽  
Anti Inflammatory

Background: Alzheimer's disease (AD) is a chronic neurodegenerative disorder and the characteristics of this devastating disorder include the progressive and disabling deficits in the cognitive functions including reasoning, attention, judgment, comprehension, memory, and language. Objective: In this article, we have focused on the recent progress that has been achieved in the development of an effective AD vaccine. Summary: Currently, available treatment options of AD are limited to deliver short-term symptomatic relief only. A number of strategies targeting amyloid-beta (Aβ) have been developed in order to treat or prevent AD. In order to exert an effective immune response, an AD vaccine should contain adjuvants that can induce an effective anti-inflammatory T helper 2 (Th2) immune response. AD vaccines should also possess the immunogens which have the capacity to stimulate a protective immune response against various cytotoxic Aβ conformers. The induction of an effective vaccine’s immune response would necessitate the parallel delivery of immunogen to dendritic cells (DCs) and their priming to stimulate a Th2-polarized response. The aforesaid immune response is likely to mediate the generation of neutralizing antibodies against the neurotoxic Aβ oligomers (AβOs) and also anti-inflammatory cytokines, thus preventing the AD-related inflammation. Conclusion: Since there is an age-related decline in the immune functions, therefore vaccines are more likely to prevent AD instead of providing treatment. AD vaccines might be an effective and convenient approach to avoid the treatment-related huge expense.

Formononetin Ameliorates Cognitive Disorder via PGC-1α Pathway in Neuroinflammation Conditions in High-Fat Diet-Induced Mice

2019 ◽  
Vol 18 (7) ◽  
pp. 566-577 ◽  
Author(s):  
Xinxin Fu ◽  
Tingting Qin ◽  
Jiayu Yu ◽  
Jie Jiao ◽  
Zhanqiang Ma ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
High Fat Diet ◽  
Trifolium Pratense ◽  
Amyloid Β ◽  
Cognitive Disorder ◽  
Mechanism Study ◽  
High Fat ◽  
Neuroprotective Effects ◽  
Underlying Mechanisms

Background: Alzheimer’s disease is one of the most common neurodegenerative diseases in many modern societies. The core pathogenesis of Alzheimer’s disease includes the aggregation of hyperphosphorylated Tau and abnormal Amyloid-β generation. In addition, previous studies have shown that neuroinflammation is one of the pathogenesis of Alzheimer’s disease. Formononetin, an isoflavone compound extracted from Trifolium pratense L., has been found to have various properties including anti-obesity, anti-inflammation, and neuroprotective effects. But there are very few studies on the treatment of Alzheimer’s disease with Formononetin. Objective: The present study focused on the protective activities of Formononetin on a high-fat dietinduced cognitive decline and explored the underlying mechanisms. Methods: Mice were fed with HFD for 10 weeks and intragastric administrated daily with metformin (300 mg/kg) and Formononetin (20 and 40 mg/kg). Results: We found that Formononetin (20, 40 mg/kg) significantly attenuated the learning and memory deficits companied by weight improvement and decreased the levels of blood glucose, total cholesterol and triglyceride in high-fat diet-induced mice. Meanwhile, we observed high-fat diet significantly caused the Tau hyperphosphorylation in the hippocampus of mice, whereas Formononetin reversed this effect. Additionally, Formononetin markedly reduced the levels of inflammation cytokines IL-1β and TNF-α in high-fat diet-induced mice. The mechanism study showed that Formononetin suppressed the pro-inflammatory NF-κB signaling and enhanced the anti-inflammatory Nrf-2/HO-1 signaling, which might be related to the regulation of PGC-1α in the hippocampus of high-fat diet -induced mice. Conclusion: Taken together, our results showed that Formononetin could improve the cognitive function by inhibiting neuroinflammation, which is attributed to the regulation of PGC-1α pathway in HFD-induced mice.

scholarly journals Two human metabolites rescue a C. elegans model of Alzheimer’s disease via a cytosolic unfolded protein response

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Priyanka Joshi ◽  
Michele Perni ◽  
Ryan Limbocker ◽  
Benedetta Mannini ◽  
Sam Casford ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Unfolded Protein Response ◽  
Neurodegenerative Disorders ◽  
C Elegans ◽  
Unfolded Protein ◽  
Model Of Alzheimer’S Disease ◽  
Age Related ◽  
Parkinson’S Diseases ◽  
Protein Response

AbstractAge-related changes in cellular metabolism can affect brain homeostasis, creating conditions that are permissive to the onset and progression of neurodegenerative disorders such as Alzheimer’s and Parkinson’s diseases. Although the roles of metabolites have been extensively studied with regard to cellular signaling pathways, their effects on protein aggregation remain relatively unexplored. By computationally analysing the Human Metabolome Database, we identified two endogenous metabolites, carnosine and kynurenic acid, that inhibit the aggregation of the amyloid beta peptide (Aβ) and rescue a C. elegans model of Alzheimer’s disease. We found that these metabolites act by triggering a cytosolic unfolded protein response through the transcription factor HSF-1 and downstream chaperones HSP40/J-proteins DNJ-12 and DNJ-19. These results help rationalise previous observations regarding the possible anti-ageing benefits of these metabolites by providing a mechanism for their action. Taken together, our findings provide a link between metabolite homeostasis and protein homeostasis, which could inspire preventative interventions against neurodegenerative disorders.

scholarly journals A novel orally active HDAC6 inhibitor T-518 shows a therapeutic potential for Alzheimer’s disease and tauopathy in mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomohiro Onishi ◽  
Ryouta Maeda ◽  
Michiko Terada ◽  
Sho Sato ◽  
Takahiro Fujii ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Therapeutic Potential ◽  
Drug Candidate ◽  
Histone Deacetylase 6 ◽  
Cellular Assays ◽  
Age Related ◽  
Acetylation State ◽  
Hdac6 Inhibitor ◽  
Orally Active

AbstractAccumulation of tau protein is a key pathology of age-related neurodegenerative diseases such as Alzheimer's disease and progressive supranuclear palsy. Those diseases are collectively termed tauopathies. Tau pathology is associated with axonal degeneration because tau binds to microtubules (MTs), a component of axon and regulates their stability. The acetylation state of MTs contributes to stability and histone deacetylase 6 (HDAC6) is a major regulator of MT acetylation status, suggesting that pharmacological HDAC6 inhibition could improve axonal function and may slow the progression of tauopathy. Here we characterize N-[(1R,2R)-2-{3-[5-(difluoromethyl)-1,3,4-oxadiazol-2-yl]-5-oxo-5H,6H,7H-pyrrolo[3,4-b]pyridin-6-yl}cyclohexyl]-2,2,3,3,3-pentafluoropropanamide (T-518), a novel, potent, highly selective HDAC6 inhibitor with clinically favorable pharmacodynamics. T-518 shows potent inhibitory activity against HDAC6 and superior selectivity over other HDACs compared with the known HDAC6 inhibitors in the enzyme and cellular assays. T-518 showed brain penetration in an oral dose and blocked HDAC6-dependent tubulin deacetylation at Lys40 in mouse hippocampus. A 2-week treatment restored impaired axonal transport and novel object recognition in the P301S tau Tg mouse, tauopathy model, while a 3-month treatment also decreased RIPA-insoluble tau accumulation. Pharmaceutical inhibition of HDAC6 is a potential therapeutic strategy for tauopathy, and T-518 is a particularly promising drug candidate.

scholarly journals Probable Causes of Alzheimer’s Disease

Sci ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 16
Author(s):  
James David Adams
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Lactic Acid ◽  
Blood Brain Barrier ◽  
Transient Receptor Potential ◽  
Brain Barrier ◽  
Folate Intake ◽  
Blood Brain ◽  
Age Related ◽  
The Brain

A three-part mechanism is proposed for the induction of Alzheimer’s disease: (1) decreased blood lactic acid; (2) increased blood ceramide and adipokines; (3) decreased blood folic acid. The age-related nature of these mechanisms comes from age-associated decreased muscle mass, increased visceral fat and changes in diet. This mechanism also explains why many people do not develop Alzheimer’s disease. Simple changes in lifestyle and diet can prevent Alzheimer’s disease. Alzheimer’s disease is caused by a cascade of events that culminates in damage to the blood–brain barrier and damage to neurons. The blood–brain barrier keeps toxic molecules out of the brain and retains essential molecules in the brain. Lactic acid is a nutrient to the brain and is produced by exercise. Damage to endothelial cells and pericytes by inadequate lactic acid leads to blood–brain barrier damage and brain damage. Inadequate folate intake and oxidative stress induced by activation of transient receptor potential cation channels and endothelial nitric oxide synthase damage the blood–brain barrier. NAD depletion due to inadequate intake of nicotinamide and alterations in the kynurenine pathway damages neurons. Changes in microRNA levels may be the terminal events that cause neuronal death leading to Alzheimer’s disease. A new mechanism of Alzheimer’s disease induction is presented involving lactic acid, ceramide, IL-1β, tumor necrosis factor α, folate, nicotinamide, kynurenine metabolites and microRNA.

scholarly journals Naringenin improves learning and memory in an Alzheimer's disease rat model: Insights into the underlying mechanisms

2015 ◽  
Vol 764 ◽  
pp. 195-201 ◽  
Author(s):  
Saeed Ghofrani ◽  
Mohammad-Taghi Joghataei ◽  
Simin Mohseni ◽  
Tourandokht Baluchnejadmojarad ◽  
Maryam Bagheri ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Learning And Memory ◽  
Rat Model ◽  
Underlying Mechanisms
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