Journal of Alzheimer's Disease - Volume 99, issue s2

Authors: Weinberg, Marc S. | He, Yingnan | Kivisäkk, Pia | Arnold, Steven E. | Das, Sudeshna

Article Type: Research Article

Abstract: Background: Alzheimer’s disease (AD) is a complicated condition involving multiple metabolic and immunologic pathophysiological processes that can occur with the hallmark pathologies of amyloid-β, tau, and neurodegeneration. Metformin, an anti-diabetes drug, targets several of these disease processes in in vitro and animal studies. However, the effects of metformin on human cerebrospinal fluid (CSF) and plasma proteins as potential biomarkers of treatment remain unexplored. Objective: Using proteomics data from a metformin clinical trial, identify the impact of metformin on plasma and CSF proteins. Methods: We analyzed plasma and CSF proteomics data collected previously …(ClinicalTrials.gov identifier: NCT01965756, conducted between 2013 and 2015), and conduced bioinformatics analyses to compare the plasma and CSF protein levels after 8 weeks of metformin or placebo use to their baseline levels in 20 non-diabetic patients with mild cognitive impairment (MCI) and positive AD biomarkers participants. Results: 50 proteins were significantly (unadjusted p  < 0.05) altered in plasma and 26 in CSF after 8 weeks of metformin use, with 7 proteins in common (AZU1, CASP-3, CCL11, CCL20, IL32, PRTN3, and REG1A). The correlation between changes in plasma and CSF levels of these 7 proteins after metformin use relative to baseline levels was high (r  = 0.98). The proteins also demonstrated temporal stability. Conclusions: Our pilot study is the first to investigate the effect of metformin on plasma and CSF proteins in non-diabetic patients with MCI and positive AD biomarkers and identifies several candidate plasma biomarkers for future clinical trials after confirmatory studies. Show more

Keywords: Alzheimer’s disease, biomarkers, cerebrospinal fluid, clinical trial, metformin, plasma

DOI: 10.3233/JAD-230899

Citation: Journal of Alzheimer's Disease, vol. 99, no. s2, pp. S355-S365, 2024

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. 99, no. s2, pp. S367-S381, 2024

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. 99, no. s2, pp. S383-S396, 2024

Authors: Noori, Ayush | Jayakumar, Rojashree | Moturi, Vaishnavi | Li, Zhaozhi | Liu, Rongxin | Serrano-Pozo, Alberto | Hyman, Bradley T. | Das, Sudeshna

Article Type: Research Article

Abstract: Background: Recent Alzheimer’s disease (AD) discoveries are increasingly based on studies from a variety of omics technologies on large cohorts. Currently, there is no easily accessible resource for neuroscientists to browse, query, and visualize these complex datasets in a harmonized manner. Objective: Create an online portal of public omics datasets for AD research. Methods: We developed Alzheimer DataLENS, a web-based portal, using the R Shiny platform to query and visualize publicly available transcriptomics and genetics studies of AD on human cohorts. To ensure consistent representation of AD findings, all datasets were processed through a uniform bioinformatics …pipeline. Results: Alzheimer DataLENS currently houses 2 single-nucleus RNA sequencing datasets, over 30 bulk RNA sequencing datasets from 19 brain regions and 3 cohorts, and 2 genome-wide association studies (GWAS). Available visualizations for single-nucleus data include bubble plots, heatmaps, and UMAP plots; for bulk expression data include box plots and heatmaps; for pathways include protein-protein interaction network plots; and for GWAS results include Manhattan plots. Alzheimer DataLENS also links to two other knowledge resources: the AD Progression Atlas and the Astrocyte Atlas. Conclusions: Alzheimer DataLENS is a valuable resource for investigators to quickly and systematically explore omics datasets and is freely accessible at https://alzdatalens.partners.org . Show more

Keywords: Alzheimer’s disease, database, genetics, multiomics, single-cell RNA-seq, transcriptomics

DOI: 10.3233/JAD-230884

Citation: Journal of Alzheimer's Disease, vol. 99, no. s2, pp. S397-S407, 2024