Journal of Alzheimer's Disease - Volume Pre-press, issue Pre-press

Authors: Zhao, Rangyin | Han, Xiaoyong | Jiang, Shangrong | Zhao, Weijing | Liu, Jia | Zhang, Hongxia | Mao, Xiaoliang | Zhang, Min | Lei, Lili | You, Hong

Article Type: Research Article

Abstract: Background: Dementia is a neuropsychiatric disorder with cognitive decline due to multiple factors. With the arrival of the aging population, the incidence of dementia has gradually increased. There is still no effective treatment for dementia, and therefore, the prevention of dementia has become crucial. Oxidative stress is considered to be one of the pathogenesis of dementia; therefore, antioxidant therapy and prevention of dementia have been gradually proposed. Objective: Our meta-analysis aimed to investigate the association of antioxidants with risk of dementia. Methods: We searched PubMed, Embase, and Web of Science databases for articles on antioxidants associated …with dementia risk, and those containing cohort studies with high-dose versus low-dose controls were included in our meta-analysis. The resulting risk ratios (RR) and hazard ratios (HR) and 95% confidence intervals were statistically analyzed using Stata12.0 free software. Results: A total of 17 articles were included in this meta-analysis. Of 98,264 participants, 7,425 had dementia after 3–23 years of follow-up. The results of the meta-analysis showed a trend towards a lower incidence of dementia with high intake of antioxidants (RR = 0.84, 95% CI 0.77–1.19 I 2  = 54.6%), but this was not statistically significant. High antioxidant intake significantly reduced the incidence of Alzheimer ‘s disease (RR = 0.85, 95% CI 0.79–0.92 I 2  = 45.5%), and we additionally carried out subgroup analyses by nutrient type, diet or supplement, region, and study quality score. Conclusion: Dietary intake of antioxidants or supplements reduces both the risk of dementia and the risk of Alzheimer’s disease. Show more

Keywords: Alzheimer’s disease, antioxidants, dementia, meta-analysis, risk

DOI: 10.3233/JAD-220909

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-16, 2023

Authors: Soto-Mercado, Viviana | Mendivil-Perez, Miguel | Velez-Pardo, Carlos | Jimenez-Del-Rio, Marlene

Article Type: Research Article

Abstract: Background: Familial Alzheimer’s disease (FAD) is caused by mutations in one or more of 3 genes known as A β PP , PSEN1 , and PSEN2 . There are currently no effective therapies for FAD. Hence, novel therapeutics are needed. Objective: To analyze the effect of treatment with a combination of epigallocatechin-3-gallate (EGCG) and Melatonin (N-acetyl-5-methoxytryptamine, aMT) in a cerebral spheroid (CS) 3D in vitro model of PSEN 1 E280A FAD. Methods: We developed a CS in vitro model based on menstrual stromal cells derived from wild-type (WT) and mutant PSEN1 E280A …menstrual blood cultured in Fast-N-Spheres V2 medium. Results: Beta-tubulin III, choline acetyltransferase, and GFAP in both WT and mutant CSs spontaneously expressed neuronal and astroglia markers when grown in Fast-N-Spheres V2 medium for 4 or 11 days. Mutant PSEN1 CSs had significantly increased levels of intracellular AβPP fragment peptides and concomitant appearance of oxidized DJ-1 as early as 4 days, and phosphorylated tau, decreased ΔΨ m , and increased caspase-3 activity were observed on Day 11. Moreover, mutant CSs were unresponsive to acetylcholine. Treatment with a combination of EGCG and aMT decreased the levels of all typical pathological markers of FAD more efficiently than did EGCG or aMT alone, but aMT failed to restore Ca2 + influx in mutant CSs and decreased the beneficial effect of EGCG on Ca2 + influx in mutant CSs. Conclusion: Treatment with a combination of EGCG and aMT can be of high therapeutic value due to the high antioxidant capacity and anti-amyloidogenic effect of both compounds. Show more

Keywords: Alzheimer’s disease, cerebral spheroids, E280A, -(–) epigallocatechin 3-gallate, melatonin, menstrual mesenchymal stromal cell, mutation, presenilin

DOI: 10.3233/JAD-220903

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-16, 2023

Authors: Zhou, Moran | Jiao, Qian | Wu, Zengrui | Li, Weihua | Liu, Guixia | Wang, Rui | Tang, Yun

Article Type: Research Article

Abstract: Background: The oxidative stress hypothesis is challenging the dominant position of amyloid-β (Aβ ) in the field of understanding the mechanisms of Alzheimer’s disease (AD), a complicated and untreatable neurodegenerative disease. Objective: The goal of the present study was to uncover the oxidative stress mechanisms causing AD, as well as the potential therapeutic targets and neuroprotective drugs against oxidative stress mechanisms. Methods: In this study, a systematic workflow combining pharmacological experiments and computational prediction were proposed. 222 drugs and natural products were collected first and then tested on SH-SY5Y cells to obtain phenotypic screening data …on neuroprotection. The preliminary screening data were integrated with drug-target interactions (DTIs) and multi-scale biomedical data, which were analyzed with statistical tests and gene set enrichment analysis. A polypharmacology network was further constructed for investigation. Results: 340 DTIs were matched in multiple databases, and 222 cell viability ratios were calculated for experimental compounds. We identified significant potential therapeutic targets based on oxidative stress mechanisms for AD, including NR3C1, SHBG, ESR1, PGR, and AVPR1A, which might be closely related to neuroprotective effects and pathogenesis. 50% of the top 14 enriched pathways were found to correlate with AD, such as arachidonic acid metabolism and neuroactive ligand-receptor interaction. Several approved drugs in this research were also found to exert neuroprotective effects against oxidative stress mechanisms, including beclometasone, methylprednisolone, and conivaptan. Conclusion: Our results indicated that NR3C1, SHBG, ESR1, PGR, and AVPR1A were promising therapeutic targets and several drugs may be repurposed from the perspective of oxidative stress and AD. Show more

Keywords: Alzheimer’s disease, computational systems pharmacology, oxidative stress hypothesis, phenotypic screening, polypharmacology networks, therapeutic targets

DOI: 10.3233/JAD-220727

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-18, 2023

Authors: Yang, Lei | Zhao, Fengxue | Sun, Yadi | Wang, Ziyi | Li, Qianwen | Wang, Hao | Lu, Ying

Article Type: Systematic Review

Abstract: Background: Mild cognitive impairment (MCI) is the prodromal stage of dementia. In this stage, reasonable intervention measures can help to delay the decline of cognitive function. Supplementation of n-3 polyunsaturated fatty acids (n-3PUFAs) may be beneficial to delay the decline of cognitive function in the elderly. Objective: To investigate the effectiveness of docosapentaenoic acid (DHA) or/and eicosapentaenoic acid (EPA) supplements in the elderly with MCI. Methods: Eight electronic databases, PubMed, Cochrane Library, Embase, VIP, SinoMed, Web of Science, CNKI, and WANFANG DATA, were searched for related articles from inception until January 2022. Subgroup analyses and sensitivity …analyses were performed to detect confounding variables. Standardized mean differences (SMD) with 95% confidence intervals (CI) were determined. Heterogeneity was evaluated by I2 statistics. Publication bias was detected using funnel plots. Stata12.0 was used for Begg’s and Egger’s test to quantify whether publication bias. Linear relationship between global cognition and covariates was examined in meta-regression analysis. Results: Twelve studies (n  = 1,124) were included. The methodological quality of research is mostly medium. Compared with placebo, n-3PUFAs supplements have benefits on global cognition [SMD = 0.51, 95% CI(0.12, 0.91), p  = 0.01]. No significant differences were observed between intervention group and placebo on language fluency, executive functions, and depression. Conclusion: Our findings indicated DHA and/or EPA supplements have benefits on global cognition, and it may also reduce the level of blood amyloid-β (Aβ)-related biomarkers (e.g., Aβ 40 , Aβ 42 ) and inflammatory factors (e.g., 1L-6, 1L-10). Since there are only two relative articles, more research is needed in the future to clarify the relationship. Show more

Keywords: Elderly, meta-analysis, mild cognitive impairment, n-3 polyunsaturated fatty acids

DOI: 10.3233/JAD-220863

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-15, 2023

Authors: Bian, Zhihong | Yu, Haibo | Hu, Xinran | Bian, Yuting | Sun, Hongming | Tadokoro, Koh | Takemoto, Mami | Yunoki, Taijun | Nakano, Yumiko | Fukui, Yusuke | Morihara, Ryuta | Abe, Koji | Yamashita, Toru

Article Type: Research Article

Abstract: Background: NADPH oxidase 2 (NOX2) is an important source of reactive oxygen species (ROS). Activated NOX2 may contribute to Alzheimer’s disease (AD). Our previous studies showed that a novel vitamin E mixture, Tocovid, had potential neuroprotective effects in a stroke mice model and an AD cell model. Objective: The aim of this study was two-fold: to assess whether long-term Tocovid treatment can regulate NOX2, and the therapeutic effects of long-term administration of Tocovid to an AD mice model. Methods: Therapeutic effects of long-term administration of Tocovid (200 mg/kg /day) on an Aβ-overexpressed transgenic AD mice model (APP23, …n  = 8) was investigated. The therapeutic effect of Tocovid in 16-month-old mice compared with the no-treatment APP23 group (n  = 9) was assessed. Results: Tocovid treatment strongly improved motor and memory deficits of APP23 mice by attenuating NOX2 expression, oxidative stress, neuroinflammation, neurovascular unit dysfunction, synaptic alteration, and Aβ deposition after 16 months. Conclusion: These findings suggest that NOX2 is a potential target in AD pathology. Long-term administration of Tocovid may be a promising candidate for AD treatment. Show more

Keywords: Alzheimer’s disease, cerebral amyloid angiopathy, NOX2, oxidative stress, Tocovid

DOI: 10.3233/JAD-220761

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-11, 2022

Authors: Qaiser, Hammad | Uzair, Mohammad | Al-Regaiey, Khalid | Rafiq, Shafia | Arshad, Muhammad | Yoo, Woo-Kyoung | Arain, Osama Zahid | Kaleem, Imdad | Abualait, Turki | Wang, Lan | Wang, Ran | Bashir, Shahid

Article Type: Review Article

Abstract: Alzheimer’s disease (AD) is the most common form of dementia and a public health problem. It exhibits significant oxidative stress and redox alterations. The antioxidant enzyme systems defend the cellular environment from oxidative stress. One of the redox systems is the thioredoxin system (TS), which exerts decisive control over the cellular redox environment. We aimed to review the protective effects of TS, which include thioredoxin (Trx), thioredoxin reductase (TrxR), and NADPH. In the following, we discussed the physiological functioning and the role of the TS in maintaining the cellular redox-homeostasis in the AD-damaged brain. Trx protects the cellular environment from …oxidative stress, while TrxR is crucial for the cellular detoxification of reactive oxygen species in the brain. However, TS dysregulation increases the susceptibility to cellular death. The changes in Trx and TrxR levels are significantly associated with AD progression. Though the data from human, animal, and cellular models support the neuroprotective role of TS in the brain of AD patients, the translational potential of these findings to clinical settings is not yet applied. This review summarizes the current knowledge on the emerging role of the TrxR-Trx system in AD. Show more

Keywords: Alzheimer’s disease, antioxidant enzymes, oxidative stress, reactive oxygen species, redox enzymes, thioredoxin, thioredoxin reductase

DOI: 10.3233/JAD-230394

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-12, 2023

Authors: Puentes-Díaz, Nicolás | Chaparro, Diego | Reyes-Marquez, Viviana | Morales-Morales, David | Flores-Gaspar, Areli | Alí-Torres, Jorge

Article Type: Research Article

Abstract: Background: Alzheimer’s disease (AD) is the most common form of dementia representing from 60% to 70% of the cases globally. It is a multifactorial disease that, among its many pathological characteristics, has been found to provoke the metal ion dysregulation in the brain, along with an increase in the oxidative stress. There is proof that metallic complexes formed by the amyloid-β peptide (Aβ) and extraneuronal copper can catalyze the production of reactive oxygen species, leading to an increase in oxidative stress, promoting neuronal death. Due to this interaction, bioavailable copper has become an important redox active target to consider within …the search protocols of multifunctional agents for AD’s treatment. Objective: In this study, we examined by using bioinformatics and electronic structure calculations the potential application of 44 salen-type copper chelating ligands and 12 further proposed molecules as possible multifunctional agents in the context of AD. Methods: The candidates were evaluated by combining bioinformatic tools and electronic structure calculations, which allowed us to classify the molecules as potential antioxidants, redistributor-like compounds, and the newly proposed suppressor mechanism. Results: This evaluation demonstrate that salen-type ligands exhibit properties suitable for interfering in the chain of copper-induced oxidative stress reactions present in AD and potential redistributor and suppressor activity for copper ions. Finally, a novel set of plausible candidates is proposed and evaluated. Conclusion: According to the evaluated criteria, a subset of 13 salen-type candidates was found to exhibit promissory pharmacological properties in the AD framework and were classified according to three plausible action mechanisms. Show more

Keywords: Alzheimer’s disease, copper binding affinities, density functional theory calculations, salen-type ligands, standard reduction potentials

DOI: 10.3233/JAD-230542

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-14, 2023

Authors: Chum, Phoebe P. | Bishara, Mary A. | Solis, Summer R. | Behringer, Erik J.

Article Type: Research Article

Abstract: Background: Alzheimer’s disease (AD) is associated with impaired cerebral circulation which underscores diminished delivery of blood oxygen and nutrients to and throughout the brain. In the 3xTg-AD mouse model, we have recently found that > 10 cerebrovascular miRNAs pertaining to vascular permeability, angiogenesis, and inflammation (e.g., let-7d, miR-99a, miR-132, miR-133a, miR-151-5p, and miR-181a) track early development of AD. Further, endothelial-specific miRNAs (miR-126-3p, miR-23a/b, miR-27a) alter with onset of overall AD pathology relative to stability of smooth muscle/pericyte-specific miRNAs (miR-143, miR-145). Objective: We tested the hypothesis that cerebrovascular miRNAs indicating AD pathology share mRNA targets that regulate key endothelial cell functions …such as angiogenesis, vascular permeability, and blood flow regulation. Methods: As detected by NanoString nCounter miRNA Expression panel for 3xTg-AD mice, 61 cerebrovascular miRNAs and respective mRNA targets were examined using Ingenuity Pathway Analysis for canonical Cardiovascular (Cardio) and Nervous System (Neuro) Signaling. Results: The number of targets regulated per miRNA were 21±2 and 33±3 for the Cardio and Neuro pathways respectively, whereby 14±2 targets overlap among pathways. Endothelial miRNAs primarily target members of the PDE, PDGF, SMAD, and VEGF families. Individual candidates regulated by≥4 miRNAs that best mark AD pathology presence in 3xTg-AD mice include CFL2, GRIN2B, PDGFB, SLC6A1, SMAD3, SYT3, and TNFRSF11B. Conclusion: miRNAs selective for regulation of endothelial function and respective downstream mRNA targets support a molecular basis for dysregulated cerebral blood flow regulation coupled with enhanced cell growth, proliferation, and inflammation. Show more

Keywords: Alzheimer’s disease, brain endothelium, mRNA targets, vascular dysfunction

DOI: 10.3233/JAD-230300

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-48, 2023

Authors: Liang, Jingjing | LaFleur, Bonnie | Hussainy, Sadiya | Perry, George

Article Type: Research Article

Abstract: Background: Alzheimer’s disease (AD) is the most common form of dementia in the elderly marked by central nervous system (CNS) neuronal loss and amyloid plaques. FAM222A , encoding an amyloid plaque core protein, is an AD brain atrophy susceptibility gene that mediates amyloid-β aggregation. However, the expression interplay between FAM222A and other AD-related pathway genes is unclear. Objective: Our goal was to study FAM222A ’s whole-genome co-expression profile in multiple tissues and investigate its interplay with other AD-related genes. Methods: We analyzed gene expression correlations in Genotype-Tissue Expression (GTEx) tissues to identify FAM222A co-expressed …genes and performed functional enrichment analysis on identified genes in CNS system. Results: Genome-wide gene expression profiling identified 673 genes significantly correlated with FAM222A (p  <  2.5×10–6 ) in 48 human tissues, including 298 from 13 CNS tissues. Functional enrichment analysis revealed that FAM222A co-expressed CNS genes were enriched in multiple AD-related pathways. Gene co-expression network analysis for identified genes in each brain region predicted other disease associated genes with similar biological function. Furthermore, co-expression of 25 out of 31 AD-related pathways genes with FAM222A was replicated in brain samples from 107 aged subjects from the Aging, Dementia and TBI Study. Conclusion: This gene co-expression study identified multiple AD-related genes that are associated with FAM222A , indicating that FAM222A and AD-associated genes can be active simultaneously in similar biological processes, providing evidence that supports the association of FAM222A with AD. Show more

Keywords: Alzheimer’s disease, FAM222A, gene co-expression network analysis, neurodegeneration, transcriptomics

DOI: 10.3233/JAD-221241

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-15, 2023

Authors: Lardelli, Michael | Baer, Lachlan | Hin, Nhi | Allen, Angel | Pederson, Stephen Martin | Barthelson, Karissa

Article Type: Research Article

Abstract: The degree to which non-human animals can be used to model Alzheimer’s disease is a contentious issue, particularly as there is still widespread disagreement regarding the pathogenesis of this neurodegenerative dementia. The currently popular transgenic models are based on artificial expression of genes mutated in early onset forms of familial Alzheimer’s disease (EOfAD). Uncertainty regarding the veracity of these models led us to focus on heterozygous, single mutations of endogenous genes (knock-in models) as these most closely resemble the genetic state of humans with EOfAD, and so incorporate the fewest assumptions regarding pathological mechanism. We have generated a number of …lines of zebrafish bearing EOfAD-like and non-EOfAD-like mutations in genes equivalent to human PSEN1 , PSEN2 , and SORL1 . To analyze the young adult brain transcriptomes of these mutants, we exploited the ability of zebrafish to produce very large families of simultaneous siblings composed of a variety of genotypes and raised in a uniform environment. This “intra-family” analysis strategy greatly reduced genetic and environmental “noise” thereby allowing detection of subtle changes in gene sets after bulk RNA sequencing of entire brains. Changes to oxidative phosphorylation were predicted for all EOfAD-like mutations in the three genes studied. Here we describe some of the analytical lessons learned in our program combining zebrafish genome editing with transcriptomics to understand the molecular pathologies of neurodegenerative disease. Show more

Keywords: Alzheimer’s disease, early onset Alzheimer’s disease, gene expression profiling, genetic, models, transcriptome, zebrafish

DOI: 10.3233/JAD-230522

Citation: Journal of Alzheimer's Disease, vol. Pre-press, no. Pre-press, pp. 1-15, 2023