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Alzheimer's disease is a progressive neurodegenerative process with multifactorial characteristics. This disease follows the natural aging process, affecting mainly people over 65 years. Pharmacotherapeutic treatment currently combats symptoms related to cognitive function. Several targets have begun to attract the interest of the scientific community to develop new drug candidates which have better pharmacokinetic and lower toxicity parameters. The present study aims to design new candidates for acetylcholinesterase/β-secretase (AChE/BACE1) multitarget inhibitor drugs. 17 natural products were selected from the literature with anticholinesterase activity and 1 synthetic molecule with inhibitory activity for BACE1. Subsequently, the molecular docking study was performed, followed by the derivation of the pharmacophoric pattern and prediction of pharmacokinetic and toxicological properties. Finally, the hybrid prototype was designed. All selected molecules showed interactions with their respective target enzymes. Derivation of the pharmacophoric pattern from molecules that interacted with the AChE enzyme resulted in 3 pharmacophoric regions: an aromatic ring, an electron-acceptor region and a hydrophobic region. The molecules showed good pharmacokinetic and toxicological results, showing no warnings of mutagenicity and/or carcinogenicity. After the hybridization process, three hybrid molecules were obtained, which showed inhibitory activity for both targets. It is concluded that research in the field of medicinal chemistry is advancing towards the discovery of new drug candidates that bring a better quality of life to patients with AD. Show less

Although an increasing number of common variants contributing to Alzheimer's disease (AD) are uncovered by genome-wide association studies, they can only explain less than half of the heritability of AD. Rare variant association studies (RVAS) has become an increasingly important area to explain the risk or trait variability of AD. To investigate the potential rare variants that cause AD, we screened 70,209 rare variants from two cohorts of a 175 AD cohort and a 214 cognitively normal cohort from the Alzheimer's Disease Neuroimaging Initiative database. MIRARE, a novel RVAS method, was performed on 232 non-synonymous variants selected by ANNOVAR annotation. Molecular docking and molecular dynamics (MD) simulation were adopted to verify the interaction between the chosen functional variants and BACE1. MIRAGE analysis revealed significant associations between AD and six potential pathogenic genes, including According to the literature search, bio-informatics analysis, and molecular docking and MD simulation, we find non-synonymous rare variants in six genes, especially FLG(rs3120654), that may play key roles in AD. Show less

Yuan-Zhi Decoction (YZD) is a traditional Chinese medical formulation with demonstrated clinical benefits in Alzheimer's disease (AD). We used liquid chromatography coupled with mass spectrometry to identify 27 unique chemical components of YZD. Analyzing these using network pharmacology and molecular docking models identified 34 potential interacting molecular targets involved in 26 biochemical pathways. When tested in an animal model of AD, the APP/PS1 transgenic mice showed measurable improvements in spatial orientation and memory after the administration of YZD. These improvements coincided with significantly reduced deposition of Aβ plaques and tau protein in the hippocampi in the treated animals. In addition, a decreased BACE1 and beta-amyloid levels, a downregulation of the p-GSK-3β/GSK-3β, and an upregulation of the PI3K and p-AKT/AKT pathway was seen in YZD treated animals. These Show less

The amyloid precursor protein (APP) processing pathway was altered in Alzheimer's disease (AD) and contributed to abnormal amyloid-beta (Aβ) production, which forms insoluble interneuron protein aggregates known as amyloid plaques in the brain. Targeting the APP processing pathway is still fundamental for AD modifying therapy. Extensive research has evaluated the protective effects of vitamin E as an antioxidant and as a signaling molecule. The present study aimed to investigate the modulatory effects of different tocopherol isomers on the expression of genes involved in regulating the APP processing pathway Show less

Alzheimer's Disease (AD) impairs memory and cognitive functions in the geriatric population and is characterized by intracellular deposition of neurofibrillary tangles, extracellular deposition of amyloid plaques, and neuronal degeneration. Literature suggests that latent viral infections in the brain act as prions and promote neurodegeneration. Memantine possesses both anti-viral and N-methyl-D-aspartate (NMDA) receptor antagonistic activity. This research was designed to evaluate the efficacy of antiviral agents, especially valacyclovir, a prodrug of acyclovir in ameliorating the pathology of AD based on the presumption that anti-viral agents targeting the Herpes Simplex Virus (HSV) can have a protective effect on neurodegenerative diseases like Alzheimer's disease. Thus, we evaluated acyclovir's potential activity by in-silico computational docking studies against acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and beta-secretase 1 (BACE-1). These findings were further evaluated by in-vivo scopolamine-induced cognitive impairment in rats. Two doses of valacyclovir, a prodrug of acyclovir (100 mg/kg and 150 mg/kg orally) were tested. Genetic Optimisation for Ligand Docking scores and fitness scores of acyclovir were comparable to donepezil. Valacyclovir improved neurobehavioral markers. It inhibited AChE and BuChE (p<0.001) enzymes. It also possessed disease-modifying efficacy as it decreased the levels of BACE-1 (p<0.001), amyloid beta 1-42 (p<0.001), amyloid beta 1-40 (p<0.001), phosphorylatedtau (p<0.001), neprilysin (p<0.01), and insulin-degrading enzyme. It ameliorated neuroinflammation through decreased levels of tumour necrosis factor α (p<0.001), nuclear factor-kappa B (p<0.001), interleukin 6 (p<0.001), interleukin 1 beta (p<0.001), and interferon-gamma (p<0.001). It also maintained synaptic plasticity and consolidated memory. Histopathology showed that valacyclovir could restore cellular density and also preserve the dentate gyrus. Valacyclovir showed comparable activity to donepezil and thus can be further researched for the treatment of Alzheimer's disease. Show less

Long non-coding RNAs (LncRNAs) are known to have regulatory consequences for aberrant gene expression in cancers. The aim of this study was to evaluate the expression levels of long non-encoding RNAs, BACE1 (β-secretase1) and LINC-PINT (Long Intergenic Non-Protein Coding RNA, P53 Induced Transcript), in colorectal cancer (CRC) with clinicopathological parameters. Bioinformatics analysis defining effectual signalling pathways Wnt. A total of 130 tissue samples (50 fresh CRC tissues with parallel adjacent normal tissues (ADJ) accompanied with 30 normal healthy control tissue samples) were collected from the Iranian population. mRNA expression analysis was performed via Real Time Q-PCR. Statistical analysis for comparing CRC expression levels with ADJ and normal healthy tissues were carried out using Kruskal-Wallis tests. The Receiver Operating Characteristic (ROC) curve was plotted for each LNC, separately. We discovered that PINT and BACE1 expression levels were decreased and increased respectively in CRC tumour samples compared with ADJ normal and healthy tissues. Clinicopathological parameter assessment revealed a significant relationship between PINT expression, tumour location, staging and distant metastasis (p < 0.009, p < 0.014, p < 0.008, respectively). Also, BACE1 over expression was significantly associated with tumour site (p < 0.009), metastasis (p < 0.017) and histological differentiation (p < 0.028) and staging (p < 0.017). Furthermore, ROC curve plotting showed LINC-PINT LNC-BACE1 may distinguish between early and late-stage of CRC, highlighting the value of both BACE1 and PINT as CRC progression biomarkers. We investigated two LNCRNAs (PINT and BACE1) as potential CRC prognostic biomarkers, which are imperative for early and effective medical intervention in CRC. Expression levels of PINT and BACE1 in CRC tissue samples may serve to identify metastasis earlier, increasing patient survival rates and expediating clinical treatment options. Show less

Tannic acid (TA) is a natural compound present abundantly in fruit such as grapes and green tea. In this study, we have evaluated the therapeutic efficacy of TA against Lipopolysaccharide (LPS)-induced oxidative stress-mediated memory impairment, neuroinflammation, insulin signaling impairment, and Amyloid Beta (Aβ) deposition in adult male mice. The LPS was administered once per week and TA twice a week to adult male mice for three months consecutively. Behavioral studies were performed using different behavioral models such as balance beam, novel object recognition (NOR), Morris water maze (MWM), and Y-maze tests. The protein expression of different mediators such as TNF-α, p-JNK, pIRS636, BACE1, APP, and Aβ was evaluated through western blot and immunofluorescence staining techniques. Biochemical assays were carried out to assess the antioxidant activities of TA. The computational study was conducted to predict the binding mode of TA with target sites of TNF-α. Behavioral studies showed that the TA-treated mice exhibited gradual memory improvement. TA significantly inhibited BACE1 activity and reduced production and accumulation of Aβ in the hippocampus of mice brains. Moreover, the TA significantly inhibited LPS-induced ROS production and enhanced the glutathione levels. Furthermore, we have shown via the computational method for the first time that TA inhibits LPS-triggered TNF-ὰ and its downstream signaling to reduce AD pathology including memory impairment, neuroinflammation, insulin signaling impairment, and Aβ deposition in adult mice. Taken together our current study demonstrates that TA is a potential candidate for the abrogation of LPS-induced neurotoxicity and AD pathology in rodent's models. Show less

Glucocorticoid (GC) exposure can lead to deterioration of the structure and function of hippocampal neurons and is closely involved in Alzheimer's disease (AD). Amyloid-β (Aβ) overproduction is an important aspect of AD pathogenesis. Our study mainly investigated the mechanism of chronic GC exposure in accelerating Aβ production in primary cultured hippocampal neurons from APP/PS1 mice. The results indicated that chronic dexamethasone (DEX, 1 μM) significantly accelerated neuronal damage and Aβ accumulation in hippocampal neurons from APP/PS1 mice. Meanwhile, DEX exposure markedly upregulated APP, NCSTN, BACE1 and p-Tau/Tau expression in hippocampal neurons from APP/PS1 mice. Our study also indicated that chronic DEX exposure significantly increased intracellular Ca Show less

Alzheimer's disease (AD) is a severe neurodegenerative disorder of the brain that manifests as dementia, disorientation, difficulty in speech, and progressive cognitive and behavioral impairment. The emerging therapeutic approach to AD management is the inhibition of β-site APP cleaving enzyme-1 (BACE1), known to be one of the two aspartyl proteases that cleave β-amyloid precursor protein (APP). Studies confirmed the association of high BACE1 activity with the proficiency in the formation of β-amyloid-containing neurotic plaques, the characteristics of AD. Only a few FDA-approved BACE1 inhibitors are available in the market, but their adverse off-target effects limit their usage. In this paper, we have used both ligand-based and target-based approaches for drug design. The QSAR study entails creating a multivariate GA-MLR (Genetic Algorithm-Multilinear Regression) model using 552 molecules with acceptable statistical performance ( Show less

We posit that Alzheimer's disease (AD) is driven by amyloid-β (Aβ) generated in the amyloid-β protein precursor (AβPP) independent pathway activated by AβPP-derived Aβ accumulated intraneuronally in a life-long process. This interpretation constitutes the Amyloid Cascade Hypothesis 2.0 (ACH2.0). It defines a tandem Show less

Triple ionic and electronic conductivity (TIEC) in cathode materials for protonic ceramic fuel cells (PCFCs) is a desirable feature that enhances the spatial expansion of active reaction sites for electrochemical oxygen reduction reaction. The realization of optimal TIEC in single-phase materials, however, is challenging. A facile route that facilitates the optimization of TIEC in PCFC cathodes is the strategic development of multiphase cathode materials. In this study, a cubic-rhombohedral TIEC nanocomposite material with the composition Ba(CeCo) Show less

Global warming is a serious public health threat to people worldwide. High body temperature is one of the important risk factors for Alzheimer's disease (AD), and the body temperature of AD patients has been found to be significantly higher than that of elderly control subjects. However, the effects of high body temperature on cognitive function and AD pathologies have not been completely elucidated. We report here that Tg2576 mice housed at a high ambient temperature of 30 °C for 13 months showed an increase in the body temperature, which is accompanied by memory impairment and an enhancement of amyloid-β peptides (Aβ) generation through the upregulation of β-site APP cleaving enzyme 1 (BACE1) level and decrease in the level of an Aβ-degrading enzyme, neprilysin (NEP) in the brain, compared with those of Tg2576 mice at 23 °C. High body temperature also increased the levels of heat shock proteins (HSPs), stress-stimulated kinases such as JNK, and total tau, leading to the enhancement of tau phosphorylation at 30 °C. Taken together, our findings suggest that high body temperature exacerbates cognitive function and AD pathologies, which provides a mechanistic insight for its prevention. Show less

Glucocorticoid (GC), secreted by adrenal cortex, plays important roles in regulating many physiological functions, while chronic stress level of GC exposure has many adverse effects on the structure and function of hippocampal neurons, and is closely implicated to the deterioration of Alzheimer's disease (AD). Oxidative stress and neuroinflammation play an important role in the occurrence and development of AD. However, it is still unclear whether chronic GC exposure promotes beta-amyloid (Aβ) accumulation and neuronal injury by increasing oxidative stress and neuroinflammation. In this study, we investigated the effects of chronic GC exposure on NOX2-NLRP1 inflammasome activation and the protective effects of NLRP1-siRNA against GC-induced neuronal injury in primary hippocampal neurons of APP/PS1 mice. The results showed that chronic dexamethasone (DEX, 1 µM) exposure 72 h had no significant effect on the primary hippocampal neurons of WT mice, but significantly increased Aβ Show less

Evidence suggests that β-secretase (BACE1), which cleaves Amyloid Precursor Protein (APP) to form sAPPβ and amyloid-β, is elevated in Alzheimer's disease (AD) brains and biofluids and, thus, BACE1 is a therapeutic target for this devastating disease. The direct product of BACE1 cleavage of APP, sAPPβ, serves as a surrogate marker of BACE1 activity in the central nervous system. This biomarker could be utilized to better understand normal APP processing, aberrant processing in the disease setting, and modulations to processing during therapeutic intervention. In this paper, we present a method for measuring the metabolism of sAPPβ and another APP proteolytic product, sAPPα, in vivo in humans using stable isotope labeling kinetics, paired with immunoprecipitation and liquid chromatography/tandem mass spectrometry. The method presented herein is robust, reproducible, and precise, and allows for the study of these analytes by taking into account their full dynamic potential as opposed to the traditional methods of absolute concentration quantitation that only provide a static view of a dynamic system. A study of in vivo cerebrospinal fluid sAPPβ and sAPPα kinetics using these methods could reveal novel insights into pathophysiological mechanisms of AD, such as increased BACE1 processing of APP. Show less

Multitarget drugs are a promising therapeutic approach against Alzheimer's disease. In this work, a new family of 5-substituted indazole derivatives with a multitarget profile including cholinesterase and BACE1 inhibition is described. Thus, the synthesis and evaluation of a new class of 5-substituted indazoles has been performed. Pharmacological evaluation includes Show less

Alzheimer disease (AD) is a degenerative brain disease, which may lead to severe memory loss and other cognitive disorders. However, few effective drugs are available in the clinic at present. Curcumin, a major ingredient of traditional Chinese medicine, Curcuma Longa, has various pharmacological activities. Therefore, exploring clinical drugs based on the inhibition of AD pathological features is imperative. First, we utilized the HERB database and Swisstarget Prediction database to get the related targets of curcumin and intersected with the AD targets. The intersection targets were used to construct the protein-protein interaction network and performed gene ontology and kyoto encyclopedia of genes and genomes analyses. Further, we obtained targets of curcumin against AD-related tau and aβ pathology via the AlzData database. These targets were applied to perform GEO and receiver operating characteristic analyses. Finally, the reliability of the core targets was evaluated using molecular docking technology. We identified 49 targets of curcumin against AD, and kyoto encyclopedia of genes and genomes pathway enrichment analysis demonstrated that the Alzheimer disease pathway (has05010) was significantly enriched. Even more, we obtained 16 targets of curcumin-related Aβ and tau pathology. Among these targets, 8 targets involved the Alzheimer disease pathway and the biological process analyses showed that positive regulation of cytokine production (GO:0001819) was significantly enriched. Bioinformatic analyses indicated that HMOX1, CSF1R, NFKB1, GSK3B, BACE1, AR, or PTGS1 expression was significantly different compared to the control group in the AD patients. Finally, molecular docking studies suggested these genes have a good binding force with curcumin. In this study, we identified curcumin exerted the effect of treating AD by regulating multitargets and multichannels through the method of network pharmacology. Show less

Silver nanoparticles (AgNPs) are widely used in a variety of consumer products because of their antibacterial and antifungal characteristics, but little is known about their toxicity to the brain. In this study, we investigated AgNP-induced neurotoxicity using the human neuroblastoma cancer (SH-SY5Y) cell line. After a 24 h treatment of AgNPs with two primary sizes (5 and 50 nm labeled as Ag-5 and Ag-50, respectively), a series of toxicological endpoints including cell viability, expression of proteins and genes in amyloid precursor protein (APP) amyloid hydrolysis process and ferritinophagy signaling pathways, oxidative stress, intracellular iron levels, and molecular regulators of iron metabolism were evaluated. Our results showed that both Ag-5 and Ag-50 induced notable neurotoxic effects on SH-SY5Y cells indicated by cell proliferation inhibition, increased BACE1 protein expression, and decreased APP and ADAM10 gene expression. Activation of nuclear receptor coactivator 4-mediated ferritinophagy and blockade of autophagic flux were induced by AgNPs, accompanied by intracellular iron accumulation and overexpression of divalent metal-ion transporter-1 and ferroportin1 in SH-SY5Y cells. In addition, AgNPs significantly decreased glutathione peroxidase 4 protein expression but increased malondialdehyde concentration, suggesting that AgNP-induced iron accumulation may trigger oxidative stress by disruption of the intracellular oxidant and antioxidant systems. In addition, compared with Ag-50, Ag-5 with higher cellular uptake efficiency caused more detrimental effects on SH-SY5Y cells. In conclusion, our findings demonstrated a size-dependent neurotoxicity in SH-SY5Y cells by AgNPs via ferritinophagy-mediated oxidative stress. Show less

Alzheimer's disease (AD) is characterized by extracellular amyloid plaques composed of amyloid-β peptide (Aβ), intracellular neurofibrillary tangles containing hyperphosphorylated tau protein and neuronal loss. Most of the FDA-approved AD drugs currently on the market are cholinesterase inhibitors, which are only effective in relieving the symptoms of AD. However, recent studies in AD drug discovery focus on multi-targeted strategies, including anti-amyloid and anti-tau therapy. In the current study, we have investigated the effects of toluidine blue O (TBO), a cholinesterase inhibitor, on amyloid precursor protein (APP) processing, tau phosphorylation, and tau kinases/phosphatase in N2a mouse neuroblastoma cells stably expressing the Swedish mutation of human APP695 (N2a-APPSwe). The results demonstrated that TBO reduces Aβ40/42 levels by decreasing expression levels of β-secretase 1 (BACE1), presenilin 1 (PS1) and total APP without causing cytotoxic effects in N2a-APPSwe cells. TBO also decreased the levels of both total tau and phosphorylated tau at residues Ser202/Thr205, Thr181, Ser396 and Ser 396/Ser404. Moreover, when the possible mechanisms underlying its effects on tau pathology were explored, TBO was found to decrease tau phosphorylation at those sites by reducing the expression levels of Akt, GSK-3β, Cdk5, inactive p-PP2A and increasing the expression levels of p-Akt Ser473 and inactive p-GSK-3β Ser9. Our new data support the idea that TBO may be a promising multi-target drug candidate for the treatment of AD. Show less

In vitro studies have been popularly used to determine the cellular and molecular mechanisms for many decades. However, the traditional two-dimension (2D) cell culture which grows cells on a flat surface does not fully recapitulate the pathological phenotypes. Alternatively, the three-dimension (3D) cell culture provides cell-cell and cell-ECM interaction that better mimics tissue-like structure. Thus, it has gained increasing attention recently. Yet, the expenses, time-consuming, and complications of cellular and biomolecular analysis are still major limitations of 3D culture. Herein, we describe a cost-effective and simplified workflow of the 3D neuronal cell-laden agarose-laminin preparation and the isolation of cells, RNAs, and proteins from the scaffold. To study the effects of the amyloidogenic condition in neurons, we utilized a neuron-like cell line, SH-SY5Y, and induced the amyloidogenic condition by using an amyloid forty-two inducer (Aftin-4). The effectiveness of RNAs, proteins and cells isolation from 3D scaffold enables us to investigate the cellular and molecular mechanisms underlying amyloidogenic cascade in neuronal cells. The results show that SH-SY5Y cultured in agarose-laminin scaffold differentiated to a mature TUJ1-expressing neuron cell on day 7. Furthermore, the gene expression profile from the Aftin-4-induced amyloidogenic condition revealed the expression of relevant gene-encoding proteins in the amyloidogenic pathway, including APP, BACE1, PS1, and PS2. This platform could induce the amyloid-beta 42 secretion and entrap secreted proteins in the scaffold. The induction of amyloidogenic conditions in a 3D culture facilitates the interaction between secreted amyloid-beta and neurons, which makes it resembles the pathological environment in Alzheimer's brain. Together, this workflow is applicable for studying the cellular and molecular analysis of amyloid-induced neuronal toxicity, such as those occurred in Alzheimer's disease progression. Importantly, our method is cost-effective, reproducible, and easy to manipulate. Show less

Multi-targeted directed ligands (MTDLs) are emerging as promising Alzheimer's disease (AD) therapeutic possibilities. Coumarin is a multifunctional backbone with extensive bioactivity that has been utilized to develop innovative anti-neurodegenerative properties and is a desirable starting point for the construction of MTDLs. Herein, we explored and synthesized a series of novel coumarin derivatives and assessed their inhibitory effects on cholinesterase (AChE, BuChE), GSK-3β, and BACE1. Among these compounds, compound 30 displayed the multifunctional profile of targeting the AChE (IC Show less

Searching for the production mechanism of synovial lesions helps to find precise therapeutic targets and improve prognosis. The previous identification and screening of differential genes in osteoarthritis (OA) pathogenesis were well combined to further build a risk prognosis model of OA, which is beneficial to the diagnosis and treatment of patients with OA. The synovia-related chip data sets GSE82107, GSE12021, GSE55457, and GSE55235 were downloaded from the public database of Gene Expression Omnibus (GEO), and 40 cases of synovial tissues of OA and 36 cases of normal synovial tissues were included. R software was used to screen differentially expressed genes (DEGs), Gene Ontology (GO) functional enrichment, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. The STRING online analysis tool and Cytoscape software were used to further screen key genes, and a prognostic model of OA susceptibility risk was constructed. The results showed 1,921 differential genes, including 762 upregulated genes and 1,159 downregulated genes, which were mainly involved cell growth, cell adhesion, skeletal muscle growth, iron ion binding, ubiquitin protein ligase binding, and hormone receptor binding. Co-acquisition based on 10 key target genes of the protein interaction network, containing Bioinformatics analysis was applied to screen out the DEG profiles of OA. This may provide functional predictions to provide new ideas for treatment of the disease and may be a biological marker for its diagnosis and a potential target for treatment. The construction of the risk and prognosis model is beneficial to the risk assessment of rehabilitation function recovery of patients with OA, the evaluation of the severity of the disease and the subsequent treatment guidance. Show less

Alzheimer's disease (AD) is a common neurodegenerative disease that often occurs in the elderly population. At present, most drugs for AD on the market are single-target drugs, which have achieved certain success in the treatment of AD. However, the efficacy and safety of single-target drugs have not achieved the expected results because AD is a multifactorial disease. Multi-targeted drugs act on multiple factors of the disease network to improve efficacy and reduce adverse reactions. Therefore, the search for effective dual-target or even multi-target drugs has become a new research trend. Many of results found that the dual-target inhibitors of the beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) and acetylcholinesterase (AChE) found from traditional Chinese medicine have a good inhibitory effect on AD with fewer side effects. This article reviews sixty-six compounds extracted from Chinese medicinal herbs, which have inhibitory activity on BACE1 and AChE. This provides a theoretical basis for the further development of these compounds as dual-target inhibitors for the treatment of AD. Show less

The formation of amyloid-ß peptides (Aß), that accumulate in Alzheimer's disease (AD) brains, involves proteolytic processing of the amyloid precursor protein (APP) firstly by ß-secretase (BACE1). Since BACE1 cleaves a plethora of other substrates, in this work we investigated whether the proteolysis and/or distribution of other BACE1 substrates, such as seizure protein 6 (Sez6) and seizure 6-like protein (Sez6L), is altered in AD. To test this we used 5xFAD mouse model brains that show an early accumulation of Aß plaques already at 2-months of age. Here we show for the first time that accumulation of BACE1 in peri-plaque regions and its enhanced levels in AD brains does not affect proteolysis of BACE1 substrates other than APP, such as Sez6 and Sez6L. We observed altered distribution of Sez6 and Sez6L in the area of Aß plaques in 5xFAD brains which is distinct to that of APP, BACE1 and/or LAMP1, suggesting different localization and/or function of these BACE1 substrates. While it is necessary to further elucidate the potential role that this may play in the course of AD, it is likely that Aß-targeted therapies may have beneficial effects against accumulation and/or altered distribution of BACE1 and its substrates, in addition to APP. Show less

Amyloid plaque deposition and axonal degeneration are early events in AD pathogenesis. Aβ disrupts microtubules in presynaptic dystrophic neurites, resulting in the accumulation of impaired endolysosomal and autophagic organelles transporting β-site amyloid precursor protein cleaving enzyme (BACE1). Consequently, dystrophic neurites generate Aβ42 and significantly contribute to plaque deposition. Farnesyltransferase inhibitors (FTIs) have recently been investigated for repositioning toward the treatment of neurodegenerative disorders and block the action of farnesyltransferase (FTase) to catalyze farnesylation, a post-translational modification that regulates proteins involved in lysosome function and microtubule stability. In postmortem AD brains, FTase and its downstream signaling are upregulated. However, the impact of FTIs on amyloid pathology and dystrophic neurites is unknown. We tested the effects of the FTIs LNK-754 and lonafarnib in the 5XFAD mouse model of amyloid pathology. In 2-month-old 5XFAD mice treated chronically for 3 months, LNK-754 reduced amyloid plaque burden, tau hyperphosphorylation, and attenuated the accumulation of BACE1 and LAMP1 in dystrophic neurites. In 5-month-old 5XFAD mice treated acutely for 3 weeks, LNK-754 reduced dystrophic neurite size and LysoTracker-Green accumulation in the absence of effects on Aβ deposits. Acute treatment with LNK-754 improved memory and learning deficits in hAPP/PS1 amyloid mice. In contrast to LNK-754, lonafarnib treatment was less effective at reducing plaques, tau hyperphosphorylation and dystrophic neurites, which could have resulted from reduced potency against FTase compared to LNK-754. We investigated the effects of FTIs on axonal trafficking of endolysosomal organelles and found that lonafarnib and LNK-754 enhanced retrograde axonal transport in primary neurons, indicating FTIs could support the maturation of axonal late endosomes into lysosomes. Furthermore, FTI treatment increased levels of LAMP1 in mouse primary neurons and in the brains of 5XFAD mice, demonstrating that FTIs stimulated the biogenesis of endolysosomal organelles. We show new data to suggest that LNK-754 promoted the axonal trafficking and function of endolysosomal compartments, which we hypothesize decreased axonal dystrophy, reduced BACE1 accumulation and inhibited amyloid deposition in 5XFAD mice. Our results agree with previous work identifying FTase as a therapeutic target for treating proteinopathies and could have important therapeutic implications in treating AD. Show less

Complex neurological disorders, including Alzheimer's disease, are one of the major therapeutic areas to which multitarget drug discovery strategies have been applied in the last twenty years. Due to the complex multifactorial etiopathogenesis of Alzheimer's disease, it has been proposed that to be successful the pharmaceutical agents should act on multiple targets in order to restore the complex disease network and to provide disease modifying effects. Here we report on the synthesis and the anticholinergic activity profiles of seven multitarget anti-Alzheimer compounds designed by combining galantamine, a well-known acetylcholinesterase inhibitor, with different peptide fragments endowed with inhibitory activity against BACE-1. A complementary approach based on molecular docking simulations of the galantamine-peptide derivatives in the active sites of acetylcholinesterase and of the related butyrylcholinesterase, as well as on inhibition kinetics, by global fitting of the reaction progress curves, allowed to gain insights into the enzyme-inhibitor mechanism of interaction. The resulting structure-activity relationships pave the way towards the design of more effective pharmacodynamic/pharmacokinetic multitarget inhibitors. Show less

Increasing evidence suggests incomplete recovery of COVID-19 patients, who continue to suffer from cardiovascular diseases, including cerebral vascular disorders (CVD) and neurological symptoms. Recent findings indicate that some of the damaging effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, especially in the brain, may be induced by the spike protein, leading to the disruption of the initial blood-brain barrier (BBB). SARS-CoV-2-infected cells and animals exhibit age-dependent pathogenesis. In this study, we identified endothelial BACE1 as a critical mediator of BBB disruption and cellular senescence induced by the SARS-CoV-2 spike S1 subunit protein. Increased BACE1 in human brain microvascular endothelial cells (HBMVEC) decreases the levels of tight junction proteins, including ZO-1, occludin, and claudins. Moreover, BACE1 overexpression leads to the accumulation of p16 and p21, typical hallmarks of cellular senescence. Our findings show that the SARS-CoV-2 spike S1 subunit protein upregulated BACE1 expression in HBMVECs, causing endothelial leakage. In addition, the SARS-CoV-2 spike S1 subunit protein induced p16 and p21 expression, indicating BACE1-mediated cellular senescence, confirmed by β-Gal staining in HBMVECs. In conclusion, this study demonstrated that BACE1-mediated endothelial cell damage and senescence may be linked to CVD after COVID-19 infection. Show less

Urokinase-type plasminogen activator (uPA) is a serine proteinase found in excitatory synapses located in the II/III and V cortical layers. The synaptic release of uPA promotes the formation of synaptic contacts and the repair of synapses damaged by various forms of injury, and its abundance is decreased in the synapse of Alzheimer's disease (AD) patients. Inactivation of the Wingless/Int1 (Wnt)-β-catenin pathway plays a central role in the pathogenesis of AD. Soluble amyloid-β (Aβ) prevents the phosphorylation of the low-density lipoprotein receptor-related protein-6 (LRP6), and the resultant inactivation of the Wnt-β-catenin pathway prompts the amyloidogenic processing of the amyloid-β protein precursor (AβPP) and causes synaptic loss. To study the role of neuronal uPA in the pathogenesis of AD. We used in vitro cultures of murine cerebral cortical neurons, a murine neuroblastoma cell line transfected with the APP-695 Swedish mutation (N2asw), and mice deficient on either plasminogen, or uPA, or its receptor (uPAR). We show that uPA activates the Wnt-β-catenin pathway in cerebral cortical neurons by triggering the phosphorylation of LRP6 via a plasmin-independent mechanism that does not require binding of Wnt ligands (Wnts). Our data indicate that uPA-induced activation of the Wnt-β-catenin pathway protects the synapse from the harmful effects of soluble Aβ and prevents the amyloidogenic processing of AβPP by inhibiting the expression of β-secretase 1 (BACE1) and the ensuing generation of Aβ40 and Aβ42 peptides. uPA protects the synapse and antagonizes the inhibitory effect of soluble Aβ on the Wnt-β-catenin pathway by providing an alternative pathway for LRP6 phosphorylation and β-catenin stabilization. Show less

Five new fawcettimine-type Lycopodium alkaloids, hupertimines A-E (1-5), were discovered from the whole plant of Huperzia serrata, along with two known alkaloids, 8α-hydroxyphlegmariurine B (6) and 8β-hydroxyphlegmariurine B (7). The structures of 1-7 were identified through HR-MS, IR, Show less