Search Results (105)

The incorporation of selenium into tacrine derivatives has been explored as a novel strategy to enhance therapeutic efficacy while minimizing toxicity in the treatment of neurodegenerative diseases such as Alzheimer’s. This study utilized computational and experimental approaches, including Density Functional Theory (DFT), molecular docking, pharmacokinetic profiling, and toxicological predictions, to evaluate the potential of these derivatives. The selenium-modified compounds demonstrated improved electronic properties, such as narrower HOMO–LUMO gaps and optimized electronegativity, resulting in enhanced stability and reactivity. Pharmacokinetic analyses revealed favorable absorption, distribution, and blood–brain barrier penetration, while toxicological assessments indicated reduced hepatotoxicity and skin sensitization risks compared to tacrine. Molecular docking and dynamic simulations highlighted strong and stable interactions of the derivatives with critical enzymes, including acetylcholinesterase (AChE) and beta-secretases (BACE1 and BACE2). Compounds 12 and 13, in particular, emerged as the most promising candidates due to their superior stability and binding affinity. These findings underscore the potential of selenium-modified tacrine derivatives as safer and more effective therapeutic agents for Alzheimer’s disease, warranting further experimental validation. Full article

Neurological disorders, encompassing neurodegenerative and neuroinflammatory conditions, present significant public health and clinical challenges. Recent research has elucidated the pivotal role of various enzymes in the onset and progression of these disorders. This review explores the therapeutic potential of targeting these enzymes with natural and synthetic molecules. Key enzymes, including acetylcholinesterase, monoamine oxidase, beta-secretase, tau kinases, caspases, and cyclooxygenase-2, are implicated in diseases such as Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis. Modulating these enzymes can alleviate symptoms, slow disease progression, or reverse pathological changes. Natural molecules derived from plants, microbes, seaweeds, and animals have long been noted for their therapeutic potential. Their ability to interact with specific enzymes with high specificity and minimal side effects makes them promising candidates for treatment. These natural agents provide a foundation for developing targeted therapies with improved safety profiles. Simultaneously, the development of synthetic chemistry has resulted in molecules designed to inhibit neurodegenerative enzymes with precision. This review examines the progress in creating small molecules, peptides, and enzyme inhibitors through sophisticated drug design techniques. It evaluates the efficacy, safety, and mechanisms of these synthetic agents, highlighting their potential for clinical application. The review offers a comprehensive overview of recent advancements in enzyme-targeted therapies for neurological disorders, covering both natural and synthetic molecules investigated in preclinical and clinical settings. It discusses the mechanisms through which these molecules exert their effects, the challenges faced in their development, and future research directions. By synthesizing current knowledge, this paper aims to illuminate the potential of enzyme-targeted interventions in managing neurological disorders, showcasing both the promise and limitations of these approaches. Full article

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. Full article

The present Perspective analyzes the remarkable evolution of the Amyloid Cascade Hypothesis 2.0 (ACH2.0) theory of Alzheimer’s disease (AD) since its inception a few years ago, as reflected in the diminishing role of amyloid-beta (Aβ) in the disease. In the initial iteration of the ACH2.0, Aβ-protein-precursor (AβPP)-derived intraneuronal Aβ (iAβ), accumulated to neuronal integrated stress response (ISR)-eliciting levels, triggers AD. The neuronal ISR, in turn, activates the AβPP-independent production of its C99 fragment that is processed into iAβ, which drives the disease. The second iteration of the ACH2.0 stemmed from the realization that AD is, in fact, a disease of the sustained neuronal ISR. It introduced two categories of AD—conventional and unconventional—differing mainly in the manner of their causation. The former is caused by the neuronal ISR triggered by AβPP-derived iAβ, whereas in the latter, the neuronal ISR is elicited by stressors distinct from AβPP-derived iAβ and arising from brain trauma, viral and bacterial infections, and various types of inflammation. Moreover, conventional AD always contains an unconventional component, and in both forms, the disease is driven by iAβ generated independently of AβPP. In its third, the current, iteration, the ACH2.0 posits that proteolytic production of Aβ is suppressed in AD-affected neurons and that the disease is driven by C99 generated independently of AβPP. Suppression of Aβ production in AD seems an oxymoron: Aβ is equated with AD, and the later is inconceivable without the former in an ingrained Amyloid Cascade Hypothesis (ACH)-based notion. But suppression of Aβ production in AD-affected neurons is where the logic leads, and to follow it we only need to overcome the inertia of the preexisting assumptions. Moreover, not only is the generation of Aβ suppressed, so is the production of all components of the AβPP proteolytic pathway. This assertion is not a quantum leap (unless overcoming the inertia counts as such): the global cellular protein synthesis is severely suppressed under the neuronal ISR conditions, and there is no reason for constituents of the AβPP proteolytic pathway to be exempted, and they, apparently, are not, as indicated by the empirical data. In contrast, tau protein translation persists in AD-affected neurons under ISR conditions because the human tau mRNA contains an internal ribosomal entry site in its 5′UTR. In current mouse models, iAβ derived from AβPP expressed exogenously from human transgenes elicits the neuronal ISR and thus suppresses its own production. Its levels cannot principally reach AD pathology-causing levels regardless of the number of transgenes or the types of FAD mutations that they (or additional transgenes) carry. Since the AβPP-independent C99 production pathway is inoperative in mice, the current transgenic models have no potential for developing the full spectrum of AD pathology. What they display are only effects of the AβPP-derived iAβ-elicited neuronal ISR. The paper describes strategies to construct adequate transgenic AD models. It also details the utilization of human neuronal cells as the only adequate model system currently available for conventional and unconventional AD. The final alteration of the ACH2.0, introduced in the present Perspective, is that AβPP, which supports neuronal functionality and viability, is, after all, potentially produced in AD-affected neurons, albeit not conventionally but in an ISR-driven and -compatible process. Thus, the present narrative begins with the “omnipotent” Aβ capable of both triggering and driving the disease and ends up with this peptide largely dislodged from its pedestal and retaining its central role in triggering the disease in only one, although prevalent (conventional), category of AD (and driving it in none). Among interesting inferences of the present Perspective is the determination that “sporadic AD” is not sporadic at all (“non-familial” would be a much better designation). The term has fatalistic connotations, implying that the disease can strike at random. This is patently not the case: The conventional disease affects a distinct subpopulation, and the basis for unconventional AD is well understood. Another conclusion is that, unless prevented, the occurrence of conventional AD is inevitable given a sufficiently long lifespan. This Perspective also defines therapeutic directions not to be taken as well as auspicious ways forward. The former category includes ACH-based drugs (those interfering with the proteolytic production of Aβ and/or depleting extracellular Aβ). They are legitimate (albeit inefficient) preventive agents for conventional AD. There is, however, a proverbial snowball’s chance in hell of them being effective in symptomatic AD, lecanemab, donanemab, and any other “…mab” or “…stat” notwithstanding. They comprise Aβ-specific antibodies, inhibitors of beta- and gamma-secretase, and modulators of the latter. In the latter category, among ways to go are the following: (1) Depletion of iAβ, which, if sufficiently “deep”, opens up a tantalizing possibility of once-in-a-lifetime preventive transient treatment for conventional AD and aging-associated cognitive decline, AACD. (2) Composite therapy comprising the degradation of C99/iAβ and concurrent inhibition of the neuronal ISR. A single transient treatment could be sufficient to arrest the progression of conventional AD and prevent its recurrence for life. Multiple recurrent treatments would achieve the same outcome in unconventional AD. Alternatively, the sustained reduction/removal of unconventional neuronal ISR-eliciting stressors through the elimination of their source would convert unconventional AD into conventional one, preventable/treatable by a single transient administration of the composite C99/iAβ depletion/ISR suppression therapy. Efficient and suitable ISR inhibitors are available, and it is explicitly clear where to look for C99/iAβ-specific targeted degradation agents—activators of BACE1 and, especially, BACE2. Directly acting C99/iAβ-specific degradation agents such as proteolysis-targeting chimeras (PROTACs) and molecular-glue degraders (MGDs) are also viable options. (3) A circumscribed shift (either upstream or downstream) of the position of transcription start site (TSS) of the human AβPP gene, or, alternatively, a gene editing-mediated excision or replacement of a small, defined segment of its portion encoding 5′-untranslated region of AβPP mRNA; targeting AβPP RNA with anti-antisense oligonucleotides is another possibility. If properly executed, these RNA-based strategies would not interfere with the protein-coding potential of AβPP mRNA, and each would be capable of both preventing and stopping the AβPP-independent generation of C99 and thus of either preventing AD or arresting the progression of the disease in its conventional and unconventional forms. The paper is interspersed with “validation” sections: every conceptually significant notion is either validated by the existing data or an experimental procedure validating it is proposed. Full article

Alzheimer’s disease (AD) prevention is a critical challenge for aging societies, necessitating the exploration of food ingredients and whole foods as potential therapeutic agents. This study aimed to identify natural compounds (NCs) with therapeutic potential in AD using an innovative bioinformatics-integrated deep neural analysis approach, combining computational predictions with molecular docking and in vitro experiments for comprehensive evaluation. We employed the bioinformatics-integrated deep neural analysis of NCs for Disease Discovery (BioDeepNat) application in the data collected from chemical databases. Random forest regression models were utilized to predict the IC₅₀ (pIC₅₀) values of ligands interacting with AD-related target proteins, including acetylcholinesterase (AChE), amyloid precursor protein (APP), beta-secretase 1 (BACE1), microtubule-associated protein tau (MAPT), presenilin-1 (PSEN1), tumor necrosis factor (TNF)-α, and valosin-containing protein (VCP). Their activities were then validated through a molecular docking analysis using Autodock Vina. Predictions by the deep neural analysis identified 166 NCs with potential effects on AD across seven proteins, demonstrating outstanding recall performance. The top five food sources of these predicted compounds were black walnut, safflower, ginger, fig, corn, and pepper. Statistical clustering methodologies segregated the NCs into six well-defined groups, each characterized by convergent structural and chemical signatures. The systematic examination of structure–activity relationships uncovered differential molecular patterns among clusters, illuminating the sophisticated correlation between molecular properties and biological activity. Notably, NCs with high activity, such as astragalin, dihydromyricetin, and coumarin, and medium activity, such as luteolin, showed promising effects in improving cell survival and reducing lipid peroxidation and TNF-α expression levels in PC12 cells treated with lipopolysaccharide. In conclusion, our findings demonstrate the efficacy of combining bioinformatics with deep neural networks to expedite the discovery of previously unidentified food-derived active ingredients (NCs) for AD intervention. Full article

We previously reported that membrane-type 5-matrix metalloproteinase (MT5-MMP) deficiency not only reduces pathological hallmarks of Alzheimer’s disease (AD) in 5xFAD (Tg) mice in vivo but also impairs interleukin-1 beta (IL-1β)-mediated neuroinflammation and Aβ production in primary Tg immature neural cell cultures after 11 days in vitro. We now investigate the effect of MT5-MMP on incipient pathogenic pathways that are activated in cortical primary cultures at 21–24 days in vitro (DIV), during which time neurons are organized into a functional mature network. Using wild-type (WT), MT5-MMP^−/− (MT5^−/−), 5xFAD (Tg), and 5xFADxMT5-MMP^−/− (TgMT5^−/−) mice, we generated primary neuronal cultures that were exposed to IL-1β and/or different proteolytic system inhibitors. We assessed neuroinflammation, APP metabolism, synaptic integrity, and electrophysiological properties using biochemical, imaging and whole-cell patch-clamp approaches. The absence of MT5-MMP impaired the IL-1β-mediated induction of inflammatory genes in TgMT5^−/− cells compared to Tg cells. Furthermore, the reduced density of dendritic spines in Tg neurons was also prevented in TgMT5^−/− neurons. IL-1β caused a strong decrease in the dendritic spine density of WT neurons, which was prevented in MT5^−/− neurons. However, the latter exhibited fewer spines than the WT under untreated conditions. The spontaneous rhythmic firing frequency of the network was increased in MT5^−/− neurons, but not in TgMT5^−/− neurons, and IL-1β increased this parameter only in Tg neurons. In terms of induced somatic excitability, Tg and TgMT5^−/− neurons exhibited lower excitability than WT and MT5^−/−, while IL-1β impaired excitability only in non-AD backgrounds. The synaptic strength of miniature global synaptic currents was equivalent in all genotypes but increased dramatically in WT and MT5^−/− neurons after IL-1β. MT5-MMP deficiency decreased endogenous and overexpressed C83 and C99 levels but did not affect Aβ levels. C99 appears to be cleared by several pathways, including γ-secretase, the autophagolysosomal system, and also α-secretase, via its conversion to C83. In summary, this study confirms that MT5-MMP is a pivotal factor affecting not only neuroinflammation and APP metabolism but also synaptogenesis and synaptic activity at early stages of the pathology, and reinforces the relevance of targeting MT5-MMP to fight AD. Full article

Alzheimer’s disease (AD), a leading neurodegenerative disorder, is closely associated with the accumulation of amyloid-beta (Aβ) peptides in the brain. The enzyme β-secretase (BACE1), pivotal in Aβ production, represents a promising therapeutic target for AD. While bioactive peptides derived from food protein hydrolysates have neuroprotective properties, their inhibitory effects on BACE1 remain largely unexplored. In this study, we evaluated the inhibitory potential of protein hydrolysates from gliadin, whey, and casein proteins prepared using bromelain, papain, and thermolysin. Through in vitro and cellular assays, bromelain-hydrolyzed gliadin (G-Bro) emerged as the most potent BACE1 inhibitor, with an IC₅₀ of 0.408 mg/mL. G-Bro significantly reduced BACE1 expression and amyloid precursor protein (APP) processing in N2a/PS/APP cell cultures, suggesting its potential to attenuate Aβ aggregation. The unique peptide profile of G-Bro likely contributes to its inhibitory effect, with proline residues disrupting β-sheets, lysine residues introducing positive charges that hinder aggregation, hydrophobic residues stabilizing binding interactions, and glutamine residues enhancing solubility and stability. These findings highlight gliadin hydrolysates, particularly G-Bro, as potential natural BACE1 inhibitors with applications in dietary interventions for AD prevention. However, further studies are warranted to elucidate specific peptide interactions and their bioactivity in neural pathways to better understand their therapeutic potential. Full article

Background/Objectives: Diabetes mellitus (DM), a widespread endocrine disorder characterized by chronic hyperglycemia, can cause nerve damage and increase the risk of neurodegenerative diseases such as Alzheimer’s disease (AD). Effective blood glucose management is essential, and sitagliptin (SITG), a dipeptidyl peptidase-4 (DPP-4) inhibitor, may offer neuroprotective benefits in type 2 diabetes mellitus (T2DM). Methods: T2DM was induced in rats using nicotinamide (NICO) and streptozotocin (STZ), and biomarkers of AD and DM-linked enzymes, inflammation, oxidative stress, and apoptosis were evaluated in the brain. Computational studies supported the in vivo findings. Results: SITG significantly reduced the brain enzyme levels of acetylcholinesterase (AChE), beta-secretase-1 (BACE-1), DPP-4, and glycogen synthase kinase-3β (GSK-3β) in T2DM-induced rats. It also reduced inflammation by lowering cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and nuclear factor-κB (NF-κB). Additionally, SITG improved oxidative stress markers by reducing malondialdehyde (MDA) and enhancing glutathione (GSH). It increased anti-apoptotic B-cell lymphoma protein-2 (Bcl-2) while reducing pro-apoptotic markers such as Bcl-2-associated X (BAX) and Caspace-3. SITG also lowered blood glucose levels and improved plasma insulin levels. To explore potential molecular level mechanisms, docking was performed on AChE, COX-2, GSK-3β, BACE-1, and Caspace-3. The potential binding affinity of SITG for the above-mentioned target enzymes were 10.8, 8.0, 9.7, 7.7, and 7.9 kcal/mol, respectively, comparable to co-crystallized ligands. Further binding mode analysis of the lowest energy conformation revealed interactions with the critical residues. Conclusions: These findings highlight SITG’s neuroprotective molecular targets in T2DM-associated neurodegeneration and its potential as a therapeutic approach for AD, warranting further clinical investigations. Full article

The major pathological characteristics of Alzheimer’s disease (AD) include senile plaques and neurofibrillary tangles (NFTs), which are mainly composed of aggregated amyloid-beta (Aβ) peptide and hyperphosphorylated tau protein, respectively. The excessive production of reactive oxygen species (ROS) and neuroinflammation are crucial contributing factors to the pathological mechanisms of AD. Hypoxia-inducible factor-1 (HIF-1) is a transcription factor critical for tissue adaption to low-oxygen tension. Growing evidence has suggested HIF-1 as a potential therapeutic target for AD; conversely, other experimental findings indicate that HIF-1 induction contributes to AD pathogenesis. These previous findings thus point to the complex, even contradictory, roles of HIF-1 in AD. In this review, we first introduce the general pathogenic mechanisms of AD as well as the potential pathophysiological roles of HIF-1 in cancer, immunity, and oxidative stress. Based on current experimental evidence in the literature, we then discuss the possible beneficial as well as detrimental mechanisms of HIF-1 in AD; these sections also include the summaries of multiple chemical reagents and proteins that have been shown to exert beneficial effects in AD via either the induction or inhibition of HIF-1. Full article

Alzheimer’s disease (AD) is a complex neurodegenerative disorder influenced by various genetic factors. In addition to the well-established amyloid precursor protein (APP), Presenilin-1 (PSEN1), Presenilin-2 (PSEN2), and apolipoprotein E (APOE), several other genes such as Sortilin-related receptor 1 (SORL1), Phospholipid-transporting ATPase ABCA7 (ABCA7), Triggering Receptor Expressed on Myeloid Cells 2 (TREM2), Phosphatidylinositol-binding clathrin assembly protein (PICALM), and clusterin (CLU) were implicated. These genes contribute to neurodegeneration through both gain-of-function and loss-of-function mechanisms. While it was traditionally thought that heterozygosity in autosomal recessive mutations does not lead to disease, haploinsufficiency was linked to several conditions, including cancer, autism, and intellectual disabilities, indicating that a single functional gene copy may be insufficient for normal cellular functions. In AD, the haploinsufficiency of genes such as ABCA7 and SORL1 may play significant yet under-explored roles. Paradoxically, heterozygous knockouts of PSEN1 or PSEN2 can impair synaptic plasticity and alter the expression of genes involved in oxidative phosphorylation and cell adhesion. Animal studies examining haploinsufficient AD risk genes, such as vacuolar protein sorting-associated protein 35 (VPS35), sirtuin-3 (SIRT3), and PICALM, have shown that their knockout can exacerbate neurodegenerative processes by promoting amyloid production, accumulation, and inflammation. Conversely, haploinsufficiency in APOE, beta-secretase 1 (BACE1), and transmembrane protein 59 (TMEM59) was reported to confer neuroprotection by potentially slowing amyloid deposition and reducing microglial activation. Given its implications for other neurodegenerative diseases, the role of haploinsufficiency in AD requires further exploration. Modeling the mechanisms of gene knockout and monitoring their expression patterns is a promising approach to uncover AD-related pathways. However, challenges such as identifying susceptible genes, gene–environment interactions, phenotypic variability, and biomarker analysis must be addressed. Enhancing model systems through humanized animal or cell models, utilizing advanced research technologies, and integrating multi-omics data will be crucial for understanding disease pathways and developing new therapeutic strategies. Full article

Background: The goal of the current study was to investigate the inhibitory activity of six phenolic compounds, i.e., rosmarinic acid, gallic acid, oleuropein, epigallocatechin gallate (EGCG), 3-hydroxytyrosol, and quercetin, against β-site amyloid precursor protein cleaving enzyme-1 (BACE1), also known as β-secretase or memapsin 2, which is implicated in the pathogenesis of Alzheimer’s disease (AD). Methods and Results: The inhibitory potential against BACE1, molecular docking simulations, as well as neurotoxicity and the effect on the AD-related gene expression of the selected phenolics were tested. BACE1 inhibitory activity was carried out using the ELISA microplate assay via fluorescence resonance energy transfer (FRET) technology. Molecular docking experiments were performed in the human BACE1 active site (PDB code: 2WJO). Neurotoxicity of the compounds was carried out in SH-SY5Y, a human neuroblastoma cell line, by the Alamar Blue method. A gene expression analysis of the compounds on fourteen genes linked to AD was conducted using the real-time polymerase chain reaction (RT-PCR) method. Rosmarinic acid, EGCG, oleuropein, and quercetin (also used as the reference) were able to inhibit BACE1 with their respective IC₅₀ values 4.06 ± 0.68, 1.62 ± 0.12, 9.87 ± 1.01, and 3.16 ± 0.30 mM. The inhibitory compounds were observed to occupy the non-catalytic site of the BACE1. However, hydrogen bonds were found to be present between rosmarinic acid and EGCG and aspartic amino acid D228 in the catalytic site. Oleuropein and quercetin effectively suppressed the expression of PSEN, APOE, and CLU, which are recognized to be linked to the pathogenesis of AD. Conclusions: The outcomes of the work bring quercetin, EGCG, and rosmarinic acid to the forefront as promising BACE1 inhibitors. Full article

Petunidin-3-O-(trans-p-coumaroylrutinoside)-5-O-glucoside (PtCG), the primary anthocyanin ingredient in Lycium ruthenicum Murr., possesses a range of biological activities, including antioxidative properties and melanin inhibition. This study aimed to investigate the protective effect of PtCG on D-galactose (D-gal)-induced aging in female mice and elucidate the underlying molecular pathways. Behavioral experiments, including the MWW and Y-maze tests, revealed that PtCG significantly ameliorated cognitive decline and enhanced learning and memory abilities in aging mice. Regarding biochemical indicators, PtCG considerably improved superoxide dismutase (SOD) and glutathione (GSH) activity while reducing malondialdehyde (MDA) and acetylcholinesterase (AChE) levels in the hippocampus and serum. Furthermore, PtCG ingestion alleviated liver injury by decreasing alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (AKP) levels, and attenuated renal damage by reducing blood urea nitrogen (BUN) and uric acid (UA) levels. Transmission electron microscopy (TEM) results demonstrated that PtCG restored the function and quantity of synapses in the hippocampus. Hematoxylin and eosin (H&E), Masson’s trichrome, and Nissl staining revealed that PtCG significantly improved the relevant pathological characteristics of liver and hippocampal tissues in aging mice. The molecular mechanism investigation showed that PtCG downregulated the protein expression of microglial marker ionized calcium-binding adapter molecule 1 (Iba1), astrocytic marker glial fibrillary acidic protein (GFAP), β-secretase 1 (BACE-1), and amyloid-beta_1–42 (Aβ_1–42) in the hippocampus of aging mice. The protein expression of inflammatory pathway components, including nuclear factor-kappa B (NF-κB), cyclooxygenase-2 (COX2), inducible nitric oxide synthase (iNOS), and interleukin-1 beta (IL-1β), was also suppressed. These findings suggest that PtCG may possess anti-aging properties, with its mechanism of action potentially linked to the attenuation of neuroinflammation, oxidative stress, and liver and kidney damage. PtCG may have future applications as a functional food for the treatment of aging-related disorders. Full article

Despite the great effort that has gone into developing new molecules as multitarget compounds to treat Alzheimer’s disease (AD), none of these have been approved to treat this disease. Therefore, it will be interesting to determine whether benzazoles such as benzimidazole, benzoxazole, and benzothiazole, employed as pharmacophores, could act as multitarget drugs. AD is a multifactorial disease in which several pharmacological targets have been identified—some are involved with amyloid beta (Aβ) production, such as beta secretase (BACE1) and beta amyloid aggregation, while others are involved with the cholinergic system as acetylcholinesterase (AChE) and butirylcholinesterase (BChE) and nicotinic and muscarinic receptors, as well as the hyperphosphorylation of microtubule-associated protein (tau). In this review, we describe the in silico and in vitro evaluation of benzazoles on three important targets in AD: AChE, BACE1, and Aβ. Benzothiazoles and benzimidazoles could be the best benzazoles to act as multitarget drugs for AD because they have been widely evaluated as AChE inhibitors, forming π–π interactions with W286, W86, Y72, and F338, as well as in the AChE gorge and catalytic site. In addition, the sulfur atom from benzothiazol interacts with S286 and the aromatic ring from W84, with these compounds having an IC₅₀ value in the μM range. Also, benzimidazoles and benzothiazoles can inhibit Aβ aggregation. However, even though benzazoles have not been widely evaluated on BACE1, benzimidazoles evaluated in vitro showed an IC₅₀ value in the nM range. Therefore, important chemical modifications could be considered to improve multitarget benzazoles’ activity, such as substitutions in the aromatic ring with electron withdrawal at position five, or a linker 3 or 4 carbons in length, which would allow for better interaction with targets. Full article

Glutamate transporter-1 (GLT-1) dynamics are implicated in excitotoxicity and Alzheimer’s disease (AD) progression. Early stages of AD are often marked by hyperactivity and increased epileptiform activity preceding cognitive decline. Previously, we identified a direct interaction between GLT-1 and Presenilin 1 (PS1) in the brain, highlighting GLT-1 as a promising target in AD research. This study reports the significance of this interaction and uncovers a novel role of GLT-1 in modulating amyloid-beta (Aβ) production. Overexpression of GLT-1 in cells reduces the levels of Aβ40 and Aβ42 by decreasing γ-secretase activity pertinent to APP processing and induces a more “open” PS1 conformation, resulting in decreased Aβ42/40 ratio. Inhibition of the GLT-1/PS1 interaction using cell-permeable peptides produced an opposing effect on Aβ, highlighting the pivotal role of this interaction in regulating Aβ levels. These findings emphasize the potential of targeting the GLT-1/PS1 interaction as a novel therapeutic strategy for AD. Full article

In this manuscript, a novel presenilin-2 (PSEN2) mutation, Val226Ala, was found in a 59-year-old Korean patient who exhibited rapid progressive memory dysfunction and hallucinations six months prior to her first visit to the hospital. Her Magnetic Resonance Imaging (MRI) showed brain atrophy, and both amyloid positron emission tomography (PET) and multimer detection system-oligomeric amyloid-beta (Aβ) results were positive. The patient was diagnosed with early onset Alzheimer’s disease. The whole-exome analysis revealed a new PSEN2 Val226Ala mutation with heterozygosity in the 5th transmembrane domain of the PSEN2 protein near the lumen region. Analyses of the structural prediction suggested structural changes in the helix, specifically a loss of a hydrogen bond between Val226 and Gln229, which may lead to elevated helix motion. Multiple PSEN2 mutations were reported in PSEN2 transmembrane-5 (TM5), such as Tyr231Cys, Ile235Phe, Ala237Val, Leu238Phe, Leu238Pro, and Met239Thr, highlighting the dynamic importance of the 5th transmembrane domain of PSEN2. Mutations in TM5 may alter the access tunnel of the Aβ substrate in the membrane to the gamma-secretase active site, indicating a possible influence on enzyme function that increases Aβ production. Interestingly, the current patient with the Val226Ala mutation presented with a combination of hallucinations and memory dysfunction. Although the causal mechanisms of hallucinations in AD remain unclear, it is possible that PSEN2 interacts with other disease risk factors, including Notch Receptor 3 (NOTCH3) or Glucosylceramidase Beta-1 (GBA) variants, enhancing the occurrence of hallucinations. In conclusion, the direct or indirect role of PSEN2 Val226Ala in AD onset cannot be ruled out. Full article