Amyloid beta: structure, biology and structure-based therapeutic development

Is age-related myelinodegenerative change an initial risk factor of neurodegenerative diseases?

Myelination, the continuous ensheathment of neuronal axons, is a lifelong process in the nervous system that is essential for the precise, temporospatial conduction of action potentials between neurons. Myelin also provides intercellular metabolic support to axons. Even minor disruptions in the integrity of myelin can impair neural performance and increase susceptibility to neurological diseases. In fact, myelin degeneration is a well-known neuropathological condition that is associated with normal aging and several neurodegenerative diseases, including multiple sclerosis and Alzheimer's disease. In the central nervous system, compact myelin sheaths are formed by fully mature oligodendrocytes. However, the entire oligodendrocyte lineage is susceptible to changes in the biological microenvironment and other risk factors that arise as the brain ages. In addition to their well-known role in action potential propagation, oligodendrocytes also provide intercellular metabolic support to axons by transferring energy metabolites and delivering exosomes. Therefore, myelin degeneration in the aging central nervous system is a significant contributor to the development of neurodegenerative diseases. Interventions that mitigate age-related myelin degeneration can improve neurological function in aging individuals. In this review, we investigate the changes in myelin that are associated with aging and their underlying mechanisms. We also discuss recent advances in understanding how myelin degeneration in the aging brain contributes to neurodegenerative diseases and explore the factors that can prevent, slow down, or even reverse age-related myelin degeneration. Future research will enhance our understanding of how reducing age-related myelin degeneration can be used as a therapeutic target for delaying or preventing neurodegenerative diseases.

Systematic review of amyloid-beta clearance proteins from the brain to the periphery: implications for Alzheimer's disease diagnosis and therapeutic targets

Amyloid-beta clearance plays a key role in the pathogenesis of Alzheimer's disease. However, the variation in functional proteins involved in amyloid-beta clearance and their correlation with amyloid-beta levels remain unclear. In this study, we conducted meta-analyses and a systematic review using studies from the PubMed, Embase, Web of Science, and Cochrane Library databases, including journal articles published from inception to June 30, 2023. The inclusion criteria included studies comparing the levels of functional proteins associated with amyloid-beta clearance in the blood, cerebrospinal fluid, and brain of healthy controls, patients with mild cognitive impairment, and patients with Alzheimer's disease. Additionally, we analyzed the correlation between these functional proteins and amyloid-beta levels in patients with Alzheimer's disease. The methodological quality of the studies was assessed via the Newcastle‒Ottawa Scale. Owing to heterogeneity, we utilized either a fixed-effect or random-effect model to assess the 95% confidence interval (CI) of the standard mean difference (SMD) among healthy controls, patients with mild cognitive impairment, and patients with Alzheimer's disease. The findings revealed significant alterations in the levels of insulin-degrading enzymes, neprilysin, matrix metalloproteinase-9, cathepsin D, receptor for advanced glycation end products, and P-glycoprotein in the brains of patients with Alzheimer's disease, patients with mild cognitive impairment, and healthy controls. In cerebrospinal fluid, the levels of triggering receptor expressed on myeloid cells 2 and ubiquitin C-terminal hydrolase L1 are altered, whereas the levels of TREM2, CD40, CD40L, CD14, CD22, cathepsin D, cystatin C, and α2 M in peripheral blood differ. Notably, TREM2 and cathepsin D showed changes in both brain (SMD = 0.31, 95% CI: 0.16-0.47, P < 0.001, I2 = 78.4%; SMD = 1.24, 95% CI: 0.01-2.48, P = 0.048, I2 = 90.1%) and peripheral blood (SMD = 1.01, 95% CI: 0.35-1.66, P = 0.003, I2 = 96.5%; SMD = 7.55, 95% CI: 3.92-11.18, P < 0.001, I2 = 98.2%) samples. Furthermore, correlations were observed between amyloid-beta levels and the levels of TREM2 ( r = 0.16, 95% CI: 0.04-0.28, P = 0.009, I2 = 74.7%), neprilysin ( r = -0.47, 95% CI: -0.80-0.14, P = 0.005, I2 = 76.1%), and P-glycoprotein ( r = -0.31, 95% CI: -0.51-0.11, P = 0.002, I2 = 0.0%) in patients with Alzheimer's disease. These findings suggest that triggering receptor expressed on myeloid cells 2 and cathepsin D could serve as potential diagnostic biomarkers for Alzheimer's disease, whereas triggering receptor expressed on myeloid cells 2, neprilysin, and P-glycoprotein may represent potential therapeutic targets.

Exploring Alzheimer's disease treatment: Established therapies and novel strategies for future care

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by a gradual decline in cognitive function, memory impairment, and alterations in behavior. As the predominant etiology of dementia, AD affects millions of individuals worldwide, with its hallmark pathological feature being the accumulation of amyloid beta (Aβ) plaques, which disrupt neuronal function and progressively compromise brain structure. Early clinical manifestations often include forgetfulness, disorientation, and social withdrawal. Primarily impacting the elderly population, AD significantly impairs daily functioning and diminishes overall quality of life. Current therapeutic approaches for AD mainly focus on symptomatic relief and decelerating the disease's progression. Cholinesterase inhibitors, such as donepezil and rivastigmine, increase acetylcholine (ACh) levels to enhance cognitive function in individuals with mild to moderate AD. For individuals in more advanced stages of the disease, NMDA receptor antagonists modulate glutamate activity to mitigate excitotoxicity. In addition to pharmacological interventions, lifestyle modifications such as adherence to a balanced diet, regular physical activity, and cognitive engagement are advocated to support brain health. Novel therapeutic avenues are being explored to address underlying pathophysiological mechanisms, such as metal ion dysregulation within the brain. Furthermore, non-pharmacological approaches, including cognitive-behavioral therapy and patient support groups, provide essential behavioral and emotional support. Cutting-edge research continues to investigate innovative treatments, such as immunotherapies targeting amyloid plaques and tau tangles and neuroprotective compounds derived from natural sources. The goal of these multifaceted strategies is to alleviate symptoms, enhance quality of life, and offer hope for individuals and families affected by AD. This review provides a comprehensive summary of both established and emerging therapeutic interventions for the management of AD.

Receptor modulated assembly and drug induced disassembly of amyloid beta aggregates at asymmetric neuronal model biomembranes

Amyloid peptide non-fibrillar oligomers cause neurotoxicity and may contribute to Alzheimer's disease (AD) pathogenesis. Mounting evidence indicates that Aβ1-42 oligomers disrupt and remodel neuronal membrane, causing neuronal cell death. The involvement of individual neuronal membrane constituents in real-time Aβ1-42 aggregate assembly is unclear due to complexity of neuronal cell membrane. We used non-Faradaic electrochemical impedance spectroscopy (EIS) to track monomeric Aβ1-42 peptide binding and aggregation pathways in real-time in asymmetric micropore suspended lipid bilayer membranes with anionic phospholipids and glycosphingolipids. Anionic DOPC:PIP2 pore suspended membrane showed pore-formation within 2 h of incubation, but peptide insertion occurred over 6 h, with an onset time of ∼6-8 h for peptide aggregation at the membrane surface. Among different gangliosides, peptide binding to GM1- and GM3-containing membranes did not result pore development, but receptor mediated peptide aggregation formation caused membrane admittance to decrease within 2 h. In contrast, partial peptide insertion in the membrane surface increases membrane admittance at GD1a and mixed GSL membranes, arresting aggregation. Time-lapsed AFM imaging at asymmetric solid supported lipid bilayers (aSLBs) corroborated EIS findings, capturing pore-formation and receptor mediated peptide assembly routes. Fluorescence lifetime imaging (FLIM) imaging and spatial resolved single-point fluorescence correlation spectroscopy (FCS) at aSLBs revealed membrane-peptide interaction, assembly, and peptide induced membrane reorganization. Treatment with antidepressants fluoxetine and imipramine therapeutics, in synergy, which are cost-effective and capable of crossing the central nervous system (CNS+), resulted in the disassembly of membrane mediated Aβ1-42 aggregates, but not fibrils. Overall, the data suggests that membrane-mediated aggregate disassembly at the correct timing of AD progression may halt or reverse amyloid assembly through the use of repurposed drugs.

Preclinical Evidence of Withania somnifera and Cordyceps spp.: Neuroprotective Properties for the Management of Alzheimer's Disease

Alzheimer's disease (AD) is considered one of the main pathologies of our time, whose incidence and prevalence are suggested to be strongly underestimated. AD presents as a complex neurodegenerative condition characterized by marked neuroinflammation and a significant decline in the cognitive and mnemonic functions of affected patients. Recognized AD pathological hallmarks include amyloid beta plaque and neurofibrillary tangle formation, synaptic dysfunction with considerable apoptosis of cholinergic and dopaminergic neurons, and high levels of oxidative stress and neuroinflammation. The available pharmacological treatments are represented by acetylcholinesterase inhibitors to treat the mild to moderate form of the disease and N-methyl-D-aspartate inhibitors alone or in combination with the previously cited ones in the late stage of the neurodegenerative condition. Furthermore, emerging drug therapies such as monoclonal antibodies are promising agents in AD management. Although scientific evidence highlights these chemicals as effective in slowing down disease progression, significant limitations behind their employment derive from the notable dose-dependent side effects and the single-target mechanism of action. In this context, two well-studied phytotherapeutics, W. somnifera (W. somnifera) and fungi belonging to the genus Cordyceps, have gained attention for their chemical composition regarding their neuroprotective and anti-inflammatory effects. Ashwagandha (obtained principally from the roots of W. somnifera) is an adaptogen that relieves stress and anxiety. It contains several ergostane-type steroidal lactones-such as withanolides and withaferin A-and various alkaloids, contributing to its antioxidant and neuroprotective effects. Likewise, cordycepin is the main bioactive principle found in Cordyceps fungi. This natural nucleoside has been reported to possess therapeutic potential as an anti-cancer, immunomodulatory, and anti-inflammatory agent, with some studies suggesting a beneficial role in AD treatment. The purpose of the present review is to investigate the pharmacological properties of W. somnifera and Cordyceps species in the context of AD treatment and explore the therapeutic potential of the constitutive bioactive molecules in preclinical models mimicking this neurodegenerative condition.

The role of α-tocopherol in the prevention and treatment of Alzheimer's disease

Scientific reports from various areas of the world indicate the potential role of tocopherols (vitamin E) in particular α-tocopherol in the prevention and therapy of Alzheimer's disease. The current phenomenon is related to the growing global awareness of eating habits and is also determined by the need to develop the prevention, management and therapy of Alzheimer's disease. This article is a review of current research on the action of the active form of vitamin E-α-tocopherol and its impact on the development and course of Alzheimer's disease. Additionally, to contrast this information, selected primary research on this topic was included. The aim of this article is to analyze and summarize the available scientific information on the effects of the active form of vitamin E, α-tocopherol, on the development and course of Alzheimer's disease. In the structure of the review, particular attention was paid to the analysis of the pathophysiological processes of the disease and the biochemical features of the action of α-tocopherol. To discuss the relationship between the effect of α-tocopherol and the occurrence of Alzheimer's disease, a literature review was conducted using the following databases: PubMed, Google Scholar, and Elsevier. During the search process, the following keywords were used: "tocopherols", "vitamin E", "α-tocopherol", "Alzheimer's disease" in various combinations. The process was conducted in accordance with the adopted search strategy taking into account the inclusion and exclusion criteria. Alzheimer's disease (AD) is the most common, irreversible neurodegenerative disease, so many scientists are actively looking for substances and/or strategies to prevent its development and to slow down its course in patients. Alpha-tocopherols (ATF) are a factor that inhibits the pathophysiological processes associated with the development of AD by reducing the formation of atherogenic amyloid B (AB). Additionally, this type of tocopherols has antioxidant and anti-inflammatory properties and has a positive effect on the metabolic functioning of mitochondria. It has been shown that a higher intake of α-tocopherol (ATF) was associated with a reduced risk of developing dementia and the occurrence of mild types of cognitive impairment (MCI). Various sources indicate an insufficient supply of ATF in the diet. ATF supplementation may potentially help to slow down the course of Alzheimer's disease, which is why this substance may be popularized in the treatment of this disease in the future. However, there is a need for further research on this issue.

Altered protein homeostasis in cardiovascular diseases contributes to Alzheimer's-like neuropathology

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. CVD is known to increase the risk of subsequent neurodegeneration but the mechanism(s) and proteins involved have yet to be elucidated. We previously showed that myocardial infarction (MI), induced in mice and compared to sham-MI mice, leads to increases in protein aggregation, endoplasmic reticulum (ER) stress in both heart and brain, and changes in proteostatic pathways. In this study, we further investigate the molecular mechanisms altered by induced MI in mice, which were also implicated by proteomics of postmortem human hippocampal aggregates from Alzheimer's disease (AD) and cardiovascular disease (CVD) patients, vs. age-matched controls (AMC). We utilized intra-aggregate crosslinking to identify protein-protein contacts or proximities, and thus to reconstruct aggregate "contactomes" (nonfunctional interactomes). We used leave-one-out analysis (LOOA) to determine the contribution of each protein to overall aggregate cohesion, and gene ontology meta-analyses of constituent proteins to define critical organelles, processes, and pathways that distinguish AD and/or CVD from AMC aggregates. We identified influential proteins in both AD and CVD aggregates, many of which are associated with pathways or processes previously implicated in neurodegeneration such as mitochondrial, oxidative, and endoplasmic-reticulum stress; protein aggregation and proteostasis; the ubiquitin proteasome system and autophagy; axonal transport; and synapses.

Proteinopathies and the Neurodegenerative Aftermath of Stroke: Potential Biomarkers and Treatment Targets

Stroke remains a predominant cause of death and long-term disability among adults worldwide. Emerging evidence suggests that proteinopathies, characterized by the aggregation and accumulation of misfolded proteins, may play a significant role in the aftermath of stroke and the progression of neurodegenerative disorders. In this review, we explore preclinical and clinical research on key proteinopathies associated with stroke, including tau, Aβ (amyloid-β), TDP-43 (TAR DNA-binding protein 43), α-synuclein, and UCH-L1 (ubiquitin C-terminal hydrolase-L1). We focus on their potential as biomarkers for recovery management and as novel treatment targets that may enhance neuronal repair and mitigate secondary neurodegeneration. The involvement of these proteinopathies in various aspects of stroke, including neuroinflammation, oxidative stress, neuronal damage, and vascular dysfunction, underscores their potential. However, further investigations are essential to validate the clinical utility of these biomarkers, elucidate the mechanisms connecting proteinopathies to poststroke neurodegeneration, and develop targeted interventions. Identifying specific protein signatures associated with stroke outcomes could facilitate the advancement of precision medicine tailored to individual patient needs, significantly enhancing the quality of life for stroke survivors.

Revealing the mechanism of two rimantadine derivatives inhibiting Aβ aggregation and destabilizing Aβ protofibrils by molecular dynamics simulation

Two rimantadine derivatives, m-aminobenzoyl rimantadine (meta) and p-aminobenzoyl rimantadine (para), have been demonstrated to effectively inhibit the aggregation of amyloid-β (Aβ) peptides. However, the exact atomic-level mechanism remains elusive. In this study, we investigated the inhibitory mechanisms of meta and para on Aβ aggregation. Using replica-exchange and microsecond classical molecular dynamics simulations, we analyzed the conformational ensembles of Aβ dimers and the structure of Aβ(1-40) protofibrils both with and without the rimantadine derivatives. Results showed that meta and para inhibit Aβ aggregation by hydrogen bonds and hydrophobic interactions with Aβ dimers. Meta mainly binds to CHC residues F19 and F20 to disrupt hydrophobic contacts, while para targets β-turns and the K28-V40 region, destabilizing the hydrophobic core and increasing structural flexibility, thus preventing stable dimer formation. Para exhibits a higher binding affinity and is more effective in inhibiting Aβ aggregation and destabilizing protofibrils. These findings provide valuable insights into the atomic-level mechanisms by which meta and para inhibit Aβ aggregation, offering promising avenues for the exploration of potential therapeutics for Alzheimer's disease (AD).

Pathogenesis, manifestations, diagnosis, and management of CNS complications in hereditary ATTR amyloidosis

The clinical efficacy of transthyretin (TTR) tetramer stabilisers and TTR gene silencers in addition to liver transplantation has been established for hereditary ATTR (ATTRv) amyloidosis. Accordingly, non-central nervous system (CNS) systemic amyloidosis manifestations, such as peripheral neuropathy and cardiomyopathy, are now being overcome. However, emerging disease-modifying therapeutics have limited effects on CNS amyloidosis since they target the blood-circulating TTR produced in the liver, and not the cerebral spinal fluid (CSF) TTR synthesised in the choroid plexus. CNS involvement is therefore becoming the most common and severe complication in patients with ATTRv amyloidosis, including transient focal neurologic episodes, haemorrhagic and ischaemic stroke, cognitive decline, and cranial nerve dysfunction. Pathologically, extensive amyloid depositions are observable in the leptomeninges and leptomeningeal vessels, which are in direct contact with the CSF. Amyloid positron emission tomography is a useful biomarker for the early detection and treatment evaluation of early-onset ATTRv amyloidosis with the V30M (p.V50M) variant. Treatment-wise, blood-brain barrier-permeable stabilisers, intrathecal injection of silencers, and monoclonal antibodies against misfolded TTR and/or ATTR amyloid may potentially ameliorate CNS ATTR amyloidosis. The development of novel imaging/CSF biomarkers and disease-modifying therapies are the greatest unmet medical need in ATTRv amyloidosis and require further clinical trials.

Advancing Alzheimer's Therapy: Computational strategies and treatment innovations

Alzheimer's disease (AD) is a multifaceted neurodegenerative condition distinguished by the occurrence of memory impairment, cognitive deterioration, and neuronal impairment. Despite extensive research efforts, conventional treatment strategies primarily focus on symptom management, highlighting the need for innovative therapeutic approaches. This review explores the challenges of AD treatment and the integration of computational methodologies to advance therapeutic interventions. A comprehensive analysis of recent literature was conducted to elucidate the broad scope of Alzheimer's etiology and the limitations of conventional drug discovery approaches. Our findings underscore the critical role of computational models in elucidating disease mechanisms, identifying therapeutic targets, and expediting drug discovery. Through computational simulations, researchers can predict drug efficacy, optimize lead compounds, and facilitate personalized medicine approaches. Moreover, machine learning algorithms enhance early diagnosis and enable precision medicine strategies by analyzing multi-modal datasets. Case studies highlight the application of computational techniques in AD therapeutics, including the suppression of crucial proteins implicated in disease progression and the repurposing of existing drugs for AD management. Computational models elucidate the interplay between oxidative stress and neurodegeneration, offering insights into potential therapeutic interventions. Collaborative efforts between computational biologists, pharmacologists, and clinicians are essential to translate computational insights into clinically actionable interventions, ultimately improving patient outcomes and addressing the unmet medical needs of individuals affected by AD. Overall, integrating computational methodologies represents a promising paradigm shift in AD therapeutics, offering innovative solutions to overcome existing challenges and transform the landscape of AD treatment.

Polyphosphate: a cellular Swiss army knife

Inorganic polyphosphate (polyP) is a ubiquitous biopolymer whose functional repertoire has rapidly expanded over the past few years. How polyP controls these seemingly unrelated functions, which range from stress resistance, motility, and DNA damage control in bacteria to blood clotting, cancer and neurodegeneration in mammals, remains largely unknown. Here, we review what is known about its synthesis and degradation pathways in mammalian cells, provide an overview over the cell compartment-specific roles of polyP, and focus on recent studies, which showed that many of polyP's activities appear to be mediated by its ability to either solubilize, scaffold, or phase separate proteins. Future studies will show how polyP achieves these vastly different effects on proteins and hence controls its many functions.

Amyloid β fragments that suppress oligomers but not fibrils are cytoprotective

Neurotoxic aggregates of amyloid beta (Aβ) peptide contribute to the etiology of Alzheimer's disease (AD). In this work, we examined how seven overlapping fragments derived from Aβ1-42 affect the oligomerization and toxicity of the full-length peptide. Four fragments inhibited the toxicity of oligomeric Aβ1-42 to various degrees, two others conferred no cellular protection against Aβ1-42 toxicity, and one fragment enhanced both Aβ1-42 oligomerization and toxicity. The structural and aggregation propensities of the peptides that support strong inhibition of Aβ1-42 toxicity have been identified. Data analysis allowed elucidation of the mechanisms of action of each of the seven peptide fragments on Aβ1-42 cytotoxicity. Our work establishes the potential therapeutic value of four Aβ fragments and supports the notion that agents directed to disruption of Aβ oligomers may be more effective AD drug candidates than those targeting Aβ fibrils.

Insulin resistance: fueling oxidative stress and neurodegeneration

The growing prevalence of age-related neurodegenerative diseases is a consequence of population aging and demands urgent treatment strategies. This literature review aims to provide a comprehensive overview of the contribution of oxidative stress and insulin resistance in neurodegenerative diseases, specifically Alzheimer's disease (AD). In addition, current therapeutic approaches to treat oxidative stress and insulin resistance in this age-related neurodegenerative disease will be discussed. AD is the most prevalent form of neurodegenerative disease and is marked at early stages by oxidative stress and insulin resistance. Results indicate that insulin resistance may be central in generating oxidative stress and exacerbating AD hallmarks. In turn, insulin resistance can be influenced by other factors, including amyloid beta (Aβ), impaired biliverdin-reductase A (BVR-A) activity, and the gut microbiota. Defective insulin signaling in the brain comes with consequences ranging from declined cognitive functions, impaired autophagy, mitochondrial dysfunction, hyperphosphorylation of Tau, and increased Aβ production. Multiple therapeutic approaches that target oxidative stress or brain insulin resistance, such as antioxidant supplementation and anti-diabetic drugs, have mostly been inconclusive, except for intranasal insulin. Positive results have been obtained in clinical trials using nasal delivery devices to administer insulin; however, results are inconsistent across studies likely due to inconsistencies in the delivery method. Future investigations should focus on investigating the molecular link between oxidative stress, insulin resistance, and AD to address current knowledge gaps. Moreover, more focus should be given to optimizing the reliability and efficacy of nasal delivery devices before considering such an approach viable to treat neurodegenerative diseases.

Hippocampal CA1 neuron, a crucial regulator for chronic stress exacerbating Alzheimer's disease progression

Chronic stress, a common risk factor for psychiatric disorders, is also implicated in the pathogenesis of Alzheimer's disease (AD). However, its underlying mechanisms remain elusive. Here, we provide evidence for chronic restraint stress (CRS), a widely used stress model in rodents, to regulate AD pathology. CRS not only induces prolonged depressive-like behaviors and cognitive deficits in young adult wild type (WT) mice, but also exacerbates a series of AD-related phenotypes in APP/PS1 mice, including impaired spatial learning and memory, increased β-amyloid plaques, promoted glial cells (astrocyte and microglial cell) activation and decreased dendritic spines in CA1 neurons. Single-nucleus RNA-sequencing analysis in hippocampus shows remarkable transcriptional changes in many cell type(s), and identifies oxidative phosphorylation pathway, a major source for adenosine triphosphate (ATP) production, is significantly downregulated in CA1 neurons by CRS stimuli. Furthermore, dysfunctional mitochondria and reduced ATP levels are also observed in CA1 neurons of CRS exposed WT and APP/PS1 mice. Interestingly, infusion of ATP in CA1 region abolishes the deficits in cognition, dendritic spines and glial activation in CRS exposed APP/PS1 mice. Taken together, these results uncover an unrecognized function of CA1 neurons in regulating CRS induced AD pathologies, and suggest ATP as a promising therapeutic strategy to improve brain health under stress condition.

Amyloid-β-induced alteration of fast and localized calcium elevations in cultured astrocytes

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that causes cognitive decline. Uncovering the mechanisms of neurodegeneration in the early stages is essential to establish a treatment for AD. Recent research has proposed the hypothesis that amyloid-β (Aβ) oligomers elicit an excessive glutamate release from astrocytes toward synapses through intracellular free Ca2+ ([Ca2+]i) elevations in astrocytes, finally resulting in neuronal dendritic spine loss. Under physiological conditions, astrocytic [Ca2+]i elevations range spatially from microdomains to network-wide propagation and temporally from milliseconds to tens of seconds. Astrocytic localized and fast [Ca2+]i elevations might correlate with glutamate release; however, the Aβ-induced alteration of localized, fast astrocytic [Ca2+]i elevations remains unexplored. In this study, we quantitatively investigated the Aβ dimers-induced changes in the spatial and temporal patterns of [Ca2+]i in a primary culture of astrocytes by two-photon excitation spinning-disk confocal microscopy. The frequency of fast [Ca2+]i elevations occurring locally in astrocytes (≤ 0.5 s, ≤ 35 µm2) and [Ca2+]i event occupancy relative to cell area significantly increased after exposure to Aβ dimers. The effect of Aβ dimers appeared above 500 nM, and these Aβ dimers-induced [Ca2+]i elevations were primarily mediated by a metabotropic purinergic receptor (P2Y1 receptor) and Ca2+ release from the endoplasmic reticulum. Our findings suggest that the Aβ dimers-induced alterations and hyperactivation of astrocytic [Ca2+]i is a candidate cellular mechanism in the early stages of AD.

Supramolecular Copolymerization of Glycopeptide Amphiphiles and Amyloid Peptides Improves Neuron Survival

Neurodegenerative diseases such as Alzheimer's disease and amyotrophic lateral sclerosis are characterized by progressive neuronal loss and the accumulation of misfolded proteins including amyloid proteins. Current therapeutic options include the use of antibodies for these proteins, but novel chemical strategies need to be developed. The disaccharide trehalose has been widely reported to prevent misfolding and aggregation of proteins, and we therefore investigated the conjugation of this moiety to biocompatible peptide amphiphiles (TPAs) known to undergo supramolecular polymerization. Using X-ray scattering, circular dichroism, and infrared spectroscopy, we found that trehalose conjugation destabilized the internal β-sheet structures within the TPA supramolecular polymers as evidenced by a lower thermal transition. Thioflavin T fluorescence showed that these metastable TPA nanofibers suppressed A42 aggregation. Interestingly, we found that the suppression involved supramolecular copolymerization of TPA polymers with Aβ42, which effectively trapped the peptides within the filamentous structures. In vitro assays with human induced pluripotent stem cell-derived neurons demonstrated that these TPAs significantly improved neuron survival compared to other conditions. Our study highlights the potential of properly tuned supramolecular polymerizations of monomers to safely remove amyloidogenic proteins in neurodegeneration.

An innovative electrochemiluminescent immunosensor using dual amplified signals from AuNPs@CoSn(OH)6 for the detection of the AD biomarker: amyloid beta 1-40

Alzheimer's disease (AD) is a degenerative condition of the nervous system that causes severe damage to patients' daily activities and quality of life. Amyloid beta 1-40 protein (Aβ40), which is involved in the formation of cerebral plaques, is one of the crucial biomarkers related to AD. Herein, a novel and highly sensitive immunosensor for the detection of Aβ40 is developed. Using a reinforced indium tin oxide-coated glass with a nanocomposite of gold nanoparticle-enhanced CoSn(OH)6 (AuNPs@CoSn(OH)6) to trigger the electrochemiluminescence (ECL) of luminol as the sensing signal, the immunosensor is fabricated by immobilizing the Aβ40 antibody onto it. By integrating the high immune specificity, excellent conductivity and catalytic activity of the nanocomposite, the resultant immunosensor can be successfully employed to detect the target in real samples. The formation of the immune complex leads to increased steric hindrance and electron transfer resistance, which in turn causes a declined ECL output when the target Aβ40 binds to the antibody on the sensor surface. Under optimized conditions, the developed ECL immunosensor exhibits a linear response for Aβ40 ranging from 1 to 800 pg mL-1 and a low detection limit of 0.47 pg mL-1. Experimentally, it is demonstrated to be highly sensitive, specific, reproducible and stable. This work extends the application of the perovskite CoSn(OH)6 and AuNPs in the field of ECL immunosensing and provides a novel strategy for clinical research on Alzheimer's disease.

Molecular Insight into Amyloid Fibril-Templated Aggregation of Biomarkers

The aggregation of misfolded proteins into β-sheet-rich fibrils constitutes a characteristic feature of neurodegenerative disorders and represents a therapeutic target. While cryo-electron microscopy has elucidated ordered binding patterns of small molecules on fibril surfaces, the mechanisms of ordered aggregate formation generally remain unclear. This study employs molecular dynamics (MD) simulations of the model ligand GTP-1 to examine fibril-templated ligand aggregation and elucidate the molecular determinants governing the aggregation process. Our results showed that in aqueous solution, GTP-1 molecules form dynamic clusters without preferential configurations, whereas tau fibril surfaces induce organized aggregation through protein-ligand hydrogen bonding and ligand-ligand π-π stacking interactions. 1000 independent 100 ns simulations were initiated from diverse ligand conformations to comprehensively sample the conformational landscape. Analysis of the MD trajectories revealed two distinct aggregation pathways. Starting from random initial configurations, on-pathway trajectories spontaneously sampled crystal-structure-like conformations during the simulation, and these conformations exhibited high kinetic stability after formation. In contrast, off-pathway trajectories were characterized by ligands adopting non-native binding geometries, with continuous interconversions between multiple disordered states. The conformational stability of on-pathway states was attributed to optimal surface complementarity and enhanced intermolecular interactions, while off-pathway configurations exhibited reduced structural order and increased conformational flexibility. Quantitative analysis demonstrated differential hydrogen-bonding patterns, with on-pathway aggregates forming 2.01 bonds per structure compared to 0.74 in off-pathway configurations. Energy decomposition identified protein-ligand interactions as the primary determinant of binding energetics, highlighting the direct influence of fibril surface properties on ligand aggregation. These findings provide a mechanistic basis for fibril-templated aggregation and offer a rational foundation for designing diagnostic agents targeting pathological protein fibrils in neurodegenerative diseases.

Immunohistochemical profile of non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) versus other thyroid follicular lesions

BACKGROUND

A follicular thyroid tumour called Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) poses crossing-over morphologic characteristics with more thyroid follicular lesions whether benign or cancerous nodules. This study focuses on analysing the expression of CD56, HBME-1, RRM2 and APLP2 IHC markers in NIFTP versus other thyroid follicular lesions and their diagnostic validity was also evaluated.

METHODS

one hundred and nine thyroidectomy specimens including 31 NIFTP, 34 non-neoplastic, 34 papillary thyroid carcinoma (PTC) and 10 invasive encapsulated follicular variant papillary thyroid carcinoma (IEFVPTC) cases, were acquired between 2019 and 2022 from the Menoufia University's Faculty of Medicine's Pathology Department. Tissue microarray construction (TMA) blocks were prepared and CD56, HBME-1, RRM2 and APLP2 immunostaining were performed.

RESULTS

For CD56, 64.5% of NIFTP, 97.1% of the non-neoplastic group and 0% of both PTC and IEFVPTC were positive. For HBME-1, 61.3% of NIFTP, 0% of non-neoplastic, 100% of PTC and 100% of IEFVPTC were positive. For RRM2, all cases of NIFTP and the non-neoplastic group were negative, 88.2% of PTC and 100.0% of IEFVPTC were positive. For APLP2, 90.3% of NIFTP, 100% of the non-neoplastic group, 100% of PTC and 100% of IEFVPTC were positive. In differentiating NIFTP from non-neoplastic cases, the most sensitive marker was CD56 at H-score < 225 (sensitivity 95%) and the most specific was HBME-1 (specificity 100%). In various combinations, the panel of combined HBME-1 with either CD56 or APLP-2 improves their specificity (96.67% and 100% respectively) and the diagnostic accuracy (86.79 and 83.87, respectively) and therefore, combined HBME-1 and CD56 seems to be the most significant than using a single marker. In differentiation between NIFTP and PTC/IEFVPTC, the most sensitive marker was RRM2 (100% sensitivity for both groups) with the highest diagnostic accuracy (93.85% and 100%, respectively) and the most specific was CD56 (specificity 100% for both groups).

CONCLUSIONS

Immunohistochemical markers such as CD56, HBME-1, RRM2, and APLP2 may aid in the diagnosis of NIFTP and its distinction from other follicular lesions.

Fully biodegradable dendrimers as novel nanodrugs for amyloid-β-induced neurotoxicity

Alzheimer's disease (AD) is a severe neurological disorder and the leading cause of dementia, affecting millions globally. Dendrimers are remarkable organic macromolecules characterised by a globular, well-defined and highly branched structure featuring a high number of tuneable functional groups on their surface. Different types of dendrimers have demonstrated antioxidant, anti-inflammatory, and anti-amyloidogenic properties, showing their potential as powerful nanodrugs in AD. However, none of these dendrimers exhibit biodegradability under physiological conditions. This study explored the therapeutic potential of biodegradable PEG-GATGE (Poly(Ethylene Glycol)-Gallic Acid-Triethylene Glycol Ester) block copolymers against the Amyloid β (Aβ) (1-42) peptide, a key player in AD pathology. We focused on two dendritic structures: one functionalised with positively charged benzylamine terminal groups (fbB) and another functionalised with negatively charged benzoic acid terminal groups (fbBz). Our research aimed to evaluate their ability to inhibit Aβ (1-42) fibrillation by examining aggregation kinetics, secondary structure, and aggregate morphology. Additionally, we assessed their interactions with preformed Aβ species and neuroprotective effects in hippocampal neuron cultures. Results showed that both dendrimers modulate Aβ fibrillation in a peptide/dendrimer ratio-dependent manner and can also interact with preformed Aβ fibrils. Notably, only the positively charged dendrimer, fbB, effectively prevented the toxic association of Aβ oligomers with neurons. These findings emphasise the substantial promise of this family of biodegradable dendrimers as innovative nanodrugs in the fight against AD, paving the way for novel therapeutic strategies in neurodegenerative disorders.

Advances in Alzheimer's Therapy: Exploring Neuropathological Mechanisms to Revolutionize the Future Therapeutic Landscape

Alzheimer's disease (AD) is still an excessively complicated neurological disorder that impacts millions of individuals globally. The ideal defensive feature of the central nervous system (CNS) is the intimate junction of endothelial cells, which functions as a biological barrier to safely control molecular transport throughout the brain. The blood-brain barrier (BBB) comprises tightly locked astrocyte cell junctions on CNS blood capillaries. This biological barrier shields the brain from hazardous toxins by preventing the entry of polar medications, cells, and ions. However, it is very challenging to provide any treatment to the brain for neurodegenerative illnesses like Alzheimer's. Different causative mechanisms, such as amyloid-β (Aβ) plaques, tubulin-associated unit (Tau) tangles, and neuroinflammation, cause neuronal dysfunction, leading to dementia and memory loss in the subject. Several treatments are approved for AD therapy, whereas most only help treat related symptoms. Disappointingly, current remedies have not been able to control the progression of AD due to associated side effects. Specific pathogenic mechanisms are involved in the initiation and development of this disease. Therefore, the expected survival of a patient with AD is limited and is approximately ten years. Hence, the pathogenic mechanism behind AD progression must be understood to better comprehend and improve the overall survival rate. This review highlighted the recent insights into AD pathogenesis, molecular mechanisms, advancements in theragnostic techniques, the existing updates of clinical trials, and emerging innovations for AD medicinal development. That has helped researchers develop other strategies to address the shortcomings of traditional medications.

Mass-Spectrometry-Based GEE Footprinting Characterizes Kinetic Mechanisms and Sites of Conformational Change in Amyloid β 1-42 Aggregation

Understanding the dynamics of Aβ aggregation is critical for elucidating Alzheimer's disease (AD) progression. This study extends our previous work on Aβ42 using fast photochemical oxidation of proteins (FPOP) and pulsed hydrogen-deuterium exchange and introduces mass spectrometry (MS)-based glycine ethyl ester (GEE) footprinting, combined with kinetic modeling, to characterize Aβ42 conformational changes and elucidate polymer populations along its aggregation pathways. We investigated Aβ42 conformational changes by analyzing three distinct peptide regions generated by Lys-N digestion, revealing three different views of the aggregation behaviors. The middle and C-terminal regions are identified as primary aggregation sites; in contrast, the N-terminal peptide exhibited only minor changes in GEE modification, supporting its limited involvement in intermolecular interactions during aggregation. Amino-acid-level analysis provided higher spatial resolution: D1 underwent relatively constant footprinting throughout aggregation, whereas E3/D7, E22, and D23 showed more substantial decreases in the level of modification, underscoring their critical roles in aggregation. By integrating these findings with kinetic modeling, we identified four predominant polymeric populations involved in Aβ1-42 aggregation. This study reports, for the first time, a stable, specific, and slow chemical footprinting approach to characterizing Aβ1-42 aggregation, offering new insights into Aβ1-42 polymerization dynamics and enhancing our understanding of its role in AD pathology. The solvent accessibility features of the six acidic amino acids and the C terminus calculated from the final, fibril state structure of Aβ42 are consistent with the footprinting results.

Comparing levetiracetam and zonisamide effects on rivastigmine anti-Alzheimer's activity in aluminum chloride-induced Alzheimer's-like disease in rats: Impact on α7 nicotinic acetylcholine receptors and amyloid β

BACKGROUND AND AIM

Alzheimer's disease (AD) is the most progressive form of neurodegenerative disease, which severely impairs cognitive function. The leading class of drugs used to treat AD is acetylcholinesterase inhibitors (AChE-Is) as Rivastigmine (RIVA), partially ameliorate its cognitive symptoms. Since epilepsy is a common comorbidity with AD, we explored the potential that new the antiepileptic drugs; Levetiracetam (LEV) and Zonisamide (ZNS) may possess an additional therapeutic benefit to RIVA in AlCl3-induced AD rat model.

MATERIALS AND METHODS

AlCl3 was used to provoke AD in rats which were then supplemented with treatment drugs for 2 weeks. Treated groups were: Control, AlCl3, RIVA, LEV, RIVA + LEV, ZNS and RIVA + ZNS. Then, the behavioral tests; passive avoidance (PA), Morris water maze (MWM) and novel object recognition (NOR) were conducted to assess cognitive behavior and memory. The Hippocampal Aβ assembly was thoroughly examined by histopathology and ELISA. α7 Nicotinic ACh receptors' (α7nAChRs) expression was assessed immunohistochemically and by real-time quantitative polymerase chain reaction (qPCR). Caspase 3 expression was also assessed by real-time qPCR in hippocampal tissues.

RESULTS

AlCl3 administration impaired memory and cognitive functions in rats, augmented hippocampal Aβ deposition, with subsequent neurodegeneration and α7nAChRs down-regulation. LEV, but not ZNS, administration significantly mitigated AlCl3-induced cognitive impairment probably through suppression of amyloid β (Aβ) deposition, enhancement of neurogenesis and α7nAChRs expression. When combined to RIVA, ZNS treatment negatively affected cognition possibly through its impact on hippocampal Aβ and subsequent neuronal damage.

CONCLUSION

Although our results indicated that neither LEV nor ZNS provided any extra benefit to cognitive enhancements in AD rats receiving rivastigmine, LEV demonstrated positive effects individually while ZNS had negative effects when combined with RIVA. As a result, this study suggests the use of LEV rather than ZNS for managing epilepsy in patients with AD given that Alzheimer's and epilepsy can coexist.

Advancing Alzheimer's disease therapy through engineered exosomal Macromolecules

Exosomes are a subject of continuous investigation due to their function as extracellular vesicles (EVs) that significantly contribute to the pathophysiology of certain neurodegenerative disorders (NDD), including Alzheimer's disease (AD). Exosomes have shown the potential to carry both therapeutic and pathogenic materials; hence, researchers have used exosomes for medication delivery applications. Exosomes have reduced immunogenicity when used as natural drug delivery vehicles. This guarantees the efficient delivery of the medication without causing significant side reactions. Exosomes have lately enabled the potential for drug delivery in AD, along with promising future therapeutic uses for the detection of neurodegenerative disorders. Furthermore, exosomes have been examined for their prospective use in illness diagnosis and prediction before the manifestation of symptoms. This review will document prior studies and will concentrate on the rationale behind the substantial potential of exosomes in the treatment of AD and their prospective use as a diagnostic and predictive tool for this condition.

Navigating the complexities of neuronal signaling and targets in neurological disorders: From pathology to therapeutics

Neurological disorders arising from structural and functional disruptions in the nervous system present major global health challenges. This review examines the intricacies of various cellular signaling pathways, including Nrf2/Keap1/HO-1, SIRT-1, JAK/STAT3/mTOR, and BACE-1/gamma-secretase/MAPT, which play pivotal roles in neuronal health and pathology. The Nrf2-Keap1 pathway, a key antioxidant response mechanism, mitigates oxidative stress, while SIRT-1 contributes to mitochondrial integrity and inflammation control. Dysregulation of these pathways has been identified in neurodegenerative and neuropsychiatric disorders, including Alzheimer's and Parkinson's diseases, characterized by inflammation, protein aggregation, and mitochondrial dysfunction. Additionally, the JAK/STAT3 signaling pathway emphasizes the connection between cytokine responses and neuroinflammation, further compounding disease progression. This review explores the crosstalk among these signaling networks, elucidating how their disruption leads to neuronal decline. It also addresses the dual roles of these pathways, presenting challenges in targeting them for therapeutic purposes. Despite the potential benefits of activating neuroprotective pathways, excessive stimulation may cause deleterious effects, including tumorigenesis. Future research should focus on designing multi-targeted therapies that enhance the effectiveness and safety of treatments, considering individual variabilities and the obstacles posed by the blood-brain barrier to drug delivery. Understanding these complex signaling interactions is crucial for developing innovative and effective neuroprotective strategies that could significantly improve the management of neurological disorders.

Can Quercetin protect against the pre-disposing factors for Alzheimer's disease via inhibiting NLRP3 inflammasome pathway?

OBJECTIVES

The brain and its cognitive functions are most liable to stress, where it is known to promote the pathological manifestation of Alzheimer's disease (AD). This study aimed to investigate the effect of a 2-week-period of restraint stress (RS), as well as the protective effect of Quercetin in a dose-dependent manner against the early start of AD via studying the NLRP3 inflammasome pathway.

METHODS

The rats were divided into four groups: control (Con), induction (Ind), where 6 h/day for 2 weeks of RS was induced, low and high doses of Q (Q1+Ind and Q2+Ind, respectively), which were administered before the induction of RS for the same period. Behavioral tests were performed to assess the cognitive functions.

KEY FINDINGS

The higher dose of Q has shown more inhibition of the NLRP3 inflammasome pathway, oxidative stress, as well as the phosphorylated-tau and amyloid-β (Aβ) protein, which were significantly fired up by the 2 weeks of RS. These results were backed with the improved cellular structure in the histopathological examination and enhanced cognitive functions, where the two doses of Q have shown their protective effect.

CONCLUSIONS

This proves that Q shielded the brain against the initial pathogenesis of AD, induced by 2 weeks of RS.

Reducing HuD Levels Alleviates Alzheimer's Disease Pathology in 5xFAD Mice

Alzheimer's disease (AD) is the most common neurodegenerative pathology in older persons. The accumulation of amyloid β (Aβ) plaques is a major contributor to AD development. The RNA-binding protein HuD/ELAVL4 has been implicated in the formation of Aβ plaques, but its role in AD is unclear. Here, we report that ablation of HuD from CAMK2A+ neurons (HuDcKO) in the 5xFAD mouse model of AD results in a significant reduction of Aβ plaques and the alleviation of some AD-associated behaviors. Given the lack of effective therapies for AD, we propose that reducing HuD levels or function can contribute to diminishing Aβ plaque formation and AD-associated pathology.

Amyloid β-Induced Inflammarafts in Alzheimer's Disease

The formation of amyloid beta (Aβ) plaques is a central process in the development of Alzheimer's disease (AD). Although its causative role or the effectiveness of therapeutic targeting is still debated, the key involvement of Aβ in the pathogenesis of neuroinflammation and neurodegeneration in AD is broadly accepted. In this review, we emphasize the role of lipid rafts, both in APP cleavage producing Aβ in neurons and in mediating Aβ inflammatory signaling in microglia. We introduce the term inflammarafts to characterize the Aβ-driven formation of enlarged, cholesterol-rich lipid rafts in activated microglia, which support protein-protein and lipid-protein interactions of inflammatory receptors. Examples reviewed include toll-like receptors (TLR2, TLR4), scavenger receptors (CD36, RAGE), and TREM2. The downstream pathways lead to the production of cytokines and reactive oxygen species, intensifying neuroinflammation and resulting in neuronal injury and cognitive decline. We further summarize emerging therapeutic strategies and emphasize the utility of apolipoprotein A-I binding protein (AIBP) in selective targeting of inflammarafts and attenuation of microglia-driven inflammation. Unlike the targeting of a single inflammatory receptor or a secretase, selective disruption of inflammarafts and preservation of physiological lipid rafts offer a novel approach to targeting multiple components and processes that contribute to neuroinflammation in AD.

Ganglioside lipids inhibit the aggregation of the Alzheimer's amyloid-β peptide

The aggregation of the amyloid-β (Aβ) peptides (Aβ42/Aβ40) into amyloid fibrils and plaques is one of the molecular hallmarks in dementia and Alzheimer's disease (AD). While the molecular mechanisms behind this aggregation process are not fully known, it has been shown that some biomolecules can accelerate this process whereas others can inhibit amyloid formation. Lipids, which are ubiquitously found in cell membranes, play a pivotal role in protein aggregation. Here, we investigate how ganglioside lipids, which are abundant in the brain and in neurons, can influence the aggregation kinetics of both Aβ42 and Aβ40. We employ a variety of biophysical assays to characterise the effect ganglioside lipids have on the aggregation of Aβ. Through kinetic analysis, we show that the primary nucleation rate is greatly affected by the addition of gangliosides and that these lipids impair Aβ42 aggregation, while completely inhibiting Aβ40 aggregation. Furthermore, we find that an Aβ-ganglioside complex is formed, which potentially disrupts the aggregation pathway and results in delayed kinetics. Taken together, our results provide a quantitative description of how lipid molecules such as gangliosides can inhibit the aggregation of Aβ and shed light on the key factors that control these processes. In view of the fact that declining levels of gangliosides in neurons have been associated with ageing, our findings could be instrumental towards establishing new approaches in the prevention of amyloid-β aggregation.

Neurotrophic and Neurotoxic Effects of Aβ42 and Its Oligomers on Neuronal Survival: Revealed by Their Opposite Influence on the Potency of Extracellular BDNF

Brain-derived neurotrophic factor (BDNF) is critical for neuronal survival. Amyloid-β monomers (Aβ42M) and oligomers (Aβ42O) have trophic and toxic effects on neuronal survival, respectively. Branched oligosaccharides (BOs) and catechins (CAs) can specifically bind to Aβ42M/Aβ42O, influencing both effects. However, whether and how Aβ42M/Aβ42O influences BDNF remains unknown. This study investigated the interaction between Aβ42M/Aβ42O and BDNF, the effects of Aβ42M and Aβ42O on BDNF binding to the TrkB/p75 receptor and their impact on BDNF-supported cell survival, and the roles of BOs and CAs in these processes. BDNF exhibited stronger binding affinity for Aβ42M and Aβ42O than BOs/CAs. Aβ42M increased neuronal viability by synergistically enhancing BDNF binding to TrkB and p75, whereas Aβ42O decreased neuronal viability by inactivating/consuming BDNF, thereby reducing its binding to these receptors. BDNF-Aβ42O binding appeared to mutually neutralize/counteract each other's biological effects; therefore, increasing BDNF levels might reduce Aβ42O's neurotoxicity. By competitively targeting Aβ42M/Aβ42O rather than BDNF or its receptors, BOs and CAs enhanced these effects. These findings suggest that Aβ42M's neurotrophicity was directly linked to its synergistic enhancement of BDNF activity, whereas Aβ42O's neurotoxicity was primarily due to its inactivation or consumption of BDNF. This study provided valuable insights for developing BOs/CAs-based neuroprotective therapeutics or nanomaterials against AD.

Nanoplatforms Targeting Intrinsically Disordered Protein Aggregation for Translational Neuroscience Applications

Intrinsically disordered proteins (IDPs), such as tau, beta-amyloid (Aβ), and alpha-synuclein (αSyn), are prone to misfolding, resulting in pathological aggregation and propagation that drive neurodegenerative diseases, including Alzheimer's disease (AD), frontotemporal dementia (FTD), and Parkinson's disease (PD). Misfolded IDPs are prone to aggregate into oligomers and fibrils, exacerbating disease progression by disrupting cellular functions in the central nervous system, triggering neuroinflammation and neurodegeneration. Furthermore, aggregated IDPs exhibit prion-like behavior, acting as seeds that are released into the extracellular space, taken up by neighboring cells, and have a propagating pathology across different regions of the brain. Conventional inhibitors, such as small molecules, peptides, and antibodies, face challenges in stability and blood-brain barrier penetration, limiting their efficacy. In recent years, nanotechnology-based strategies, such as multifunctional nanoplatforms or nanoparticles, have emerged as promising tools to address these challenges. These nanoplatforms leverage tailored designs to prevent or remodel the aggregation of IDPs and reduce associated neurotoxicity. This review discusses recent advances in nanoplatforms designed to target tau, Aβ, and αSyn aggregation, with a focus on their roles in reducing neuroinflammation and neurodegeneration. We examine critical aspects of nanoplatform design, including the choice of material backbone and targeting moieties, which influence interactions with IDPs. We also highlight key mechanisms including the interaction between nanoplatforms and IDPs to inhibit their aggregation, redirect aggregation cascade towards nontoxic, off-pathway species, and disrupt fibrillar structures into soluble forms. We further outline future directions for enhancing IDP clearance, achieving spatiotemporal control, and improving cell-specific targeting. These nanomedicine strategies offer compelling paths forward for developing more effective and targeted therapies for neurodegenerative diseases.

Potential therapeutic targets for Alzheimer's disease: Fibroblast growth factors and their regulation of ferroptosis, pyroptosis and autophagy

Alzheimer's disease (AD) is a progressively worsening neurodegenerative disorder characterized primarily by the deposition of amyloid beta (Aβ) plaques in the brain and the abnormal aggregation of tau protein forming neurofibrillary tangles. These pathological changes lead to impaired neuronal function and cell death, subsequently affecting the structure and function of the brain. Fibroblast growth factors (FGFs) are a group of proteins that play crucial roles in various biological processes, including cell proliferation, differentiation, and survival. This article reviews the expression and regulation of FGFs in the central nervous system and how they affect neuronal survival, as well as the changes in FGF signaling pathways and its regulation of programmed cell death in AD. It particularly focuses on the impact of FGF1, FGF2, FGF21, other members of the FGF family, and FGFR on the pathophysiological mechanisms of AD. The potential of the PI3K/AKT/GSK-3β, Wnt/β-catenin, and NF-κB signaling pathways as targets for AD treatment is also discussed. Furthermore, the relationship between FGF-regulated ferroptosis, Pyroptosis and Autophagy and AD is explored, along with the role of these mechanisms in improving the progression of AD.

Autonomic dysfunction in neurodegenerative disease

In addition to their more studied cognitive and motor effects, neurodegenerative diseases are also associated with impairments in autonomic function - the regulation of involuntary physiological processes. These autonomic impairments manifest in different ways and at different stages depending on the specific disease. The neural networks responsible for autonomic regulation in the brain and body have characteristics that render them particularly susceptible to the prion-like spread of protein aggregation involved in neurodegenerative diseases. Specifically, the axons of these neurons - in both peripheral and central networks - are long and poorly myelinated axons, which make them preferential targets for pathological protein aggregation. Moreover, cortical regions integrating information about the internal state of the body are highly connected with other brain regions, which increases the likelihood of intersection with pathological pathways and prion-like spread of abnormal proteins. This leads to an autonomic 'signature' of dysfunction, characteristic of each neurodegenerative disease, that is linked to the affected networks and regions undergoing pathological aggregation.

Hemoglobin in the brain frontal lobe tissue of patients with Alzheimer's disease is susceptible to reactive nitrogen species-mediated oxidative damage

Brain inflammation in Alzheimer's disease (AD) involves reactive nitrogen species (RNS) generation. Protein contents of 3-nitrotyrosine, a product of RNS generation, were assessed in frontal lobe brain homogenates from patients with AD, patients with vascular dementia (VaD) and non-dementia (ND) controls. Western blotting revealed a dominant 15 kDa nitrated protein band in both dementia (AD/VaD) and ND frontal lobe brain tissue. Surprisingly, this protein band was identified by mass spectrometry as hemoglobin, an erythrocytic protein. The same band stained positively when western blotted using an anti-hemoglobin antibody. On western blots, the median (IQR) normalized staining intensity for 3-nitrotyrosine in hemoglobin was increased in both AD [1.71 (1.20-3.05) AU] and VaD [1.50 (0.59-3.04) AU] brain tissue compared to ND controls [0.41 (0.09-0.75) AU] (Mann-Whitney U test: AD v ND, P < 0.0005; VaD v ND, P < 0.05; n = 11). The median normalized staining of the nitrated hemoglobin band was higher in advanced AD patients compared with early-stage AD (P < 0.005). The median brain tissue NO2- levels (nmol/mg protein) were significantly higher in AD samples than in ND controls (P < 0.05). Image analysis of western blots of lysates from peripheral blood erythrocytes suggested that hemoglobin nitration was increased in AD compared to ND (P < 0.05; n = 4 in each group). Total protein-associated 3-nitrotyrosine was measured by an electrochemiluminescence-based immunosorbent assay, but showed no statistically significant differences between AD, VaD and ND. Females showed larger increases in hemoglobin nitration and NO2- levels between disease and control groups compared to males, although the group sizes in these sub-analyses were small. In conclusion, the extent of hemoglobin nitration was increased in AD and VaD brain frontal lobe tissue compared with ND. We propose that reactive nitrogen species-mediated damage to hemoglobin may be involved in the pathogenesis of AD.

Circulating amyloid beta 1-40 peptide as an associate of renal function decline

BACKGROUND

Recent evidence suggests that Alzheimer's amyloid-beta (1-40) (Αβ1-40), an emerging biomarker of cardiovascular disease, may be involved in the heart-brain-renal axis. We aimed to comprehensively explore the association between circulating Aβ1-40 levels and renal function and its clinical relevance.

METHODS

Consecutively recruited subjects in the Athens Angiometabolic Registry with measured Aβ1-40 plasma levels (n = 811) were analysed. Αβ1-40 was measured by enzyme-linked immunosorbent assay and glomerular filtration rate (GFR) was calculated using the abbreviated four-variable Modification of Diet in Renal Disease (MDRD) formula. All-cause mortality was the main clinical endpoint across a median follow-up of 47 months.

RESULTS

Cross-sectionally, a bidirectional association between Αβ1-40 [adjusted odds ratio (adjOR) = 3.67 for highest tertile of Αβ1-40 and chronic kidney disease (CKD) stage ≥3, p < .001] and CKD stage ≥3 (adjOR = 3.52 for association with highest Aβ1-40 tertile, p < .001) was observed. Longitudinally, increased Αβ1-40 at baseline was associated with decline in renal function at follow-up (adjOR for CKD stage ≥3 = 2.26, p = .033). Similarly, longitudinal changes in Aβ1-40 were inversely associated with changes in GFR (OR = .77 per 1 SD increase in Aβ1-40, p = .006). Aβ1-40 was associated with all-cause mortality, independently of traditional risk factors (hazard ratio = 1.20 per 1 SD increase in Aβ1-40, p = .016). An indirect effect of GFR on the association between Aβ1-40 and mortality (p < .05) with an estimated indirect-to-total effect ratio of .334, but not of Αβ1-40 on GFR with mortality, was observed.

CONCLUSIONS

In a population with a wide range of GFR, we found a bidirectional association between Αβ1-40 levels and renal function. The association of Αβ1-40 with all-cause mortality was partly mediated by lower GFR.

Investigating the combined effect of copper, zinc, and iron ions on truncated and full-length Aβ peptides: insights from molecular dynamics simulation

The truncated Aβ1 - 16 peptide containing the metal-binding domain is frequently used in in silico and experimental investigations because it is more soluble and thus more suitable for studies in solution and does not form amyloids. Several spectroscopic studies have shown that the metal binding of Aβ1 - 16 is very similar to that of the full-length Aβ1 - 42. However, since small changes can have a significant impact on aggregation, further experimental and theoretical are needed to elucidate the detailed structures of truncated and full-length Aβ. In this research, the binding of copper ion to the Aβ1 - 16 and Aβ1 - 42 has been studied by molecular dynamics simulation method. To investigate the effect of copper ion on beta-amyloid peptide structure, the simulations were repeated in the copper and zinc ions, copper and iron binary system, and the copper, zinc and iron ions ternary system. The conformation factor was calculated to calculate the binding affinity of copper ion to beta-amyloid peptide residues. The results showed that the initial 16 residues of the beta-amyloid peptide have high binding affinity for copper ions, and histidine 13 and histidine 14 have significantly higher binding affinity for copper ions in all studied systems. Zinc and iron ions were found to reduce the conformational factor of peptide residues in binding to copper ions, and the aggregation tendency was lower in the truncated structure. The SASA results suggest that the side chains of peptide residues are more affected by shortening and the presence of ions.

The neuroinflammatory role of microRNAs in Alzheimer's disease: pathological insights to therapeutic potential

Alzheimer's disease (AD) is a neurodegenerative disease and the most common cause of dementia, contributing to around 60-80% of cases. The main pathophysiology of AD is characterized by an abnormal accumulation of protein aggregates extracellularly (beta-amyloid plaques) and intracellularly (neurofibrillary tangles of hyperphosphorylated tau). However, an increasing number of studies have also suggested neuroinflammation may have a crucial role in precipitating the cascade reactions that result in the development of AD neuropathology. In particular, several studies indicate microRNAs (miRNAs) can act as regulatory factors for neuroinflammation in AD, with potential to affect the occurrence and/or progression of AD inflammation by targeting the expression of multiple genes. Therefore, miRNAs may have potential as therapeutic targets for AD, which requires more research. This article will review the existing studies on miRNAs that have been identified to regulate neuroinflammation, aiming to gain further insights into the specific regulatory processes of miRNAs, highlight the diagnostic and therapeutic potential of miRNAs as biomarkers in AD, as well as current challenges, and suggest the further work to bridge the gap in knowledge to utilize miRNAs as therapeutic targets for AD.

Alzheimer's disease as an auto-innate immune pathology with potential cell trans-differentiation and enhanced trained immunity in 3xTg-AD mouse model

BackgroundAlzheimer's disease (AD) is a neurodegenerative disorder characterized by memory impairment. Neuroinflammatory processes, mediated by glial and immune cells, contribute to neuronal damage. Emerging evidence implicates innate immune mechanisms, including trained immunity and cell trans-differentiation, in AD pathogenesis, though their roles remain unclear.ObjectiveTo investigate transcriptomic changes in the 3xTg-AD mouse model, focusing on trained immunity and cell trans-differentiation in disease mechanisms.MethodsRNA-sequencing was performed on brain tissue (cortex plus hippocampus) from 11-month-old female 3xTg-AD and wild-type mice (n = 3/group). Differentially expressed genes (fold change > 1.5, p < 0.05) were identified and followed by bioinformatics and knowledge-based transcriptomic profiling. Public AD datasets were also analyzed.Results3xTg-AD mice exhibited 316 upregulated and 412 downregulated genes. Downregulated genes included those for blood-brain barrier protein, while upregulated genes related to cerebrospinal fluid. Increased expression of proinflammatory markers, as well as genes related to cell differentiation, proliferation, activation, and adhesion. Upregulation of genes associated with cell migration and trans-differentiation suggests a potential role for inflammation and cellular plasticity. Additionally, genes involved in inflammasome pathways, immunometabolism, and trained immunity were upregulated. Mechanistically, these genes were modulated by knockdown of trained immunity promoter SET-7, overexpression of trained immunity inhibitor IL-37, and knockout of inflammasome genes IL-1 receptor, caspase-1, and pattern recognition receptor CD36.ConclusionsThe finding underscore the potential role of trained immunity and cell trans-differentiation in AD, revealing a mechanistic framework in which danger-associated molecular patterns drive innate immune responses, inflammasome activation, and cell plasticity contribute to AD, offering therapeutic targets for neuroinflammation and cellular reprograming.

Inborn errors of canonical autophagy in neurodegenerative diseases

Neurodegenerative disorders (NDDs), characterized by a progressive loss of neurons and cognitive function, are a severe burden to human health and mental fitness worldwide. A hallmark of NDDs such as Alzheimer's disease, Huntington's disease, Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and prion diseases is disturbed cellular proteostasis, resulting in pathogenic deposition of aggregated protein species. Autophagy is a major cellular process maintaining proteostasis and integral to innate immune defenses that mediates lysosomal protein turnover. Defects in autophagy are thus frequently associated with NDDs. In this review, we discuss the interplay between NDDs associated proteins and autophagy and provide an overview over recent discoveries in inborn errors in canonical autophagy proteins that are associated with NDDs. While mutations in autophagy receptors seems to be associated mainly with the development of ALS, errors in mitophagy are mainly found to promote PD. Finally, we argue whether autophagy may impact progress and onset of the disease, as well as the potential of targeting autophagy as a therapeutic approach. Concludingly, understanding disorders due to inborn errors in autophagy-"autophagopathies"-will help to unravel underlying NDD pathomechanisms and provide unique insights into the neuroprotective role of autophagy, thus potentially paving the way for novel therapeutic interventions.

Peripheral Inflammation and Insulin Resistance: Their Impact on Blood-Brain Barrier Integrity and Glia Activation in Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, memory impairment, and synaptic dysfunction. The accumulation of amyloid beta (Aβ) plaques and hyperphosphorylated tau protein leads to neuronal dysfunction, neuroinflammation, and glial cell activation. Emerging evidence suggests that peripheral insulin resistance and chronic inflammation, often associated with type 2 diabetes (T2D) and obesity, promote increased proinflammatory cytokines, oxidative stress, and immune cell infiltration. These conditions further damage the blood-brain barrier (BBB) integrity and promote neurotoxicity and chronic glial cell activation. This induces neuroinflammation and impaired neuronal insulin signaling, reducing glucose metabolism and exacerbating Aβ accumulation and tau hyperphosphorylation. Indeed, epidemiological studies have linked T2D and obesity with an increased risk of developing AD, reinforcing the connection between metabolic disorders and neurodegeneration. This review explores the relationships between peripheral insulin resistance, inflammation, and BBB dysfunction, highlighting their role in glial activation and the exacerbation of AD pathology.

Interaction Between Glucagon-like Peptide 1 and Its Analogs with Amyloid-β Peptide Affects Its Fibrillation and Cytotoxicity

Clinical data as well as animal and cell studies indicate that certain antidiabetic drugs, including glucagon-like peptide 1 receptor agonists (GLP-1RAs), exert therapeutic effects in Alzheimer's disease (AD) by modulating amyloid-β peptide (Aβ) metabolism. Meanwhile, the direct interactions between GLP-1RAs and Aβ and their functional consequences remain unexplored. In this study, the interactions between monomeric Aβ40/Aβ42 of GLP-1(7-37) and its several analogs (semaglutide (Sema), liraglutide (Lira), exenatide (Exen)) were studied using biolayer interferometry and surface plasmon resonance spectroscopy. The quaternary structure of GLP-1RAs was investigated using dynamic light scattering. The effects of GLP-1RAs on Aβ fibrillation were assessed using the thioflavin T assay and electron microscopy. The impact of GLP-1RAs on Aβ cytotoxicity was evaluated via the MTT assay. Monomeric Aβ40 and Aβ42 directly bind to GLP-1(7-37), Sema, Lira, and Exen, with the highest affinity for Lira (the lowest estimates of equilibrium dissociation constants were 42-60 nM). GLP-1RAs are prone to oligomerization, which may affect their binding to Aβ. GLP-1(7-37) and Exen inhibit Aβ40 fibrillation, whereas Sema promotes it. GLP-1 analogs decrease Aβ cytotoxicity toward SH-SY5Y cells, while GLP-1(7-37) enhances Aβ40 cytotoxicity without affecting the cytotoxic effect of Aβ42. Overall, GLP-1RAs interact with Aβ and differentially modulate its fibrillation and cytotoxicity, suggesting the need for further studies of our observed effects in vivo.

Implications of Mucin-Type O-Glycosylation in Alzheimer's Disease

Alzheimer's disease (AD) is one of the most common neurodegenerative disorders linked to aging. Major hallmarks of AD pathogenesis include amyloid-β peptide (Aβ) plaques, which are extracellular deposits originating from the processing of the amyloid precursor protein (APP), and neurofibrillary tangles (NFTs), which are intracellular aggregates of tau protein. Recent evidence indicates that disruptions in metal homeostasis and impaired immune recognition of these aggregates trigger neuroinflammation, ultimately driving disease progression. Therefore, a more comprehensive approach is needed to understand the underlying causes of the disease. Patients with AD present abnormal glycan profiles, and most known AD-related molecules are either modified with glycans or involved in glycan regulation. A deeper understanding of how O-glycosylation influences the balance between amyloid-beta peptide production and clearance, as well as microglia's pro- and anti-inflammatory responses, is crucial for deciphering the early pathogenic events of AD. This review aims to provide a comprehensive summary of the extensive research conducted on the role of mucin-type O-glycosylation in the pathogenesis of AD, discussing its role in disease onset and immune recognition.

Apolipoprotein E in Alzheimer's disease: molecular insights and therapeutic opportunities

Apolipoprotein E (APOE- gene; apoE- protein) is the strongest genetic modulator of late-onset Alzheimer's disease (AD), with its three major isoforms conferring risk for disease ε2 < ε3 < ε4. Emerging protective gene variants, such as APOE Christchurch and the COLBOS variant of REELIN, an alternative target of certain apoE receptors, offer novel insights into resilience against AD. In recent years, the role of apoE has been shown to extend beyond its primary function in lipid transport, influencing multiple biological processes, including amyloid-β (Aβ) aggregation, tau pathology, neuroinflammation, autophagy, cerebrovascular integrity and protection from lipid peroxidation and the resulting ferroptotic cell death. While the detrimental influence of apoE ε4 on these and other processes has been well described, the molecular mechanisms underpinning this disadvantage require further enunciation, particularly to realize therapeutic opportunities related to apoE. This review explores the multifaceted roles of apoE in AD pathogenesis, emphasizing recent discoveries and translational approaches to target apoE-mediated pathways. These findings underscore the potential for apoE-based therapeutic strategies to prevent or mitigate AD in genetically at-risk populations.

Neuroadaptation in neurodegenerative diseases: compensatory mechanisms and therapeutic approaches

Progressive neuronal loss is a hallmark of neurodegenerative diseases including Alzheimer's, Parkinson's, Huntington's, and Amyotrophic Lateral Sclerosis (ALS), which cause cognitive and motor impairment. Delaying the onset and course of symptoms is largely dependent on neuroadaptation, the brain's ability to restructure in response to damage. The molecular, cellular, and systemic processes that underlie neuroadaptation are examined in this study. These mechanisms include gliosis, neurogenesis, synaptic plasticity, and changes in neurotrophic factors. Axonal sprouting, dendritic remodelling, and compensatory alterations in neurotransmitter systems are important adaptations observed in NDDs; nevertheless, these processes may shift to maladaptive plasticity, which would aid in the advancement of the illness. Amyloid and tau pathology-induced synaptic alterations in Alzheimer's disease emphasize compensatory network reconfiguration. Dopamine depletion causes a major remodelling of the basal ganglia in Parkinson's disease, and non-dopaminergic systems compensate. Both ALS and Huntington's disease rely on motor circuit rearrangement and transcriptional dysregulation to slow down functional deterioration. Neuroadaptation is, however, constrained by oxidative stress, compromised autophagy, and neuroinflammation, particularly in elderly populations. The goal of emerging therapy strategies is to improve neuroadaptation by pharmacologically modifying neurotrophic factors, neuroinflammation, and synaptic plasticity. Neurostimulation, cognitive training, and physical rehabilitation are instances of non-pharmacological therapies that support neuroplasticity. Restoring compensating systems may be possible with the use of stem cell techniques and new gene treatments. The goal of future research is to combine biomarkers and individualized medicines to maximize neuroadaptive responses and decrease the course of illness. In order to reduce neurodegeneration and enhance patient outcomes, this review highlights the dual function of neuroadaptation in NDDs and its potential as a therapeutic target.

P-glycoprotein and Alzheimer's Disease: Threats and Opportunities

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects more than 50 million people worldwide. One of the hallmark features of AD is the accumulation of amyloid β-peptide (Aβ) protein in the brain. P-glycoprotein (P-gp) is a membrane-bound protein expressed in various tissues, including the cerebrovascular endothelium. It plays a crucial role in the efflux of toxic substances, including Aβ, from the brain. Aberrations in P-gp levels or activity have been implicated in the pathogenesis of AD by promoting the accumulation of Aβ in the brain. Therefore, modulating the P-gp function represents a promising therapeutic strategy for treating AD. P-gp has multiple substrate binding sites, creating the potential for substrates to fall into complementation groups based on these sites; two substrates in the same complementation group may compete with one other, but two substrates in different groups may exhibit cooperativity. Thus, a given P-gp substrate may interfere with Aβ efflux whereas another may promote clearance. These threats and opportunities, as well as other aspects of P-gp relevance to AD, are discussed here.

Recent Advances in Drug Development for Alzheimer's Disease: A Comprehensive Review

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder characterized by cognitive impairments such as memory loss and executive dysfunction. The primary pathological features of AD include the deposition of amyloid-beta (Aβ) plaques, the hyperphosphorylation of tau proteins leading to neurofibrillary tangles, disruptions of neuronal and synaptic functions, and chronic inflammatory responses. These multifactorial interactions drive disease progression. To date, various therapeutic agents targeting these pathological mechanisms have been developed. This article provides a comprehensive review of the pathogenesis of AD, recent advances in drug development targeting different pathways, current challenges, and future directions, aiming to offer valuable insights for clinical treatment and research.

A computational ontology framework for the synthesis of multi-level pathology reports from brain MRI scans

BackgroundConvolutional neural network (CNN) based volumetry of MRI data can help differentiate Alzheimer's disease (AD) and the behavioral variant of frontotemporal dementia (bvFTD) as causes of cognitive decline and dementia. However, existing CNN-based MRI volumetry tools lack a structured hierarchical representation of brain anatomy, which would allow for aggregating regional pathological information and automated computational inference.ObjectiveDevelop a computational ontology pipeline for quantifying hierarchical pathological abnormalities and visualize summary charts for brain atrophy findings, aiding differential diagnosis.MethodsUsing FastSurfer, we segmented brain regions and measured volume and cortical thickness from MRI scans pooled across multiple cohorts (N = 3433; ADNI, AIBL, DELCODE, DESCRIBE, EDSD, and NIFD), including healthy controls, prodromal and clinical AD cases, and bvFTD cases. Employing the Web Ontology Language (OWL), we built a semantic model encoding hierarchical anatomical information. Additionally, we created summary visualizations based on sunburst plots for visual inspection of the information stored in the ontology.ResultsOur computational framework dynamically estimated and aggregated regional pathological deviations across different levels of neuroanatomy abstraction. The disease similarity index derived from the volumetric and cortical thickness deviations achieved an AUC of 0.88 for separating AD and bvFTD, which was also reflected by distinct atrophy profile visualizations.ConclusionsThe proposed automated pipeline facilitates visual comparison of atrophy profiles across various disease types and stages. It provides a generalizable computational framework for summarizing pathologic findings, potentially enhancing the physicians' ability to evaluate brain pathologies robustly and interpretably.

Potential Correlation Between Molecular Biomarkers and Oxidative Stress in Traumatic Brain Injury

Diagnosing traumatic brain injury (TBI) remains challenging due to an incomplete understanding of its neuropathological mechanisms. TBI is recognised as a complex condition involving both primary and secondary injuries. Although oxidative stress is a non-specific molecular phenomenon observed in various neuropathological conditions, it plays a crucial role in brain injury response and recovery. Due to these aspects, we aimed to evaluate the interaction between some known TBI molecular biomarkers and oxidative stress in providing evidence for its possible relevance in clinical diagnosis and outcome prediction. We found that while many of the currently validated molecular biomarkers interact with oxidative pathways, their patterns of variation could assist the diagnosis, prognosis, and outcomes prediction in TBI cases.

Unravelling the Proteinopathic Engagement of α-Synuclein, Tau, and Amyloid Beta in Parkinson's Disease: Mitochondrial Collapse as a Pivotal Driver of Neurodegeneration

Parkinson's disease is a complex neurological ailment manifested by dopaminergic neurodegeneration in the substantia nigra of the brain. This study investigates the molecular tripartite interaction between Lewy bodies, amyloid beta, and tau protein in the pathogenesis of Parkinson's disease. Lewy bodies which have been found as the important pathological hallmark in the degenerative neurons of Parkinson's patients, are mainly composed of α-synuclein. The accumulation of α-synuclein has been directly and indirectly linked to the severity and degree of progression of the disease. In addition, approximately 50% of Parkinson's disease cases are also described by hyperphosphorylation of tau protein indicating its significant involvement in the disease. The study further explains how α-synuclein, tau and amyloid beta can spread via cross-seeding mechanisms and accelerate each other's aggregation leading to neuronal death. Both GSK-3β and CDK5 are involved in phosphorylation which among other effects contributes to the misfolding of both α-synuclein and tau proteins that lead to neurodegeneration in Alzheimer's disease. Several mediators, that contribute to mitochondrial damage through elevated oxidative stress pathology are clearly described. Because of the increase in the incidence of Parkinson's disease, as predicted to be 17 million when the study was being conducted, studying these pathological mechanisms is very important in trying to establish treatments. This work contributes a path to finding a multi-target treatment regimen to alleviate the burden of this devastating disease.