Protective Effect of Rivaroxaban Against Amyloid Pathology and Neuroinflammation Through Inhibiting PAR-1 and PAR-2 in Alzheimer’s Disease Mice

2022 ◽  
pp. 1-13
Author(s):  
Zhihong Bian ◽  
Xia Liu ◽  
Tian Feng ◽  
Haibo Yu ◽  
Xiao Hu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Oral Anticoagulant ◽  
Amyloid Β ◽  
Underlying Mechanism ◽  
Amyloid Angiopathy ◽  
Mice Model ◽  
Barrier Dysfunction ◽  
Term Administration ◽  
Anticoagulant Drug

Background: Recent studies have revealed that atrial fibrillation (AF) patients have a high risk of developing cognitive impairment, vascular dementia, and Alzheimer’s disease (AD). Some reports suggest that the application of oral anticoagulant with an appropriate dose may have a preventive effect on AD. However, which oral anticoagulant drug is more appropriate for preventing AD and the underlying mechanism(s) is still unknown. Objective: The aim of the present study was to assess the treatment effect of rivaroxaban administration as well as investigate the roles of PAR-1 and PAR-2 in the AD + CAA mice model. Methods: In the present study, we compared a traditional oral anticoagulant, warfarin, and a direct oral anticoagulant (DOAC), rivaroxaban, via long-term administration to an AD with cerebral amyloid angiopathy (CAA) mice model. Results: Rivaroxaban treatment attenuated neuroinflammation, blood-brain barrier dysfunction, memory deficits, and amyloid-β deposition through PAR-1/PAR-2 inhibition in the AD + CAA mice model compared with warfarin and no-treatment groups. Conclusion: The present study demonstrates that rivaroxaban can attenuate AD progress and can be a potential choice to prevent AD.

scholarly journals Alzheimer’s Disease—Rationales for Potential Treatment with the Thrombin Inhibitor Dabigatran

2021 ◽  
Vol 22 (9) ◽  
pp. 4805
Author(s):  
Klaus Grossmann
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Vascular Dysfunction ◽  
Amyloid Β ◽  
Brain Parenchyma ◽  
Thrombin Inhibitor ◽  
Amyloid Angiopathy ◽  
Barrier Dysfunction ◽  
Neuron Death ◽  
The Brain

Alzheimer’s disease (AD) is caused by neurodegenerative, but also vascular and hemostatic changes in the brain. The oral thrombin inhibitor dabigatran, which has been used for over a decade in preventing thromboembolism and has a well-known pharmacokinetic, safety and antidote profile, can be an option to treat vascular dysfunction in early AD, a condition known as cerebral amyloid angiopathy (CAA). Recent results have revealed that amyloid-β proteins (Aβ), thrombin and fibrin play a crucial role in triggering vascular and parenchymal brain abnormalities in CAA. Dabigatran blocks soluble thrombin, thrombin-mediated formation of fibrin and Aβ-containing fibrin clots. These clots are deposited in brain parenchyma and blood vessels in areas of CAA. Fibrin-Aβ deposition causes microvascular constriction, occlusion and hemorrhage, leading to vascular and blood–brain barrier dysfunction. As a result, blood flow, perfusion and oxygen and nutrient supply are chronically reduced, mainly in hippocampal and neocortical brain areas. Dabigatran has the potential to preserve perfusion and oxygen delivery to the brain, and to prevent parenchymal Aβ-, thrombin- and fibrin-triggered inflammatory and neurodegenerative processes, leading to synapse and neuron death, and cognitive decline. Beneficial effects of dabigatran on CAA and AD have recently been shown in preclinical studies and in retrospective observer studies on patients. Therefore, clinical studies are warranted, in order to possibly expand dabigatran approval for repositioning for AD treatment.

Gut Microbiota Alterations and Cognitive Impairment Are Sexually Dissociated in a Transgenic Mice Model of Alzheimer’s Disease

2021 ◽  
pp. 1-20
Author(s):  
Daniel Cuervo-Zanatta ◽  
Jaime Garcia-Mena ◽  
Claudia Perez-Cruz
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Gut Microbiota ◽  
Cognitive Skills ◽  
Amyloid Β ◽  
Short Chain Fatty Acids ◽  
Mice Model ◽  
Model Of Alzheimer’S Disease ◽  
Cognitive Deficiencies

Background: Normal aging is accompanied by cognitive deficiencies, affecting women and men equally. Aging is the main risk factor for Alzheimer’s disease (AD), with women having a higher risk. The higher prevalence of AD in women is associated with the abrupt hormonal decline seen after menopause. However, other factors may be involved in this sex-related cognitive decline. Alterations in gut microbiota (GM) and its bioproducts have been reported in AD subjects and transgenic (Tg) mice, having a direct impact on brain amyloid-β pathology in male (M), but not in female (F) mice. Objective: The aim of this work was to determine GM composition and cognitive dysfunction in M and F wildtype (WT) and Tg mice, in a sex/genotype segregation design. Methods: Anxiety, short term working-memory, spatial learning, and long-term spatial memory were evaluated in 6-month-old WT and Tg male mice. Fecal short chain fatty acids were determined by chromatography, and DNA sequencing and bioinformatic analyses were used to determine GM differences. Results: We observed sex-dependent differences in cognitive skills in WT mice, favoring F mice. However, the cognitive advantage of females was lost in Tg mice. GM composition showed few sex-related differences in WT mice. Contrary, Tg-M mice presented a more severe dysbiosis than Tg-F mice. A decreased abundance of Ruminococcaceae was associated with cognitive deficits in Tg-F mice, while butyrate levels were positively associated with better working- and object recognition-memory in WT-F mice. Conclusion: This report describes a sex-dependent association between GM alterations and cognitive impairment in a mice model of AD.

scholarly journals Relationship Between Amyloid-β Deposition and Blood–Brain Barrier Dysfunction in Alzheimer’s Disease

2021 ◽  
Vol 15 ◽  
Author(s):  
Dong Wang ◽  
Fanglian Chen ◽  
Zhaoli Han ◽  
Zhenyu Yin ◽  
Xintong Ge ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Blood Brain Barrier ◽  
Amyloid Β ◽  
Brain Barrier ◽  
Barrier Dysfunction ◽  
Factors Affecting ◽  
Blood Brain ◽  
Normal Metabolism

Amyloid-β (Aβ) is the predominant pathologic protein in Alzheimer’s disease (AD). The production and deposition of Aβ are important factors affecting AD progression and prognosis. The deposition of neurotoxic Aβ contributes to damage of the blood–brain barrier. However, the BBB is also crucial in maintaining the normal metabolism of Aβ, and dysfunction of the BBB aggravates Aβ deposition. This review characterizes Aβ deposition and BBB damage in AD, summarizes their interactions, and details their respective mechanisms.

scholarly journals Cerebrospinal fluid profiles with increasing number of cerebral microbleeds in a continuum of cognitive impairment

2015 ◽  
Vol 36 (3) ◽  
pp. 621-628 ◽  
Author(s):  
Sara Shams ◽  
Tobias Granberg ◽  
Juha Martola ◽  
Xiaozhen Li ◽  
Mana Shams ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cerebrospinal Fluid ◽  
Cognitive Impairment ◽  
Serum Albumin ◽  
Amyloid Β ◽  
Cerebral Microbleeds ◽  
Csf Biomarkers ◽  
Barrier Dysfunction ◽  
T Tau

Cerebral microbleeds (CMBs) are hypothesised to have an important yet unknown role in the dementia disease pathology. In this study we analysed increasing number of CMBs and their independent associations with routine cerebrospinal fluid (CSF) biomarkers in a continuum of cognitive impairment. A total of 1039 patients undergoing dementia investigation were analysed and underwent lumbar puncture, and an MRI scan. CSF samples were analysed for amyloid β (Aβ) 42, total tau (T-tau), tau phosphorylated at threonine 18 (P-tau) and CSF/serum albumin ratios. Increasing number of CMBs were independently associated with low Aβ42 levels, in the whole cohort, Alzheimer’s disease and mild cognitive impairment ( p < 0.05). CSF/serum albumin ratios were high with multiple CMBs ( p < 0.001), reflecting accompanying blood–brain barrier dysfunction. T-tau and P-tau levels were lower in Alzheimer’s patients with multiple CMBs when compared to zero CMBs, but did not change in the rest of the cohort. White matter hyperintensities were associated with low Aβ42 in the whole cohort and Alzheimer’s disease ( p < 0.05). Aβ42 is the routine CSF-biomarker mainly associated with CMBs in cognitive impairment, and there is an accumulative effect with increasing number of CMBs.

scholarly journals Toll-Like Receptor 2 and NLRP3 Cooperate To Recognize a Functional Bacterial Amyloid, Curli

2014 ◽  
Vol 83 (2) ◽  
pp. 693-701 ◽  
Author(s):  
Glenn J. Rapsinski ◽  
Meghan A. Wynosky-Dolfi ◽  
Gertrude O. Oppong ◽  
Sarah A. Tursi ◽  
R. Paul Wilson ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Nlrp3 Inflammasome ◽  
Amyloid Β ◽  
Underlying Mechanism ◽  
Secondary Amyloidosis ◽  
Toll Like Receptor ◽  
Content Type ◽  
Caspase 1 ◽  
Toll Like Receptor 2

Amyloids are proteins with cross-β-sheet structure that contribute to pathology and inflammation in complex human diseases, including Alzheimer's disease, Parkinson's disease, type II diabetes, and secondary amyloidosis. Bacteria also produce amyloids as a component of their extracellular matrix during biofilm formation. Recently, several human amyloids were shown to activate the NLRP3 inflammasome, leading to the activation of caspase 1 and production of interleukin 1β (IL-1β). In this study, we investigated the activation of the NLRP3 inflammasome by bacterial amyloids using curli fibers, produced bySalmonella entericaserovar Typhimurium andEscherichia coli. Here, we show that curli fibers activate the NLRP3 inflammasome, leading to the production of IL-1β via caspase 1 activation. Investigation of the underlying mechanism revealed that activation of Toll-like receptor 2 (TLR2) by curli fibers is critical in the generation of IL-1β. Interestingly, activation of the NLRP3 inflammasome by curli fibers or by amyloid β of Alzheimer's disease does not cause cell death in macrophages. Overall, these data identify a cross talk between TLR2 and NLRP3 in response to the bacterial amyloid curli and generation of IL-1β as a product of this interaction.

scholarly journals Postmortem Neocortical 3H-PiB Binding and Levels of Unmodified and Pyroglutamate Aβ in Down Syndrome and Sporadic Alzheimer’s Disease

2021 ◽  
Vol 13 ◽  
Author(s):  
Violetta N. Pivtoraiko ◽  
Tamara Racic ◽  
Eric E. Abrahamson ◽  
Victor L. Villemagne ◽  
Benjamin L. Handen ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Down Syndrome ◽  
Late Onset ◽  
Amyloid Β ◽  
Molecular Profile ◽  
Amyloid Angiopathy ◽  
Neuritic Plaques ◽  
Amyloid Deposits

Individuals with Down syndrome (DS) have a genetic predisposition for amyloid-β (Aβ) overproduction and earlier onset of Aβ deposits compared to patients with sporadic late-onset Alzheimer’s disease (AD). Positron emission tomography (PET) with Pittsburgh Compound-B (PiB) detects fibrillar Aβ pathology in living people with DS and AD, but its relationship with heterogeneous Aβ forms aggregated within amyloid deposits is not well understood. We performed quantitative in vitro3H-PiB binding assays and enzyme-linked immunosorbent assays of fibrillar (insoluble) unmodified Aβ40 and Aβ42 forms and N-terminus truncated and pyroglutamate-modified AβNpE3-40 and AβNpE3-42 forms in postmortem frontal cortex and precuneus samples from 18 DS cases aged 43–63 years and 17 late-onset AD cases aged 62–99 years. Both diagnostic groups had frequent neocortical neuritic plaques, while the DS group had more severe vascular amyloid pathology (cerebral amyloid angiopathy, CAA). Compared to the AD group, the DS group had higher levels of Aβ40 and AβNpE3-40, while the two groups did not differ by Aβ42 and AβNpE3-42 levels. This resulted in lower ratios of Aβ42/Aβ40 and AβNpE3-42/AβNpE3-40 in the DS group compared to the AD group. Correlations of Aβ42/Aβ40 and AβNpE3-42/AβNpE3-40 ratios with CAA severity were strong in DS cases and weak in AD cases. Pyroglutamate-modified Aβ levels were lower than unmodified Aβ levels in both diagnostic groups, but within group proportions of both pyroglutamate-modified Aβ forms relative to both unmodified Aβ forms were lower in the DS group but not in the AD group. The two diagnostic groups did not differ by 3H-PiB binding levels. These results demonstrate that compared to late-onset AD cases, adult DS individuals with similar severity of neocortical neuritic plaques and greater CAA pathology have a preponderance of both pyroglutamate-modified AβNpE3-40 and unmodified Aβ40 forms. Despite the distinct molecular profile of Aβ forms and greater vascular amyloidosis in DS cases, cortical 3H-PiB binding does not distinguish between diagnostic groups that are at an advanced level of amyloid plaque pathology. This underscores the need for the development of CAA-selective PET radiopharmaceuticals to detect and track the progression of cerebral vascular amyloid deposits in relation to Aβ plaques in individuals with DS.

Screening for cerebral amyloid angiopathy based on serological biomarkers analysis using a dielectrophoretic force-driven biosensor platform

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Hye Jin Kim ◽  
Dongsung Park ◽  
Gyihyaon Yun ◽  
Hongrae Kim ◽  
Hyug-Gi Kim ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cerebral Amyloid Angiopathy ◽  
Amyloid Β ◽  
Amyloid Angiopathy ◽  
Dielectrophoretic Force ◽  
Highly Sensitive ◽  
Cerebral Amyloid ◽  
Serological Biomarkers

Screening of cerebral amyloid angiopathy and Alzheimer's disease by analyzing plasma amyloid-β using a highly sensitive dielectrophoretic force-driven biosensor platform.

GINKGETIN AMELIORATES NEUROPATHOLOGICAL CHANGES IN APP/PS1 TRANSGENICAL MICE MODEL

2015 ◽  
pp. 1-6
Author(s):  
Y.-Q. Zeng ◽  
Y.-J. Wang ◽  
X.-F. Zhou
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Beta ◽  
Biological Properties ◽  
Amyloid Angiopathy ◽  
Amyloid Beta Protein ◽  
Mice Model ◽  
Cerebral Microhemorrhage ◽  
The Brain

The extracellular accumulation of amyloid beta protein (Aβ), reactive gliosis and cerebral amyloid angiopathy (CAA) play critical roles in the pathogenesis of Alzheimer’s disease (AD). Ginkgetin, a biflavone isolated from Ginkgo biloba leaves, was previously reported to exhibit strong neuroprotection against cytotoxic insults induced by oxidative stress and amyloid beta, but it remains unclear whether ginkgetin has therapeutic effect on Alzheimer’s disease (AD) in vivo. In the present study, we investigated 9 months treatment effects of ginkgetin diet in APP/PS1 mice. Our results show that ginkgetin can significantly reduce plasma Aβ levels 59% and Aβ plaque 51% in the brain of APP/PS1 transgenic mice (P<0.05), effectively inhibits cerebral microhemorrhage 69% (P<0.05), significantly decreases astrogliosis 50% and ameliorate inflammation (P<0.05), exhibits several biological properties for AD.

scholarly journals Alzheimer’s disease: A matter of blood–brain barrier dysfunction?

2017 ◽  
Vol 214 (11) ◽  
pp. 3151-3169 ◽  
Author(s):  
Axel Montagne ◽  
Zhen Zhao ◽  
Berislav V. Zlokovic
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Blood Brain Barrier ◽  
Amyloid Β ◽  
Brain Barrier ◽  
Barrier Dysfunction ◽  
Neurodegenerative Process ◽  
Blood Brain ◽  
Underlying Mechanisms

The blood–brain barrier (BBB) keeps neurotoxic plasma-derived components, cells, and pathogens out of the brain. An early BBB breakdown and/or dysfunction have been shown in Alzheimer’s disease (AD) before dementia, neurodegeneration and/or brain atrophy occur. However, the role of BBB breakdown in neurodegenerative disorders is still not fully understood. Here, we examine BBB breakdown in animal models frequently used to study the pathophysiology of AD, including transgenic mice expressing human amyloid-β precursor protein, presenilin 1, and tau mutations, and apolipoprotein E, the strongest genetic risk factor for AD. We discuss the role of BBB breakdown and dysfunction in neurodegenerative process, pitfalls in BBB measurements, and how targeting the BBB can influence the course of neurological disorder. Finally, we comment on future approaches and models to better define, at the cellular and molecular level, the underlying mechanisms between BBB breakdown and neurodegeneration as a basis for developing new therapies for BBB repair to control neurodegeneration.

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