Plaque formation and the intraneuronal accumulation of β-amyloid in Alzheimer's disease

Impact of long-term deltamethrin exposure on Alzheimer's-related neurodegeneration in rats

In recent years, epidemiological studies have emerged indicating a potential association between chronic exposure to pesticides and the development of chronic neurodegenerative nervous system diseases such as Alzheimer's disease. In this study, we aimed to investigate the potential role of long-term nonfatal exposure to Deltamethrin in spreading this disease. To this end, a range of aspects of brain damage were discussed in rats administered deltamethrin in oral doses of 0.65 mg/kg b.w. and 1.3 mg/kg b.w. for 30 days. The activation of beta-amyloid, the primary component of plaques characteristic of Alzheimer's disease, and the NG2, a type 1 transmembrane protein, was assessed by immunohistochemistry and western blot methods in rat brain. In addition, the expression level of the APP, GFAP, NfL, TNF-alpha, CXCL9, CCL5, and IL-1 alpha genes in deltamethrin-exposed brain tissue was measured using qRT-PCR. In addition, levels of pTau181 and Abeta42 were measured with ELISA. A strong positive immunohistochemical reaction for beta-amyloid was detected in the deltamethrin-exposed brain tissues. A decrease in NG2 immunofluorescence positivity was found in the application groups compared to the control group. It was demonstrated that deltamethrin exposure significantly up-regulated the expressions of APP, GFAP, NfL, TNF-alpha, CXCL9, CCL5, and IL-1 alpha genes, also significantly higher the levels of pTau181 and Abeta42 (pg/ml) in rat brain tissues. This study provides scientific evidence that exposure to chronic doses of deltamethrin may play a positive role in the development of diseases such as Alzheimer's. Future studies should investigate similar projects and expand knowledge on the topic.

Explore peptides extracted from gliadin hydrolysates suppressing BACE1 activity and restraining Aβ protein deposition

Alzheimer's Disease (AD) constitutes approximately 70 % of dementia cases and is the most prevalent form of dementia. Current therapeutic options, including acetylcholinesterase inhibitors and N-methyl d-aspartate (NMDA) receptor antagonists, provide symptomatic relief but do not cure the disease and often come with side effects. The primary pathological features of AD are amyloid plaques and neurofibrillary tangles, with amyloid plaques formed by the abnormal accumulation of Amyloid-β (Aβ). BACE1 (β-site APP-cleaving enzyme 1), a β-secretase, is a key initiator in amyloidosis. Previous research has shown that G-Bro hydrolysate, produced from the bromelain hydrolysis of gliadin, has optimal BACE1 inhibitory efficiency. This study employs G-Bro hydrolysate for nano UHPLC-ESI Q-TOF mass spectrometry to identify peptide fragment sequences and conducts BACE1 inhibition assays to isolate the most effective peptide, VR-peptide. Using the N2a/PS/APP cell model, we explored the impact of chemically synthesized VR-peptide on BACE1 protein expression, the secretion of soluble APP (sAPP), and levels of Aβ and intracellular Aβ1-42. Results demonstrate that VR-peptide achieves a BACE1 inhibitory rate of 63.8 % and reduces BACE1 expression by over 90 % in comparison with untreated N2a/PS/APP cells. It shifts the balance between extracellular Aβ monomers and aggregates, favoring monomer formation and decreasing intracellular Aβ1-42 levels by over 56 %, underscoring its neuroprotective potential. In conclusion, VR-peptide exhibits promise as a BACE1 inhibitor and a preventive agent against Alzheimer's disease. Derived from hydrolyzed cereal foods, it could be effectively paired with a suitable drug delivery system for enhanced neuronal penetration, paving the way for neuroprotective peptide products targeting Alzheimer's disease.

Tailoring MAPK Pathways: New Therapeutic Avenues for Treating Alzheimer's Disease

Alzheimer's disease (AD) is irreversible, progressive, and refractory in nature and is managed very poorly clinically due to very limited treatment outcomes. Unfortunately, most of the multiple clinical trials involving AD patients were unsuccessful in improving the disease prognosis. At the cellular level, many signaling pathways have been proposed to be involved in the sterile/refractory behavior of degenerating neurons in AD. Due to the involvement of p38MAPK in the pathogenesis of Alzheimer's disease, numerous investigations have attempted to determine the beneficial effects of MAPK targeting on memory, inflammatory programming of the brain, and synaptic plasticity. In view of this, various clinical trials involving several MAPK inhibitors (with good safety profiles and few side effects) have yielded positive results in AD patients, suggesting that MAPK targeting may be effective for reducing the pathogenesis of AD, but due to selectivity, dosing, and patient stratification, this aspect still needs further development. In view of their selectivity and off-target effects, only a few MAPK inhibitors have been employed in clinical trials against AD, indicating the scope of their development in this area. Therefore, this study focused on MAPK-based interventions as an upcoming and innovative approach for alleviating AD, with a special emphasis on clinical studies.

Combination of Epigallocatechin-3-Gallate and Tramiprosate Prevent Accumulation of Intracellular Aβ and Dysfunctional Autophagy-Lysosomal Pathway at Earliest Stage of Transdifferentiation of Mesenchymal Stromal Cells into PSEN1 E280A Cholinergic-like Neurons

Familial Alzheimer's disease (FAD) caused by presenilin 1 (PSEN1) E280A induces the aberrant accumulation of intracellular Aβ (iAβ) in cholinergic-like neurons (ChLNs). How early iAβ accumulates in the development of ChLNs is still unknown. Consequently, the timing of appropriate therapeutic approaches against FAD is unclear. To determine the earliest iAβ in PSEN1 E280A ChLNs, flow cytometry and immunofluorescence microscopy were used to follow the development of menstrual mesenchymal stromal cells (MenSCs) into ChLNs (proliferation marker Ki67, cluster of differentiation 73 (CD73), neuronal nuclei (NeuN) marker, choline acetyl transferase (ChAT)), the kinetics of iAβ accumulation, and the simultaneous evaluation of other associated markers (e.g., DJ-1C106-SO3; lysosomes; phosphatidylethanolamine-conjugated microtubule-associated protein 1A/1B light chain 3, LC3-II; cleaved caspase 3 (CC3)) at 0, 1, 3, 5, and 7 days. To reverse the PSEN1 E280A phenotype, we used rapamycin (RAP), verubecestat (VER), compound E (CE), epigallocatechin-3-gallate (EGCG), and tramiprosate (TM) in WT and mutant ChLNs. We found that PSEN1 E280A did not induce significant differences in the NeuN marker and ChAT in MenSCs transitioning to ChLNs. The iAβ accumulates at the earliest cholinergic developmental stage from day 0 (18%, at MenSCs stage) to day 7 (46%, at ChLNs stage), i.e., iAβ increased +156% in mutant compared to WT cells (1-6%). A significant increase in DJ-1C106-SO3 occurs only at day 7 (+250%). While neither CC3 (0-1%) nor lysosomes were different between WT and mutant cells at any time point, a stepwise increase in autophagosome accumulation was observed from day 3 (15%) to day 7 (79%), i.e., +427%, in mutant cells. While neither RAP, VER, nor CE was able to completely reduce all PSEN1 E280A-induced markers in ChLNs, the combination of EGCG and TM was more effective in removing these markers than EGCG and TM alone in PSEN1 E280A ChLNs. Given that this investigation is based on a single menstrual blood sample from WT and PSEN1 E280A, our results should be considered exploratory. Larger sample sizes are needed.

Research progress of extracellular vesicles derived from mesenchymal stem cells in the treatment of neurodegenerative diseases

As the world's population ages, neurodegenerative diseases are becoming more widely acknowledged as serious global health and socioeconomic issues. Although many resources have been devoted to the research of these illnesses, little progress has been made in the creation of novel diagnostic and therapeutic approaches. Extracellular vesicles (EVs) are released by all cell types and contain proteins, microRNAs, mRNAs, and other biologically active molecules. EVs play an important role in intercellular communication as well as in the regulation of neuroinflammation. Determining the mechanisms by which EVs contribute to the pathogenesis of neurodegenerative diseases will aid in the development of new therapeutic approaches and diagnostic tools. Mesenchymal stem cells (MSCs) have been shown in studies to control immunological responses, promote the growth of new brain connections, promote the production of blood vessels, and heal damaged tissues. There is growing evidence that MSCs' ability to treat patients is mostly due to the neurotrophic compounds they secrete through EVs. Since their tiny size allows them to pass through biological barriers and reach injured parts of the central nervous system, MSC-derived extracellular vesicles (MSC-EVs) retain many of the therapeutic qualities of their parent MSCs. This review discusses the role of EVs in neurodegenerative diseases and highlights the potential of MSC-EVs in the treatment of neurodegenerative diseases. The paper also examines the challenges that still need to be overcome and the prospects for using MSC-EVs to treat neurodegenerative illnesses.

Exosomes as Therapeutic and Diagnostic Tools: Advances, Challenges, and Future Directions

Exosomes are tiny extracellular vesicles that are essential for intercellular communication and have shown great promise in the detection and treatment of disease. They are especially useful in the treatment of cancer, cardiovascular conditions, and neurological diseases because of their capacity to transport bioactive substances including proteins, lipids, and nucleic acids. Because of their low immunogenicity, ability to traverse biological barriers, and biocompatibility, exosome-based medicines have benefits over conventional treatments. Large-scale production, standardization of separation methods, possible immunological reactions, and worries about unforeseen biological effects are some of the obstacles that still need to be overcome. Furthermore, there are major barriers to the clinical use of exosomes due to their complex cargo sorting mechanisms and heterogeneity. Future studies should concentrate on enhancing separation and purification procedures, optimizing exosome engineering techniques, and creating plans to reduce immune system modifications. This review examines the most recent developments in exosome-based diagnostics and treatments, identifies current issues, and suggests ways to improve their clinical translation in the future.

Neurobiological role and therapeutic potential of exercise-induced irisin in Alzheimer's disease management

Alzheimer's disease (AD) poses a significant obstacle in today's healthcare landscape, with limited effective treatments. Recent studies have revealed encouraging findings about how exercise-triggered irisin might help slow down the advancement of AD. Irisin, a myokine, released during physical activity, has garnered significant attention for its pleiotropic effects, extending beyond its traditional role in metabolic regulation. This review explores irisin's multifaceted potential in combating AD. Research indicates that irisin enhances synaptic plasticity, crucial for learning and memory, and exhibits neuroprotective properties that may slow AD progression by safeguarding neurons from degeneration. Additionally, irisin's ability to modulate inflammatory responses is significant, as neuroinflammation is a key feature of AD pathology. Irisin may also influence the metabolism and clearance of amyloid-beta plaques and tau tangles, hallmark pathological markers of AD. Furthermore, irisin boosts brain-derived neurotrophic factor expression, vital for neuronal health, and improves insulin glucose regulation, addressing impaired brain insulin signaling observed in AD. Exercise-induced irisin presents a non-pharmacological strategy, leveraging physical activity's brain health benefits. Future research should focus on elucidating irisin's mechanisms and conducting clinical trials to assess its therapeutic efficacy and safety in AD patients. Overall, irisin therapy offers a promising avenue for AD treatment, potentially slowing disease progression and enhancing cognitive function, paving the way for innovative therapeutic strategies in the fight against AD.

Adolescent binge alcohol exposure accelerates Alzheimer's disease-associated basal forebrain neuropathology through proinflammatory HMGB1 signaling

Human studies suggest that heavy alcohol use may be an etiological factor contributing to the development of Alzheimer's disease (AD) neuropathology. Both alcohol use disorder (AUD) and AD share common underlying neuropathology, including proinflammatory high-mobility group box 1 (HMGB1)-mediated neuroimmune signaling and basal forebrain cholinergic neuron degeneration. Adolescent onset of binge drinking represents a significant risk factor for later development of an AUD, and accumulating evidence suggests that adolescent initiation of heavy alcohol use induces HMGB1 signaling and causes degeneration of the basal forebrain cholinergic system that persists into adulthood. However, it is unknown whether adolescent binge drinking confers increased risk for later development of AD-associated neuropathology through persistent induction of proinflammatory HMGB1 neuroimmune signaling. To investigate this question, we first (Experiment 1) assessed AD-associated neuropathology in the post-mortem human basal forebrain of individuals with AUD and an adolescent age of drinking onset relative to age-matched moderate drinking controls (CONs). In Experiment 2, we treated non-transgenic and 5xFAD male and female mice, which overexpress both mutant human APP and PS1, with adolescent intermittent ethanol (AIE; 5.0 g/kg, i.g. 2-days on/2-days off; postnatal day [P]30 - P55), and assessed AD-associated neuropathology in the adult (P100) basal forebrain. In Experiment 3, 5xFAD female mice received AIE treatment followed by glycyrrhizic acid (150 mg/L), an HMGB1 inhibitor, in drinking water from P56 to P100, and basal forebrain tissue was collected on P100 for assessment of AD-associated neuropathology. In the post-mortem human AUD basal forebrain (Experiment 1), we report upregulation of Hmgb1 and the HMGB1 receptors Rage and Tlr4 as well as microglial activation and increased intraneuronal Aβ1-42 accumulation in association with reduced cholinergic neuron marker expression (ChAT). In the 5xFAD mouse model (Experiment 2), AIE accelerated AD-associated induction of Hmgb1 proinflammatory neuroimmune genes, microglial activation, and reductions of ChAT+ basal forebrain cholinergic neurons in the adult female, but not male, basal forebrain. In Experiment 3, post-AIE treatment with glycyrrhizic acid rescued the AIE-induced acceleration of AD-associated increases in proinflammatory HMGB1 neuroimmune signaling, microglial activation, and persistent reductions of basal forebrain cholinergic neurons in adult 5xFAD female mice. Together, these findings suggest that adolescent binge ethanol exposure may represent an underappreciated etiological factor contributing to onset of AD-associated neuropathology in adulthood through HMGB1- mediated neuroimmune signaling.

Lingguizhugan decoction enhances autophagy of Alzheimer's disease via regulating the mTOR/ p70s6K pathway in vivo and in vitro

Introduction

Lingguizhugan decoction (LGZG) has been reported to treat Alzheimer's disease (AD) by anti-inflammatory and transporting amyloid-β (Aβ).

Methods

Using APP/PS1 transgenic mice as in vivo model and gave LGZG decoction by oral gavage. Using Aβ25-35-induced SH-SY5Y cells as in vitro model and then added LGZG medicated serum (LMS) to observe the regulatory effect of LGZG on AD autophagy-related pathways. Morris water maze (MWM) was used to evaluate the mice's learning and memory ability. Mice's hippocampus tissue sections were stained immunohistochemically to observe hippocampal Aβ deposition. Transmission electron microscopy monitored autophagosomes and autolysosomes. Western blot analysis measured protein expression levels of beclin-1, p62 and light chain 3II (LC3 II) and mTOR signaling. Results: LGZG could greatly improve learning and memory ability of APP/PS1 mice, and enhance autophagy in vitro and in vivo. LGZG increased the levels of beclin-1 and LC3 II and decreased the levels of p62.

Conclusion

LGZG enhanced autophagy and showed therapeutic potential in AD by inhibiting mTOR/p70s6K signaling.

4,6-Disubstituted pyrimidine-based microtubule affinity-regulating kinase 4 (MARK4) inhibitors: synthesis, characterization, in-vitro activity and in-silico studies

Introduction

Alzheimer's disease (AD) is a neurodegenerative disorder that significantly impacts the cognitive function and memory of a person. Despite the significant research efforts, the ability to completely prevent or effectively treat AD and its related dementias remains limited. Protein kinases are integral to AD pathology and represent promising targets for therapeutic intervention.

Methods

A series of pyrimidine-based compounds 4-(4-(arylsulfonyl)piperazin-1-yl)-6-(thiophen-3-yl)pyrimidine derivatives (8-14) were synthesized and characterised. ATPase inhibition was carried out against the MARK4 enzyme. Molecular docking and molecular dynamics (MD) simulation at 500 ns was carried out against MARK4 (PDB: 5ES1). The drug-likeness feature and toxicity of the molecules were evaluated using QikProp and other tools.

Results

Compounds were synthesized following a multi-step approach and characterized using multi-nuclear magnetic resonance (1H/13C-NMR) and mass spectrometry. ATPase inhibition assay of the compounds against MARK4 showed an IC50 value in the micromolar (μM) range. The results of the docking studies were consistent with the in-vitro experiments and identified (9) and (14) as the candidates with the highest affinity towards MARK4. MD simulation further supported these results, showing that the binding of ligands stabilises the target protein.

Conclusion

Using experimental and theoretical approaches, we demonstrated that the reported class of pyrimidine derivatives are an excellent starting point for developing the next-generation anti-AD drugs.

Evidence Suggesting That Alzheimer's Disease May Be a Transmissible Disorder

Alzheimer's disease (AD) is characterised by progressive neurodegeneration with the formation of amyloid beta (Aβ) plaques and neurofibrillary tau tangles in the brain parenchyma. The causes of AD have been attributed to a combination of age-related changes within the brain as well as genetic, environmental and lifestyle factors. However, a recent study by Banerjee et al. highlights the possibility that AD may be a transmissible disease and that iatrogenic AD could be environmentally acquired, similar to iatrogenic Creutzfeldt-Jakob disease (iCJD). The study reports that contaminated Aβ in cadaver-derived pituitary growth hormone (c-hGH) therapy, which patients received during childhood inoculation, may accidentally transmit into their brains, triggering neurodegeneration and AD onset in older age. Furthermore, corroborating evidence from various animal model studies and human case reports suggests that AD can be potentially transmissible.

Impact of the Ketogenic Diet on Neurological Diseases: A Review

BACKGROUND

The ketogenic diet (KD), high in fat and low in carbohydrates, was introduced in the 1920s as a non-pharmacological treatment for refractory epilepsy. Although its mechanism of action is not fully understood, beneficial effects have been observed in neurological diseases such as epilepsy, Alzheimer's disease, and Parkinson's disease.

OBJECTIVE

This review examines the impact of the ketogenic diet and its molecular and neuroglial effects as a complementary therapy for neurological diseases.

DISCUSSION

KD is associated with neuroprotective and antioxidant effects that improve mitochondrial function, regulate neurotransmitter flow, and reduce neuroinflammation and oxidative stress. Glial cells play an essential role in the utilization of ketone bodies (KBs) within the central nervous system's metabolism, particularly during ketosis induced by the KD. Thus, the KD represents a broad and promising strategy that involves both neurons and glial cells, with a molecular impact on brain metabolism and neuroinflammatory homeostasis.

CONCLUSION

Multiple molecular mechanisms have been identified to explain the benefits of the KD in neurological diseases; however, further experimental and clinical studies are needed to address various molecular pathways in order to achieve conclusive results.

Cutting-edge Strategies for Overcoming Therapeutic Barriers in Alzheimer's Disease

Alzheimer's disease (AD) remains one of the hardest neurodegenerative diseases to treat due to its enduring cognitive deterioration and memory loss. Despite extensive research, few viable treatment approaches have been found; these are mostly due to several barriers, such as the disease's complex biology, limited pharmaceutical efficacy, and the BBB. This presentation discusses current strategies for addressing these therapeutic barriers to enhance AD treatment. Innovative drug delivery methods including liposomes, exosomes, and nanoparticles may be able to pass the blood-brain barrier and allow medicine to enter specific brain regions. These innovative strategies of medicine distribution reduce systemic side effects by improving absorption. Moreover, the development of disease-modifying treatments that target tau protein tangles, amyloid-beta plaques, and neuroinflammation offers the chance to influence the course of the illness rather than only treat its symptoms. Furthermore, gene therapy and CRISPR-Cas9 technologies have surfaced as potentially groundbreaking methods for addressing the underlying genetic defects associated with AD. Furthermore, novel approaches to patient care may involve the utilization of existing medications having neuroprotective properties, such as those for diabetes and cardiovascular conditions. Furthermore, biomarker research and personalized medicine have made individualized therapy approaches possible, ensuring that patients receive the best care possible based on their unique genetic and molecular profiles.

'Knock down the brain': a nonlinear analysis of electroencephalography to study the effects of sub-concussion in boxers

BACKGROUND AND PURPOSE

Boxing is associated with a high risk of head injuries and increases the likelihood of chronic traumatic encephalopathy. This study explores the effects of sub-concussive impacts on boxers by applying both linear and nonlinear analysis methods to electroencephalogram (EEG) data.

METHODS

Twenty-one boxers were selected (mean ± SD, age 28.38 ± 5.5 years; weight 67.55 ± 8.90 kg; years of activity 6.76 ± 5.45; education 14.19 ± 3.08 years) and divided into 'beginner' and 'advanced' groups. The Montreal Cognitive Assessment and the Frontal Assessment Battery were administered; EEG data were collected in both eyes-open (EO) and eyes-closed (EC) conditions during resting states. Analyses of EEG data included normalized power spectral density (nPSD), power law exponent (PLE), detrended fluctuation analysis and multiscale entropy. Statistical analyses were used to compare the groups.

RESULTS

Significant differences in nPSD and PLE were observed between the beginner and advanced boxers, with advanced boxers showing decreased mean nPSD and PLE (nPSD 4-7 Hz, p = 0.013; 8-13 Hz, p = 0.003; PLE frontal lobe F3 EC, p = 0.010). Multiscale entropy analysis indicated increased entropy at lower frequencies and decreased entropy at higher frequencies in advanced boxers (F3 EC, p = 0.024; occipital lobe O1 EO, p = 0.029; occipital lobe O2 EO, p = 0.036). These changes are similar to those seen in Alzheimer's disease.

CONCLUSION

Nonlinear analysis of EEG data shows potential as a neurophysiological biomarker for detecting the asymptomatic phase of chronic traumatic encephalopathy in boxers. This methodology could help monitor athletes' health and reduce the risk of future neurological injuries in sports.

Minocycline mitigates Aβ and TAU pathology, neuronal dysfunction, and death in the PSEN1 E280A cholinergic-like neurons model of familial Alzheimer's disease

Familial Alzheimer's disease (FAD) presenilin 1 E280A (PSEN1 E280A) is a severe neurological condition due to the loss of cholinergic neurons (ChNs), accumulation of amyloid beta (Aβ), and abnormal phosphorylation of the TAU protein. Up to date, there are no effective therapies available. The need for innovative treatments for this illness is critical. We found that minocycline (MC, 5 μM) was innocuous toward wild-type (WT) PSEN1 ChLNs but significantly (i) reduces the accumulation of intracellular Aβ by -69%, (ii) blocks both abnormal phosphorylation of the protein TAU at residue Ser202/Thr205 by -33% and (iii) phosphorylation of the proapoptotic transcription factor c-JUN at residue Ser63/Ser73 by -25%, (iv) diminishes oxidized DJ-1 at Cys106-SO3 by -29%, (v) downregulates the expression of transcription factor TP53, (vi) BH-3-only protein PUMA, and (vii) cleaved caspase 3 (CC3) by -33, -86, and -78%, respectively, compared with untreated PSEN1 E280A ChLNs. Additionally, MC increases the response to ACh-induced Ca2+ influx by +92% in mutant ChLNs. Oxygen radical absorbance capacity (ORAC) and ferric ion-reducing antioxidant power (FRAP) analysis showed that MC might operate more efficiently as a hydrogen atom transfer agent than a single electron transfer agent. In silico molecular docking analysis predicts that MC binds with high affinity to Aβ (Vina Score -6.6 kcal/mol), TAU (VS -6.5 kcal/mol), and caspase 3 (VS -7.1 kcal/mol). Taken together, our findings suggest that MC demonstrates antioxidant, anti-amyloid, and anti-apoptosis activity and promotes physiological ACh-induced Ca2+ influx in PSEN1 E280A ChLNs. The MC has therapeutic potential for treating early-onset FAD.

Aβ-mediated synaptic glutamate dynamics and calcium dynamics in astrocytes associated with Alzheimer's disease

The accumulation of amyloid β peptide A β is assumed to be one of the main causes of Alzheimer's disease AD . There is increasing evidence that astrocytes are the primary targets of Aβ. Aβ can cause abnormal synaptic glutamate, aberrant extrasynaptic glutamate, and astrocytic calcium dysregulation through astrocyte glutamate transporters facing the synaptic cleft (GLT-syn), astrocyte glutamate transporters facing the extrasynaptic space (GLT-ess), metabotropic glutamate receptors in astrocytes (mGluR), N-methyl-D-aspartate receptors in astrocytes (NMDAR), and glutamatergic gliotransmitter release (Glio-Rel). However, it is difficult to experimentally identify the extent to which each pathway affects synaptic glutamate, extrasynaptic glutamate, and astrocytic calcium signaling. Motivated by these findings, this work established a concise mathematical model of astrocyteCa 2 + dynamics, including the above Aβ-mediated glutamate-related multiple pathways. The model results presented the extent to which five mechanisms acted upon by Aβ affect synaptic glutamate, extrasynaptic glutamate, and astrocytic intracellularCa 2 + signals. We found that GLT-syn is the main pathway through which Aβ affects synaptic glutamate. GLT-ess and Glio-Rel are the main pathways through which A β affects extrasynaptic glutamate. GLT-syn, mGluR, and NMDAR are the main pathways through which Aβ affects astrocytic intracellularCa 2 + signals. Additionally, we discovered a strong, monotonically increasing relationship between the mean glutamate concentration and the meanCa 2 + oscillation amplitude (or frequency). Our results may have therapeutic implications for slowing cell death induced by the combination of glutamate imbalance andCa 2 + dysregulation in AD.

Nitroxyl Hybrids with Curcumin and Stilbene Scaffolds Display Potent Antioxidant Activity, Remodel the Amyloid Beta Oligomer, and Reverse Amyloid Beta-Induced Cytotoxicity

The disorder and heterogeneity of low-molecular-weight amyloid-beta oligomers (AβOs) underlie their participation in multiple modes of cellular dysfunction associated with the etiology of Alzheimer's disease (AD). The lack of specified conformational states in these species complicates efforts to select or design small molecules to targeting discrete pathogenic states. Furthermore, targeting AβOs alone may be therapeutically insufficient, as AD progresses as a multifactorial, self-amplifying cascade. To address these challenges, we have screened the activity of seven new candidates that serve as Paramagnetic Amyloid Ligand (PAL) candidates. PALs are bifunctional small molecules that both remodel the AβO structure and localize a potent antioxidant that mimics the activity of SOD within live cells. The candidates are built from either a stilbene or curcumin scaffold with nitroxyl moiety to serve as catalytic antioxidants. Measurements of PAL AβO binding and remolding along with assessments of bioactivity allow for the extraction of useful SAR information from screening data. One candidate (HO-4450; PMT-307), with a six-membered nitroxyl ring attached to a stilbene ring, displays the highest potency in protecting against cell-derived Aβ. A preliminary low-dose evaluation in AD model mice provides evidence of modest treatment effects by HO-4450. The results for the curcumin PALs demonstrate that the retention of the native curcumin phenolic groups is advantageous to the design of the hybrid PAL candidates. Finally, the PAL remodeling of AβO secondary structures shows a reasonable correlation between a candidate's bioactivity and its ability to reduce the fraction of antiparallel β-strand.

Sex Differences in Blood Accumulation of Neurodegenerative-Related Proteins and Antioxidant Responses to Regular Physical Exercise

Physical activity has been demonstrated to improve cognitive function, thereby preventing/slowing neurodegenerative diseases (NDs). Biological responses to physical activity and vulnerabilities to NDs are emerging to be gender-related. Herein, known ND-associated markers (β-amyloid, tau, α-synuclein), main sex steroid hormones, antioxidant responses, and key gene transcription modulators were evaluated in the blood of physically active and sedentary women and men. In our hands, females presented higher basal erythrocytes β-amyloid and α-synuclein amounts than males. Regular physical activity was able to significantly reduce the erythrocyte content of β-amyloid in females and the tau levels in males, suggesting that these differences may be mediated by organizational actions of sex steroid hormones during development. Furthermore, despite a comparable plasma antioxidant capability (AOC) between males and females, in the latter group, physical activity significantly enhances AOC versus peroxynitrite radicals only. Finally, regular physical activity modulated the levels of transcription factor Nrf2 in erythrocytes, as well as the plasma concentration of the microRNA miR-195 and miR-153, suggesting the promotion of antioxidant/autophagic processes associated with ND-related proteins. Overall, these results could shed light on how cerebral adaptations to physical activity differ between males and females, especially with regard to blood accumulation of ND proteins and mechanisms of antioxidant responses to regular exercise.

Interleukin-6 deficiency reduces neuroinflammation by inhibiting the STAT3-cGAS-STING pathway in Alzheimer's disease mice

BACKGROUND

The Interleukin-6 (IL-6)-signal transducer and activator of transcription 3 (STAT3) pathway, along with the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, are critical contributors to neuroinflammation in Alzheimer's disease (AD). Although previous research outside the context of AD has indicated that the IL-6-STAT3 pathway may regulate the cGAS-STING pathway, the exact molecular mechanisms through which IL-6-STAT3 influences cGAS-STING in AD are still not well understood.

METHODS

The activation of the IL-6-STAT3 and cGAS-STING pathways in the hippocampus of 5×FAD and WT mice was analyzed using WB and qRT-PCR. To explore the effects of IL-6 deficiency, Il6+/- mice were crossed with 5×FAD mice, and the subsequent impact on hippocampal STAT3 pathway activity, cGAS-STING pathway activation, amyloid pathology, neuroinflammation, and cognitive function was evaluated through WB, qRT-PCR, immunohistochemistry, ThS staining, ELISA, and behavioral tests. The regulatory role of STAT3 in the transcription of the Cgas and Sting genes was further validated using ChIP-seq and ChIP-qPCR on hippocampal tissue from 5×FAD and Il6-/-: 5×FAD mice. Additionally, in the BV2 microglial cell line, the impact of STAT3 activation on the transcriptional regulation of Cgas and Sting genes, as well as the production of inflammatory mediators, was examined through WB and qRT-PCR.

RESULTS

We observed marked activation of the IL-6-STAT3 and cGAS-STING pathways in the hippocampus of AD mice, which was attenuated in the absence of IL-6. IL-6 deficiency reduced beta-amyloid deposition and neuroinflammation in the hippocampus of AD mice, contributing to cognitive improvements. Further analysis revealed that STAT3 directly regulates the transcription of both the Cgas and Sting genes. These findings suggest a potential mechanism involving the STAT3-cGAS-STING pathway, wherein IL-6 deficiency mitigates neuroinflammation in AD mice by modulating this pathway.

CONCLUSION

These findings indicate that the STAT3-cGAS-STING pathway is critical in mediating neuroinflammation associated with AD and may represent a potential therapeutic target for modulating this inflammatory process in AD.

Somatostatin: Linking Cognition and Alzheimer Disease to Therapeutic Targeting

Over 4 decades of research support the link between Alzheimer disease (AD) and somatostatin [somatotropin-releasing inhibitory factor (SRIF)]. SRIF and SRIF-expressing neurons play an essential role in brain function, modulating hippocampal activity and memory formation. Loss of SRIF and SRIF-expressing neurons in the brain rests at the center of a series of interdependent pathological events driven by amyloid-β peptide (Aβ), culminating in cognitive decline and dementia. The connection between the SRIF and AD further extends to the neuropsychiatric symptoms, seizure activity, and inflammation, whereas preclinical AD investigations show SRIF or SRIF receptor agonist administration capable of enhancing cognition. SRIF receptor subtype-4 activation in particular presents unique attributes, with the potential to mitigate learning and memory decline, reduce comorbid symptoms, and enhance enzymatic degradation of Aβ in the brain. Here, we review the links between SRIF and AD along with the therapeutic implications. SIGNIFICANCE STATEMENT: Somatostatin and somatostatin-expressing neurons in the brain are extensively involved in cognition. Loss of somatostatin and somatostatin-expressing neurons in Alzheimer disease rests at the center of a series of interdependent pathological events contributing to cognitive decline and dementia. Targeting somatostatin-mediated processes has significant therapeutic potential for the treatment of Alzheimer disease.

MAD-microbial (origin of) Alzheimer's disease hypothesis: from infection and the antimicrobial response to disruption of key copper-based systems

Microbes have been suspected to cause Alzheimer's disease since at least 1908, but this has generally remained unpopular in comparison to the amyloid hypothesis and the dominance of Aβ and Tau. However, evidence has been accumulating to suggest that these earlier theories are but a manifestation of a common cause that can trigger and interact with all the major molecular players recognized in AD. Aβ, Tau and ApoE, in particular appear to be molecules with normal homeostatic functions but also with alternative antimicrobial functions. Their alternative functions confer the non-immune specialized neuron with some innate intracellular defenses that appear to be re-appropriated from their normal functions in times of need. Indeed, signs of infection of the neurons by biofilm-forming microbial colonies, in synergy with herpes viruses, are evident from the clinical and preclinical studies we discuss. Furthermore, we attempt to provide a mechanistic understanding of the AD landscape by discussing the antimicrobial effect of Aβ, Tau and ApoE and Lactoferrin in AD, and a possible mechanistic link with deficiency of vital copper-based systems. In particular, we focus on mitochondrial oxidative respiration via complex 4 and ceruloplasmin for iron homeostasis, and how this is similar and possibly central to neurodegenerative diseases in general. In the case of AD, we provide evidence for the microbial Alzheimer's disease (MAD) theory, namely that AD could in fact be caused by a long-term microbial exposure or even long-term infection of the neurons themselves that results in a costly prolonged antimicrobial response that disrupts copper-based systems that govern neurotransmission, iron homeostasis and respiration. Finally, we discuss potential treatment modalities based on this holistic understanding of AD that incorporates the many separate and seemingly conflicting theories. If the MAD theory is correct, then the reduction of microbial exposure through use of broad antimicrobial and anti-inflammatory treatments could potentially alleviate AD although this requires further clinical investigation.

Development of quantitative detection methods for four Alzheimer's disease specific biomarker panels using electrochemical immunosensors based on enzyme immunoassay

Accurate and timely diagnosis of Alzheimer's disease (AD) is necessary to maximize the effectiveness of treatment and using biomarkers for diagnosis is attracting attention as a minimally invasive method with few side effects. Electrochemical immunosensor (EI) is a method that is in the spotlight in the medical and bioanalytical fields due to its portability and field usability. Here, we quantified four AD specific biomarkers using EIs based on enzyme immunoassay. We selected and developed quantitative methods for the biomarkers using screen-printed gold electrodes. For three biomarkers, quantification was performed using competition immunoassays in which antigen-antibody premix mixtures were applied to antigen-immobilized electrodes and the limit of detection (LOD) values were secured, 1.20 ng/ml, 1.30 ng/ml, and 1.74 ng/ml, respectively. For the other, a sandwich immunoassay using antibody pair was selected for quantification and LOD was also achieved as 0.077 ng/ml. All four biomarkers in buffer samples were successfully quantified and reliable R2 values were obtained, and reliable calibration curves were secured for three biomarkers in spiked human serum samples. The immunosensors developed and will be optimized are expected to be used in various fields, including detection of biomarkers for not only AD but also related diseases.

The epigenetic modification of DNA methylation in neurological diseases

Methylation, a key epigenetic modification, is essential for regulating gene expression and protein function without altering the DNA sequence, contributing to various biological processes, including gene transcription, embryonic development, and cellular functions. Methylation encompasses DNA methylation, RNA methylation and histone modification. Recent research indicates that DNA methylation is vital for establishing and maintaining normal brain functions by modulating the high-order structure of DNA. Alterations in the patterns of DNA methylation can exert significant impacts on both gene expression and cellular function, playing a role in the development of numerous diseases, such as neurological disorders, cardiovascular diseases as well as cancer. Our current understanding of the etiology of neurological diseases emphasizes a multifaceted process that includes neurodegenerative, neuroinflammatory, and neurovascular events. Epigenetic modifications, especially DNA methylation, are fundamental in the control of gene expression and are critical in the onset and progression of neurological disorders. Furthermore, we comprehensively overview the role and mechanism of DNA methylation in in various biological processes and gene regulation in neurological diseases. Understanding the mechanisms and dynamics of DNA methylation in neural development can provide valuable insights into human biology and potentially lead to novel therapies for various neurological diseases.

Comprehending the Efficacy of Whitlock's Caffeine-Pincered Molecular Tweezer on β-Amyloid Aggregation

Alzheimer's disease (AD) stands as one of the most prevalent neurodegenerative conditions, leading to cognitive impairment, with no cure and preventive measures. Misfolding and aberrant aggregation of amyloid-β (Aβ) peptides are believed to be the underlying cause of AD. These amyloid aggregates culminate in the development of toxic Aβ oligomers and subsequent accumulation of β-amyloid plaques amidst neuronal cells in the brain, marking the hallmarks of AD. Drug development for the potentially curative treatment of Alzheimer's is, therefore, a tremendous challenge for the scientific community. In this study, we investigate the potency of Whitlock's caffeine-armed molecular tweezer in combating the deleterious effects of Aβ aggregation, with special emphasis on the seven residue Aβ16-22 fragment. Extensive all-atom molecular dynamics simulations are conducted to probe the various structural and conformational transitions of the peptides in an aqueous medium in both the presence and absence of tweezers. To explore the specifics of peptide-tweezer interactions, radial distribution functions, contact number calculations, binding free energies, and 2-D kernel density plots depicting the variation of distance-angle between the aromatic planes of the peptide-tweezer pair are computed. The central hydrophobic core, particularly the aromatic Phe residues, is crucial in the development of harmful amyloid oligomers. Notably, all analyses indicate reduced interpeptide interactions in the presence of the tweezer, which is attributed to the tweezer-Phe aromatic interaction. Upon increasing the tweezer concentration, the residues of the peptide are further encased in a hydrophobic environment created by the self-aggregating tweezer cluster, leading to the segregation of the peptide residues. This is further aided by the weakening of interstrand hydrogen bonding between the peptides, thereby impeding their self-aggregation and preventing the formation of neurotoxic β-amyloid. Furthermore, the study also highlights the efficacy of the molecular tweezer in destabilizing preformed amyloid fibrils as well as hindering the aggregation of the full-length Aβ1-42 peptide.

Strategies for measuring concentrations and forms of amyloid-β peptides

Alzheimer's disease (AD) is affecting more and more people worldwide without the effective treatment, while the existed pathological mechanism has been confirmed barely useful in the treatment. Amyloid-β peptide (Aβ), a main component of senile plaque, is regarded as the most promising target in AD treatment. Aβ clearance from AD brain seems to be a reliably therapeutic strategy, as the two exited drugs, GV-971 and aducanumab, are both developed based on it. However, doubt still exists. To exhaustive expound on the pathological mechanism of Aβ, rigorous analyses on the concentrations and aggregation forms are essential. Thus, it is attracting broad attention these years. However, most of the sensors have not been used in pathological studies, as the lack of the bridge between analytical chemist and pathologists. In this review, we made a brief introduce on Aβ-related pathological mechanism included in β-amyloid hypothesis to elucidate the detection conditions of sensor methods. Furthermore, a summary of the sensor methods was made, which were based on Aβ concentrations and form detections that have been developed in the past 10 years. As the greatest number of the sensors were built on fluorescent spectroscopy, electrochemistry, and Roman spectroscopy, detailed elucidation on them was made. Notably, the aggregation process is another important factor in revealing the progress of AD and developing the treatment methods, so the sensors on monitoring Aβ aggregation processes were also summarized.

A Comprehensive Exploration of the Multifaceted Neuroprotective Role of Cannabinoids in Alzheimer's Disease across a Decade of Research

Alzheimer's disease (AD), a progressive neurodegenerative disorder, manifests through dysregulation of brain function and subsequent loss of bodily control, attributed to β-amyloid plaque deposition and TAU protein hyperphosphorylation and aggregation, leading to neuronal death. Concurrently, similar cannabinoids to the ones derived from Cannabis sativa are present in the endocannabinoid system, acting through receptors CB1R and CB2R and other related receptors such as Trpv-1 and GPR-55, and are being extensively investigated for AD therapy. Given the limited efficacy and adverse effects of current available treatments, alternative approaches are crucial. Therefore, this review aims to identify effective natural and synthetic cannabinoids and elucidate their beneficial actions for AD treatment. PubMed and Scopus databases were queried (2014-2024) using keywords such as "Alzheimer's disease" and "cannabinoids". The majority of natural (Δ9-THC, CBD, AEA, etc.) and synthetic (JWH-133, WIN55,212-2, CP55-940, etc.) cannabinoids included showed promise in improving memory, cognition, and behavioral symptoms, potentially via pathways involving antioxidant effects of selective CB1R agonists (such as the BDNF/TrkB/Akt pathway) and immunomodulatory effects of selective CB2R agonists (TLR4/NF-κB p65 pathway). Combining anticholinesterase properties with a cannabinoid moiety may enhance therapeutic responses, addressing cholinergic deficits of AD brains. Thus, the positive outcomes of the vast majority of studies discussed support further advancing cannabinoids in clinical trials for AD treatment.

Delineation of the role of G6PD in Alzheimer's disease and potential enhancement through microfluidic and nanoparticle approaches

Alzheimer's disease (AD) is a neurodegenerative pathologic entity characterized by the abnormal presence of tau and macromolecular Aβ deposition that leads to the degeneration or death of neurons. In addition to that, glucose-6-phosphate dehydrogenase (G6PD) has a multifaceted role in the process of AD development, where it can be used as both a marker and a target. G6PD activity is dysregulated due to its contribution to oxidative stress, neuroinflammation, and neuronal death. In this context, the current review presents a vivid depiction of recent findings on the relationship between AD progression and changes in the expression or activity of G6PD. The efficacy of the proposed G6PD-based therapeutics has been demonstrated in multiple studies using AD mouse models as representative animal model systems for cognitive decline and neurodegeneration associated with this disease. Innovative therapeutic insights are made for the boosting of G6PD activity via novel innovative nanotechnology and microfluidics tools in drug administration technology. Such approaches provide innovative methods of surpassing the blood-brain barrier, targeting step-by-step specific neural pathways, and overcoming biochemical disturbances that accompany AD. Using different nanoparticles loaded with G6DP to target specific organs, e.g., G6DP-loaded liposomes, enhances BBB penetration and brain distribution of G6DP. Many nanoparticles, which are used for different purposes, are briefly discussed in the paper. Such methods to mimic BBB on organs on-chip offer precise disease modeling and drug testing using microfluidic chips, requiring lower sample amounts and producing faster findings compared to conventional techniques. There are other contributions to microfluid in AD that are discussed briefly. However, there are some limitations accompanying microfluidics that need to be worked on to be used for AD. This study aims to bridge the gap in understanding AD with the synergistic use of promising technologies; microfluid and nanotechnology for future advancements.

Exploring the most promising anti - Depressant drug targeting Microtubule Affinity Receptor Kinase 4 involved in Alzheimer's Disease through molecular docking and molecular dynamics simulation

Alzheimer's Disease (AD) is the prevailing type of neurodegenerative illness, characterised by the accumulation of amyloid beta plaques. The symptoms associated with AD are memory loss, emotional variability, and a decline in cognitive functioning. To date, the pharmaceuticals currently accessible in the marketplace are limited to symptom management. According to several research, antidepressants have demonstrated potential efficacy in the management of AD. In this particular investigation, a total of 24 anti-depressant medications were selected as ligands, while the Microtubule Affinity Receptor Kinase 4 (MARK4) protein was chosen as the focal point of our study. The selection of MARK4 was based on its known involvement in the advancement of AD and other types of malignancies, rendering it a highly prospective target for therapeutic interventions. The initial step involved doing ADMET analysis, which was subsequently followed by molecular docking of 24 drugs. This was succeeded by molecular dynamics simulation and molecular mechanics generalised Born surface area (MMGBSA) calculations. Upon conducting molecular docking experiments, it has been determined that the binding affinities observed fall within the range of -5.5 kcal/mol to -9.0 kcal/mol. In this study, we selected six anti-depressant compounds (CID ID - 4184, 2771, 4205, 5533, 4543, and 2160) based on their binding affinities, which were determined to be -9.0, -8.7, -8.4, -8.3, -8.2, and -8.2, respectively. Molecular dynamics simulations were conducted for all six drugs, with donepezil serving as the control drug. Various analyses were performed, including basic analysis and post-trajectory analysis such as free energy landscape (FEL), polarizable continuum model (PCM), and MMGBSA calculations. Based on the findings from molecular dynamics simulations and the MMGBSA analysis, it can be inferred that citalopram and mirtazapine exhibit considerable potential as anti-depressant agents. Consequently, these compounds warrant further investigation through in vitro and in vivo investigations in the context of treating AD.

Disruption of sphingomyelin synthase 2 gene alleviates cognitive impairment in a mouse model of Alzheimer's disease

The membrane raft accommodates the key enzymes synthesizing amyloid β (Aβ). One of the two characteristic components of the membrane raft, cholesterol, is well known to promote the key enzymes that produce amyloid-β (Aβ) and exacerbate Alzheimer's disease (AD) pathogenesis. Given that the raft is a physicochemical platform for the sound functioning of embedded bioactive proteins, the other major lipid component sphingomyelin may also be involved in AD. Here we knocked out the sphingomyelin synthase 2 gene (SMS2) in 3xTg AD model mice by hybridization, yielding SMS2KO mice (4S mice). The novel object recognition test in 9/10-month-old 4S mice showed that cognitive impairment in 3xTg mice was alleviated by SMS2KO, though performance in the Morris water maze (MWM) was not improved. The tail suspension test detected a depressive trait in 4S mice, which may have hindered the manifestation of performance in the wet, stressful environment of MWM. In the hippocampal CA1, hyperexcitability in 3xTg was also found alleviated by SMS2KO. In the hippocampal dentate gyrus of 4S mice, the number of neurons positive with intracellular Aβ or its precursor proteins, the hallmark of young 3xTg mice, is reduced to one-third, suggesting an SMS2KO-led suppression of syntheses of those peptides in the dentate gyrus. Although we previously reported that large-conductance calcium-activated potassium (BK) channels are suppressed in 3xTg mice and their recovery relates to cognitive amelioration, no changes occurred by hybridization. Sphingomyelin in the membrane raft may serve as a novel target for AD drugs.

Revisiting the role of phospholipases in alzheimer's: crosstalk with processed food

Phospholipases such as phospholipase-A, phospholipase-B, phospholipase-C and phospholipase-D are important functional enzymes of the cell membrane responsible for a variety of functions such as signal transduction, production of lipid mediators, metabolite digestion and playing a pathological role in central nervous system diseases. Phospholipases have shown an association with Alzheimer's disease and these enzymes have found a correlation with several metabolic pathways that can lead to the activation of inflammatory signals via astrocytes and microglial cells. We also highlighted unhealthy practices like smoking and consuming processed foods, rich in nitroso compounds and phosphatidic acid, which contribute to neuronal damage in AD through phospholipases. A few therapeutic approaches such as the use of inhibitors of phospholipase-D,phospholipase A2 as well as autophagy-mediated inhibition have been discussed to control the onset of AD. This paper serves as a crosstalk between phospholipases and their role in neurodegenerative pathways as well as their influence on other biomolecules of lipid membranes, which are acquired through unhealthy diets and possible methods to treat these anomalies occurring due to their metabolic disorder involving phospholipases acting as major signaling molecules.

Pyrogallol intermediates elicit beta-amyloid secretion via radical formation and alterations in intracellular trafficking, distinct from pyrogallol-generated superoxide

This study unveils a novel role of pyrogallol (PG), a recognized superoxide generator, in inducing beta-amyloid (Aβ) secretion in an Alzheimer's disease (AD) cellular model. Contrary to expectations, the analysis of dihydroethidium fluorescence and UV-VIS spectrum scanning reveals that Aβ secretion arises from PG reaction intermediates rather than superoxide or other by-products. Investigation into Aβ secretion mechanisms identifies dynasore-dependent endocytosis and BFA-dependent exocytosis as independent pathways, regulated by tiron, tempol, and superoxide dismutase. Cell-type specificity is observed, with 293sw cells showing both pathways, while H4sw cells and primary astrocytes from an AD animal model exclusively exhibit the Aβ exocytosis pathway. This exploration contributes to understanding PG's chemical reactions and provides insights into the interplay between environmental factors, free radicals, and AD, linking occupational PG exposure to AD risk as reported in the literature.

Extracellular vesicles as nanotheranostic platforms for targeted neurological disorder interventions

Central Nervous System (CNS) disorders represent a profound public health challenge that affects millions of people around the world. Diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and traumatic brain injury (TBI) exemplify the complexities and diversities that complicate their early detection and the development of effective treatments. Amid these challenges, the emergence of nanotechnology and extracellular vesicles (EVs) signals a new dawn for treating and diagnosing CNS ailments. EVs are cellularly derived lipid bilayer nanosized particles that are pivotal in intercellular communication within the CNS and have the potential to revolutionize targeted therapeutic delivery and the identification of novel biomarkers. Integrating EVs with nanotechnology amplifies their diagnostic and therapeutic capabilities, opening new avenues for managing CNS diseases. This review focuses on examining the fascinating interplay between EVs and nanotechnology in CNS theranostics. Through highlighting the remarkable advancements and unique methodologies, we aim to offer valuable perspectives on how these approaches can bring about a revolutionary change in disease management. The objective is to harness the distinctive attributes of EVs and nanotechnology to forge personalized, efficient interventions for CNS disorders, thereby providing a beacon of hope for affected individuals. In short, the confluence of EVs and nanotechnology heralds a promising frontier for targeted and impactful treatments against CNS diseases, which continue to pose significant public health challenges. By focusing on personalized and powerful diagnostic and therapeutic methods, we might improve the quality of patients.

Neuritic Plaques - Gateways to Understanding Alzheimer's Disease

Extracellular deposits of amyloid-β (Aβ) in the form of plaques are one of the main pathological hallmarks of Alzheimer's disease (AD). Over the years, many different Aβ plaque morphologies such as neuritic plaques, dense cored plaques, cotton wool plaques, coarse-grain plaques, and diffuse plaques have been described in AD postmortem brain tissues, but correlation of a given plaque type with AD progression or AD symptoms is not clear. Furthermore, the exact trigger causing the development of one Aβ plaque morphological subtype over the other is still unknown. Here, we review the current knowledge about neuritic plaques, a subset of Aβ plaques surrounded by swollen or dystrophic neurites, which represent the most detrimental and consequential Aβ plaque morphology. Neuritic plaques have been associated with local immune activation, neuronal network dysfunction, and cognitive decline. Given that neuritic plaques are at the interface of Aβ deposition, tau aggregation, and local immune activation, we argue that understanding the exact mechanism of neuritic plaque formation is crucial to develop targeted therapies for AD.

Combination of Tramiprosate, Curcumin, and SP600125 Reduces the Neuropathological Phenotype in Familial Alzheimer Disease PSEN1 I416T Cholinergic-like Neurons

Familial Alzheimer's disease (FAD) is a complex and multifactorial neurodegenerative disorder for which no curative therapies are yet available. Indeed, no single medication or intervention has proven fully effective thus far. Therefore, the combination of multitarget agents has been appealing as a potential therapeutic approach against FAD. Here, we investigated the potential of combining tramiprosate (TM), curcumin (CU), and the JNK inhibitor SP600125 (SP) as a treatment for FAD. The study analyzed the individual and combined effects of these two natural agents and this pharmacological inhibitor on the accumulation of intracellular amyloid beta iAβ; hyperphosphorylated protein TAU at Ser202/Thr205; mitochondrial membrane potential (ΔΨm); generation of reactive oxygen species (ROS); oxidized protein DJ-1; proapoptosis proteins p-c-JUN at Ser63/Ser73, TP53, and cleaved caspase 3 (CC3); and deficiency in acetylcholine (ACh)-induced transient Ca2+ influx response in cholinergic-like neurons (ChLNs) bearing the mutation I416T in presenilin 1 (PSEN1 I416T). We found that single doses of TM (50 μM), CU (10 μM), or SP (1 μM) were efficient at reducing some, but not all, pathological markers in PSEN 1 I416T ChLNs, whereas a combination of TM, CU, and SP at a high (50, 10, 1 μM) concentration was efficient in diminishing the iAβ, p-TAU Ser202/Thr205, DJ-1Cys106-SO3, and CC3 markers by -50%, -75%, -86%, and -100%, respectively, in PSEN1 I417T ChLNs. Although combinations at middle (10, 2, 0.2) and low (5, 1, 0.1) concentrations significantly diminished p-TAU Ser202/Thr205, DJ-1Cys106-SO3, and CC3 by -69% and -38%, -100% and -62%, -100% and -62%, respectively, these combinations did not alter the iAβ compared to untreated mutant ChLNs. Moreover, a combination of reagents at H concentration was able to restore the dysfunctional ACh-induced Ca2+ influx response in PSEN 1 I416T. Our data suggest that the use of multitarget agents in combination with anti-amyloid (TM, CU), antioxidant (e.g., CU), and antiapoptotic (TM, CU, SP) actions might be beneficial for reducing iAβ-induced ChLN damage in FAD.

Risk factors and metabolomics of mild cognitive impairment in type 2 diabetes mellitus

Objective: This study aimed to explore the risk factors, metabolic characteristics, and potential biomarkers of mild cognitive impairment in type 2 diabetes mellitus (T2DM-MCI) and to provide potential evidence for the diagnosis, prevention, and treatment of mild cognitive impairment (MCI) in patients with type 2 diabetes mellitus (T2DM). Methods: A total of 103 patients with T2DM were recruited from the Endocrinology Department of The Second Affiliated Hospital of Dalian Medical University for inclusion in the study. The Montreal Cognitive Assessment (MoCA) was utilized to evaluate the cognitive functioning of all patients. Among them, 50 patients were categorized into the T2DM-MCI group (MoCA score < 26 points), while 53 subjects were classified into the T2DM without cognitive impairment (T2DM-NCI) group (MoCA score ≥ 26 points). Serum samples were collected from the subjects, and metabolomics profiling data were generated by Ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS). These groups were analyzed to investigate the differences in expression of small molecule metabolites, metabolic pathways, and potential specific biomarkers. Results: Comparison between the T2DM-MCI group and T2DM-NCI group revealed significant differences in years of education, history of insulin application, insulin resistance index, insulin-like growth factor-binding protein-3 (IGFBP-3), and creatinine levels. Further binary logistic regression analysis of the variables indicated that low educational level and low serum IGFBP-3 were independent risk factor for T2DM-MCI. Metabolomics analysis revealed that differential expression of 10 metabolites between the T2DM-MCI group and T2DM-NCI group (p < 0.05 and FDR<0.05, VIP>1.5). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathway analysis revealed that fatty acid degradation was the most significant pathway. Receiver operating characteristic (ROC) analysis shows that lysophosphatidylcholine (LPC) 18:0 exhibited greater diagnostic efficiency. Conclusion: This study revealed that a shorter duration of education and lower serum IGFBP-3 levels are independent risk factors for T2DM-MCI. Serum metabolites were found to be altered in both T2DM-MCI and T2DM-NCI groups. T2DM patients with or without MCI can be distinguished by LPC 18:0. Abnormal lipid metabolism plays a significant role in the development of MCI in T2DM patients.

The bidirectional links between coronavirus disease 2019 and Alzheimer's disease

Coronavirus disease 2019 (COVID-19) can be a critical disease, particularly in the elderly and those with comorbidities. Patients with Alzheimer's disease are more vulnerable to COVID-19 consequences. The latest results have indicated some common risk factors for both diseases. An understanding of the pathological link between COVID-19 and Alzheimer's disease will help develop timely strategies to treat both diseases. This review explores the bidirectional links between COVID-19 and Alzheimer's disease.

Role of ferroptosis pathways in neuroinflammation and neurological disorders: From pathogenesis to treatment

Ferroptosis is a newly discovered non-apoptotic and iron-dependent type of cell death. Ferroptosis mainly takes place owing to the imbalance of anti-oxidation and oxidation in the body. It is regulated via a number of factors and pathways both inside and outside the cell. Ferroptosis is closely linked with brain and various neurological disorders (NDs). In the human body, the brain contains the highest levels of polyunsaturated fatty acids, which are known as lipid peroxide precursors. In addition, there is also a connection of glutathione depletion and lipid peroxidation with NDs. There is growing evidence regarding the possible link between neuroinflammation and multiple NDs, such as Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, Huntington's disease, and stroke. Recent studies have demonstrated that disruptions of lipid reactive oxygen species (ROS), glutamate excitatory toxicity, iron homeostasis, and various other manifestations linked with ferroptosis can be identified in various neuroinflammation-mediated NDs. It has also been reported that damage-associated molecular pattern molecules including ROS are generated during the events of ferroptosis and can cause glial activation via activating neuroimmune pathways, which subsequently leads to the generation of various inflammatory factors that play a role in various NDs. This review summarizes the regulation pathways of ferroptosis, the link between ferroptosis as well as inflammation in NDs, and the potential of a range of therapeutic agents that can be used to target ferroptosis and inflammation in the treatment of neurological disorders.

A Novel Drosophila Model of Alzheimer's Disease to Study Aβ Proteotoxicity in the Digestive Tract

Amyloid-β (Aβ) proteotoxicity is associated with Alzheimer's disease (AD) and is caused by protein aggregation, resulting in neuronal damage in the brain. In the search for novel treatments, Drosophila melanogaster has been extensively used to screen for anti-Aβ proteotoxic agents in studies where toxic Aβ peptides are expressed in the fly brain. Since drug molecules often are administered orally there is a risk that they fail to reach the brain, due to their inability to cross the brain barrier. To circumvent this problem, we have designed a novel Drosophila model that expresses the Aβ peptides in the digestive tract. In addition, a built-in apoptotic sensor provides a fluorescent signal from the green fluorescent protein as a response to caspase activity. We found that expressing different variants of Aβ1-42 resulted in proteotoxic phenotypes such as reduced longevity, aggregate deposition, and the presence of apoptotic cells. Taken together, this gut-based Aβ-expressing fly model can be used to study the mechanisms behind Aβ proteotoxicity and to identify different substances that can modify Aβ proteotoxicity.

Bridging neurotrophic factors and bioactive peptides to Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder. As the demographic shifting towards an aging population, AD has emerged as a prominent public health concern. The pathogenesis of AD is complex, and there are no effective treatment methods for AD until now. In recent years, neurotrophic factors and bioactive peptides including brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), irisin, melatonin, have been discovered to exert neuroprotective functions for AD. Bioactive peptides can be divided into two categories based on their sources: endogenous and exogenous. This review briefly elaborates on the pathogenesis of AD and analyzes the regulatory effects of endogenous and exogenous peptides on the pathogenesis of AD, thereby providing new therapeutic targets for AD and a theoretical basis for the application of bioactive peptides as adjunctive therapies for AD.

Remote Associations Between Tau and Cortical Amyloid-β Are Stage-Dependent

Background

Histopathologic studies of Alzheimer's disease (AD) suggest that extracellular amyloid-β (Aβ) plaques promote the spread of neurofibrillary tau tangles. However, these two proteinopathies initiate in spatially distinct brain regions, so how they interact during AD progression is unclear.

Objective

In this study, we utilized Aβ and tau positron emission tomography (PET) scans from 572 older subjects (476 healthy controls (HC), 14 with mild cognitive impairment (MCI), 82 with mild AD), at varying stages of the disease, to investigate to what degree tau is associated with cortical Aβ deposition.

Methods

Using multiple linear regression models and a pseudo-longitudinal ordering technique, we investigated remote tau-Aβ associations in four pathologic phases of AD progression based on tau spread: 1) no-tau, 2) pre-acceleration, 3) acceleration, and 4) post-acceleration.

Results

No significant tau-Aβ association was detected in the no-tau phase. In the pre-acceleration phase, the earliest stage of tau deposition, associations emerged between regional tau in medial temporal lobe (MTL) (i.e., entorhinal cortex, parahippocampal gyrus) and cortical Aβ in lateral temporal lobe regions. The strongest tau-Aβ associations were found in the acceleration phase, in which tau in MTL regions was strongly associated with cortical Aβ (i.e., temporal and frontal lobes regions). Strikingly, in the post-acceleration phase, including 96% of symptomatic subjects, tau-Aβ associations were no longer significant.

Conclusions

The results indicate that associations between tau and Aβ are stage-dependent, which could have important implications for understanding the interplay between these two proteinopathies during the progressive stages of AD.

Investigating Bacopa monnieri L. Therapeutic Potential for the Treatment of Neurological Diseases

The popular perennial creeping plant known as Bacopa monnieri (also known as Brahmi) is being utilized in the Indian Ayurvedic medicine practice. It has a variety of bioactive phytoconstituents that have been used therapeutically to treat a number of serious illnesses. Ancient Vedic scholars used this herb because of its pharmacological effects, particularly as a nerve booster and nootropic supporter. However, it is vital to comprehend the active phytochemical components of Bacopa monnieri extract (BME) and their molecular mechanisms in order to better grasp the effect of BME on neurological illnesses and diseases. Understanding its active phytochemical constituents and their molecular processes is essential. Numerous clinical investigations indicated that BME may have neuroprotective benefits, so it is worthwhile to re-evaluate this wellknown plant. Here, we focused on neurological problems as we examined the pharmacological and phytochemical characteristics of BME. For their effective usage in neuroprotection and cognition, many clinical concerns and the synergistic potential of Bacopa extract have been investigated. Alzheimer's disease is a neurological condition caused by the production of reactive oxygen species, which also causes amyloid-beta (Aβ) and tau protein aggregation and increases neuro-inflammation and neurotoxicity. Our review offers a more indepth molecular understanding of the neuroprotective functions of BME, which can also be connected to its therapeutic management of neurological illnesses and cognitive-improving effects.

Reduced lysosomal activity and increased amyloid beta accumulation in silica-coated magnetic nanoparticles-treated microglia

Nanoparticles have been used in neurological research in recent years because of their blood-brain barrier penetration activity. However, their potential neuronanotoxicity remains a concern. In particular, microglia, which are resident phagocytic cells, are mainly exposed to nanoparticles in the brain. We investigated the changes in lysosomal function in silica-coated magnetic nanoparticles containing rhodamine B isothiocyanate dye [MNPs@SiO2(RITC)]-treated BV2 murine microglial cells. In addition, we analyzed amyloid beta (Aβ) accumulation and molecular changes through the integration of transcriptomics, proteomics, and metabolomics (triple-omics) analyses. Aβ accumulation significantly increased in the 0.1 μg/μl MNPs@SiO2(RITC)-treated BV2 cells compared to the untreated control and 0.01 μg/μl MNPs@SiO2(RITC)-treated BV2 cells. Moreover, the MNPs@SiO2(RITC)-treated BV2 cells showed lysosomal swelling, a dose-dependent reduction in proteolytic activity, and an increase in lysosomal swelling- and autophagy-related protein levels. Moreover, proteasome activity decreased in the MNPs@SiO2(RITC)-treated BV2 cells, followed by a concomitant reduction in intracellular adenosine triphosphate (ATP). By employing triple-omics and a machine learning algorithm, we generated an integrated single molecular network including reactive oxygen species (ROS), autophagy, lysosomal storage disease, and amyloidosis. In silico analysis of the single triple omics network predicted an increase in ROS, suppression of autophagy, and aggravation of lysosomal storage disease and amyloidosis in the MNPs@SiO2(RITC)-treated BV2 cells. Aβ accumulation and lysosomal swelling in the cells were alleviated by co-treatment with glutathione (GSH) and citrate. These findings suggest that MNPs@SiO2(RITC)-induced reduction in lysosomal activity and proteasomes can be recovered by GSH and citrate treatment. These results also highlight the relationship between nanotoxicity and Aβ accumulation.

Phosphorylation-state dependent intraneuronal sorting of Aβ differentially impairs autophagy and the endo-lysosomal system

ABBREVIATIONS

AD: Alzheimer disease; APP: amyloid beta precursor protein; ATG: autophagy related; Aβ: amyloid-β; CTSD: cathepsin D; DAPI: 4',6-diamidino-2-phenylindole; EEA1: early endosome antigen 1; FA: formic acid; GFP: green fluorescent protein; LAMP2: lysosomal-associated membrane protein 2; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MAP2: microtubule-associated protein 2; nmAβ: non-modified amyloid-β; npAβ: non-phosphorylated amyloid-β; pAβ: phosphorylated amyloid-β; p-Ser26Aβ: amyloid-β phosphorylated at serine residue 26; p-Ser8Aβ: amyloid-β phosphorylated at serine residue 8; RAB: RAB, member RAS oncogene family; RFP: red fluorescent protein; SQSTM1/p62: sequestome 1; YFP: yellow fluorescent protein.

Development of Neuroprotective Agents for the Treatment of Alzheimer's Disease using Conjugates of Serotonin with Sesquiterpene Lactones

BACKGROUND

Sesquiterpene lactones are secondary plant metabolites with a wide variety of biological activities. The process of lactone conjugation to other pharmacophores can increase the efficacy and specificity of the conjugated agent effect on molecular targets in various diseases, including brain pathologies. Derivatives of biogenic indoles, including neurotransmitter serotonin, are of considerable interest as potential pharmacophores. Most of these compounds have neurotropic activity and, therefore, can be used in the synthesis of new drugs with neuroprotective properties.

AIM

The aim of this experimental synthesis was to generate potential treatment agents for Alzheimer's disease using serotonin conjugated with natural sesquiterpene lactones.

METHODS

Three novel compounds were obtained via the Michael reaction and used for biological testing. The obtained conjugates demonstrated complex neuroprotective activities. Serotonin conjugated to isoalantolactone exhibited strong antioxidant and mitoprotective activities.

RESULTS

The agent was also found to inhibit β-site amyloid precursor protein cleaving enzyme 1 (BACE-1), prevent the aggregation of β-amyloid peptide 1-42, and protect SH-SY5Y neuroblastoma cells from neurotoxins such as glutamate and H2O2. In a transgenic animal model of Alzheimer's disease (5xFAD line), the conjugated agent restored declined cognitive functions and improved learning and memory.

CONCLUSION

In conclusion, the obtained results indicate that serotonin conjugates to sesquiterpene lactones are promising agents for the treatment of symptoms associated with Alzheimer's disease.

Protein retention in the endoplasmic reticulum rescues Aβ toxicity in Drosophila

Amyloid β (Aβ) accumulation is a hallmark of Alzheimer's disease. In adult Drosophila brains, human Aβ overexpression harms climbing and lifespan. It's uncertain whether Aβ is intrinsically toxic or activates downstream neurodegeneration pathways. Our study uncovers a novel protective role against Aβ toxicity: intra-endoplasmic reticulum (ER) protein accumulation with a focus on laminin and collagen subunits. Despite high Aβ, laminin B1 (LanB1) overexpression robustly counters toxicity, suggesting a potential Aβ resistance mechanism. Other laminin subunits and collagen IV also alleviate Aβ toxicity; combining them with LanB1 augments the effect. Imaging reveals ER retention of LanB1 without altering Aβ secretion. LanB1's rescue function operates independently of the IRE1α/XBP1 ER stress response. ER-targeted GFP overexpression also mitigates Aβ toxicity, highlighting broader ER protein retention advantages. Proof-of-principle tests in murine hippocampal slices using mouse Lamb1 demonstrate ER retention in transduced cells, indicating a conserved mechanism. Though ER protein retention generally harms, it could paradoxically counter neuronal Aβ toxicity, offering a new therapeutic avenue for Alzheimer's disease.

Uncovering the Significance of STEP61 in Alzheimer's Disease: Structure, Substrates, and Interactome

STEP (STriatal-Enriched Protein Tyrosine Phosphatase) is a brain-specific phosphatase that plays an important role in controlling signaling molecules involved in neuronal activity and synaptic development. The striatum is the main location of the STEP enzyme. An imbalance in STEP61 activity is a risk factor for Alzheimer's disease (AD). It can contribute to the development of numerous neuropsychiatric diseases, including Parkinson's disease (PD), schizophrenia, fragile X syndrome (FXS), Huntington's disease (HD), alcoholism, cerebral ischemia, and stress-related diseases. The molecular structure, chemistry, and molecular mechanisms associated with STEP61's two major substrates, Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPAr) and N-methyl-D-aspartate receptors (NMDARs), are crucial in understanding the relationship between STEP61 and associated illnesses. STEP's interactions with its substrate proteins can alter the pathways of long-term potentiation and long-term depression. Therefore, understanding the role of STEP61 in neurological illnesses, particularly Alzheimer's disease-associated dementia, can provide valuable insights for possible therapeutic interventions. This review provides valuable insights into the molecular structure, chemistry, and molecular mechanisms associated with STEP61. This brain-specific phosphatase controls signaling molecules involved in neuronal activity and synaptic development. This review can aid researchers in gaining deep insights into the complex functions of STEP61.

Advancements in the Application of Nanomedicine in Alzheimer's Disease: A Therapeutic Perspective

Alzheimer's disease (AD) is a progressive neurodegenerative disease that affects most people worldwide. AD is a complex central nervous system disorder. Several drugs have been designed to cure AD, but with low success rates. Because the blood-brain and blood-cerebrospinal fluid barriers are two barriers that protect the central nervous system, their presence has severely restricted the efficacy of many treatments that have been studied for AD diagnosis and/or therapy. The use of nanoparticles for the diagnosis and treatment of AD is the focus of an established and rapidly developing field of nanomedicine. Recent developments in nanomedicine have made it possible to effectively transport drugs to the brain. However, numerous obstacles remain to the successful use of nanomedicines in clinical settings for AD treatment. Furthermore, given the rapid advancement in nanomedicine therapeutics, better outcomes for patients with AD can be anticipated. This article provides an overview of recent developments in nanomedicine using different types of nanoparticles for the management and treatment of AD.

ApoE-modified liposomes encapsulating resveratrol and salidroside alleviate manifestations of Alzheimer's disease in APP/PS-1 mice

OBJECTIVE

Alzheimer's disease (AD) is a neurodegenerative disease that is associated with aging and is influenced by both genetic and environmental factors. Several studies and clinical trials have demonstrated that resveratrol (Res) and salidroside (Sal) are not only biologically safe but also influence AD biomarker trajectories. However, their clinical applications have been quite limited due to poor specificity, low solubility, and insufficient blood-brain barrier (BBB) penetration. Therefore, we developed a nano-drug delivery system in which Res and Sal were encapsulated in liposomes, which were surface-modified with ApoE (ApoE-Res/Sal-Lips) to compensate for these deficiencies.

METHOD

In this study, ApoE-Res/Sal-Lips were prepared using a standard thin-film hydration method for liposomes. Then, cellular uptake of the loaded liposomes was assessed in vitro using fluorescent staining assays. A BBB model was constructed to investigate the capacity of the liposomes to cross the BBB in vitro, and the ability of liposomes to target the brain was observed by in vivo imaging. In addition, the neuroprotective effects of the different liposome formulations in APP/PS-1 mice were evaluated by measuring the changes in levels of oxidative, anti-inflammatory, and anti-apoptotic factors in the mice brains.

RESULTS

In vitro, ApoE-Res/Sal-Lips increased the uptake of Res and Sal by bEnd.3 and N2a cells, enhanced BBB penetration, and improved transport efficiency. In vivo, the ApoE-Res/Sal-Lips were found to alleviate AD pathological symptoms, reduce learning and memory impairments, and improve brain function.

CONCLUSION

ApoE-Res/Sal-Lips provide a new method for the treatment of AD.

Paraoxonase 1 activity in patients with Alzheimer disease: Systematic review and meta-analysis

Cumulating evidence links environmental toxicants, such as organophosphate (OP) pesticides, to the pathogenesis of Alzheimer's disease (AD). The calcium-dependent Paraoxonase 1 (PON1) can neutralize these toxicants with good catalytic efficiency, thus protecting from OP-induced biological damage. Although different previous studies have already partially described an association between PON1 activity and AD, this intriguing relationship has not yet been comprehensively examined. To fill this gap, we performed a meta-analysis of existing data comparing the PON1 arylesterase activity in AD and healthy subjects from the general population. Data were obtained by searching MEDLINE, Embase and CENTRAL, Google Scholar, and SCOPUS electronic databases for all studies published at any time up to February 2023, reporting and comparing the PON1- paraoxonase activity between AD patients and controls. Seven studies, based on 615 subjects (281 AD and 356 controls) met the inclusion criteria and were included into the final analysis. A random effect model revealed that PON1 arylesterase activity was significantly lower in the AD group compared to controls, exhibiting low level of heterogeneity (SMD = - 1.62, 95% CI = -2.65 to -0.58, p = 0.0021, I2 = 12%). These findings suggest that PON1 activity might be reduced in AD reflecting a major susceptibility to OPs neurotoxicity. Further studies should be conducted to definitely ascertain this link and to establish the cause-effect relationship between PON1 reduction and AD onset.

Cholinergic-like neurons and cerebral spheroids bearing the PSEN1 p.Ile416Thr variant mirror Alzheimer's disease neuropathology

Familial Alzheimer's disease (FAD) is a complex neurodegenerative disorder for which there are no therapeutics to date. Several mutations in presenilin 1 (PSEN 1), which is the catalytic component of γ-secretase complex, are causal of FAD. Recently, the p.Ile416Thr (I416T) PSEN 1 mutation has been reported in large kindred in Colombia. However, cell and molecular information from I416T mutation is scarce. Here, we demonstrate that menstrual stromal cells (MenSCs)-derived planar (2D) PSEN 1 I416T cholinergic-like cells (ChLNS) and (3D) cerebral spheroids (CSs) reproduce the typical neuropathological markers of FAD in 4 post-transdifferentiating or 11 days of transdifferentiating, respectively. The models produce intracellular aggregation of APPβ fragments (at day 4 and 11) and phosphorylated protein TAU at residue Ser202/Thr205 (at day 11) suggesting that iAPPβ fragments precede p-TAU. Mutant ChLNs and CSs displayed DJ-1 Cys106-SO3 (sulfonic acid), failure of mitochondria membrane potential (ΔΨm), and activation of transcription factor c-JUN and p53, expression of pro-apoptotic protein PUMA, and activation of executer protein caspase 3 (CASP3), all markers of cell death by apoptosis. Moreover, we found that both mutant ChLNs and CSs produced high amounts of extracellular eAβ42. The I416T ChLNs and CSs were irresponsive to acetylcholine induced Ca2+ influx compared to WT. The I416T PSEN 1 mutation might work as dominant-negative PSEN1 mutation. These findings might help to understanding the recurring failures of clinical trials of anti-eAβ42, and support the view that FAD is triggered by the accumulation of other intracellular AβPP metabolites, rather than eAβ42.