scholarly journals The combination of β-asarone and icariin inhibits amyloid-β and reverses cognitive deficits by promoting mitophagy in models of Alzheimer’s disease

2021 ◽  
Author(s):  
Nanbu Wang ◽  
Haoyu Wang ◽  
Qi Pan ◽  
Jian Kang ◽  
Ziwen Liang ◽  
...  
Keyword(s):  
Cognitive Deficits ◽  
Pc12 Cell ◽  
Cell Model ◽  
Amyloid Β ◽  
Beclin 1 ◽  
Group Model ◽  
Cell Models ◽  
Age Related ◽  
Transmission Electron ◽  
Potential Strategy

Abstract Background: β-Asarone is the main constituent of Acorus tatarinowii Schott and exhibits important effects in diseases such as neurodegenerative and neurovascular diseases. Icariin (ICA) is a major active ingredient of Epimedium that has attracted increasing attention because of its unique pharmacological effects in degenerative disease. In this paper, we primarily explored the effects of the combination of β-asarone and ICA in clearing noxious proteins and reversing cognitive deficits. The accumulation of damaged mitochondria and mitophagy are characteristics of ageing and age-related neurodegeneration, including AD.Methods: APP/PS1 mice and in Aβ1-42-induced PC12 cell models were used. The groups were divided into five: normal group, model group (above animals and cells), icariin combined with β-asarone group, A3 and CSA group. Transmission electron microscopy was used to observe brain tissues (hippocampus and temporal lobe)/cell mitochondria, autophagosomes and other structures. IF and WB were used to detect the expression of Beclin-1, LC3, p62, Pink1, Parkin and p-Parkin. Dal-autophagy combined with LSCM was used to detect the occurrence of Autophagy. Mitophagy Detection Kit combined with LSCM was used to detect the occurrence of mitochondrial autophagy, and the effects of icariin combined with β-asarone on mitochondrial autophagy in AD animal and cell model were investigated.Results: We showed evidence that autophagy/mitophagy is damaged in the hippocampus of APP/PS1 mice and in Aβ1-42-induced PC12 cell models. Then, we found that the combination therapy can reduce the cytotoxicity caused by Aβ1-42, increase cell viability, inhibit the expression of Aβ, APP, PS1 and BACE1, and promote the expression of SYN. The efficacy of the combination is better than that of the single drug. What’s more, it also promoted the expression of Beclin-1, LC3 Ⅰ/ in, Pink1, Parkin and p-parkin while inhibited p62. Conclusion: These conclusions suggest that weakened removal of defective mitochondria is a pivotal event in AD pathogenesis and that combination treatment with mitophagy inducers represents a potential strategy for therapeutic intervention.

scholarly journals Tip60 protects against amyloid-β peptide-induced transcriptomic alterations via different modes of action in early versus late stages of neurodegenerative progression

2020 ◽  
Author(s):  
Haolin Zhang ◽  
Bhanu Chandra Karisetty ◽  
Akanksha Bhatnagar ◽  
Ellen M. Armour ◽  
Mariah Beaver ◽  
...  
Keyword(s):  
Cell Death ◽  
Cognitive Deficits ◽  
Late Stage ◽  
Neurodegenerative Disorder ◽  
Amyloid Β ◽  
Neuronal Cell ◽  
Amyloid Β Peptide ◽  
Histone Deacetylase 2 ◽  
Age Related ◽  
Late Stages

ABSTRACTAlzheimer’s disease (AD) is an age-related neurodegenerative disorder hallmarked by amyloid-β (Aβ) plaque accumulation, neuronal cell death, and cognitive deficits that worsen during disease progression. Histone acetylation dysregulation, caused by an imbalance between reduced histone acetyltransferases (HAT) Tip60 and increased histone deacetylase 2 (HDAC2) levels, can directly contribute to AD pathology. However, whether such AD-associated neuroepigenetic alterations occur in response to Aβ peptide production and can be protected against by increasing Tip60 levels over the course of neurodegenerative progression remains unknown. Here we profile Tip60 HAT/HDAC2 dynamics and transcriptome-wide changes across early and late stage AD pathology in the Drosophila brain produced solely by human amyloid-β42. We show that early Aβ42 induction leads to disruption of Tip60 HAT/HDAC2 balance during early neurodegenerative stages preceding Aβ plaque accumulation that persists into late AD stages. Correlative transcriptome-wide studies reveal alterations in biological processes we classified as transient (early-stage only), late-onset (late-stage only), and constant (both). Increasing Tip60 HAT levels in the Aβ42 fly brain protects against AD functional pathologies that include Aβ plaque accumulation, neural cell death, cognitive deficits, and shorter life-span. Strikingly, Tip60 protects against Aβ42-induced transcriptomic alterations via distinct mechanisms during early and late stages of neurodegeneration. Our findings reveal distinct modes of neuroepigenetic gene changes and Tip60 neuroprotection in early versus late stages in AD that can serve as early biomarkers for AD, and support the therapeutic potential of Tip60 over the course of AD progression.

scholarly journals Avoiding the Pitfalls of siRNA Delivery to the Retinal Pigment Epithelium with Physiologically Relevant Cell Models

Pharmaceutics ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 667
Author(s):  
Eva Ramsay ◽  
Manuela Raviña ◽  
Sanjay Sarkhel ◽  
Sarah Hehir ◽  
Neil R. Cameron ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Cell Model ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Sirna Delivery ◽  
Target Cells ◽  
Cell Models ◽  
Rpe Cells ◽  
Age Related

Inflammation is involved in the pathogenesis of several age-related ocular diseases, such as macular degeneration (AMD), diabetic retinopathy, and glaucoma. The delivery of anti-inflammatory siRNA to the retinal pigment epithelium (RPE) may become a promising therapeutic option for the treatment of inflammation, if the efficient delivery of siRNA to target cells is accomplished. Unfortunately, so far, the siRNA delivery system selection performed in dividing RPE cells in vitro has been a poor predictor of the in vivo efficacy. Our study evaluates the silencing efficiency of polyplexes, lipoplexes, and lipidoid-siRNA complexes in dividing RPE cells as well as in physiologically relevant RPE cell models. We find that RPE cell differentiation alters their endocytic activity and causes a decrease in the uptake of siRNA complexes. In addition, we determine that melanosomal sequestration is another significant and previously unexplored barrier to gene silencing in pigmented cells. In summary, this study highlights the importance of choosing a physiologically relevant RPE cell model for the selection of siRNA delivery systems. Such cell models are expected to enable the identification of carriers with a high probability of success in vivo, and thus propel the development of siRNA therapeutics for ocular disease.

scholarly journals The Combination of β-Asarone and Icariin Inhibits Amyloid-β and Reverses Cognitive Deficits by Promoting Mitophagy in Models of Alzheimer’s Disease

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Nanbu Wang ◽  
Haoyu Wang ◽  
Qi Pan ◽  
Jian Kang ◽  
Ziwen Liang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Combination Therapy ◽  
Cognitive Deficits ◽  
Amyloid Β ◽  
In Vivo Models ◽  
Age Related ◽  
The Individual

β-Asarone is the main constituent of Acorus tatarinowii Schott and exhibits important effects in diseases such as neurodegenerative and neurovascular diseases. Icariin (ICA) is a major active ingredient of Epimedium that has attracted increasing attention because of its unique pharmacological effects in degenerative disease. In this paper, we primarily explored the effects of the combination of β-asarone and ICA in clearing noxious proteins and reversing cognitive deficits. The accumulation of damaged mitochondria and mitophagy are hallmarks of aging and age-related neurodegeneration, including Alzheimer’s disease (AD). Here, we provide evidence that autophagy/mitophagy is impaired in the hippocampus of APP/PS1 mice and in Aβ1-42-induced PC12 cell models. Enhanced mitophagic activity has been reported to promote Aβ and tau clearance in in vitro and in vivo models. Meanwhile, there is growing evidence that treatment of AD should be preceded by intervention before the formation of pathological products. The efficacy of the combination therapy was better than that of the individual therapies applied separately. Then, we found that the combination therapy also inhibited cell and mitochondrial damage by inducing autophagy/mitophagy. These findings suggest that impaired removal of defective mitochondria is a pivotal event in AD pathogenesis, and that combination treatment with mitophagy inducers represents a potential strategy for therapeutic intervention.

scholarly journals Age-Related Tau Burden and Cognitive Deficits Are Attenuated in KLOTHO KL-VS Heterozygotes

2021 ◽  
pp. 1-9
Author(s):  
Ira Driscoll ◽  
Yue Ma ◽  
Catherine L. Gallagher ◽  
Sterling C. Johnson ◽  
Sanjay Asthana ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Executive Function ◽  
Cognitive Deficits ◽  
Neuropsychological Testing ◽  
Amyloid Β ◽  
Csf Biomarkers ◽  
Age Related ◽  
Testing Data ◽  
Related Pattern

Background: Identification of new genetic variants that modify Alzheimer’s disease (AD) risk will elucidate novel targets for curbing the disease progression or delaying symptom onset. Objective: To examine whether the functionally advantageous KLOTHO gene KL-VS variant attenuates age-related alteration in cerebrospinal fluid (CSF) biomarkers or cognitive function in middle-aged and older adults enriched for AD risk. Methods: Sample included non-demented adults (N = 225, mean age = 63±8, 68% women) from the Wisconsin Registry for Alzheimer’s Prevention and the Wisconsin Alzheimer’s Disease Research Center who were genotyped for KL-VS, underwent CSF sampling and had neuropsychological testing data available proximal to CSF draw. Covariate-adjusted multivariate regression examined relationships between age group (Younger versus Older; mean split at 63 years), AD biomarkers, and neuropsychological performance tapping memory and executive function, and whether these relationships differed between KL-VS non-carriers (KL-VSNC) and heterozygote (KL-VSHET). Results: In the pooled analyses, older age was associated with higher levels of total tau (tTau), phosphorylated tau (pTau), and their respective ratios to amyloid-β (Aβ)42 (ps ≤ 0.002), and with poorer performance on neuropsychological tests (ps ≤ 0.001). In the stratified analyses, KL-VSNC exhibited this age-related pattern of associations with CSF biomarkers (all ps ≤ 0.001), and memory and executive function (ps ≤ 0.003), which were attenuated in KL-VSHET (ps≥0.14). Conclusion: Worse memory and executive function, and higher tau burden with age were attenuated in carriers of a functionally advantageous KLOTHO variant. KL-VS heterozygosity seems to be protective against age-related cognitive and biomolecular alterations that confer risk for AD.

NPD1 Enhances Autophagy and Reduces Hyperphosphorylated Tau and Amyloid-β42 by Inhibiting GSK3β Activation in N2a/APP695swe Cells

2021 ◽  
pp. 1-13
Author(s):  
Songyang Dai ◽  
Fanlin Zhou ◽  
Jieyun Sun ◽  
Yu Li
Keyword(s):  
Glycogen Synthase ◽  
Cell Model ◽  
Amyloid Β ◽  
Hyperphosphorylated Tau ◽  
Neuroprotective Effects ◽  
Transmission Electron ◽  
Associated Proteins ◽  
Gsk 3Β ◽  
Neuroprotective Function ◽  
Autophagy Activity

Background: The most prevalent kind of dementia, Alzheimer’s disease (AD), is a neurodegenerative disease. Previous research has shown that glycogen synthase kinase-3β (GSK-3β) is involved in the etiology and progression of AD, including amyloid-β (Aβ), phosphorylated tau, and mitochondrial dysfunction. NPD1 has been shown to serve a neuroprotective function in AD, although the mechanism is unclear. Objective: The effects of NPD1 on Aβ expression levels, tau protein phosphorylation, apoptosis ratio, autophagy activity, and GSK-3β activity in N2a/APP695swe cells (AD cell model) were studied, as well as the mechanism behind such effects. Methods: N2a/APP695swe cells were treated with NPD1, SB216763, or wortmannin as an AD cell model. The associated proteins of hyperphosphorylated tau and autophagy, as well as the activation of GSK3β, were detected using western blot and RT-PCR. Flow cytometry was utilized to analyze apoptosis and ELISA was employed to observe Aβ 42. Images of autophagy in cells are captured using transmission electron microscopy. Results: In N2a/APP695swe cells, NPD1 decreased Aβ 42 and hyperphosphorylated tau while suppressing cell death. NPD1 also promoted autophagy while suppressing GSK-3β activation in N2a/APP695swe cells. The outcome of inhibiting GSK-3β is comparable to that of NPD1 therapy. However, after activating GSK-3β, the opposite experimental results were achieved. Conclusion: NPD1 might minimize cell apoptosis, downregulate Aβ expression, control tau hyperphosphorylation, and enhance autophagy activity in AD cell models to promote neuronal survival. NPD1’s neuroprotective effects may be mediated via decreasing GSK-3β.

Resveratrol Rescues Tau-Induced Cognitive Deficits and Neuropathology in a Mouse Model of Tauopathy

2019 ◽  
Vol 16 (8) ◽  
pp. 710-722 ◽  
Author(s):  
Xiao-Ying Sun ◽  
Quan-Xiu Dong ◽  
Jie Zhu ◽  
Xun Sun ◽  
Li-Fan Zhang ◽  
...  
Keyword(s):  
Cognitive Deficits ◽  
Therapeutic Potential ◽  
Amyloid Β ◽  
Synaptic Proteins ◽  
Morris Water Maze Test ◽  
Phosphorylated Tau ◽  
Tau Pathology ◽  
Maze Test ◽  
N2a Cells ◽  
Tau Aggregation

Background: Alzheimer’s Disease (AD) is characterized by the presence of extracellular amyloid-β (Aβ) plaques and intraneuronal neurofibrillary tangles assembled by the microtubuleassociated protein tau. Increasing evidence demonstrated that tau pathology played an important role in AD progression. Resveratrol (RSV) has previously proved to exert neuroprotective effect against AD by inhibiting Aβ generation and Aβ-induced neurocytotoxicity, while its effect on tau pathology is still unknown. Method: The effect of RSV on tau aggregation was measured by Thioflavin T fluorescence and Transmission electron microscope imaging. The effect of RSV on tau oligomer-induced cytotoxicity was assessed by MTT assay and the uptake of extracellular tau by N2a cells was determined by immunocytochemistry. 6-month-old male PS19 mice were treated with RSV or vehicle by oral administration (gavage) once a day for 5 weeks. The cognitive performance was determined using Morris water maze test, object recognition test and Y-maze test. The levels of phosphorylated-tau, gliosis, proinflammatory cytokines such as TNF-α and IL-1β, and synaptic proteins including synaptophysin and PSD95 in the brains of the mice were evaluated by immunoblotting, immunostaining and ELISA, respectively. Results: RSV significantly inhibited tau aggregation and tau oligomer-induced cytotoxicity, and blocked the uptake of extracellular tau oligomers by N2a cells. When applied to PS19 mice, RSV treatment effectively rescued cognitive deficits, reducing the levels of phosphorylated tau, neuroinflammation and synapse loss in the brains of mice. Conclusion: These findings suggest that RSV has promising therapeutic potential for AD and other tauopathies.

scholarly journals Role of amyloid β-peptide in the pathogenesis of age-related macular degeneration

2021 ◽  
Vol 6 (1) ◽  
pp. e000774
Author(s):  
Minwei Wang ◽  
Shiqi Su ◽  
Shaoyun Jiang ◽  
Xinghuai Sun ◽  
Jiantao Wang
Keyword(s):  
Mitochondrial Dysfunction ◽  
Macular Degeneration ◽  
Vision Loss ◽  
Cell Structure ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Amyloid Β ◽  
Age Related Macular Degeneration ◽  
Amyloid Β Peptide ◽  
Age Related

Age-related macular degeneration (AMD) is the most common eye disease in elderly patients, which could lead to irreversible vision loss and blindness. Increasing evidence indicates that amyloid β-peptide (Aβ) might be associated with the pathogenesis of AMD. In this review, we would like to summarise the current findings in this field. The literature search was done from 1995 to Feb, 2021 with following keywords, ‘Amyloid β-peptide and age-related macular degeneration’, ‘Inflammation and age-related macular degeneration’, ‘Angiogenesis and age-related macular degeneration’, ‘Actin cytoskeleton and amyloid β-peptide’, ‘Mitochondrial dysfunction and amyloid β-peptide’, ‘Ribosomal dysregulation and amyloid β-peptide’ using search engines Pubmed, Google Scholar and Web of Science. Aβ congregates in subretinal drusen of patients with AMD and participates in the pathogenesis of AMD through enhancing inflammatory activity, inducing mitochondrial dysfunction, altering ribosomal function, regulating the lysosomal pathway, affecting RNA splicing, modulating angiogenesis and modifying cell structure in AMD. The methods targeting Aβ are shown to inhibit inflammatory signalling pathway and restore the function of retinal pigment epithelium cells and photoreceptor cells in the subretinal region. Targeting Aβ may provide a novel therapeutic strategy for AMD.

scholarly journals 4-(Phenylsulfanyl) Butan-2-One Attenuates the Inflammatory Response Induced by Amyloid-β Oligomers in Retinal Pigment Epithelium Cells

Marine Drugs ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 1
Author(s):  
Peeraporn Varinthra ◽  
Shun-Ping Huang ◽  
Supin Chompoopong ◽  
Zhi-Hong Wen ◽  
Ingrid Y. Liu
Keyword(s):  
Retinal Pigment Epithelium ◽  
Inflammatory Response ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Amyloid Β ◽  
Age Related Macular Degeneration ◽  
Epithelial Cell Line ◽  
Age Related ◽  
Tnf Α ◽  
Cox 2

Age-related macular degeneration (AMD) is a progressive eye disease that causes irreversible impairment of central vision, and effective treatment is not yet available. Extracellular accumulation of amyloid-beta (Aβ) in drusen that lie under the retinal pigment epithelium (RPE) has been reported as one of the early signs of AMD and was found in more than 60% of Alzheimer’s disease (AD) patients. Extracellular deposition of Aβ can induce the expression of inflammatory cytokines such as IL-1β, TNF-α, COX-2, and iNOS in RPE cells. Thus, finding a compound that can effectively reduce the inflammatory response may help the treatment of AMD. In this research, we investigated the anti-inflammatory effect of the coral-derived compound 4-(phenylsulfanyl) butan-2-one (4-PSB-2) on Aβ1-42 oligomer (oAβ1-42) added to the human adult retinal pigment epithelial cell line (ARPE-19). Our results demonstrated that 4-PSB-2 can decrease the elevated expressions of TNF-α, COX-2, and iNOS via NF-κB signaling in ARPE-19 cells treated with oAβ1-42 without causing any cytotoxicity or notable side effects. This study suggests that 4-PSB-2 is a promising drug candidate for attenuation of AMD.

scholarly journals The Novel Alpha-2 Adrenoceptor Inhibitor Beditin Reduces Cytotoxicity and Huntingtin Aggregates in Cell Models of Huntington’s Disease

2021 ◽  
Vol 14 (3) ◽  
pp. 257
Author(s):  
Elisabeth Singer ◽  
Lilit Hunanyan ◽  
Magda M. Melkonyan ◽  
Jonasz J. Weber ◽  
Lusine Danielyan ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Neurodegenerative Disorder ◽  
Cell Model ◽  
Resonance Energy Transfer ◽  
Neuronal Cell ◽  
Resonance Energy ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tunel Staining ◽  
Cell Models

Huntington’s disease (HD) is a monogenetic neurodegenerative disorder characterized by the accumulation of polyglutamine-expanded huntingtin (mHTT). There is currently no cure, and therefore disease-slowing remedies are sought to alleviate symptoms of the multifaceted disorder. Encouraging findings in Alzheimer’s and Parkinson’s disease on alpha-2 adrenoceptor (α2-AR) inhibition have shown neuroprotective and aggregation-reducing effects in cell and animal models. Here, we analyzed the effect of beditin, a novel α2- adrenoceptor (AR) antagonist, on cell viability and mHTT protein levels in cell models of HD using Western blot, time-resolved Foerster resonance energy transfer (TR-FRET), lactate dehydrogenase (LDH) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) cytotoxicity assays. Beditin decreases cytotoxicity, as measured by TUNEL staining and LDH release, in a neuronal progenitor cell model (STHdh cells) of HD and decreases the aggregation propensity of HTT exon 1 fragments in an overexpression model using human embryonic kidney (HEK) 293T cells. α2-AR is a promising therapeutic target for further characterization in HD models. Our data allow us to suggest beditin as a valuable candidate for the pharmaceutical manipulation of α2-AR, as it is capable of modulating neuronal cell survival and the level of mHTT.

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