scholarly journals 5-Caffeoylquinic Acid Ameliorates Cognitive Decline and Reduces Aβ Deposition by Modulating Aβ Clearance Pathways in APP/PS2 Transgenic Mice

Nutrients ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 494 ◽  
Author(s):  
Keiko Ishida ◽  
Koichi Misawa ◽  
Hitomi Nishimura ◽  
Tomoya Hirata ◽  
Masaki Yamamoto ◽  
...  
Keyword(s):  
Cognitive Decline ◽  
Cognitive Dysfunction ◽  
Amyloid Β ◽  
Density Lipoprotein ◽  
Neuronal Loss ◽  
Chronic Administration ◽  
Pathological Feature ◽  
Caffeoylquinic Acid ◽  
Aβ Clearance ◽  
The Brain

The accumulation of amyloid β (Aβ) in the brain is a major pathological feature of Alzheimer’s disease (AD). In our previous study, we demonstrated that coffee polyphenols (CPP) prevent cognitive dysfunction and Aβ deposition in the brain of an APP/PS2 transgenic mouse AD model. The underlying mechanisms, however, remain to be elucidated. Here, we investigated the effects of the chronic administration of 5-caffeoylquinic acid (5-CQA), the most abundant component of CPP, on cognitive dysfunction in APP/PS2 mice to identify the role of CPP in Aβ elimination. Relative to the untreated controls, the mice fed a 5-CQA-supplemented diet showed significant improvements in their cognitive function assessed by Y-maze and novel object recognition tests. Histochemical analysis revealed that 5-CQA substantially reduced Aβ plaque formation and neuronal loss in the hippocampi. Moreover, 5-CQA upregulated the gene encoding low-density lipoprotein receptor-related protein 1, an Aβ efflux receptor, and normalized the perivascular localization of aquaporin 4, which facilitates Aβ clearance along the paravascular pathway. These results suggest that 5-CQA reduces Aβ deposition in the brain by modulating the Aβ clearance pathways and ameliorating cognitive decline and neuronal loss in APP/PS2 mice. Thus, 5-CQA may be effective in preventing cognitive dysfunction in AD.

scholarly journals Sodium rutin ameliorates Alzheimer’s disease–like pathology by enhancing microglial amyloid-β clearance

2019 ◽  
Vol 5 (2) ◽  
pp. eaau6328 ◽  
Author(s):  
Rui-Yuan Pan ◽  
Jun Ma ◽  
Xiang-Xi Kong ◽  
Xiao-Feng Wang ◽  
Shuo-Shuo Li ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Late Onset ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Spatial Learning And Memory ◽  
Metabolic Switch ◽  
Sufficient Energy ◽  
Aβ Clearance ◽  
The Brain

The accumulation of aggregated amyloid-β (Aβ) in the brain is the first critical step in the pathogenesis of Alzheimer’s disease (AD), which also includes synaptic impairment, neuroinflammation, neuronal loss, and eventual cognitive defects. Emerging evidence suggests that impairment of Aβ phagocytosis and clearance is a common phenotype in late-onset AD. Rutin (quercetin-3-rutinoside) has long been investigated as a natural flavonoid with different biological functions in some pathological circumstances. Sodium rutin (NaR), could promote Aβ clearance by increasing microglial by increasing the expression levels of phagocytosis-related receptors in microglia. Moreover, NaR promotes a metabolic switch from anaerobic glycolysis to mitochondrial OXPHOS (oxidative phosphorylation), which could provide microglia with sufficient energy (ATP) for Aβ clearance. Thus, NaR administration could attenuate neuroinflammation and enhance mitochondrial OXPHOS and microglia-mediated Aβ clearance, ameliorating synaptic plasticity impairment and eventually reversing spatial learning and memory deficits. Our findings suggest that NaR is a potential therapeutic agent for AD.

scholarly journals Circulating Insulin-Like Growth Factor I is Involved in the Effect of High Fat Diet on Peripheral Amyloid β Clearance

2020 ◽  
Vol 21 (24) ◽  
pp. 9675
Author(s):  
Raquel Herrero-Labrador ◽  
Angel Trueba-Saiz ◽  
Laura Martinez-Rachadell ◽  
Mᵃ Estrella Fernandez de Sevilla ◽  
Jonathan A. Zegarra-Valdivia ◽  
...  
Keyword(s):  
Growth Factor ◽  
High Fat Diet ◽  
Amyloid Β ◽  
Insulin Like Growth Factor ◽  
High Fat ◽  
Factor I ◽  
Igf I ◽  
Peripheral Clearance ◽  
Aβ Clearance ◽  
The Brain

Obesity is a risk factor for Alzheimer’s disease (AD), but underlying mechanisms are not clear. We analyzed peripheral clearance of amyloid β (Aβ) in overweight mice because its systemic elimination may impact brain Aβ load, a major landmark of AD pathology. We also analyzed whether circulating insulin-like growth factor I (IGF-I) intervenes in the effects of overweight as this growth factor modulates brain Aβ clearance and is increased in the serum of overweight mice. Overweight mice showed increased Aβ accumulation by the liver, the major site of elimination of systemic Aβ, but unaltered brain Aβ levels. We also found that Aβ accumulation by hepatocytes is stimulated by IGF-I, and that mice with low serum IGF-I levels show reduced liver Aβ accumulation—ameliorated by IGF-I administration, and unchanged brain Aβ levels. In the brain, IGF-I favored the association of its receptor (IGF-IR) with the Aβ precursor protein (APP), and at the same time, stimulated non-amyloidogenic processing of APP in astrocytes, as indicated by an increased sAPPα/sAPPβ ratio after IGF-I treatment. Since serum IGF-I enters into the brain in an activity-dependent manner, we analyzed in overweight mice the effect of brain activation by environmental enrichment (EE) on brain IGF-IR phosphorylation and its association to APP, as a readout of IGF-I activity. After EE, significantly reduced brain IGF-IR phosphorylation and APP/IGF-IR association were found in overweight mice as compared to lean controls. Collectively, these results indicate that a high-fat diet influences peripheral clearance of Aβ without affecting brain Aβ load. Increased serum IGF-I likely contributes to enhanced peripheral Aβ clearance in overweight mice, without affecting brain Aβ load probably because its brain entrance is reduced.

scholarly journals Neuronal heparan sulfates promote amyloid pathology by modulating brain amyloid-β clearance and aggregation in Alzheimer’s disease

2016 ◽  
Vol 8 (332) ◽  
pp. 332ra44-332ra44 ◽  
Author(s):  
Chia-Chen Liu ◽  
Na Zhao ◽  
Yu Yamaguchi ◽  
John R. Cirrito ◽  
Takahisa Kanekiyo ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Late Onset ◽  
Amyloid Β ◽  
Amyloid Plaques ◽  
Therapeutic Interventions ◽  
Postmortem Human Brain ◽  
Aβ Clearance ◽  
Heparan Sulfates ◽  
The Brain

Accumulation of amyloid-β (Aβ) peptide in the brain is the first critical step in the pathogenesis of Alzheimer’s disease (AD). Studies in humans suggest that Aβ clearance from the brain is frequently impaired in late-onset AD. Aβ accumulation leads to the formation of Aβ aggregates, which injure synapses and contribute to eventual neurodegeneration. Cell surface heparan sulfates (HSs), expressed on all cell types including neurons, have been implicated in several features in the pathogenesis of AD including its colocalization with amyloid plaques and modulatory role in Aβ aggregation. We show that removal of neuronal HS by conditional deletion of the Ext1 gene, which encodes an essential glycosyltransferase for HS biosynthesis, in postnatal neurons of amyloid model APP/PS1 mice led to a reduction in both Aβ oligomerization and the deposition of amyloid plaques. In vivo microdialysis experiments also detected an accelerated rate of Aβ clearance in the brain interstitial fluid, suggesting that neuronal HS either inhibited or represented an inefficient pathway for Aβ clearance. We found that the amounts of various HS proteoglycans (HSPGs) were increased in postmortem human brain tissues from AD patients, suggesting that this pathway may contribute directly to amyloid pathogenesis. Our findings have implications for AD pathogenesis and provide insight into therapeutic interventions targeting Aβ-HSPG interactions.

scholarly journals Low-density lipoprotein receptor overexpression enhances the rate of brain-to-blood Aβ clearance in a mouse model of β-amyloidosis

2012 ◽  
Vol 109 (38) ◽  
pp. 15502-15507 ◽  
Author(s):  
Joseph M. Castellano ◽  
Rashid Deane ◽  
Andrew J. Gottesdiener ◽  
Philip B. Verghese ◽  
Floy R. Stewart ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Brain Barrier ◽  
Low Density ◽  
Lipoprotein Receptor ◽  
Low Density Lipoprotein Receptor ◽  
Density Lipoprotein Receptor ◽  
Aβ Clearance ◽  
The Brain

The apolipoprotein E (APOE)-ε4 allele is the strongest genetic risk factor for late-onset, sporadic Alzheimer's disease, likely increasing risk by altering amyloid-β (Aβ) accumulation. We recently demonstrated that the low-density lipoprotein receptor (LDLR) is a major apoE receptor in the brain that strongly regulates amyloid plaque deposition. In the current study, we sought to understand the mechanism by which LDLR regulates Aβ accumulation by altering Aβ clearance from brain interstitial fluid. We hypothesized that increasing LDLR levels enhances blood–brain barrier-mediated Aβ clearance, thus leading to reduced Aβ accumulation. Using the brain Aβ efflux index method, we found that blood–brain barrier-mediated clearance of exogenously administered Aβ is enhanced with LDLR overexpression. We next developed a method to directly assess the elimination of centrally derived, endogenous Aβ into the plasma of mice using an anti-Aβ antibody that prevents degradation of plasma Aβ, allowing its rate of appearance from the brain to be measured. Using this plasma Aβ accumulation technique, we found that LDLR overexpression enhances brain-to-blood Aβ transport. Together, our results suggest a unique mechanism by which LDLR regulates brain-to-blood Aβ clearance, which may serve as a useful therapeutic avenue in targeting Aβ clearance from the brain.

scholarly journals GPCR19 regulates P2X7R-mediated NLRP3 inflammasomal activation of microglia by Amyloid β in Alzheimer’s diseases

2020 ◽  
Author(s):  
Jahirul Islam ◽  
Jung-Ah Cho ◽  
Ju-yong Kim ◽  
Kyung-Sun Park ◽  
Young-Jae koh ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Nlrp3 Inflammasome ◽  
Memory Function ◽  
Scavenger Receptor ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Priming Phase ◽  
5Xfad Mice ◽  
The Brain

Abstract Amyloid β (Aβ) and/or ATP activates NLRP3 inflammasome (N3I) by P2 × 7R ion channel of microglia, which is crucial in neuroinflammation shown in Alzheimer’s disease (AD). Due to polymorphisms, subtypes, and ubiquitous expression of P2 × 7R, inhibition of P2 × 7R has not been effective for AD. We first report that GPCR19 is a prerequisite for P2 × 7R-mediated N3I activation and Taurodeoxycholate (TDCA), a GPCR19 ligand, inhibited the priming phase of N3I activation, suppressed P2 × 7R expression and P2 × 7R-mediated Ca++ mobilization, and N3I oligomerization which is essential for production of IL-1β/IL-18. Further, TDCA increased expression of scavenger receptor (SR) A, enhanced phagocytosis of Aβ, and decreased Aβ plaque numbers in the brain of 5x Familial Alzheimer’s disease (5xFAD) mice. TDCA also reduced microgliosis, prevented neuronal loss, and improved memory function of 5xFAD mice. The pleiotropic roles of GPCR19 in P2 × 7-mediated N3I activation suggest that targeting GPCR19 might resolve neuroinflammation in AD patients.

scholarly journals Coffee polyphenols prevent cognitive dysfunction and suppress amyloid β plaques in APP/PS2 transgenic mouse

2018 ◽  
Author(s):  
Keiko Ishida ◽  
Masaki Yamamoto ◽  
Koichi Misawa ◽  
Noriyasu Ota ◽  
Akira Shimotoyodome
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Transgenic Mouse ◽  
Cognitive Dysfunction ◽  
Amyloid Β ◽  
Morris Water Maze Test ◽  
Dependent Manner ◽  
Chlorogenic Acids ◽  
Caffeoylquinic Acid ◽  
Model Of Alzheimer’S Disease

AbstractEpidemiological studies have found that habitual coffee consumption may reduce the risk of Alzheimer’s disease. Coffee contains numerous phenolic compounds (coffee polyphenols) such as chlorogenic acids. However, evidence demonstrating the contribution of chlorogenic acids in preventing cognitive dysfunction induced by Alzheimer’s disease is limited. In this study, we investigated the effect of chlorogenic acids on prevention of cognitive dysfunction in APP/PS2 transgenic mouse model of Alzheimer’s disease. Five-week-old APP/PS2 mice were administered a diet supplemented with coffee polyphenols daily for 5 months. The memory and cognitive function of mice was determined using the novel object recognition test, the Morris water maze test, and the step-through passive avoidance test. We found that chronic treatment with coffee polyphenols prevented cognitive dysfunction and significantly reduced hippocampal Aβ deposition. We then determined the effect of 5-caffeoylquinic acid, one of the primary components of coffee polyphenols, on Aβ formation. 5-Caffeoylquinic acid did not inhibit Aβ fibrillation, but degraded Aβ fibrils in a dose-dependent manner. In conclusion, these results demonstrate that coffee polyphenols prevented cognitive deficits and alleviated Aβ plaque deposition via disaggregation of Aβ in APP/PS2 mouse.

scholarly journals Ketone Bodies Promote Amyloid-β1–40 Clearance in a Human in Vitro Blood–Brain Barrier Model

2020 ◽  
Vol 21 (3) ◽  
pp. 934 ◽  
Author(s):  
Romain Versele ◽  
Mariangela Corsi ◽  
Andrea Fuso ◽  
Emmanuel Sevin ◽  
Rita Businaro ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Ketone Bodies ◽  
Amyloid Β ◽  
Brain Barrier ◽  
Therapeutic Approaches ◽  
Protein Levels ◽  
Blood Brain ◽  
Aβ Clearance ◽  
The Brain

Alzheimer’s disease (AD) is characterized by the abnormal accumulation of amyloid-β (Aβ) peptides in the brain. The pathological process has not yet been clarified, although dysfunctional transport of Aβ across the blood–brain barrier (BBB) appears to be integral to disease development. At present, no effective therapeutic treatment against AD exists, and the adoption of a ketogenic diet (KD) or ketone body (KB) supplements have been investigated as potential new therapeutic approaches. Despite experimental evidence supporting the hypothesis that KBs reduce the Aβ load in the AD brain, little information is available about the effect of KBs on BBB and their effect on Aβ transport. Therefore, we used a human in vitro BBB model, brain-like endothelial cells (BLECs), to investigate the effect of KBs on the BBB and on Aβ transport. Our results show that KBs do not modify BBB integrity and do not cause toxicity to BLECs. Furthermore, the presence of KBs in the culture media was combined with higher MCT1 and GLUT1 protein levels in BLECs. In addition, KBs significantly enhanced the protein levels of LRP1, P-gp, and PICALM, described to be involved in Aβ clearance. Finally, the combined use of KBs promotes Aβ efflux across the BBB. Inhibition experiments demonstrated the involvement of LRP1 and P-gp in the efflux. This work provides evidence that KBs promote Aβ clearance from the brain to blood in addition to exciting perspectives for studying the use of KBs in therapeutic approaches.

scholarly journals Aging Brain: Prevention of Oxidative Stress by Vitamin E and Exercise

2009 ◽  
Vol 9 ◽  
pp. 366-372 ◽  
Author(s):  
Sambe Asha Devi
Keyword(s):  
Oxidative Stress ◽  
Vitamin E ◽  
Cognitive Decline ◽  
Middle Age ◽  
Neuronal Loss ◽  
Aging Brain ◽  
Key Factors ◽  
Esterase Inhibitors ◽  
The Brain ◽  
And Oxidative Stress

With aging, the brain undergoes neuronal loss in many areas. Although the loss of cells in the cerebral cortex, in particular the frontal cortex, has been recognized with aging, the influence of synaptic losses has a larger impact on cognitive decline. Much of the recent research on animals, as well as humans, has been aimed at slowing the cognitive decline through enrichment, and it has been found that the key factors are antioxidants and exercise. Several reports support the concept that regular supplementation of vitamin E and physical activity from as early as middle age can slow the cognitive decline observed during the later years. A few studies have also suggested that exercise is analogous to acetylcholine esterase inhibitors that are also used extensively to treat cognitive impairment and dementia in Alzheimer's disease. In addition, reports also support that vitamin E and exercise may act synergistically to overcome free radical injury and oxidative stress in the aging brain.

scholarly journals Early-onset and Robust Cerebral Microvascular Accumulation of Amyloid β-Protein in Transgenic Mice Expressing Low Levels of a Vasculotropic Dutch/Iowa Mutant Form of Amyloid β-Protein Precursor

2004 ◽  
Vol 279 (19) ◽  
pp. 20296-20306 ◽  
Author(s):  
Judianne Davis ◽  
Feng Xu ◽  
Rashid Deane ◽  
Galina Romanov ◽  
Mary Lou Previti ◽  
...  
Keyword(s):  
Early Onset ◽  
Amyloid Β ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mutant Form ◽  
Amyloid Β Protein ◽  
Pathological Feature ◽  
High Association ◽  
Cerebral Microvessels ◽  
Β Protein ◽  
The Brain

Cerebrovascular deposition of amyloid β-protein (Aβ) is a common pathological feature of Alzheimer's disease and related disorders. In particular, the Dutch E22Q and Iowa D23N mutations in Aβ cause familial cerebrovascular amyloidosis with abundant diffuse amyloid plaque deposits. Both of these charge-altering mutations enhance the fibrillogenic and pathogenic properties of Aβin vitro. Here, we describe the generation of several transgenic mouse lines (Tg-SwDI) expressing human neuronal Aβ precursor protein (AβPP) harboring the Swedish K670N/M671L and vasculotropic Dutch/Iowa E693Q/D694N mutations under the control of the mouse Thy1.2 promoter. Tg-SwDI mice expressed transgenic human AβPP only in the brain, but at levels below those of endogenous mouse AβPP. Despite the paucity of human AβPP expression, quantitative enzyme-linked immunosorbent assay measurements revealed that Tg-SwDI mice developed early-onset and robust accumulation of Aβ in the brain with high association with isolated cerebral microvessels. Tg-SwDI mice exhibited striking perivascular/vascular Aβ deposits that markedly increased with age. The vascular Aβ accumulations were fibrillar, exhibiting strong thioflavin S staining, and occasionally presented signs of microhemorrhage. In addition, numerous largely diffuse, plaque-like structures were observed starting at 3 months of age.In vivotransport studies demonstrated that Dutch/Iowa mutant Aβ was more readily retained in the brain compared with wild-type Aβ. These results with Tg-SwDI mice demonstrate that overexpression of human AβPP is not required for early-onset and robust accumulation of both vascular and parenchymal Aβ in mouse brain.

scholarly journals Can Anti–β-amyloid Monoclonal Antibodies Work in Autosomal Dominant Alzheimer Disease?

2020 ◽  
Vol 7 (1) ◽  
pp. e535
Author(s):  
Bruno P. Imbimbo ◽  
Ugo Lucca ◽  
Mark Watling
Keyword(s):  
Alzheimer Disease ◽  
Cognitive Decline ◽  
Autosomal Dominant ◽  
Amyloid Β ◽  
Functional Deficits ◽  
Β Amyloid ◽  
Set Up ◽  
The Brain ◽  
Dominant Theory

The dominant theory of Alzheimer disease (AD) has been that amyloid-β (Aβ) accumulation in the brain is the initial cause of the degeneration leading to cognitive and functional deficits. Autosomal dominant Alzheimer disease (ADAD), in which pathologic mutations of the amyloid precursor protein (APP) or presenilins (PSENs) genes are known to cause abnormalities of Aβ metabolism, should thus offer perhaps the best opportunity to test anti-Aβ drugs. Two long-term preventive studies (Dominantly Inherited Alzheimer Network Trials Unit Adaptive Prevention Trial [DIAN-TU-APT] and Alzheimer Preventive Initiative–ADAD) were set up to evaluate the efficacy of monoclonal anti-Aβ antibodies (solanezumab, gantenerumab, and crenezumab) in carriers of ADAD, but the results of the DIAN-TU-APT study have shown that neither solanezumab nor gantenerumab slowed cognitive decline in 144 subjects with ADAD followed for 4 years, despite one of the drugs (gantenerumab) significantly affected biomarkers relevant to their intended mechanism of action. Surprisingly, solanezumab significantly accelerated cognitive decline of both asymptomatic and symptomatic subjects. These failures further undermine the Aβ hypothesis and could support the suggestion that ADAD is triggered by accumulation of other APP metabolites, rather than Aβ.

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