RESUMEN
The aggregation of ß-amyloid peptide (Aß) is associated with neurodegenerative diseases such as Alzheimer's disease (AD). Several therapies aimed at reducing the aggregation of this peptide have emerged as potential strategies for the treatment of AD. This paper describes the design and preparation of new hybrid molecules based on steroids, selenosugars, and [60]fullerene as potential inhibitors of Aß oligomerization. These moieties were selected based on their antioxidant properties and possible areas of interaction with the Aß. Cyclopropanations between C60 and malonates bearing different steroid and selenosugar moieties using the Bingel-Hirsch protocol have enabled the synthesis of functionalized molecular hybrids. The obtained derivatives were characterized by physical and spectroscopic techniques. Theoretical calculations for all the selenium compounds were performed using the density functional theory DFT/B3LYP-D3(BJ)/6-311G(2d,p) predicting the most stable conformations of the synthesized derivatives. Relevant geometrical parameters were investigated to relate the stereochemical behavior and the spectroscopic data obtained. The affinity of the compounds for Aß-peptide was estimated by molecular docking simulation, which predicted an increase in affinity and interactions for Aß for the hybrids containing the C60 core. In addition, parameters such as lipophilicity, polar surface area, and dipole moment were calculated to predict their potential interaction with membrane cells.
RESUMEN
Beta-amyloid (Aß), the most pivotal pathological hallmark for Alzheimer's disease (AD) diagnosis and drug evaluation, was recognized by TZ095, a high-affinity fluorescent probe developed by rational molecular design. With a TICT mechanism, TZ095 exhibited remarkable affinity with Aß aggregates (Kd = 81.54 nM for oligomers; Kd = 66.70 nM for fibril) and substantial fluorescence enhancement (F/F0 = 44), enabling real-time monitoring of Aß in live cells and nematodes. Significantly, this work used TZ095 to construct a new protocol that can quickly and conveniently monitor Aß changes at the cellular and nematode levels to evaluate the anti-AD efficacy of candidate compounds, and four reported Aß-lowering drug candidates were administrated for validation. Imaging data demonstrated that TZ095 can visually and quantitatively track the effect of Aß elimination after drug treatment. Furthermore, TZ095 excelled in ex vivo histological staining of 12-month-old APP/PS1 mouse brains, accurately visualizing Aß plaques. Integrating CUBIC technology, TZ095 facilitated whole-brain, 3D imaging of Aß distribution in APP/PS1 mice, enabling high-resolution in situ analysis of Aß plaques. Collectively, these innovative applications of TZ095 offer a promising strategy for rapid, convenient, and real-time monitoring of Aß levels in preclinical therapeutic assessments.
RESUMEN
Synaptic plasticity is believed to underlie the cellular and molecular basis of memory formation. Mitochondria are one of the main organelles involved in metabolism and energy maintenance as plastic organelles that change morphologically and functionally in response to cellular needs and regulate synaptic function and plasticity through multiple mechanisms, including ATP generation, calcium homeostasis, and biogenesis. An increased neuronal activity enhances synaptic efficiency, during which mitochondria's spatial distribution and morphology change significantly. These organelles build up in the pre-and postsynaptic zones to produce ATP, which is necessary for several synaptic processes like neurotransmitter release and recycling. Mitochondria also regulate calcium homeostasis by buffering intracellular calcium, which ensures proper synaptic activity. Furthermore, mitochondria in the presynaptic terminal have distinct morphological properties compared to dendritic or postsynaptic mitochondria. This specialization enables precise control of synaptic activity and plasticity. Mitochondrial dysfunction has been linked to synaptic failure in many neurodegenerative disorders, like Alzheimer's disease (AD). In AD, malfunctioning mitochondria cause delays in synaptic vesicle release and recycling, ionic gradient imbalances, and mostly synaptic failure. This review emphasizes mitochondrial plasticity's contribution to synaptic function. It also explores the profound effect of mitochondrial malfunction on neurodegenerative disorders, focusing on AD, and provides an overview of how they sustain cellular health under normal conditions and how their malfunction contributes to neurodegenerative diseases, highlighting their potential as a therapeutic target for such conditions.
Asunto(s)
Enfermedad de Alzheimer , Mitocondrias , Plasticidad Neuronal , Humanos , Plasticidad Neuronal/fisiología , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/fisiopatología , Mitocondrias/metabolismo , Animales , Sinapsis/fisiología , Sinapsis/patología , Sinapsis/metabolismoRESUMEN
Studies of the structure and dynamics of oligomeric aggregates of amyloidogenic peptides pose challenges due to their transient nature. This concept article provides a brief overview of various nucleation mechanisms with reference to the classical nucleation theory and illustrates the advantages of incubating amyloidogenic peptides in reverse micelles (RMs). The use of RMs not only facilitates size regulation of oligomeric aggregates but also provides an avenue to explore protein-protein interactions among the oligomeric aggregates of various amyloidogenic peptides. Additionally, we envision the feasibility of preparing brain tissue-derived oligomeric aggregates using RMs, potentially advancing the development of monoclonal antibodies with enhanced potency against these pathological species in vivo.
RESUMEN
Introduction: The gut microbiota (MB), although one of the main producers of Aß in the body, in physiological conditions contributes to the maintainance of a healthy brain. Dysbiosis, the dysbalance between Gram-negative and Gram-positive bacteria in the MB increases Aß production, contributing to the accumulation of Aß plaques in the brain, the main histopathological hallmark of Alzheimer's disease (AD). Administration of prebiotics and probiotics, maintaining or recovering gut-MB composition, could represent a nutraceutical strategy to prevent or reduce AD sympthomathology. Aim of this research was to evaluate whether treatment with pre- and probiotics could modify the histopathological signs of neurodegeneration in hippocampal CA1 and CA3 areas of a transgenic mouse model of AD (APP/PS1 mice). The hippocampus is one of the brain regions involved in AD. Methods: Tg mice and Wt littermates (Wt-T and Tg-T) were fed daily for 6 months from 2 months of age with a diet supplemented with prebiotics (a multi-extract of fibers and plant complexes, containing inulin/fruit-oligosaccharides) and probiotics (a 50%-50% mixture of Lactobacillus rhamnosus and Lactobacillus paracasei). Controls were Wt and Tg mice fed with a standard diet. Brain sections were immunostained for Aß plaques, neurons, astrocytes, microglia, and inflammatory proteins that were evaluated qualitatively and quantitatively by immunofluorescence, confocal microscopy and digital imaging with ImageJ software. Results: Quantitative analyses demonstrated that: 1) The treatment with pre- and probiotics significantly decreased Aß plaques in CA3, while in CA1 the reduction was not significant; 2) Neuronal damage in CA1 Stratum Pyramidalis was significantly prevented in Tg-T mice; no damage was found in CA3; 3) In both CA1 and CA3 the treatment significantly increased astrocytes density, and GFAP and IBA1 expression, especially around plaques; 4) Microglia reacted differently in CA1 and CA3: in CA3 of Tg-T mice there was a significant increase of CD68+ phagocytic microglia (ball-and-chain phenomic) and of CX3CR1 compared with CA1. Discussion: The higher microglia reactivity could be responsible for their more efficient scavenging activity towards Aß plaques in CA3 in comparison to CA1. Treatment with pre- and probiotics, modifying many of the physiopathological hallmarks of AD, could be considered an effective nutraceutical strategy against AD symptomatology.
RESUMEN
INTRODUCTION: Memory deficits are the primary symptom in amnestic Mild Cognitive Impairment (aMCI); however, executive function (EF) deficits are common. The current study examined EF in aMCI based upon amyloid status (A+/A-) and regional atrophy in signature areas of Alzheimer's disease (AD). METHOD: Participants included 110 individuals with aMCI (A+ = 66; A- = 44) and 33 cognitively healthy participants (HP). EF was assessed using four neuropsychological assessment measures. The cortical thickness of the AD signature areas was calculated using structural MRI data. RESULTS: A + had greater EF deficits and cortical atrophy relative to A - in the supramarginal gyrus and superior parietal lobule. A - had greater EF deficits relative to HP, but no difference in signature area cortical thickness. DISCUSSION: The current study found that the degree of EF deficits in aMCI are a function of amyloid status and cortical thinning in the parietal cortex.
RESUMEN
RATIONALE: The accumulation of beta-amyloid peptide (Aß) in the forebrain leads to cognitive dysfunction and neurodegeneration in Alzheimer's disease. Studies have shown that individuals with a consistently cognitively active lifestyle are less vulnerable to Aß toxicity. Recent research has demonstrated that intrahippocampal Aß can impact catecholaminergic release and spatial memory. Interestingly, exposure to novelty stimuli has been found to stimulate the release of catecholamines in the hippocampus. However, it remains uncertain whether repeated enhancing catecholamine activity can effectively alleviate cognitive impairment in individuals with Alzheimer's disease. OBJECTIVES: Our primary aim was to investigate whether repeated exposure to novelty could enable cognitive resilience against Aß. This protection could be achieved by modulating catecholaminergic activity within the hippocampus. METHODS: To investigate this hypothesis, we subjected mice to three different conditions-standard housing (SH), repeated novelty (Nov), or daily social interaction (Soc) for one month. We then infused saline solution (SS) or Aß (Aß1-42) oligomers intrahippocampally and measured spatial memory retrieval in a Morris Water Maze (MWM). Stereological analysis and extracellular baseline dopamine levels using in vivo microdialysis were assessed in independent groups of mice. RESULTS: The mice that received Aß1-42 intrahippocampal infusions and remained in SH or Soc conditions showed impaired spatial memory retrieval. In contrast, animals subjected to the Nov protocol demonstrated remarkable resilience, showing strong spatial memory expression even after Aß1-42 intrahippocampal infusion. The stereological analysis indicated that the Aß1-42 infusion reduced the tyrosine hydroxylase axonal length in SH or Soc mice compared to the Nov group. Accordingly, the hippocampal extracellular dopamine levels increased significantly in the Nov groups. CONCLUSIONS: These compelling results demonstrate the potential for repeated novelty exposure to strengthen the dopaminergic system and mitigate the toxic effects of Aß1-42. They also highlight new and promising therapeutic avenues for treating and preventing AD, especially in its early stages.
RESUMEN
Neuropathologic changes of Alzheimer disease (AD) including Aß accumulation and neuroinflammation are frequently observed in the cerebral cortex of patients with idiopathic normal pressure hydrocephalus (iNPH). We created an automated analysis platform to quantify Aß load and reactive microglia in the vicinity of Aß plaques and to evaluate their association with cognitive outcome in cortical biopsies of patients with iNPH obtained at the time of shunting. Aiforia Create deep learning software was used on whole slide images of Iba1/4G8 double immunostained frontal cortical biopsies of 120 shunted iNPH patients to identify Iba1-positive microglia somas and Aß areas, respectively. Dementia, AD clinical syndrome (ACS), and Clinical Dementia Rating Global score (CDR-GS) were evaluated retrospectively after a median follow-up of 4.4 years. Deep learning artificial intelligence yielded excellent (>95%) precision for tissue, Aß, and microglia somas. Using an age-adjusted model, higher Aß coverage predicted the development of dementia, the diagnosis of ACS, and more severe memory impairment by CDR-GS whereas measured microglial densities and Aß-related microglia did not correlate with cognitive outcome in these patients. Therefore, cognitive outcome seems to be hampered by higher Aß coverage in cortical biopsies in shunted iNPH patients but is not correlated with densities of surrounding microglia.
RESUMEN
The misfolding and aggregation of beta-amyloid (Aß) peptides have been implicated as key pathogenic events in the early stages of Alzheimer's disease (AD). Inhibiting Aß aggregation represents a potential disease-modifying therapeutic approach to AD treatment. Previous studies have identified various molecules that inhibit Aß aggregation, some of which share common chemical substructures (fragments) that may be key to their inhibitory activity. Employing fragment-based drug discovery (FBDD) methods may facilitate the identification of these fragments, which can subsequently be used to screen new inhibitors and provide leads for further drug development. In this study, we used an in silico FBDD approach to identify 17 fragment clusters that are significantly enriched among Aß aggregation inhibitors. These fragments were then used to screen anti-infective agents, a promising drug class for repurposing against amyloid aggregation. This screening process identified 16 anti-infective drugs, 5 of which were chosen for further investigation. Among the 5 candidates, anidulafungin, an antifungal compound, showed high efficacy in inhibiting Aß aggregation in vitro. Kinetic analysis revealed that anidulafungin selectively blocks the primary nucleation step of Aß aggregation, substantially delaying Aß fibril formation. Cell viability assays demonstrated that anidulafungin can reduce the toxicity of oligomeric Aß on BV2 microglia cells. Molecular docking simulations predicted that anidulafungin interacted with various Aß species, including monomers, oligomers, and fibrils, potentially explaining its activity against Aß aggregation and toxicity. This study suggests that anidulafungin is a potential drug to be repurposed for AD, and FBDD is a promising approach for discovering drugs to combat Aß aggregation.
Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Anidulafungina , Descubrimiento de Drogas , Reposicionamiento de Medicamentos , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Reposicionamiento de Medicamentos/métodos , Péptidos beta-Amiloides/metabolismo , Descubrimiento de Drogas/métodos , Humanos , Anidulafungina/farmacología , Animales , Equinocandinas/farmacología , Equinocandinas/química , Simulación del Acoplamiento Molecular/métodos , Fragmentos de Péptidos/farmacología , Fragmentos de Péptidos/metabolismoRESUMEN
Human brain aging is characterized by the production and deposition of ß-amyloid (Aß) in the form of senile plaques and cerebral amyloid angiopathy and the intracellular accumulation of hyper-phosphorylated tau (Hp-tau) to form neurofibrillary tangles (NFTs) and dystrophic neurites of senile plaques. The process progresses for years and eventually manifests as cognitive impairment and dementia in a subgroup of aged individuals. Aß is produced and deposited first in the neocortex in most aged mammals, including humans; it is usually not accompanied by altered behavior and cognitive impairment. Hp-tau is less frequent than Aß pathology, and NFTs are rare in most mammals. In contrast, NFTs are familiar from middle age onward in humans; NFTs first appear in the paleocortex and selected brain stem nuclei. NFTs precede for decades or years Aß deposition and correlate with dementia in about 5% of individuals at the age of 65 and 25% at the age of 85. Based on these comparative data, (a) Aß deposition is the most common Alzheimer's disease neuropathological change (ADNC) in the brain of aged mammals; (b) Hp-tau is less common, and NFTs are rare in most aged mammals; however, NFTs are the principal cytoskeletal pathology in aged humans; (c) NFT in aged humans starts in selected nuclei of the brain stem and paleocortical brain regions progressing to the most parts of the neocortex and other regions of the telencephalon; (d) human brain aging is unique among mammalian species due to the early appearance and dramatic progression of NFTs from middle age onward, matching with cognitive impairment and dementia in advanced cases; (e) neither mammalian nor human brain aging supports the concept of the amyloid cascade hypothesis.
Asunto(s)
Envejecimiento , Enfermedad de Alzheimer , Ovillos Neurofibrilares , Proteínas tau , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/metabolismo , Animales , Humanos , Envejecimiento/patología , Envejecimiento/metabolismo , Ovillos Neurofibrilares/patología , Ovillos Neurofibrilares/metabolismo , Proteínas tau/metabolismo , Encéfalo/patología , Encéfalo/metabolismo , Péptidos beta-Amiloides/metabolismo , Mamíferos/metabolismo , Placa Amiloide/patología , Placa Amiloide/metabolismoRESUMEN
Alzheimer's disease (AD) is the most frequent neurodegenerative disorder in the elderly aged over 65. The extracellular accumulation of beta-amyloid (Aß) aggregates in the brain is considered as the major event worsening the AD symptoms, but its underlying reason has remained unclear. Here the piezoelectric characteristics of Aß aggregates are revealed. The vector piezoresponse force microscopy (PFM) analysis results exhibit that Aß fibrils have spiraling piezoelectric domains along the length and a lateral piezoelectric constant of 44.1 pC N-1. Also, the continuous sideband Kelvin probe force microscopy (KPFM) images display that the increment of charge-induced surface potential on a single Aß fibril is allowed to reach above +1700 mV in response to applied forces. These findings shed light on the peculiar mechano-electrical surface properties of pathological Aß fibrils that exceed those of normal body components.
RESUMEN
Positron emission tomography (PET) and magnetic resonance spectroscopy (1H-MRS) are complementary techniques that can be applied to study how proteinopathy and neurometabolism relate to cognitive deficits in preclinical stages of Alzheimer's disease (AD)-mild cognitive impairment (MCI) and late-life depression (LLD). We acquired beta-amyloid (Aß) PET and 7â¯T 1H-MRS measures of GABA, glutamate, glutathione, N-acetylaspartate, N-acetylaspartylglutamate, myo-inositol, choline, and lactate in the anterior and posterior cingulate cortices (ACC, PCC) in 13 MCI and 9 LLD patients, and 13 controls. We used linear regression to examine associations between metabolites, Aß, and cognitive scores, and whether metabolites and Aß explained cognitive scores better than Aß alone. In the ACC, higher Aß was associated with lower GABA in controls but not MCI or LLD patients, but results depended upon MRS data quality control criteria. Greater variance in California Verbal Learning Test scores was better explained by a model that combined ACC glutamate and Aß deposition than by models that only included one of these variables. These findings identify preliminary associations between Aß, neurometabolites, and cognition.
Asunto(s)
Péptidos beta-Amiloides , Disfunción Cognitiva , Depresión , Tomografía de Emisión de Positrones , Humanos , Disfunción Cognitiva/metabolismo , Disfunción Cognitiva/diagnóstico por imagen , Anciano , Femenino , Masculino , Péptidos beta-Amiloides/metabolismo , Tomografía de Emisión de Positrones/métodos , Depresión/metabolismo , Depresión/diagnóstico por imagen , Giro del Cíngulo/metabolismo , Giro del Cíngulo/diagnóstico por imagen , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/psicología , Enfermedad de Alzheimer/patología , Espectroscopía de Resonancia Magnética/métodos , Anciano de 80 o más Años , Persona de Mediana Edad , Tiazoles , Imagen Multimodal/métodos , Compuestos de AnilinaRESUMEN
Developing multitargeted ligands as promising therapeutics for Alzheimer's disease (AD) has been considered important. Herein, a novel class of cinnamamide/ester-triazole hybrids with multifaceted effects on AD was developed based on the multitarget-directed ligands strategy. Thirty-seven cinnamamide/ester-triazole hybrids were synthesized, with most exhibiting significant inhibitory activity against Aß-induced toxicity at a single concentration in vitro. The most optimal hybrid compound 4j inhibited copper-induced Aß toxicity in AD cells. its action was superior to that of donepezil and memantine. It also moderately inhibited intracellular AChE activity and presented favorable bioavailability and blood-brain barrier penetration with low toxicity in vivo. Of note, it ameliorated cognitive impairment, neuronal degeneration, and Aß deposition in Aß1-42-injured mice. Mechanistically, the compound regulated APP processing by promoting the ADAM10-associated nonamyloidogenic signaling and inhibiting the BACE1-mediated amyloidogenic pathway. Moreover, it suppressed intracellular AChE activity and tau phosphorylation. Therefore, compound 4j may be a promising multitargeted active molecule against AD.
Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Cinamatos , Triazoles , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Animales , Triazoles/química , Triazoles/farmacología , Triazoles/síntesis química , Cinamatos/química , Cinamatos/farmacología , Cinamatos/síntesis química , Humanos , Ratones , Péptidos beta-Amiloides/metabolismo , Péptidos beta-Amiloides/antagonistas & inhibidores , Relación Estructura-Actividad , Estructura Molecular , Ésteres/química , Ésteres/farmacología , Ésteres/síntesis química , Relación Dosis-Respuesta a Droga , Acetilcolinesterasa/metabolismo , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/farmacología , Inhibidores de la Colinesterasa/síntesis química , Descubrimiento de Drogas , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/síntesis química , Fragmentos de Péptidos/metabolismo , Fragmentos de Péptidos/antagonistas & inhibidores , MasculinoRESUMEN
Alzheimer's disease (AD) is a degenerative neurological condition that gradually impairs cognitive abilities, disrupts memory retention, and impedes daily functioning by impacting the cells of the brain. A key characteristic of AD is the accumulation of amyloid-beta (Aß) plaques, which play pivotal roles in disease progression. These plaques initiate a cascade of events including neuroinflammation, synaptic dysfunction, tau pathology, oxidative stress, impaired protein clearance, mitochondrial dysfunction, and disrupted calcium homeostasis. Aß accumulation is also closely associated with other hallmark features of AD, underscoring its significance. Aß is generated through cleavage of the amyloid precursor protein (APP) and plays a dual role depending on its processing pathway. The non-amyloidogenic pathway reduces Aß production and has neuroprotective and anti-inflammatory effects, whereas the amyloidogenic pathway leads to the production of Aß peptides, including Aß40 and Aß42, which contribute to neurodegeneration and toxic effects in AD. Understanding the multifaceted role of Aß, particularly in AD, is crucial for developing effective therapeutic strategies that target Aß metabolism, aggregation, and clearance with the aim of mitigating the detrimental consequences of the disease. This review aims to explore the mechanisms and functions of Aß under normal and abnormal conditions, particularly in AD, by examining both its beneficial and detrimental effects.
Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Humanos , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Animales , Encéfalo/metabolismo , Encéfalo/patologíaRESUMEN
Neurological disorders pose a huge worldwide challenge to the healthcare system, necessitating innovative strategies for targeted drug delivery to the central nervous system. Alzheimer's disease (AD) is an untreatable neurodegenerative condition characterized by dementia and alterations in a patient's physiological and mental states. Since ancient times, medicinal plants have been an important source of bioactive phytochemicals with immense therapeutic potential. This review investigates new and safer alternatives for prevention and treatment of disease related to inevitable side effects associated with synthetic compounds. This review examines how nanotechnology can help in enhancing the delivery of neuroprotective phytochemicals in AD. Nevertheless, despite their remarkable neuroprotective properties, these natural products often have poor therapeutic efficacy due to low bioavailability, limited solubility and imperfect blood brain barrier (BBB) penetration. Nanotechnology produces personalized drug delivery systems which are necessary for solving such problems. In overcoming these challenges, nanotechnology might be employed as a way forward whereby customized medication delivery systems would be established as a result. The use of nanocarriers in the design and application of important phytochemicals is highlighted by this review, which indicate potential for revolutionizing neuroprotective drug delivery. We also explore the complications and possibilities of using nanocarriers to supply nutraceuticals and improve patients' standard of living, and preclinical as well as clinical investigations displaying that these techniques are effective in mitigating neurodegenerative diseases. In order to fight brain diseases and improve patient's health, scientists and doctors can employ nanotechnology with its possible therapeutic interventions.
Asunto(s)
Enfermedad de Alzheimer , Fármacos Neuroprotectores , Fitoquímicos , Humanos , Enfermedad de Alzheimer/tratamiento farmacológico , Fitoquímicos/uso terapéutico , Fitoquímicos/administración & dosificación , Fármacos Neuroprotectores/uso terapéutico , Fármacos Neuroprotectores/administración & dosificación , Animales , Nanopartículas/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Portadores de Fármacos/química , Nanotecnología/métodos , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/metabolismoRESUMEN
Alzheimer's disease (AD) and Diabetes mellitus (DM) exhibit comparable pathophysiological pathways. Genetic abnormalities in APP, PS-1, and PS-2 are linked to AD, with diagnostic aid from CSF and blood biomarkers. Insulin dysfunction, termed "type 3 diabetes mellitus" in AD, involves altered insulin signalling and neuronal shrinkage. Insulin influences beta-amyloid metabolism, exacerbating neurotoxicity in AD and amyloid production in DM. Both disorders display impaired glucose transporter expression, hastening cognitive decline. Mitochondrial dysfunction and Toll-like receptor 4-mediated inflammation worsen neurodegeneration in both diseases. ApoE4 raises disease risk, especially when coupled with dyslipidemia common in DM. Targeting shared pathways like insulin-degrading enzyme activation and HSP60 holds promise for therapeutic intervention. Recognizing these interconnected mechanisms underscores the imperative for developing tailored treatments addressing the overlapping pathophysiology of AD and DM, offering potential avenues for more effective management of both conditions.
RESUMEN
Cerebrospinal fluid (CSF) core biomarkers of Alzheimer's disease (AD), including amyloid peptide beta-42 (Aß42), Aß42/40 ratio, and phosphorylated tau (pTau), are precious tools for supporting AD diagnosis. However, their use in clinical practice is limited due to the invasiveness of CSF collection. Thus, there is intensive research to find alternative, noninvasive, and widely accessible biological matrices to measure AD core biomarkers. In this study, we measured AD core biomarkers in saliva and plasma by a fully automated platform. We enrolled all consecutive patients with cognitive decline. For each patient, we measured Aß42, Aß40, and pTau levels in CSF, saliva, and plasma by Lumipulse G1200 (Fujirebio). We included forty-two patients, of whom 27 had AD. Levels of all biomarkers significantly differed in the three biofluids, with saliva having the lowest and CSF the highest levels of Aß42, Aß40, and pTau. A positive correlation of pTau, Aß42/40 ratio, and pTau/Aß42 ratio levels in CSF and plasma was detected, while no correlation between any biomarker in CSF and saliva was found. Our findings suggest that plasma but not saliva could represent a surrogate biofluid for measuring core AD biomarkers. Specifically, plasma Aß42/40 ratio, pTau/Aß42 ratio, and pTau could serve as surrogates of the corresponding CSF biomarkers.
Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Biomarcadores , Saliva , Proteínas tau , Humanos , Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/líquido cefalorraquídeo , Enfermedad de Alzheimer/metabolismo , Saliva/metabolismo , Saliva/química , Biomarcadores/sangre , Biomarcadores/líquido cefalorraquídeo , Femenino , Masculino , Anciano , Péptidos beta-Amiloides/líquido cefalorraquídeo , Péptidos beta-Amiloides/sangre , Péptidos beta-Amiloides/análisis , Proteínas tau/líquido cefalorraquídeo , Proteínas tau/sangre , Proteínas tau/análisis , Persona de Mediana Edad , Fragmentos de Péptidos/líquido cefalorraquídeo , Fragmentos de Péptidos/sangre , Fragmentos de Péptidos/análisis , Mediciones Luminiscentes/métodos , Anciano de 80 o más AñosRESUMEN
Alzheimer's disease (AD) poses a significant health challenge worldwide, affecting millions of individuals, and projected to increase further as the global population ages. Current pharmacological interventions primarily target acetylcholine deficiency and amyloid plaque formation, but offer limited efficacy and are often associated with adverse effects. Given the multifactorial nature of AD, there is a critical need for novel therapeutic approaches that simultaneously target multiple pathological pathways. Targeting key enzymes involved in AD pathophysiology, such as acetylcholinesterase, butyrylcholinesterase, beta-site APP cleaving enzyme 1 (BACE1), and gamma-secretase, is a potential strategy to mitigate disease progression. To this end, our research group has conducted comprehensive in silico screening to identify some lead compounds, including IQ6 (SSZ), capable of simultaneously inhibiting the enzymes mentioned above. Building upon this foundation, we synthesized SSZ, a novel multitargeted ligand/inhibitor to address various pathological mechanisms underlying AD. Chemically, SSZ exhibits pharmacological properties conducive to AD treatment, featuring pyrrolopyridine and N-cyclohexyl groups. Preclinical experimental evaluation of SSZ in AD rat model showed promising results, with notable improvements in behavioral and cognitive parameters. Specifically, SSZ treatment enhanced locomotor activity, ameliorated gait abnormalities, and improved cognitive function compared to untreated AD rats. Furthermore, brain morphological analysis demonstrated the neuroprotective effects of SSZ, attenuating Aß-induced neuronal damage and preserving brain morphology. Combined treatment of SSZ and conventional drugs (DON and MEM) showed synergistic effects, suggesting a potential therapeutic strategy for AD management. Overall, our study highlights the efficacy of multitargeted ligands like SSZ in combating AD by addressing the complex etiology of the disease. Further research is needed to elucidate the full therapeutic potential of SSZ and the exploration of similar compounds in clinical settings, offering hope for an effective AD treatment in the future.